N-porphyrinylamino and -amido compounds by addition of an amino or amido nitrogen to a porphyrin meso position

Article abstract of DOI:10.1021/ic000112r

This report describes the synthesis and characterization of a series of octaethylpcrphyrin derivatives in which the porphyrin π-network is connected to phenyl, 3-fluoranthenyl, or 1-pyrenyl aromatic systems through a meso amino or amido nitrogen. Metal-free bases and zinc(II) and iron(III) complexes have been obtained. These compounds represent the first examples of linkages between porphyrins and extended π-networks through a nitrogen atom directly attached to a porphyrin meso position. ¹H NMR studies of the metal-free bases and zinc complexes showed that in the amido-linked adducts, the plane containing the aryl substituent was oriented perpendicular to the plane of the porphyrin. Linkage through the secondary amino nitrogen, however, allowed the aryl plane to rotate toward coplanarity with the porphyrin plane, resulting in conjugation of the highest occupied aryl and porphyrin molecular orbitals through the nitrogen lone pair. In developing routes to the amino-linked compounds, the facile formation of fused azaaryl chlorins via an oxidative intramolecular cycloaddition was observed. An aryl carbon ortho to the meso linkage attacked the β-carbon of an adjacent pyrrole ring, accompanied by 1,2-migration of a pyrrole β-ethyl substituent and a two-electron oxidation of the initially formed macrocycle. The resulting structures are analogous to benzochlorins. The electronic spectra of the metal-free bases are characterized by intense, long-wavelength bands in the visible region. Molecular structures of the chloroferric complexes of the azabenzofluorantheno- and azabenzpyrenoporphyrin macrocycles (derived from fusion of the fluoranthenyl and pyrenyl substituents, respectively) were obtained by X-ray diffraction. The porphyrin moiety in the azabenzofluoranthenoporphyrin adopted a gable structure, with a 22°fold along a diagonal including the pyrrole-ring C4 and C16 α-carbons. By contrast, the azabenzpyrenoporphyrin was virtually planar.

Full text of DOI:10.1021/ic000112r

3652
Inorg. Chem. 2000, 39, 3652-3664
N-Porphyrinylamino and -amido Compounds by Addition of an Amino or Amido Nitrogen
to a Porphyrin Meso Position
K. Jayaraj,† A. Gold,*,† L. M. Ball,† and P. S. White‡
Department of Environmental Sciences and Engineering and Department of Chemistry,
The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
ReceiVed February 3, 2000
This report describes the synthesis and characterization of a series of octaethylporphyrin derivatives in which the
porphyrin π-network is connected to phenyl, 3-fluoranthenyl, or 1-pyrenyl aromatic systems through a meso
amino or amido nitrogen. Metal-free bases and zinc(II) and iron(III) complexes have been obtained. These
compounds represent the first examples of linkages between porphyrins and extended π-networks through a nitrogen
atom directly attached to a porphyrin meso position. 1H NMR studies of the metal-free bases and zinc complexes
showed that in the amido-linked adducts, the plane containing the aryl substituent was oriented perpendicular to
the plane of the porphyrin. Linkage through the secondary amino nitrogen, however, allowed the aryl plane to
rotate toward coplanarity with the porphyrin plane, resulting in conjugation of the highest occupied aryl and
porphyrin molecular orbitals through the nitrogen lone pair. In developing routes to the amino-linked compounds,
the facile formation of fused azaaryl chlorins via an oxidative intramolecular cycloaddition was observed. An
aryl carbon ortho to the meso linkage attacked the â-carbon of an adjacent pyrrole ring, accompanied by 1,2-
migration of a pyrrole â-ethyl substituent and a two-electron oxidation of the initially formed macrocycle. The
resulting structures are analogous to benzochlorins. The electronic spectra of the metal-free bases are characterized
by intense, long-wavelength bands in the visible region. Molecular structures of the chloroferric complexes of the
azabenzofluorantheno- and azabenzpyrenoporphyrin macrocycles (derived from fusion of the fluoranthenyl and
pyrenyl substituents, respectively) were obtained by X-ray diffraction. The porphyrin moiety in the azabenzof-
luoranthenoporphyrin adopted a gable structure, with a 22° fold along a diagonal including the pyrrole-ring C4
and C16 R-carbons. By contrast, the azabenzpyrenoporphyrin was virtually planar.
Introduction
naphthoporphyrins,6-9 and a bischlorin fused along the bc and
gh edges of 1,5-naphthyridine.10
Porphyrins and porphinoid compounds offer opportunities for
modulation of physicochemical properties by a wide variety of
peripheral substituents. Among structures of interest are those
in which the porphyrin π-network is connected to an aromatic
system or to additional porphyrin systems by linkers. There are
as yet no examples of linkers in which a porphyrin meso carbon
is bonded directly to an amino nitrogen. This report describes
the synthesis and characterization of 5-(N-arylamino) and 5-(N-
arylamido)octaethylporphyrin derivatives with phenyl-, 3-fluo-
ranthenyl-, and 1-pyrenylaryl groups. In developing routes to
amino-linked octaethylporphyrin systems, we observed the facile
formation of fused azaaryl chlorins from 5-(N-arylamino)-
octaethylporphyrins via an intramolecular cycloaddition involv-
ing attack of an aryl carbon ortho to the meso linkage at the
â-carbon of an adjacent pyrrole ring. There are only a few
examples of such pyrrole â-to-meso-carbon fused systems.
These include several benzochlorins,1-5 naphthochlorins,
Novel porphyrin bases and Zn(II) complexes of potential
utility to research on dyes, photodynamic therapy and disinfec-
tion, electrooptical properties, and the photosynthetic reaction
center are accessible through application of the synthetic routes
developed here. Iron complexes are of interest as models for
heme adducts derived from peroxidative metabolism of aryl-
amines by hemoglobin and myoglobin.11-13
Results
Synthesis and Characterization. Initial efforts to synthesize
5-(N-arylamino) derivatives of octaethylporphyrin (OEP) deriva-
tives followed the procedure reported for meso substitution of
octaalkyl porphyrins by pyridine and imidazole.14 In contrast
to the more usual electrophilic substitution scheme, these
(6) Krattinger, B.; Nurco, D. J.; Smith, K. M. Chem. Commun. 1998, 757-
758.
(7) Barloy, L.; Dolphin, D.; Dupre, D.; Wijesekera, T. P. J. Org. Chem,
1994, 59, 7976-7985.
† Department of Environmental Sciences and Engineering.
‡ Department of Chemistry.
(1) Garca, M.; Vicente, H.; Rezzano, I. N.; Smith, K. M. Tetrahedron
Lett. 1990, 31, 1365-1368.
(2) Mettath, S.; Shibata, M.; Alderfer, J. L.; Senge, M. O.; Smith, K. M.;
Rein, R.; Dougherty, T. J.; Pandey, R. J. Org. Chem. 1998, 63, 1646-
1656.
(8) Callot, H. J.; Schaeffer, E.; Cromer, R.; Metz, F. Tetrahedron 1990,
46, 52553-5262.
(9) Lash, T. D.; Roper, T. J. Tetrahedron Lett. 1994, 35, 7715-7718.
(10) Johnson, C. K.; Dolphin, D. Tetrahedron Lett. 1998, 39, 4753-4756.
(11) El-Bayoumy, K. Health Effects Institute Research Report No. 64,
Cambridge, MA, 1994.
(3) Kosyrev, A. N.; Zheng, G.; Zhu, C.; Dougherty, T. J.; Smith, K. M.;
Pandey, R. Tetrahedron Lett. 1996, 36, 6431-6434.
(4) Boyle, R. W.; Dolphin, D. J. Chem. Soc., Chem. Commun. 1994,
2463-2464.
(5) Barkigia, K. M.; Thompson, M. A.; Fajer, J. New J. Chem. 1992, 16,
599-607.
(12) Ringe, D.; Petsko, G. A.; Kerr, D. E.; Ortiz de Montellano, P. R.
Biochemistry 1984, 23, 2-4.
(13) Everse, J.; Johnson, M. C.; Marini, M. A. Methods Enzymol. 1994,
231, 547-561.
(14) Smith, K. M.; Barnett, G. H.; Evans, B.; Martynenko, Z. J. Am. Chem.
Soc. 1979, 101, 5953-5961.
10.1021/ic000112r CCC: $19.00 © 2000 American Chemical Society
Published on Web 07/12/2000

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3653
Scheme 1
substitutions involve coupling the π-cation radical of meso-
unsubstituted Zn(II) or Mg(II) porphyrin complexes with the
nitrogen heterocycles. However, when the coupling reaction was
performed using primary arylamines, the weaker nucleophilicity
of these bases resulted in formation of only trace quantities of
products. To enhance the reactivity of the primary arylamines,
coupling reactions were repeated with the anionic forms
generated from the corresponding N-acetamido compounds by
treatment with NaH15 (Scheme 1). Addition of the anionic
species generated from acetanilide, 3-acetamidofluoranthene, or
1-acetamidopyrene to Zn(II)OEP•+ yielded the expected meso-
substituted 5-(N-arylacetamido)Zn(II)porphyrin complexes 1a-
3a (Table 1), respectively. Extraction of Zn(II) by treatment
with HCl-saturated methylene chloride yielded the correspond-
ing 5-(N-arylacetamido) porphyrin bases 1b-3b (Table 1). Iron
could be inserted into 1b under mild conditions16,17 to give ferric
complex 1c (Table 1). However, attempts to insert iron under
similar mild conditions into 2b and 3b yielded complexes with
molecular weights 44 amu lower than required for the target
N-arylacetamido adducts. These products proved to be ferric
complexes of azabenzofluorantheno and azabenzpyreno-fused
chlorins described below.
Attempts to obtain meso-N-arylamino porphyrins from the
acetamido derivatives by deacetylation in 3 M methanolic HCl
resulted in demetalation. Deacetylation of acetamides 1a-3a
did not occur under the mildly reducing conditions used to avoid
macrocycle reduction (stirring at ambient temperature with
excess NaH in THF). Zinc complexes 1a-3a were recovered
unchanged following treatment under a variety of basic condi-
tions. These included refluxing in NH3-saturated methanol/
CHCl3/THF, refluxing in methanol/chloroform with excess
triethylamine, or refluxing in methanol/THF with the strong base
sodium methoxide. Under more forcing conditions of stirring
with excess n-butyllithium in THF, the porphyrin ring degraded
rapidly even at 0 °C. Consequently, preparation of meso adducts
from the more labile trifluoroacetamide derivatives was under-
taken (Scheme 1).
Figure 1. Structural diagrams and numbering schemes for fused
systems 8-10.
(Figure 1). Partial metalation of 6b with ferrous chloride in
methanol/chloroform at ambient temperature16,17 for 10 min
yielded the corresponding meso-substituted ferric complex 6c
(Table 1), but even brief refluxing of the metalation reaction
mixture yielded fused ferric complex 8b exclusively. Attempts
to insert Fe(II) into 7b yielded fused ferric complex 9c. Mass
spectra of compounds 8a,b and 9a-9c showed molecular ions
2 amu less than required for meso adducts. A distinctive feature
of the 1H NMR spectra of the diamagnetic compounds in series
8 and 9 was the presence of two methylene resonances shifted
to higher field than expected for pyrrole â-ethyl substituents of
porphyrins.2 A similar upfield shift has been reported for the
methylene signals of the gem ethyl substituents of the sp3
â-carbon of the partially saturated pyrrole ring of benzochlorins
derived from octaethylporphyrin.2 The 1H NMR spectra of the
paramagnetic ferric complexes 8b and 9c showed signals
integrating to 12 protons in the range of hyperfine shifts
expected for pyrrole â-methylene protons of high-spin ferric
porphyrins. Two broad meso proton resonances could be
identified over the range -20 to -85 ppm. Both the large
upfield shifts and wide range observed for these iron complexes
are characteristic of high-spin ferric chlorins.18 The electronic
spectra of all compounds in series 8 and 9 displayed strong
bands at long wavelengths, in the range reported for chlorins19
and benzochlorins.1,2 Altogether, these data suggested that the
macrocycles comprising series 8 and 9 are benzochlorin
analogues via formation of a bond between the aryl carbon ortho
to the meso amino nitrogen and an adjacent pyrrole â-carbon.
The adduct of Zn(II)OEP•+ with 5-N-(1-pyrenyl)trifluoro-
acetamide could not be obtained, but addition of the anion
generated from 1-(2,4-dinitrobenzenesulfonamido)pyrene to Zn-
(II)OEP•+ yielded a 1:1 adduct. Because of low solubility and
cochromatography with minor byproducts, the Zn(II) complex
could not be completely purified. However, after demetalation,
a pure compound 10a could be isolated, which gave ferric
complex 10b on insertion of iron. Spectroscopic characteristics
of 10a and 10b showed them to be analogues of the corre-
sponding metal-free bases 8a and 9b and ferric complexes 8b
and 9c, respectively. Thus, the 2,4-dinitrobenzenesulfonyl
moiety was apparently eliminated during workup, concomitant
with intramolecular cyclization to give the pyrene-fused struc-
Thus, Zn(II) complexes of 5-N-phenyl- and N-fluoranthenyl-
trifluoroacetamide adducts, 4 and 5, respectively (Table 1), were
prepared by coupling the anions derived from trifluoroacetanilide
and N-(3-fluoranthenyl)trifluoroacetamide with Zn(II)OEP•+.
The Zn(II) complexes of these derivatives were smoothly
deacylated by treatment with 20-fold molar excess sodium
methoxide in refluxing THF/methanol to the corresponding
amino complexes 6a and 7a (Table 1). Purification of 7a also
yielded a small quantity of the fused complex 9a (Figure 1)
derived from intramolecular cyclization. Removal of Zn(II) from
6a gave porphyrin 6b; however, demetalation of 7a yielded both
the expected porphyrin 7b (Table 1) and fused porphyrin 9b
(15) Bray, B. L.; Mathies, P. H.; Naef, R.; Solas, D. R.; Tidwell, T. T.;
Artis, D. R.; Muchowski, J. M. J. Org. Chem. 1990, 55, 6317-6328.
(16) Jagessar, R. C.; Shang, M.; Scheidt, W. R.; Burns, D. H. J. Am. Chem.
Soc. 1998, 120, 11684-11692.
(18) Licoccia, S.; Chatfield, M. J.; La Mar, G. N.; Smith, K. M.; Mansfield,
K. E.; Ancerson, R. R. J. Am. Chem. Soc. 1989, 111, 6087-6093.
(19) Stolzenberg, A. M.; Strauss, S. H.; Holm, R. H. J. Am. Chem. Soc.
1981, 103, 4763-4778.
(17) Borovkov, V.; Lintuluoto, J. M.; Inoue, Y. Synlett 1999, 61-62.

3654 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
Table 1. Structures and Numbering of Meso N-Substituted Porphyrins
ture. UV-vis and 1H NMR spectra of 9c and 10b were identical
to the spectra of the products isolated from attempted insertion
of iron into N-arylacetamido porphyrin bases 2b and 3b,
respectively. Thus, conditions of insertion of iron into 2b and
3b resulted in deacetylation accompanied by intramolecular
cyclization to the fused systems. Comparison of UV-vis and
1H NMR spectra of products isolated from attempted insertion
of iron into porphyrins 2b and 3b established their identities as
9c and 10b, respectively. Apparently, redox chemistry ac-
companying insertion of iron into these porphyrin bases causes
deacetylation and cycloaddition with formation of the fused
compounds. X-ray structures of ferric complexes 9c and 10b
confirm the fused chlorin ring structures.
rotation on an NMR time scale will cause the porphyrin plane
to lose σh symmetry. In 1a, 2a, and 3a, this leaves a C2V plane
bisecting the 5,15-meso positions as the only remaining sym-
metry element. In the spectra of the metal-free bases 1b, 2b,
and 3b, two pyrrole NH resonances are resolved, indicating that
exchange of the pyrrole protons is slow on the NMR time scale.
Slow tautomerization along with elimination of the in-plane
mirror plane formally removes all symmetry elements. However,
the perturbation of C2V symmetry is not sufficient to cause
splitting of the meso signals, the most sensitive probes of
symmetry. Thus, an approximate C2V plane bisecting the 5,15-
meso positions is preserved and three meso proton signals appear
as two singlet resonances in a 2:1 ratio in the 1H NMR spectra
of the Zn(II) complexes and metal-free bases of all 5-N-
arylacetamido derivatives. If rotation of the methylene groups
is slow on the NMR time scale, the methylene protons of the
flanking pyrrole â-ethyl substituents will be diastereotopic. In
chloroform-d, rapid rotation of the C3 and C7 ethyl groups
causes the methylene signals of 1a,b to appear as a four-proton
quartet. In methylene-d2 chloride, however, the signal broadens
and the multiplicity increases, indicating incipient resolution of
diastereotopic protons (Figure 2).
1H NMR. NMR studies of meso-dialkylaminoporphyrins with
flanking pyrrole â-substituents show that the amino substituents
adopt an orthogonal conformation with respect to the porphyrin
plane to minimize unfavorable steric interactions.20 In com-
pounds 1a,b, 2a,b, and 3a,b, steric interactions between the
amido nitrogen substituents and the flanking pyrrole â-ethyl
groups at C3 and C7 of the porphyrin ring are thus expected to
cause the meso-N-arylacetamido groups to adopt an orthogonal
conformation. Steric hindrance can also be expected to slow
rotation of the acetamido group around the meso-carbon-to-
amido-nitrogen bond as well as rotation around the pyrrole
â-methylene bonds of the C3 and C7 ethyl substituents.20,21
Since the amido substituent bears two different substituents, slow
The upfield position of the methylene multiplet with respect
to the envelope representing the remaining â-methylene groups
can be can be attributed in part to out-of-plane displacement
resulting from steric interactions and in part to rotation of the
(20) Abraham, R. J.; Smith, K. M.; Bobe, F. W.; Minnetian, O. M. Org.
Magn. Reson. 1984, 22, 771-774.
(21) Smith, K. M.; Bobe, F. W.; Minnetian, O. M.; Abraham, R. J.
Tetrahedron 1984, 40, 3263-3272.

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3655
Figure 2. Expansion of methylene region of 1H NMR (500 MHz,
ambient temperature) of compound 1b in (a) chloroform-d and (b)
methylene-d2 chloride. Signals between 3.7 and 3.8 ppm belong to the
methylene protons of pyrrole â-ethyl substituents at C3 and C7 adjacent
to the substituted meso position.
methylene protons into or through the shielding region of the
aryl group.21 In the aromatic region of the 1H NMR spectra of
the acetanilide adducts 1a,b, one- and two-proton triplets are
readily assigned to the p- and m-phenyl protons, respectively.
The remaining broadened, deshielded two-proton resonance is
assigned to the phenyl o-protons. Rotation around the amide
nitrogen-phenyl bond would place both o-protons in proximity
to the deshielding region created by the ring current of the
porphyrin and would result in the broadened, averaged peak
observed.
Figure 3. 2D NOESY proton spectrum of compound 3a. Complete
proton assignments are given in the Experimental Section.
substituents at C3 and C7 have a cross-peak with the highest
field methyl triplet (1.12 ppm) arising from the ethyl substit-
uents. This triplet may thus be assigned to the C3 and C7 ethyl
substituents. A cross-peak between the high-field methyls and
the acetyl methyl indicates that these groups are cofacial with
respect to the porphyrin plane, confirming a fixed geometry
about the C5 meso-acetamido nitrogen bond. Cross-peaks are
observed between H10′ of pyrene and both diastereotopic C3-
(C7) methylene protons as well as the methyl protons of the
flanking ethyl substituents. A cross-peak is also observed
between the C3(C7) methyl protons and H2′ of pyrene. These
interactions can be explained either by rapid rotation of pyrene
around the pyrene C1′-acetamido nitrogen bond or by equally
populated conformations in which either the C2′-C3′ or the
C9′-C10′ edge of pyrene is oriented toward the acetate
substituent. Since the rotation of the less bulky phenyl group
in 1a is slowed, rapid rotation of pyrene is unlikely and the
latter explanation seems preferable. Consistent with expectation,
cross-peaks occur between the symmetry-related meso C10(C20)
protons and resonances assigned to the C2(C8) and C12(C18)
ethyl protons and between the meso C15 proton and the
resonances of the C13(C17) ethyl protons. In the aromatic region
of complex 3a, a pseudotriplet signal at 8.05 ppm can be
assigned to H7′ and unambiguous identification of the remaining
aromatic protons follows from connectivities established by 2D
NOESY NMR.
The increasing size of the acetamido nitrogen aryl substituent
in 2a,b and 3a,b slows the rotation of the flanking methylenes
of the C3 and C7 ethyl substituents so that the diastereotopic
methylene proton signals are completely resolved as two two-
proton multiplets appearing upfield from the envelope containing
the remaining methylene resonances. The aryl proton assign-
ments for the N-(3-fluoranthenyl)acetamido adducts 2a,b are
based on analysis of proton-proton coupling and comparison
1
with H NMR spectra of 3-amino-, 3-acetamido-, and 3-tri-
fluoroacetamidofluoranthene.22 Two upfield pseudotriplets are
assigned to H8′ and H9′ of the fluoranthenyl system (Table 1),
while the remaining pseudotriplet can be attributed to H5′. The
highest and lowest field doublets are assigned to H2′ and H4′,
respectively. This assignment is supported by broadening of the
1
H2′ and H4′ resonances observed in the H NMR spectrum of
the trifluoroacetamido congener 5 (vide infra). H2′ and H4′ are
the fluoranthenyl protons closest to the porphyrin periphery and
are thus expected to experience the largest variation of ring
current effect during rotation about the fluorenyl C3′-amide
nitrogen bond. Assignment of the remaining sets of doublets is
based on the analysis of coupling constants along with com-
parison of the NMR spectra with those of other 3-fluoranthenyl
compounds.
1
The porphyrin resonances in the H NMR spectrum of the
chloroiron(III) complex 1c appear within hyperfine shift ranges
typical of high-spin iron(III) octaalkyl porphyrins.23,24 Slow
rotation around pyrrole â-carbon-methylene carbon bonds
superimposed on the asymmetry of unpaired electron spin
density distribution arising from the meso amido substituent
gives rise to a complex pattern of pyrrole â-methylene reso-
nances. Extremely broad meso resonances appear at -50.2 and
-60.7 ppm in a 2:1 ratio, respectively. Two broad signals at
10.2 and 11.3 ppm are tentatively assigned to the phenyl
o-proton resonances, which are the phenyl protons expected to
show the largest contact shift. Resolution of two o-proton signals
Strong cross-peaks between the upfield multiplets in the 2D
NOESY spectrum of complex 3a (Figure 3) confirm diaste-
reotopic methylenes on pyrrole â-carbons C3 and C7 as the
origin of the upfield methylene multiplets for 3a as well as for
3b, 2a,b, and 1a,b. The most upfield of the multiplets is assigned
to the diastereotopic protons oriented toward the aryl substituent
because these should experience the most pronounced shielding
effect from the aryl ring current. In 3a, the resonances of the
methylenes at C2 and C8 are also resolved; the multiplet
structure as well as cross-peaks between the two-proton mul-
tiplets indicate that these protons are also diastereotopic. The
multiplets assigned to the methylene protons or the ethyl
(23) La Mar, G. N.; Walker, F. A. In The Porphyrins; Dolphin, D., Ed.;
Academic Press: New York, 1978; Vol. IVB, pp 61-157.
(24) Goff, H. In Iron Porphyrins; Lever, A. B. P., Gray, H. B., Eds.;
Addison-Wesley: Reading, MA, 1983; Part I, pp 237-281.
(22) Ball, L. M.; Stocking, L. M.; Kohan, M. J.; Warren, S. H.; Lewtas, J.
Mutagenesis 1995, 10, 497-504.

3656 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
suggests slow rotation about the phenyl-amido nitrogen bond,
superimposing rotational broadening upon paramagnetic broad-
ening.
1
The H NMR spectra of the Zn(II) N-aryltrifluoracetamido
adduct complexes 4 and 5 are similar to the spectra of acetamide
analogues. Rotation about the aryl-amide nitrogen bond at an
intermediate rate on the NMR time scale results in considerable
broadening of the o- and m-phenyl resonances in the spectrum
of 4 and of the H4′ and H2′ fluoranthenyl resonances in the
spectrum of 5.
The 1H NMR spectra of 5-N-phenylamino-substituted Zn(II)
complex 6a and porphyrin 6b are consistent with approximate
C2V symmetry, as in the case of the acetamido adducts. The
three meso proton signals appear as two singlets with an integral
ratio of 2:1. A notable feature of the o-proton signals is rotational
broadening and a marked shift upfield by ∼2 ppm higher with
respect to the o-phenyl resonances of acetanilide derivatives
1a,b. Both rotational broadening and increased shielding may
be explained by decreased steric interaction between the flanking
pyrrole C3 and C7 â-ethyl substituents and the monosubstituted
meso-amino group. Rotation of the amino substituent toward a
coplanar orientation becomes thermodynamically favorable to
allow conjugation between the nitrogen lone pair and the
porphyrin frontier π molecular orbitals.24,25 Some increased
conjugation of the amino lone pair is supported by increased
shielding of the meso proton resonances compared to those of
the acetanilide or trifluoroacetanilide derivatives.25 Molecular
models suggest that rotation of the amino substituent toward
the porphyrin plane will position one phenyl o-proton over a
flanking pyrrole ring, within the shielding region of the
porphyrin ring current. Since only a single two-proton o-phenyl
resonance is observed for 6a and 6b, the o-positions must be
averaged by rotation of the phenyl group around the phenyl-
amino nitrogen bond. Steric interaction between the phenyl ring
and pyrrole â-ethyl group would be expected to slow rotation,
resulting in the observed signal broadening. The two-proton
pseudotriplet of the phenyl m-protons also shows rotational
broadening. The amino proton resonance (7.81 ppm) appears
as a sharp singlet as does the signal of the strongly shielded
pyrrole NH protons of porphyrin 6b. The appearance of the
methylene resonances of the C3 and C7 â-ethyl substituents as
two two-proton diastereotopic signals requires that there be no
rotation about the pyrrole C â-methylene bonds.
The porphyrin proton signals of chloroiron(III) complex 6c
appear at shifts expected for a high-spin ferric complex (Figure
4). The methylene signals are spread over the range 37-44 ppm
as three sets of broadened singlets representing four methylene
protons each and four one-proton singlet resonances. This pattern
suggests perturbation of unpaired spin density distribution by
the meso substituent superimposed upon approximate C2V
symmetry. The pattern also implies rotational averaging of
methylene positions of the pyrrole â-C substituents, with the
exception of those at C3 and C7, which flank the substituted
meso carbon. Percolation of 6c through NaHCO3 causes no
significant change in the methylene pattern, but new resonances
develop at -67.5 and -69.4 ppm in the region of the meso
proton signals. Percolation of a methylene chloride/methanol
solution of 6c through grade I basic alumina in an attempt to
Figure 4. 1H NMR spectra, from top to bottom: complex 6c (500
MHz, chloroform-d); complex 8b (600 MHz, chloroform-d); compound
9c (500 MHz, chloroform-d); complex 10b (500 MHz, methylene-d2
chloride). Sharp resonances in the region +20 to -12 ppm are assigned
to protons of the fused aromatic moiety. Additional proton assignments
are given in the Experimental Section.
generate an authentic µ-oxodiiron complex26 yielded a com-
pound with broad methylene resonances between 27 and 33
ppm. The possible significance of these changes along with
correlated changes in electronic spectra is discussed below.
1
The H NMR spectra of the Zn(II) complex of the 5-N-(3-
fluoranthenyl)amino adduct 7a and the corresponding porphyrin
7b show one significant change relative to the amido derivatives.
The resonance of fluoranthene H2′ experiences a strong shield-
ing effect, shifting upfield to 5.3 ppm in Zn(II) complex 7a
and to 5.6 ppm in porphyrin 7b. The shielding parallels the
behavior of the phenyl o-proton signals of 6a and 6b, caused
by rotation of the monosubstituted amine toward the porphyrin
plane to allow conjugation of the amino nitrogen lone pair with
the porphyrin frontier π-MOs. Consistent with this picture, the
meso proton signals of 7a and 7b are less deshielded than those
of the amido derivatives. The signals of the meso amino protons
of 7a and 7b appear as singlets at ∼8.8 ppm.
1
The H NMR spectra of the metal-free chlorin bases are
closely similar to each other and show that fusion of the aromatic
moiety causes major perturbation of porphyrin electronic
structure. The meso resonances of 8a appear as three widely
spaced singlets (7.59, 8.00, 8.73 ppm) and methylene proton
resonances of pyrrole â-ethyl substituents as six multiplets
ranging from 2.8 to 4.2 ppm (Figure 5).
In addition, the markedly diminished deshielding of the meso
protons indicates major disruption of ring current relative to
the porphyrin macrocycle, as reported for octaethylbenzochlorin
and other benzo-fused chlorin systems.1-3 Proton assignments
1
were made by 2D NOESY H NMR. The shifts of two two-
proton methylene multiplets at 2.82 and 3.03 ppm are consistent
with gem substituents on sp3-hybridized C3 of the macrocycle.
A strong cross-peak between these signals in the NOESY
spectrum confirms this assignment and establishes the diaste-
reotopic character of these protons. Since the C3 ethyl groups
are symmetry-related through reflection in the macrocycle plane,
each multiplet represents two diastereotopic protons related by
this symmetry operation. The signal at 3.03 ppm has a cross-
peak with the quinoline doublet at 8.70 ppm. It is therefore
assigned to the diastereotopic methylene protons facing the fused
ring, while the doublet at 8.70 ppm must arise from quinolino
proton H5′ adjacent to the site of fusion at C2 of the heme
macrocycle (Figure 1). This assignment is consistent with the
expectation that the gem methylene protons facing the fused
quinolino system experience a deshielding ring current effect.
Identification of H5′ allows connectivity to be established for
(25) Scheer, H.; Katz, J. K. In Porphyrins and Metalloporphyrins; Smith,
K. M., Ed.; Elsevier Scientific Publishing Co.: Amsterdam, The
Netherlands, 1975; pp 426-437.
(26) La Mar, G. N.; Eaton, G. R.; Holm, R. H.; Walker, F. A. J. Am. Chem.
Soc. 1973, 95, 63-75.

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3657
diamagnetic signals around 0 ppm. The low-field region of the
three ferric complexes are qualitatively similar to that reported
for the chloroferric complex of octaethyl chlorin.28 In the
spectrum of complex 8b (Figure 4), 12 signals appearing
between 37 and 60 ppm are thus assigned to the methylene
protons of pyrrole â-ethyl substituents. Four additional one-
proton singlets at 33.8, 32.6, 10.2, and 8.8 ppm are paramag-
netically broadened and on this basis can be assigned to the
gem methylene protons. One-proton singlets at 18.9, 17.8, -5.5,
and -11.9 ppm show considerably smaller paramagnetic
interaction, consistent with expectations for the quinolino
protons. The methyl resonances of the pyrrole â-ethyl substit-
uents appear as poorly resolved, highly broadened resonances
between 5 and 7 ppm. A broad three-proton resonance at -1.4
ppm is tentatively assigned to the methyl group of a gem ethyl
substituent from analogy to the crystal structures of ferric
complexes 9c and 10b, in which a methyl group is situated in
the shielding region created by the porphyrin ring current.
The 1H NMR spectrum of ferric complex 9c (Figure 4), like
that of the quinolino-fused ferric complex 8b, is consistent with
a high-spin ferric complex having a highly asymmetric distribu-
tion of unpaired electron spin density. Resonances of 12 pyrrole
â-methylene protons extend from 37 to 59 ppm. Four broadened
resonances at 34.8, 33.3, 10.7, and 9.5 ppm are assigned to the
methylene protons of the gem ethyl substituents. The methyl
signals of the pyrrole â-ethyl groups are included within an
envelope spanning 6.7-5.9 ppm. A highly shielded, paramag-
netically broadened three-proton resonance at -1.3 ppm is
tentatively assigned to the methyl group of a gem ethyl on the
basis of the crystal structure, which shows one methyl situated
within the shielding region of the macrocycle ring current. One-
proton resonances with relatively little paramagnetic broadening
are assigned to the aryl protons of the fused azabenzofluoran-
thene.
Figure 5. Cross-peaks between the aromatic protons and heme â-ethyl
protons in 2D NOESY proton spectrum of compound 8a.
the quinoline proton resonances. The gem methylene protons
facing away from the fused system have a cross-peak with the
chlorin meso signal at 7.59 ppm, which is therefore assigned
to meso H5. The methylene protons of the C18 pyrrole â-ethyl
substituent are situated within a molecular indentation facing
the quinolino system and would be expected to experience a
deshielding effect. On this basis, the signal at 4.20 ppm is
assigned to the C18 methylene group. The methylene resonance
at 3.61 ppm has cross-peaks with a signal at 4.20 ppm and the
meso singlet at 8.73 ppm, leading to the assignment of the signal
at 3.61 ppm to the C17 methylene group and of the meso
resonance to H15. The remaining quinolino doublet must belong
to H8′. From NOESY cross-peaks the pseudotriplets at 7.84
and ∼8 ppm are assigned to H6′ and H7′, respectively. An
ambiguity in proton assignments involves the methylene groups
at C8 and C12, which have cross-peaks with meso H10 but
with no other signals and thus cannot be distinguished. Proton
assignments for 9b and 10a (2D NOESY spectra and connec-
tivities presented in Supporting Information) were made using
a similar approach and are given for each compound in the
Experimental Section.
The hyperfine shifts of the iron complexes of the fused
porphyrins are in accord with high-spin ferric complexes, with
superposition of large asymmetry in the distribution of unpaired
electron spin density at porphyrin ring carbons induced by the
fused aryl rings27 and concomitant saturation of one pyrrole
carbon.18 These effects are evident from comparison of the 1H
NMR spectra of the ferric complexes in Figure 5. In general,
meso proton resonances of high-spin ferric chlorins are expected
to be extremely broad and to experience upfield hyperfine shifts,
with signals from inequivalent meso protons spread over a wide
range.18,28 Ferric complexes 8b, 9c, and 10b all show two
resonances at about -80 and about -20 ppm. While extreme
broadening and poor resolution rule out a definitive conclusion
that the peaks represent one-proton signals, absence of a
symmetry element leads to the expectation of a third undetected
meso resonance, most likely obscured within the envelope of
1
In the H NMR spectrum of ferric complex 10b (Figure 4),
like that of 9c, signals of 12 pyrrole â-methylene protons appear
over the range 37-60 ppm. Paramagnetically broadened one-
proton resonances at 33.8, 32.9, 9.1, and 8.7 ppm are assigned
to methylene protons of the gem ethyl substituents. The methyl
signals of the pyrrole â-ethyl substituents appear within an
envelope of broad absorbances ranging from 7.3 to 3.1 ppm.
As for 9c, a broadened three-proton resonance at -1.3 ppm is
assigned to the methyl signal of a gem ethyl group. Signals
with smaller paramagnetic interactions must arise from the fused
azabenzpyrene protons.
Electronic Spectra. The porphyrin chromophore of the meso
acetamido adducts shows no significant perturbation relative
to that of octaalkyl porphyrin compounds. The spectra of Zn-
(II) complexes 1a, 2a, and 3a do differ slightly from the
spectrum of unmodified Zn(II)OEP by an increase in the Q1,0
/
Q0,0 band intensity ratio.29 In the electronic spectra of the
fluoranthene and pyrene derivatives 2a,b and 3a,b, bands
characteristic of the aromatic chromophores are resolved.30 The
limited interaction between the π-systems indicates that the
amido group is oriented perpendicular to the porphyrin plane,
preventing conjugation of the nonbonding amido nitrogen
electrons with the porphyrin π-frontier MOs. An orthogonal
orientation of the acetamido group is also indicated in the
electronic spectrum of ferric complex 1c, which is qualitatively
similar to that of the chloroferric complex of octaethylporphyrin,
(27) Wojaczynski, J.; Latos-Grazynski, L.; Glowiak, T. Inorg. Chem. 1997,
36, 6299-6306.
(28) Pawlik, M. J.; Miller, P. K.; Sullivan, E. P., Jr.; Levstik, M. A.;
Almond, D. A.; Strauss, S. H. J. Am. Chem. Soc. 1988, 110, 3007-
3012.
(29) Gouterman, M. In The Prophyrins; Dolphin, D., Ed.; Academic
Press: New York, 1978; Vol. I, pp 1-166.
(30) Clar, E. Polycyclic Hydrocarbons; Academic Press: New York, 1964;
Vol. 2, pp 110-126, 295-302.

3658 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
Figure 6. Electronic spectra (methanol, ambient temperature) of (a)
8a, (b) 9b, and (c) 10a.
Figure 7. ORTEP drawing of complex 9c with numbering scheme
used in solving the structure.
but slightly red-shifted, with the B band at 396 nm and visible
bands at 500 and 625 nm. The electronic spectra of Zn(II)
N-aryltrifluoracetamido compounds 4 and 5 are similar to the
spectra of the acetamide analogues.
exceptionally long wavelength of 725 nm. Similar marked global
red shifts in the electronic spectra of Zn(II) complexes relative
to those of metal-free bases have been observed for benzochlorin
derivatives.2 The electronic spectrum of the fused azabenzpyrene
system 10a is qualitatively similar to that of chlorin base 9b,
but bands in both B band and visible regions are red-shifted
relative to 9b. Multiple λmax appear in the B band region at
421, 439, and 465 nm, and an intense visible band appears at
716 nm.
The electronic spectra of meso-anilinyl-substituted porphyrin
6b and Zn(II) complex 6a appear qualitatively similar to those
of the corresponding unmodified OEP compounds. Absorption
maxima are slightly red-shifted relative to the absorption
maxima of the acetanilides 1a,b and exhibit a 5-10 nm global
red shift relative to those of octaethylporphyrin and its Zn(II)
complex, respectively. Some conjugation of the amino nitrogen
lone pair with the porphyrin ring in 6a,b is thus indicated,
consistent with NMR data showing rotation of the N-phenyl
substituent toward the porphyrin plane. As is the case for Zn-
(II) complexes 1a, 2a, and 3a, the ratio of the visible bands
While Zn(II) and Ni(II) derivatives of fused benzo- and
naphthooctaalkylchlorins have been reported, no reports of
analogous iron complexes are available for direct comparison
with isostructural models. However, the salient features of the
chloroferric complexes of the fused systems in this report are
in general conformity with expectations for ferric chlorins,
having visible bands strongly red-shifted relative to the corre-
sponding porphyrin absorbances.19 The identifying features of
the electronic spectrum of 8b are a B band at 414 nm with the
most prominent visible band at 686 nm. The electronic spectrum
of ferric complex 9c consists of a red-shifted B band at 438 nm
and a broad band at 675 nm in the visible region. The B band
of the ferric complex 10b appears at 437 nm, with the visible
region displaying broad, poorly resolved low-intensity bands
at 642 and 702 nm.
Q
1,0/Q0,0 of Zn(II) complex 6b is reversed in intensity relative
to OEPZn(II). The chloroiron(III) complex generated by treat-
ment of ferric meso-N-phenylaminoporphyrin 6c with HCl has
an electronic spectrum very similar to that of the chloroiron-
(III) complex of octaethylporphyrin. Following percolation of
6c through NaHCO3, the electronic spectrum is characterized
by splitting of the B band, with maxima appearing at 354 and
404 nm and a broad visible band at 563 nm. These changes are
concomitant with changes in the NMR spectrum described
above. On percolation of a methylene chloride/methanol solution
of 6c through activity grade I basic alumina, the electronic
spectrum is characterized by B band splitting with maxima at
354 and 404 nm and a visible band at 580 nm.
The electronic spectra of the meso-N-(3-fluoranthenyl)amino
adduct of octaethylporphyrin 7b and the Zn(II) complex 7a are
similar to those of the respective N-phenyl homologues, showing
effects of conjugation of the aryl π-system with the porphyrin
ring by global red shifts of both B and visible bands. Bands in
the UV region are perturbed relative to both fluoranthenyl and
3-aminofluoranthenyl chromophores. In accord with the NMR
data, these changes in the electronic spectra suggest some
conjugation of the nitrogen lone pair with the porphyrin
π-system.
The electronic spectra of metal-free fused bases (Figure 6)
are qualitatively similar to spectra reported for octaalkyl
benzochlorins, characterized by fine structure in the B bands
and intense, strongly red-shifted Q bands.1,2 In the spectrum of
quinolinochlorin 8a, shoulders on both the short and long
wavelength edges of the B band are resolved. The strongly
enhanced, red-shifted Q band appears at 687 nm.
In the electronic spectrum of the metal-free base 9b multiple
B bands at 439 and 455 nm are observed (Figure 7), with a Q
band at 686 nm. The electronic spectrum of Zn(II) complex 9a
features multiple B bands at 447 and 471 nm strongly red-shifted
relative to the metal-free base. An intense Q band occurs at the
Crystal Structures. The molecular structures of ferric
complexes 9c and 10b were determined by X-ray crystal-
lography. Crystallographic data are summarized in Table 2.
Complex 9c crystallizes in space group P21/c, which imposes
no particular symmetry on the molecular structure of 9c. In the
unit cell, molecules of 9c are associated as face-to-face pairs,
related by an inversion center, with the axial chloro ligands
coordinated to iron on the outside faces. Figure 7 is an ORTEP
drawing of a single molecule of 9c showing the atom numbering
scheme used in solution of the structure.
Each macrocycle is folded along a line passing through C4
and C16 so that the molecule has a distinct “gable” roof
conformation with an angle of 22.28(7)° between the mean
dihedral planes of the gable roof. The macrocycles are slipped
so that the planes comprising the long roof overlap and are
parallel. The associated gables thus nest in a complementary
fashion (Figure 8). Minimum distances between overlapping
planes of nested molecules are 3.35 Å between C29 and C20
of a facing molecule and 3.46 Å between C15 and C34 of a
facing molecule. These separations are indicative of π-π
interactions, primarily between the fluoranthene ring and the
quadrant of the opposing chlorin-containing pyrrole ring C16-
C19-N24 between meso positions C15 and C20. In this regard
stacking differs from that found for the metal-free base of

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3659
Table 2. Summary of Crystallographic Data
9c
10b
formula
mol wt
cryst syst
a (Å)
b (Å)
c (Å)
C53H52Cl4FeN5
956.68
C54H53Cl7FeN5
1076.06
monoclinic
9.8832(5)
22.0438(11)
12.3407(6)
108.856(1)
2544.30(22)
2
monoclinic
13.1268(11)
14.9253(13)
23.9850(20)
95.990(2)
4673.5(7)
4
â (deg)
V (Å3)
Z
D
calc (Mg m3)
1.360
1.405
λ (Å)
0.710 73
5.9
P21/c
0.710 73
7.1
P21
µ (cm-1
)
Figure 9. Displacement of the 24 porphyrin core atoms of 9c from
space group
mean plane of the core in units of 0.01 Å.
diffractometer
cryst size (mm)
temp (°C)
radiation
monochromator
mode
scan width (deg)
octants
2θ (min/max) (deg)
no. data collected
no. unique data
Bruker SMART 1K Bruker SMART 1K
0.20 × 0.20 × 0.10 0.20 × 0.20 × 0.05
-173
-173
Mo KR
graphite
ω
Mo KR
graphite
ω
0.3
0.3
(h (k (l
5.0/50.0
91 177
8284
(h (k (l
5.0/50.0
17 243
8718
no. data with I > 2.5σ(I) 5013
5143
603
0.071 (0.128)
0.074 (0.079)
0.490
no. variables
R(F)
563
0.051 (0.084)
0.057 (0.060)
0.690
Rw(F)
largest peak in final
difference map (e Å-3
GOF
)
Figure 10. ORTEP drawing of complex 10b with numbering scheme
used in solving the structure.
1.3951
1.9166
10). The C2-C3 and C3-C4 bonds of the partially saturated
pyrrole have, as expected, predominantly single bond character
(Table 2), and the C2-C3-C4 bond angle of 100° is smaller
than for a pyrrole ring. This distortion is accompanied by a slight
spreading of the internal angles at pyrrole N21 and R-C (C1,
C4). The six-membered heterocyclic ring bridging the fluoran-
thene system and porphyrin periphery is fully aromatic. One
internal angle C2-C41-C26 (at the junction of the partially
saturated pyrrole ring and aromatic system) is compressed to
114°. Thus, the entire macrocycle framework forms an extended,
conjugated π-system with the exception of gem-substituted, sp3-
hybridized C3.
Complex 10b crystallizes in the space group P21, which
imposes no symmetry on the molecular structure of 10b. In the
absence of a symmetry element in the molecular structure, the
space group requires that the crystals contain single enantiomers
and therefore that the crystals be chiral. Figure 10 is an ORTEP
drawing showing the numbering scheme used in solving the
structure. In contrast to the structure 9c, the entire macrocycle
of 10b is virtually planar, with only a very small doming (Figure
11). The only overlap between symmetry-related molecules is
between pyrene C37-C38 and pyrrole C7-C8 peripheral bonds
(Figure 12).
octaethylbenzochlorin in which neither the pyrrole nor fused
benzo rings overlap directly.
Figure 9 shows the deviation of atoms from the mean plane
defined by the 24-atom chlorin core in units of 0.01 Å. The
general structural features of 9c are similar to those expected
for a high-spin ferric heme complex, with iron displaced 0.5076-
(11) Å out of the mean plane of the 24 core atoms and 0.4423
(19) Å out of the mean plane of the four coordinated nitrogens
toward the chloro ligand situated at 2.2245(14) Å from iron.
There are two long and two short Fe-Npyrrole distances. The
long bonds are between iron and the nitrogen of the fused,
partially saturated pyrrole and between iron and the nitrogen
of the pyrrole adjacent to the fused meso position (Table 1).
The pyrrole rings are planar, but displacements of the pyrrole
â-carbons with respect to the mean plane of the 24-atom chlorin
core show a slight twist around the Fe-Npyrrole bonds (Figure
The shortest intermolecular distances are C37-C7 ) 3.49 Å
and C38-C8 ) 3.38 Å, indicating that overlap involves π-π
interaction between these bonds. As for complex 9c, other
structural features are consistent with a high-spin ferric heme
complex. Iron is displaced 0.5168(24) Å from the mean plane
of the 24 core atoms and 0.436(4) Å from the mean plane of
the four pyrrole nitrogens toward the chloro ligand, which is
situated at 2.22430(24) Å from iron. As for 9c, iron is
coordinated to the macrocycle by two long and two short bonds,
the long distances being to the nitrogen of the partially saturated
pyrrole and to the nitrogen of the pyrrole ring adjacent to the
fused meso carbon (Table 3). The C2-C3 and C3-C4 bonds
Figure 8. Unit cell of 9c with two symmetry-related molecules
removed for clear illustration of nesting.

3660 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
Table 3. Selected Bond Distances (Å) and Bond Angles (deg) with
Estimated Standard Deviations in Parentheses
9c
10b
Fe(1)-Cl(1)
Fe(1)-N(21)
Fe(1)-N(22)
Fe(1)-N(23)
Fe(1)-N(24)
C(2)-C(3)
2.2250(14)
2.058(3)
2.048(3)
2.033(3)
2.067(3)
1.512(5)
2.2430(24)
2.078(7)
2.054(7)
2.024(7)
2.089(7)
1.500(13)
Cl(1)-Fe(1)-N(21)
Cl(1)-Fe(1)-N(22)
Cl(1)-Fe(1)-N(23)
Cl(1)-Fe(1)-N(24)
N(21)-Fe(1)-N(22)
N(21)-Fe(1)-N(24)
N(22)-Fe(1)-N(23)
N(23)-Fe(1)-N(24)
C(4)-C(5)-C(6)
100.73(10)
101.39(11)
104.35(11)
103.25(11)
86.71(13)
86.40(12)
86.91(13)
89.32(13)
126.0(4)
125.2(4)
125.8(4)
128.4(4)
124.0(4)
100.28(22)
102.21(21)
103.90(22)
102.40(23)
86.3(3)
86.4(3)
86.1(3)
Figure 11. Displacement of the 24 porphyrin core atoms of 10b from
mean plane of the core in units of 0.01 Å.
90.9(3)
127.9(9)
124.3(9)
128.0(10)
126.3(9)
124.8(9)
C(5)-C(6)-C(7)
C(9)-C(10)-C(11)
C(14)-C(15)-C(16)
C(1)-C(20)-C(19)
importance of steric interactions between the C3 and C7 pyrrole
â-ethyl groups and the amido/amino aryl substituents in
determining amino substituent conformation. On the basis of
the published correlation between the degree of conjugation of
the meso nitrogen lone pair and the level of deshielding of the
remaining meso protons,25 none of the compounds described
here, including aminoporphyrins 6a-c and 7a,b, exhibit strong
conjugation. Support for this conclusion is evident in the
relatively small extent to which the electronic spectra of
porphyrins 6b and 7b are perturbed when compared to the
spectra of octaethylporphyrin and the meso-amido-substituted
porphyrins. Similarly, comparison of the electronic spectra of
zinc(II) complexes 6a and 7a with the zinc(II) complexes of
octaethylporphyrin and the meso-amido- or trifluoroacetami-
doporphyrins indicates relatively little effect of conjugation.
Nevertheless, the orientational effects reported here suggest an
approach to modulating conjugation of the meso nitrogen lone
pair with the porphyrin π-system by engineering the extent of
substituent interactions. Thus, it should be possible to achieve
control of communication between the porphyrin and appended
meso-amido/amino substituents, which should be useful in
exploring models of biological relevance to charge transfer.
Of the amino complexes, iron could be inserted only into
the meso-N-phenylamino derivative without causing intramo-
lecular cycloaddition to form a fused system. Treatment of the
ferric meso-N-phenylaminoporphyrin 6c with HCl leaves am-
biguity with regard to the protonation state of the meso amino
nitrogen. Formation of an ammonium ion would block conjuga-
tion of the lone pair of the amino nitrogen with the porphyrin.
As a result, the electronic spectrum would be expected to show
little perturbation relative to that of the chloroiron complex of
octaethylporphyrin, as observed. However, in the absence of a
crystal structure, it is not possible to distinguish this situation
from one in which the amino substituent has adopted an
orthogonal orientation. The tendency of the monosubstituted
arylamine to assume a coplanar orientation in the ferric complex
cannot be assessed on the basis of published studies, which
include only porphyrin bases and the corresponding dications
generated with trifluoroacetic acid. Percolation of 6c through
NaHCO3 will ensure the presence of the meso amino substituent
in the neutral form. However, the nature of the axial ligand is
uncertain. Complex 6c was treated with activity grade I basic
alumina in an attempt to generate a µ-oxodiiron derivative for
purposes of comparison. This treatment yielded a compound
Figure 12. Packing of molecules of 10b in the unit cell.
of the partially saturated pyrrole have predominantly single bond
character (Table 3), with the C2-C3-C4 bond compressed to
103°. As in the case of the fused fluoranthene system, the six-
membered heterocyclic ring bridging the porphyrin and aromatic
moieties is aromatic so that the entire macrocyclic framework,
with the exception of gem-substituted sp3-hybridized C3, is a
delocalized π-system.
Discussion
The modified procedure for nucleophilic addition of amide
nitrogen to the porphyrin meso position provides accessibility
to a wide variety of meso-arylamido- and arylamino-substituted
porphyrins. NMR data acquired in characterizing the compounds
in series 1-7 can be interpreted according to studies on meso
mono- and disubstituted aminoporphyrins.20,21 These reports
demonstrate that the orientation of the amino substituents with
respect to the porphyrin plane is a function of steric interactions
between the amino substituents and flanking pyrrole â-substit-
uents. Thus, meso-arylaminoporphyrins 6a-c and 7a,b show a
dramatic shielding of aryl protons ortho to the amino nitrogen,
resulting from rotation of the amino substituent toward the plane
of the porphyrin and into the shielding region of the porphyrin
ring current. Consistent with this change in orientation, the meso
protons are less deshielded in the meso-N-arylamino-substituted
compounds than in the meso-N-arylamido derivatives. The
appearance of diastereotopic methylene signals confirms the

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3661
Scheme 2
in weakening of the two Fe-N bonds nearest the site of fusion.
The effect is more pronounced in the fused pyrene derivative
and probably reflects the greater aromaticity of the pyrene
structure inferred from the relative enthalpies of formation,
∆H°f,298 ) 53.7 kcal mol-1 for pyrene34 and ∆H°f,298 ) 69.2
kcal mol-1 for fluoranthene.35,36
Experimental Section
General Information. Solvents were purchased commercially
(Fisher). Methylene chloride and tetrahydrofuran were distilled from
NaH prior to use. Other solvents were used as received. Acetanilide
and 1-acetamidopyrene were purchased commercially (Aldrich). 3-Ac-
etamidofluoranthene was synthesized according to a published proce-
dure.22 Trifluoroacetanilide, 3-trifluoroacetamidofluoranthene, and 1-tri-
fluoracetamidopyrene were obtained in quantitative yields by refluxing
the appropriate arylamine (Aldrich) in methylene chloride with tri-
fluoroacetic anhydride, washing the cooled solution twice× with water,
and then drying the organic layer over sodium sulfate and removing
solvent under reduced pressure.
NMR spectra were recorded either at 500 MHz on a Varian 500
INOVA 500 or at 600 MHz on a Varian INOVA 600. Exact mass
measurements and low-resolution mass spectrometric scans were
obtained by FAB on a VG70 250SEQ operating in a positive ion mode
using p-nitrobenzyl alcohol as a matrix. UV-vis spectra were obtained
(215-800 nm) on a Milton Roy Spectronic 1201 spectrophotometer.
Crystallization. Crystals of complexes 9c and 10b suitable for
structural determination by X-ray crystallography were obtained by slow
diffusion of hexane into chloroform solutions of the complexes.
X-ray Experimental Section. Small, well-shaped crystals of 9a and
10b were attached to the tip of a glass fiber with a small amount of oil
and then mounted in the cold stream of a Bruker SMART 1K
diffractometer. Initial cell dimensions and orientation matrices were
determined and the frames used to evaluate the quality of the crystals.
A full sphere of intensity data was then collected with the CCD set to
a maximum 2θ of 50°. The Bruker routine SAINT was used to integrate
the frames and produce a set of intensities, which were corrected for
absorption effects using SADABS. All subsequent computations were
performed with the NRCVAX suite of programs37 using scattering
factors taken from ref 38.
with pyrrole â-methylene signals having hyperfine shifts
between those of a high-spin ferric monomer and µ-oxodiiron
complex26 and an electronic spectrum similar to that of
bicarbonate-treated 6c. While no definitive structural assignment
is possible, these data could be explained by formation of a
hydroxo complex with bicarbonate and a hexacoordinate
intermediate-spin31 or spin-admixed complex (S ) 3/2, 5/2)32 on
treatment with basic alumina in methanol/methylene chloride.
The formation of fused systems 8-10 is an unusual reaction.
The apparent facility of this reaction may stem from rotation
of the arylamino substituents toward the porphyrin plane. This
orientation brings the aromatic carbons ortho to the meso N-aryl
substituent into proximity with an adjacent pyrrole â-carbon,
which likely facilitates the cycloaddition reaction. A possible
mechanism, summarized in Scheme 1, is nucleophilic attack of
the imino tautomer of the aryl substituent, which places electron
density on an ortho position, at the adjacent pyrrole â-carbon
followed by oxidation. This type of fused azaaromatic system
is unique. Bond distances in the crystal structures of 9c and
10b indicate that the entire π-framework is appropriately treated
as one system. This picture is supported by the 1H NMR spectra
where proton signals assignable to the fused aromatic systems
show hyperfine shifts. The electronic spectra of the azaarene-
fused chlorins, both as metal-free bases and metal complexes,
are also perturbed, having strongly red-shifted bands compared
to octaethyl chlorins. Of interest is the intense band in the visible
spectrum of the metal-free bases, which appears >80 nm to
the red of the corresponding band of octaethylchlorin and about
20 nm to the red of the corresponding band of octaethylben-
zochlorin. Because of the intense, long wavelength absorbance,
benzochlorins have been investigated as potential agents for use
in photodynamic therapy.2,33 In addition to extending the visible
bands further into the red portion of the electronic spectrum,
fused systems, exemplified by compounds such as 8-10, offer
potential flexibility in designing physical properties through use
of a variety of arenes or peripherally substituted arenes. The
crystal structures of iron complexes 9c and 10b indicate that
fusion of the aromatic systems to the porphyrin periphery and
concomitant delocalization of macrocycle electron density result
The structures were solved using direct methods to locate the non-
hydrogen atoms. After several cycles of least-squares refinement the
hydrogen atoms were inserted in computed positions and included in
the final least-squares cycles using a riding model. Final difference
syntheses showed no significant features. The experimental data are
summarized in Table 2.
General Procedure: 5-(N-Aryltrifluoroacetamido)-2,3,7,8,12,13,
17,18-octaethylporphyrinatozinc(II). The trifluoroacetamido arene
(0.5 mmol) in 10 mL of THF is stirred with NaH (0.75 mmol) under
argon for 15 min. Under argon pressure, the clear solution is added by
cannula to a solution of zinc(II) octaethylporphyrin π-cation radical
generated in situ by treating zinc(II) octaethylporphyrin (0.05 mmol)
in 13 mL of THF with tris(p-bromophenyl)aminium hexachloroanti-
monate (0.1 mmol) in 10 mL of methylene chloride for 5 min. The
resulting purple solution is stirred for 3 h under argon and the solvent
removed under reduced pressure. The remaining solid is chromato-
graphed on silica eluted with hexane/methylene chloride, 1:1. Unreacted
zinc octaethylporphyrin is eluted first followed by the product.
General Procedure: 5-Arylamino-2,3,7,8,12,13,17,18-octaeth-
ylporphyrinatozinc (II). The 5-(N-aryltrifluoroacetamido)porphyrin
complex synthesized above (1 mmol) in methanol/THF, 1:1, was
refluxed with sodium methoxide (20 mmol) under argon for 1 h. The
(34) Smith, N. K.; Stewart, R. C.; Osborn, A. G.; Scott, D. W. J. Chem.
Thermodyn. 1980, 12, 919-926.
(31) Dolphin, D. H.; Sams, J. R.; Tsin, T. B. Inorg. Chem. 1977, 16, 711-
713.
(32) Cheng, B.; Safo, M. K.; Orosz, R. D.; Reed, C. A.; Debrunner, P. G.;
Scheidt, W. R. Inorg. Chem. 1994, 33, 1319-1324.
(33) Morgan, A. R.; Skalkos, D.; Maguire, G.; Rampersaud, A.; Garbo,
G.; Keck, R.; Selman, S. H. Photochem. Photobiol. 1992, 55, 133-
136.
(35) Ling, Y.; Lifshitz, C. J. Phys. Chem. 1995, 99, 11074-11080.
(36) Boyd, R. H.; Christensen, R. L.; Pua, R. J. Am. Chem. Soc. 1965, 87,
3554-3559.
(37) Gabe, E. J.; Le Page, Y.; Charland, J.-P.; Lee, F. L.; White, P. S. J.
Appl. Crystallog. 1989, 22, 384-387.
(38) International Tables for X-ray Crystallography; The Kynoch Press:
Birmingham, England, 1974; Vol IV.

3662 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
solvents were removed under reduced pressure and the residue taken
up in methylene chloride and washed twice× with equal volumes of
water. The organic layer was dried over sodium sulfate and evaporated.
The residue was filtered through silica with methylene chloride eluant.
The material recovered from the filtrate was purified by TLC on a silica
plate (20 cm × 20 cm × 1000 µm) eluted with hexane/methylene
chloride, 1:1. Yields are calculated based on Zn(II)OEP starting
complex.
for C44H53N5O [M+]: 667.4250. Found: 667.4232. 1H NMR (500 MHz,
methylene-d2 chloride): δ 10.15 (s, 2H, H10, H20), 9.97 (s, 1H, H15),
7.66 (d, 2H, phenyl o-H, J ) 7.7 Hz), 7.07 (pseudo t, 2H, phenyl m-H,
Jave ) 7.7 Hz), 6.94 (t, 1H, phenyl p-H, J ) 7.7 Hz), 4.06-3.97 (m,
12H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 3.72-3.62 (m, 4H, 3-, 7-â-
methylene), 1.9-1.8 (m, 18H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3),
1.62 (s, 3H, acetyl), 1.17 (t, 6H, 3-, 7-â- CH2CH3, J ) 7.5 Hz), -3.27
(s, 1H, pyrrole NH), -3.33 (s, 1H, pyrrole NH).
a. 5-N-Phenylacetamido-2,3,7,8,12,13,17,18-octaethylporphyri-
natozinc(II) (1a). Purified 1a was isolated in 50% yield. UV-vis
(MeOH, λmax, nm (ꢀ × 10-3)): 242 (14.26), 337 (16.93), 408 (92.71),
543 (11.42), 582 (10.55). HRMS (FAB+) m/z calcd for C44C51N5O64Zn
[M+]: 729.3385. Found: 729.3517. LRMS (FAB+), m/z (rel inten-
sity): 734 (26), 733 (51), 732 (50), 731 (74), 730 (68), 729 (100) [M+],
690 (13), 689 (14), 688 (16), 687 (16), 686 (20). 1H NMR (500 MHz,
methylene-d2 chloride): δ 10.14 (s, 2H, H10, H20), 10.10 (s, 1H, H15),
7.69 (bs, 2H, phenyl o-H), 7.05 (pseudo t, 2H, phenyl m-H, Jave ) 8.0
Hz), 6.92 (t, 1H, phenyl p-H, J ) 7.3 Hz), 3.96-4.08 (m, 12H, 2-, 8-,
12-, 13-, 17-, 18-â-CH2CH3), 3.63-3.73 (m, 4H, 3-,7-â-CH2CH3), 1.83,
1.86 (overlapping t, 18H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3, J ) 7.6
Hz), 1.56 (s, 3H, acetyl), 1.13 (t, 6H, 3-,7-â-CH2CH3; J ) 7.6 Hz).
b. 5-(N-3-Fluoranthenyl)acetamido-2,3,7,8,12,13,17,18-octaeth-
ylporphyrinatozinc(II) (2a). The product demetalated during initial
chromatography and was isolated as the metal-free base 2b in 35%
yield based on OEP. Zn(II) was inserted by refluxing for 5 min in
hexane/methylene chloride, 1:1, with 20-fold excess ZnOAc. Purified
2a was obtained in 90% yield based on 2b. UV-vis (MeOH, λmax, nm
(ꢀ × 10-3)): 301 (23.43), 413 (147.20), 546 (15.28), 585 (12.55).
HRMS (FAB+) m/z calcd for C54H55N5O64Zn: 853.3698. Found:
853.3683. MS (FAB+), m/z (rel intensity): 859 (34), 858 (57), 857
(59), 856 (84), 855 (75), 854 (100) [M + H]+, 815 (15), 814 (16), 813
b. 5-(N-3-Fluoranthenyl)acetamido-2,3,7,8,12,13,17,18-octaeth-
ylporphyrin (2b). Porphyrin 2b was obtained in 35% yield directly
from chromatographic purification of the coupling reaction product.
UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 299 (18.74), 405 (90.06), 507
(9.40), 540 (4.54), 576 (3.93), 628 (2.60). HRMS (FAB+) m/z calcd
for C54H57N5O [M+]: 791.4563. Found: 791.4547. 1H NMR (500 MHz,
chloroform-d): δ 10.19 (s, 2H, H10, H20), 9.95 (s, 1H, H15), 8.61 (d,
1H, H4′, J ) 8.2 Hz), 8.03 (d, 1H, H6′, J ) 6.9 Hz), 7.90 (d, 1H, H7′
or H10′, J ) 7.6 Hz), 7.78 (pseudo t, 1H, H5′, Jave ) 7.7 Hz), 7.61 (d,
1H, H10′ or H7′, J ) 7.2 Hz), 7.37 (d, 1H, H1′, J ) 7.9 Hz), 7.31
(pseudo t, 1H, H8′ or H9′, Jave ) 7.5 Hz), 7.24 (pseudo t [partially
obscured by solvent protons], H9′ or H8′), 7.13 (d, 1H, H2′, J ) 7.9
Hz), 4.12-3.98 (m, 12H, 2-, 8-, 12-, 13-, 17-, 18-â-methylene), 3.98-
3.90 (m, 2H, diastereotopic 3-, 7-â-CH2CH3), 3.86-3.78 (m, 2H,
diastereotopic 3-, 7-â-CH2CH3), 1.92-1.84 (overlapping, 3 × t at 1.91,
1.90, 1.87, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3, J ) 7.6 Hz, and s, 1H
at 1.84, COCH3, total 21H), 1.21 (t, 6H, 3-, 7-â-CH2CH3, Jave ) 7.6
Hz).
c. 5-(N-1-Pyrenyl)acetamido-2,3,7,8,12,13,17,18-octaethylporphy-
rin (3b). UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 234 (20.9), 278
(10.79), 408 (32.79), 507 (2.86), 541 (1.82), 578 (1.79), 629 (1.05).
HRMS (FAB+) m/z calcd for C54H57N5O [M+]: 791.4563. Found:
1
791.4519. H NMR (500 MHz, methylene-d2 chloride): δ 10.15 (s,
1
(22), 812 (19), 811 (25) [M + H - COCH3]+. H NMR (500 MHz,
2H, H10, H20), 9.92 (s, 1H, H15), 8.72 (d, 1H, H10′, J ) 9.4 Hz),
8.32 (d, 1H, H9′, J ) 9.4 Hz), 8.31 (d, 1H, H8′, J ) 7.4 Hz), 8.21 (d,
1H, H6′, J ) 7.6 Hz), 8.06 (pseudo t, 1H, H7′, Jave ) 7.6 Hz), 8.02 (d,
1H, H5′, J ) 8.8 Hz), 7.84 (d, 1H, H4′, J ) 8.8 Hz), 7.69 (d, 1H, H3′,
J ) 8.8 Hz), 7.56 (d, 1H, H2′, J ) 8.8 Hz), 4.07-3.90 (m, 12H, 2-,
8-, 12-, 13-, 17-, 18-â-CH2CH3), 3.79-3.71 (m, 2H, diastereotopic 3-,
7-â-CH2CH3), 3.60-3.52 (m, 2H, diastereotopic 3-, 7-â-CH2CH3),
1.850, 1.845 (overlapping: 2 × t, 12H, 12-, 13-, 17-, 18-â-CH2CH3, J
) 7.7 Hz), 1.78 (t, 6H, 2-, 8-â-CH2CH3, J ) 7.7 Hz), 1.77 (s, 3H,
COCH3), 1.15 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.7 Hz).
Chloro-5-N-phenylacetamido-2,3,7,8,12,13,17,18-octaethylpor-
phyrinatoiron(III) (1c). To a degassed solution of 0.02 mmol porphyrin
1b in 1:1 methanol/chloroform, 1 mmol ferrous chloride tetrahydrate
was added, and the mixture was refluxed under argon for 2 min. The
solvent was removed under reduced pressure and the solid residue
chromatographed on silica eluted with 5% methanol in methylene
chloride to remove inorganic salts. The complex was rechromatographed
by TLC on alumina with methylene chloride eluant. The recovered
product was converted to the chloro complex by treatment of a
methylene chloride solution with HCl gas. Complex 1c was obtained
in >95% yield upon removal of solvent under reduced pressure. UV-
vis (MeOH, λmax, nm (ꢀ × 10-3)): 396 (81.4), 500 (6.18), 625 (3.30).
HRMS (FAB+) m/z calcd for C44H51N5O56Fe [M+]: 721.3443. Found:
721.3356. 1H NMR (500 MHz, chloroform-d): δ 45.1, 44.7, 43.7, 43.2,
42.5, 40.0, 39.1, 38.1, 37.0 (1:2:1:1:2:4:3:1:1; 2, 3, 7-, 8-, 12-, 13-,
17-, 18-â-CH2CH3), 11.3, 10.2 (phenyl o-H), 6.90-5.70 (2-, 3-, 7-,
8-,12-, 13-, 17-, 18-â-CH2CH3 + OCH3), -50.2, -60.7 (1:2, meso-
H).
5-N-Phenyltrifluoroacetamido-2,3,7,8,12,13,17,18-octaethylpor-
phyrin (4). Trifluoroacetanilide (0.5 mmol) in 10 mL of THF was
stirred with NaH (1.0 mmol) under argon for 15 min. The resulting
clear solution was added to a solution of Zn(II)OEP•+ generated from
Zn(II)OEP (0.05 mmol) by treatment with tris(4-bromophenyl)aminium
hexachloroantimonate (0.1 mmol) in 1:1 methylene chloride/THF
solution. The green color of Zn(II)OEP•+ rapidly discharged, and the
resulting purple solution was stirred for 3 h under argon. The solid
remaining after evaporation of solvent under reduced pressure was
chromatographed on silica eluted with 1:1 hexane/methylene chloride.
Unreacted Zn(II)OEP was followed by 4, which was isolated in 30%
yield based on Zn(II)OEP. UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 245
methylene-d2 chloride): δ 10.14 (s, 2H, H10, H20), 10.06 (s, 1H, H15),
8.44 (bd, 1H, H4′, J ) 7.2 Hz), 7.97 (d, 1H, H6′, J ) 7.0 Hz), 7.86 (d,
1H, H7′ or H10′, J ) 7.5 Hz), 7.63 (pseudo t, 1H, H5′, Jave ) 7.6 Hz),
7.56 (d, 1H, H10′ or H7′, J ) 7.2 Hz), 7.35 (d, 1H, H1′, J ) 7.9 Hz),
7.26 (pseudo t, 1H, H8′ or H9′, Jave ) 7.5 Hz), 7.18 (pseudo t, 1H, H9′
or H8′, Jave ) 7.5), 7.14 (d, 1H, H2′, J ) 7.9 Hz), 4.05-3.94 (m, 12H,
2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 3.86-3.93 (m, 2H, diastereotopic
H, 3-, 7-â-CH2CH3), 3.74-3.82 (m, 2H, diastereotopic 3-, 7-â-CH2-
CH3), 1.86, 1.85 (overlapping t, 12H, 12-, 13-, 17-, 18-â-CH2CH3, J
) 7.6 Hz), 1.82 (t, 6H, 2-, 8-â-methyl, J ) 7.6 Hz), 1.62 (s, 3H,
COCH3), 1.12 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.6 Hz).
c. 5-(N-1-Pyrenyl)acetamido-2,3,7,8,12,13,17,18-octaethylporphy-
rinatozinc(II) (3a). Compound 3a was obtained in 18% yield. UV-
vis (MeOH, λmax, nm (ꢀ × 10-3)): 237 (15.09), 279 (8.96), 338 (11.29),
418 (72.51), 547 (4.72), 585 (3.61). HRMS (FAB+) m/z calcd for
C54H55N5O64Zn [M+]: 853.3698. Found: 853.3653. MS (FAB+) m/z
(rel intensity): 859 (17), 858 (33), 857 (58), 856 (56), 855 (82), 854
(78), 853 (92) [M+], 814 (26), 813 (26), 812 (35), 811 (32), 810 (35)
[M-COCH3]+, 601 (28), 600 (49), 599 (52), 598 (72), 597 (67), 596
(100) [M-acetamidopyrene]+. 1H NMR (500 MHz, methylene-d2
chloride): δ 10.13 (s, 2H, H10, H20), 10.05 (s, 1H, H15), 8.75 (d, 1H,
H10′, J ) 9.2 Hz), 8.29 (overlapping: 2 × d, 2H, H9′, J ) 9.2 Hz and
H8′, J ) 7.4 Hz), 8.19 (d, 1H, H6′, J ) 7.7 Hz), 8.04 (pseudo t, 1H,
H7′, Jave ) 7.7 Hz), 7.99 (d, 1H, H5′, J ) 8.6 Hz), 7.83 (d, 1H, H4′,
J ) 8.6 Hz), 7.66 (d, 1H, H3′, J ) 8.9 Hz), 7.59 (d, 1H, H2′, J ) 8.9
Hz), 4.08-4.00 (m, 8H, 12-, 13-, 17-, 18-â-CH2CH3), 4.00-3.93 (m,
2H, diastereotopic 2-, 8-â-CH2CH3), 3.93-3.86 (m, 2H, diastereotopic
2-, 8-â-CH2CH3), 3.82-3.74 (m, 2H, diastereotopic 3-, 7-â-CH2CH3),
3.62-3.53 (m, 2H, diastereotopic 3-, 7-â-CH2CH3), 1.91-1.82 (over-
lapping, 2 × t at 1.86, 1.84, total 12H, 12-, 13-, 17-, 18-â-CH2CH3, J
) 7.6 Hz), 1.78 (t, 6H, 2-, 8-â-CH2CH3, J ) 7.6 Hz), 1.62 (s, 3H,
COCH3), 1.12 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.6 Hz).
General Procedure: 5-Arylamino-2,3,7,8,12,13,17,18-octaeth-
ylporphyrin. The zinc complex of the 5-arylaminoporphyrin obtained
above was demetalated by stirring for 0.5 h in methylene chloride
saturated with HCl. Removal of Zn(II) was accomplished quantitatively.
a. 5-N-Phenylacetamido-2,3,7,8,12,13,17,18-octaethylporphyrin
(1b). UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 236 (5.15), 398 (25.49),
503 (2.91), 537 (1.61), 573 (1.28), 627 (0.94). HRMS (FAB+) m/z calcd

Amino and Amido Compounds
Inorganic Chemistry, Vol. 39, No. 16, 2000 3663
(17.36), 338 (27.64), 409 (196.4), 543 (17.78), 583 (22.64). MS (FAB+)
3.66 (m, 2H, diastereotopic 3-, 7-â-CH2CH3), 1.94, 1.93 (overlapping
2 × t, 12H, 12-, 13-, 17-, 18-â-CH2CH3, J ) 7.6 Hz), 1.82 (t, 6H, 2-,
8-â-CH2CH3, J ) 7.6 Hz), 1.76 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.6 Hz).
General Procedure: 5-N-Arylaminoporphyrins from 5-N-Aryl-
aminoporphyrinatozinc(II) Complexes. The Zn(II) complexes were
quantitatively demetalated by stirring methylene chloride solutions for
15 min following addition of 5% v/v concentrated HCl. The methylene
chloride solution was then washed with an equal volume of water and
twice with equal volumes of saturated bicarbonate solution, dried over
sodium sulfate, and evaporated under reduced pressure.
m/z (rel intensity): 788 (24), 787 (52), 786 (45), 785 (68), 784 (64),
1
783 (100) [M]+, 597 (13), 596 (18) [M - trifluoroacetanilide]+. H
NMR (500 MHz, chloroform-d): δ 10.20 (s, 2H, H10, H20), 10.14 (s,
1H, H15), 7.79 (bs, 2H, phenyl o-H), 7.25-7.16 (m, 2H, phenyl m-H),
7.11 (t, 1H, phenyl p-H, Jave ) 7.1 Hz), 4.11-4.02 (m, 12H, 2-, 8-,
12-, 13-, 17-, 18-â-CH2CH3), 3.78-3.65 (m, 4H, 3-, 7-â-CH2CH3),
1.95-1.87 (m, 18H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 1.09 (t, 6H,
3-, 7-â-CH2CH3, J ) 7.5 Hz).
5-(N-3-Fluoranthenyl)trifluoroacetamido-2,3,7,8,12,13,
17,18-octaethylporphyrinatozinc(II) (5). 3-Trifluoroacetamidofluo-
ranthene (0.5 mmol) in 10 mL of THF was stirred with NaH (0.75
mmol) under argon for 15 min. The resulting clear solution was added
to a solution of Zn(II)OEP•+ generated from Zn(II)OEP (0.05 mmol)
by treatment with tris(p-bromophenyl)aminium hexachloroantimonate
(0.1 mmol) in 1:1 methylene chloride/THF solution. The green color
of the Zn(II)OEP•+ was rapidly discharged, and the resulting purple
solution was stirred an additional 3 h under argon. After removal of
the solvent under reduced pressure, the solid residue was chromato-
graphed on silica eluted with 1:1 hexane/methylene chloride. The
product was isolated in 30% yield (based on Zn(II)OEP) following
elution of unreacted Zn(II)OEP and 3-trifluoroacetamidofluoranthene.
UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 216 (43.58), 300 (25.44), 416
(188.0), 547 (14.88), 585 (14.44). MS (FAB+) m/z (rel intensity): 913
(10), 912 (28), 911 (55), 910 (53), 909 (69), 908 (73), 907 (100) [M]+,
810 (10) [M - 3-trifluoroacetamidofluoranthene]+. 1H NMR (500 MHz,
chloroform-d): δ 10.19 (s, 2H, H10, H20), 10.11 (s, 1H, H15), 8.41
(bs, 1H, H4′), 8.06 (d, 1H, H6′, J ) 6.9 Hz), 7.91 (d, 1H, H7′, J ) 7.7
Hz), 7.84 (bs, 1H, H5′), 7.63 (d, 1H, H10′, J ) 7.4 Hz), 7.42 (d, 1H,
H1′, J ) 8.0 Hz), 7.34 (pseudo t, 1H, H8′ or H9′, Jave ) 7.6 Hz),
4.13-3.98 (m, 12H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 3.98-3.89
(m, 2H, diastereotopic 3-, 7-â-CH2CH3), 3.81-3.71 (m, 2H, diaste-
reotopic 3-, 7-â-CH2CH3), 1.912, 1.905 (overlapping: 2 × t, 12H, 12-,
13-, 17-, 18-â-CH2CH3, J ) 7.5 Hz), 1.87 (t, 6H, 2-, 8-â-CH2CH3, J
) 7.5 Hz), 0.92 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.5 Hz).
a. 5-N-Phenylamino-2,3,7,8,12,13,17,18-octaethylporphyrin (6b).
UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 240 (12.97), 405 (47.03), 507
(9.00), 535 (5.96), 575 (5.65), 618 (3.82). HRMS (FAB+) m/z calcd
for C42H51N5 [M+]: 625.4144. Found: 625.4086. 1H NMR (500 MHz,
chloroform-d): δ 10.06 (s, 2H, H10, H20), 9.88 (s, 1H, H15), 7.79 (s,
1H, amino NH), 7.06 (pseudo t, 2H, phenyl m-H, Jave ) 7.4 Hz), 6.75
(t, 1H, phenyl p-H, J ) 7.4 Hz), 6.50 (bs, 2H, phenyl o-H), 4.12-3.98
(m, 12H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 3.98-3.88 (m, 2H, 3-,
7-â-CH2CH3), 3.78-3.68 (m, 2H, 3-, 7-â-CH2CH3), 1.91, 1.90 (over-
lapping 2 × t, 12H, 12-, 13-, 17-, 18-â-CH2CH3, J ) 7.6 Hz), 1.81 (t,
6H, 2-, 8-â-CH2CH3, J ) 7.6 Hz), 1.69 (t, 6H, 3-, 7-â-CH2CH3, J )
7.6 Hz), -3.12 (s, 2H, NH).
b. 5-N-(3-Fluoranthenyl)amino-2,3,7,8,12,13,17,18-octaethylpor-
phyrin (7b) and 12-Azabenzo[b]fluorantheno[9,10,11-tu]-3,3,7,8,
12,13,17,18-octaethyl-2H-porphyrin (9b). Demetalation of 7a yielded
two compounds, 7b and 9b, in 2:1 ratio, separated by TLC on silica
with 3:1 hexane/methylene chloride eluant.
Porphyrin 7b. UV-vis (CH2Cl2, λmax, nm (ꢀ × 10-3)): 245 (19.39),
308 (13.04), 403 (46.33), 508 (7.94), 538 (2.92), 575 (3.58), 627 (1.24).
HRMS (FAB+) m/z calcd for C52H55N5 [M+]: 749.4457. Found:
1
749.4449. H NMR (500 MHz, methylene-d2 chloride): δ 10.15 (s,
2H, H10, H20), 10.00 (s, 1H, H15), 8.78 (s, 1H, amino NH), 8.66 (d,
2H, H4′, J ) 7.7 Hz), 8.23 (d, 1H, H6′, J ) 7.1 Hz), 8.02-7.96 (m,
2H, H5′, H10′), 7.59 (d, 1H, H7′, J ) 6.9 Hz), 7.30-7.26 (m, 2H,
H8′, H9′), 7.22 (d, 1H, H1′, J ) 7.8 Hz), 5.57 (bd, 1H, H2′, J ) 7.8
Hz), 4.15-4.14 (m, 10H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 4.04-
3.95 (m, 2H, 2-, 8-â-CH2CH3), 3.89-3.80 (m, 2H, 3-, 7-â-CH2CH3),
3.75-3.65 (m, 2H, 3-, 7-â-CH2CH3), 1.92 (t, 12H, 12-, 13-, 17-, 18-
â-CH2CH3, J ) 7.7 Hz), 1.81 (t, 6H, 2-, 8-â-CH2CH3, J ) 7.7 Hz),
1.70 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.7 Hz), -3.23 (bs, 2H, NH).
Porphyrin 9b. UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 234 (1.28),
359 (1.43), 437 (5.23), 451 (6.87), 574 (0.32), 625 (0.55), 683 (1.28).
HRMS (FAB+) m/z calcd for C52H53N5 [M+]: 747.4227. Found:
747.4301. 1H NMR (500 MHz, methylene-d2 chloride): δ 9.49 (d, 1H,
H1′, J ) 8.0 Hz), 9.19 (s, 1H, H8′), 9.08 (s, 1H, H15), 8.41 (s, 1H,
H10), 8.33-8.30 (m, 1H, H7′), 8.25 (d, 1H, H3′), 8.10 (pseudo t, 1H,
H2′, Jave ) 8.3 Hz), 8.09 (d, 1H, H4′, J ) 7.5 Hz), 8.05 (s, 1H, H5),
7.60-7.53 (m, 2H, H5′, H6′), 4.58 (q, 2H, 18-â-CH2CH3, J ) 7.4 Hz),
3.83 (q, 2H, 17-â-CH2CH3, J ) 7.5 Hz), 3.64-3.56 (m, 4H, 7-, 8- or
12-â-CH2CH3), 3.54 (q, 2H, 13-â-CH2CH3, J ) 7.6 Hz), 3.47 (q, 2H,
12- or 8-â-CH2CH3, J ) 7.5 Hz), 3.36-3.27 (m, 2H, gem-â-CH2CH3),
3.13-3.05 (gem-â-CH2CH3), 2.02 (t, 3H, 18-â-CH2CH3, J ) 7.4 Hz),
1.76 (t, 3H, â-CH2CH3, J ) 7.6 Hz), 1.73 (t, 3H, 7-â-CH2CH3, J )
7.6 Hz), 1.71 (t, 3H, â-CH2CH3, J ) 7.6 Hz), 1.67 (t, 3H, 13- or 17-
â-CH2CH3, J ) 7.6 Hz), 1.64 (t, 3H, 8- or 12-â-CH2CH3, J ) 7.6 Hz),
-0.01 (t, 6H, gem-â-CH2CH3, J ) 7.3 Hz).
General Procedure: Deacetylation of 5-(N-Aryltrifluoroaceta-
mido)porphyrinatozinc(II) Derivatives. The porphyrinatozinc(II)
complex (1 mmol) in 20 mL of 1:1 THF/methanol was refluxed with
sodium methoxide (20 mmol) under argon for 1 h. Following removal
of solvents under reduced pressure, the residue was taken up in
methylene chloride and washed twice× with equal volumes of water.
The organic layer was separated, dried over sodium sulfate, and
evaporated to dryness under reduced pressure. The resulting solid was
chromatographed by TLC on silica with 1:1 hexane/methylene chloride
eluant.
a. 5-N-Phenylamino-2,3,7,8,12,13,17,18-octaethylporphyrinatozinc-
(II) (6a). Complex 6a was isolated in 40% yield. UV-vis (MeOH,
λ
max, nm (ꢀ × 10-3)): 243 (11.6), 331 (12.88), 414 (103.5), 545 (10.83),
579 (6.70). HRMS (FAB+) m/z calcd for C42H49N564Zn [M+]: 687.32794.
Found: 687.33161. FAB/MS m/z (rel intensity): 692 (25), 691 (51),
690 (49), 689 (75), 688 (67), 687 (100), 686 (20) [M]+. 1H NMR (500
MHz, chloroform-d): δ 10.11 (s, 2H, H10, H20), 10.03 (s, 1H, H15),
7.85 (s, H, amino NH), 7.01 (bs, 2H, phenyl m-H), 6.69 (t, 1H, phenyl
p-H, J ) 7.1 Hz), 6.35 (bs, 2H, phenyl o-H), 4.08 (q, 8H, 12-, 13-,
17-, 18-â-CH2CH3, J ) 7.6 Hz), 4.12 (m, 4H, 2-, 3-, 7-, 8-â-CH2-
CH3), 3.81-3.73 (m, 2H, diastereotopic 3-, 7-â-CH2CH3), 1.92 (t, 12H,
12-, 13-, 17-, 18-â-CH2CH3, J ) 7.6 Hz), 1.83 (t, 6H, 2-, 8-â-CH2CH3,
J ) 7.6 Hz), 1.74 (t, 6H, 3-, 7-â-CH2CH3, J ) 7.6 Hz).
Chloro-5-N-Phenylamino-2,3,7,8,12,13,17,18-octaethylporphyri-
natoiron(III) (6c). A total of 0.7 mmol of ferrous chloride tetrahydrate
was added to a degassed solution of 0.024 mmol of porphyrin 6b in
1:1 methanol/chloroform (20 mL). The reaction mixture was stirred
under a nitrogen atmosphere for 10 min at ambient temperature and
partitioned between chloroform and water. The organic layer was dried
over sodium sulfate and evaporated to dryness under reduced pressure.
The solid residue was flash-chromatographed over silica. Elution with
1:1 hexane/methylene chloride yielded the fused metal-free base 8a
(see below). Further elution with 5% MeOH in chloroform gave meso-
substituted iron complex 6c in 25% yield based on starting porphyrin.
UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 270 (11.07), 353 (19.97), 404
(29.51), 563 (4.42). HRMS (FAB+) m/z calcd for C42H49N556Fe [M+]:
b. 5-(N-3-Fluoranthenyl)amino-2,3,7,8,12,13,17,18-octaethylpor-
phyrinatozinc(II) (7a). Complex 7a was obtained in 30% yield along
with a trace quantity of the fused Zn(II) complex 9a. UV-vis (MeOH,
λmax, nm (rel intensity)): 309 (0.18), 320 (0.19), 361 (0.20), 404 (1.00),
539 (0.12), 577 (0.10). HRMS (FAB+) m/z calcd for C52H53N564Zn
[M+]: 811.35924. Found: 811.35000. 1H NMR (500 MHz, chloroform-
d): δ 10.15 (s, 2H, H10, H20), 10.09 (s, 1H, H15), 8.83 (s, 1H, amino
NH), 8.63 (d, 1H, H4′, J ) 8.0 Hz), 8.20 (d, 1H, H6′, J ) 7.1 Hz),
7.99-7.92 (m, 2H, H5′, H7′), 7.55 (d, 1H, H10′, J ) 7.8 Hz), 7.28-
7.21 (overlapping with residual solvent protons, H8′, H9′), 7.11 (d,
1H, H1′, J ) 7.8 Hz), 5.31 (d, 1H, H2′, J ) 7.8 Hz), 4.15-4.02 (m,
10H, 2-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 4.02-3.95 (m, 2H, 2-, 8-â-
CH2CH3), 3.95-3.87 (m, 2H, diastereotopic 3-, 7-â-CH2CH3), 3.75-
1
679.3337. Found: 679.3271. H NMR (500 MHz, chloroform-d): δ
43.5, 43.3, 42.1, 40.0, 39.7, 39.4, 38.6, 37.2 (2:2:4:2:1:1:1:4, 2-, 3-,

3664 Inorganic Chemistry, Vol. 39, No. 16, 2000
Jayaraj et al.
7-, 8-, 12-, 13-, 17-, 18-â-CH2CH3 + NH), 6.58, 6.23, 5.84 (2-, 3-, 7-,
8-, 12-, 13-, 17-, 18-â-CH2CH3), -57.1 (H15), -61.2 (H10, H20).
Quinolino[2,3,4-tu]-3,3,7,8,12,13,17,18-octaethyl-2H-porphyrin (8a).
Porphyrin 8a was obtained in 25% yield from metalation of porphyrin
6b described above. UV-vis (MeOH, λmax, nm (ꢀ × 10-3)): 270 (4.49),
354sh (7.08), 409 (17.99), 425sh (12.66), 450sh (3.97), 550 (1.25),
595 (1.42), 629 (2.05), 687 (4.06). HRMS (FAB+) m/z calcd for
10-Azabenzo[a]pyreno[7,8,9-tu]-3,3,7,8,12,13,17,18-octaethyl-2H-
porphyrin (10a). 1-(2,4-Dinitrobenzenesulfonamido)pyrene (0.3 mmol)
in THF (10 mL) was stirred for 10 min with NaH (1.2 mmol) at 42 °C
under argon. This solution was added to a solution of Zn(II)OEP•+
(0.05 mmol) generated from Zn(II)OEP (0.05 mmol) with tris(4-
bromophenyl)aminium hexachloroantimonate (0.1 mmol) in 1:1
methylene chloride/THF. The reaction was stirred for 3 h at ambient
temperature under argon. Following evaporation of the solvent under
reduced pressure, the residue was chromatographed on silica. Unreacted
Zn(II)OEP was eluted with 1:1 hexane/methylene chloride, and the Zn-
(II) complex of the porphyrin 10a followed on elution with methylene
chloride. The crude product was demetalated by stirring 5% v/v
methylene chloride/concentrated HCl, and the porphyrin was purified
by TLC on silica eluted with 2:1 hexane/methylene chloride. The yield
of purified 10a was 5% based on starting Zn(II)OEP. UV-vis (MeOH,
1
C42H48N5 [(M - H•)+]: 622.4056. Found: 622.3910. H NMR (600
MHz, chloroform-d): δ 8.81 (d, 1H, H8′, J ) 8.5 Hz), 8.73 (s, 1H,
H15), 8.70 (d, 1H, H5′, J ) 8.5 Hz), 8.00 (s, 1H, H10), 8.01-7.97 (s,
overlapping with pseudo triplet, 2H, H10, H7′), 7.84 (pseudo t, 1H,
H6′, Jave ) 7.5 Hz), 7.59 (s, 1H, H5′), 4.20 (q, 2H, 18-â-CH2CH3, J )
7.4 Hz), 3.61 (q, 2H, 17-â-CH2CH3, J ) 7.6 Hz), 3.42-3.34 (m, 6H,
7-, 12- or 8-, 13-â-CH2CH3), 3.30 (q, 2H, 8- or 12-â-CH2CH3, J ) 7.4
Hz), 3.07-2.99 (m, 2H, gem-â-CH2CH3), 2.86-2.78 (m, 2H, gem-â-
CH2CH3), 1.79 (t, 3H, 18-â-CH2CH3, J ) 7.4 Hz), 1.65-1.58 (m, 15H,
7-, 8-, 12-, 13-â-CH2CH3), 0.09 (t, 6H, gem-â-CH2CH3, J ) 7.4 Hz).
Chloroquinolino[2,3,4-tu]-3,3,7,8,12,13,17,18-octaethyl-2H-por-
phyrinatoiron(III) (8b). To a degassed solution of 0.0074 mmol of
porphyrin 6b in 1:1 methanol/chloroform (20 mL), 1.3 mmol of ferrous
chloride tetrahydrate was added, and the reaction mixture was refluxed
under argon for 5 min. The solvents were removed under reduced
pressure and the residue chromatographed on silica with 4% MeOH in
methylene chloride as eluant. Final purification was accomplished by
TLC on silica with methylene chloride eluant. Following removal from
the plate, the iron complex was dissolved in methylene chloride and
treated with HCl gas for complete conversion to the chloro form.
Complex 8b was obtained in 75% yield based on porphyrin 6b. UV-
vis (MeOH, λmax, nm (ꢀ × 10-3)): 275 (28.85), 414 (79.94), 546 (8.04),
629 (7.29), 686 (9.07). HRMS (FAB+) m/z calcd for C42H47N556Fe [M+]:
677.3180. Found: 677.3211. 1H NMR (600 MHz, chloroform-d): δ
59.6, 51.4, 51.0, 50.8, 49.5, 49.2, 43.9, 43.5, 42.4, 40.1, 37.4 (1:1:1:
1:1:1:1:1:1:1:2, 7-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 33.8, 32.6 (gem-
â-CH2CH3), 18.9, 17.6 (quinolino H′), 10.2, 8.8 (gem-â-CH2CH3), 6.5,
6.1, 5.8 (â-CH2CH3), -1.4 (â-CH2CH3), -5.5, -11.9 (quinolino H′),
-21.3, -84.4 (meso-H).
λ
max, nm (ꢀ × 10-3)): 240 (5.04), 341 (4.85), 420 (7.17), 439 (7.25),
465 (7.99) 598 (1.13), 6.52 (1.19), 716 (1.70). HRMS (FAB+) m/z calcd
for C52H53N5 [M+]: 747.4301. Found: 747.4210. 1H NMR (500 MHz,
chloroform-d): δ 10.35 (d, 1H, H11′, J ) 8.9 Hz), 9.28 (s, 1H, H6′),
8.82 (s, 1H, H15), 8.65 (d, 1H, H12′, J ) 8.9 Hz), 8.40 (d, 1H, H1′,
J ) 7.8 Hz), 8.27 (d, 1H, H3′, J ) 9.0 Hz), 8.18 (d, 1H, H4′, J ) 7.3
Hz), 8.08-8.05 (m, 3H, H2′, H5′, H10), 7.75 (s, 1H, H5), 4.58 (q, 2H,
18-â-CH2CH3, J ) 7.4 Hz), 3.73 (q, 2H, 17-â-CH2CH3, J ) 7.6 Hz),
3.50-3.39 (m, 6H, 7-, 8- or 12-, 13-â-CH2CH3), 3.38-3.29 (m, 4H,
gem-, 12- or 8-â-CH2CH3), 3.04-2.95 (m, 2H, gem-â-CH2CH3), 2.04
(t, 3H, 18-â-CH2CH3, J ) 7.4 Hz), 1.72 (t, 3H, 17-â-CH2CH3, J ) 7.6
Hz), 1.67 (t, 3H, 7-â-CH2CH3, J ) 7.6 Hz), 1.65 (t, 3H, 8- or 12-â-
CH2CH3, J ) 7.7 Hz), 1.61 (t, 3H, 13-â-CH2CH3, J ) 7.6 Hz), 1.57 (t,
3H, 12- or 8-â-CH2CH3, J ) 7.7 Hz), -0.03 (t, 6H, gem-â-CH2CH3,
J ) 7.4 Hz).
Chloro-10-Azabenzo[a]pyreno[7,8,9-tu]-3,3,7,8,12,13,17,18-octa-
ethyl-2H-porphyrinatoiron(III) (10b). Ferrous chloride tetrahydrate
(1.45 mmol) was added to a degassed solution of porphyrin 10a (0.007
mmol) in 1:1 methanol/chloroform, and the reaction was refluxed for
6 min. Following removal of solvent under reduced pressure, the residue
was chromatographed on silica. A small quantity of 10a was eluted
with methylene chloride, and the ferric complex 10b was eluted with
10% methanol in methylene chloride. The iron complex was further
purified by TLC on silica eluted with methylene chloride. The recovered
product was treated in methylene chloride with HCl gas to conversion
to the chloro complex 10b, obtained in 90% yield from 10a. UV-vis
(MeOH, λmax, nm (ꢀ × 10-3)): 258 (14.41), 280 (13.94), 340 (16.49)
437 (35.81), 642 (4.31), 702 (4.03). HRMS (FAB+) m/z calcd for
C52H51N556Fe [M+]: 801.3493. Found 801.3448. 1H NMR (500 MHz,
methylene-d2 chloride): δ 59.7, 51.2, 49.6.49.4, 49.0, 43.8, 42.8, 41.0,
38.2, 37.5 (1:2:1:1:1:2:1:1:1:1, 7-, 8-, 12-, 13-, 17-, 18-â-CH2CH3),
33.8, 32.9 (gem-â-CH2CH3), 12.1, 10.8, 10.6, 10.3 (10-azabenzo[a]-
pyreno H′), 9.1, 8.7 (gem-â-CH2CH3), 7.3 (â-CH2CH3), 6.6 (10-
azabenzo[a]pyreno H′), 6.5 (â-CH2CH3), 5.9 (â-CH2CH3), 4.6 (10-
azabenzo[a]pyreno H′), 3.1 (â-CH2CH3), -1.3 (gem-â-CH2CH3), -3.8
(10-azabenzo[a]pyreno H′), -23.8 (meso-H), -81 (meso-H).
Chloro-12-Azabenzo[b]fluorantheno[9,10,11-tu]-3,3,7,8,12,13,
17,18-octaethyl-2H-porphyrinatoiron(III) (9c). To a degassed solution
of porphyrin 7b (0.0045 mmol) in 1:1 methanol/chloroform (20 mL)
was added 0.615 mmol of ferrous sulfate tetrahydrate. The reaction
was refluxed under argon for 20 min, and the solvent was evaporated
under reduced pressure. The solid residue was chromatographed on
silica eluted with 4% methanol in chloroform. Final purification was
achieved by TLC on alumina eluted with methylene chloride. The
desorbed product was dissolved in methylene chloride and treated with
HCl gas to ensure complete conversion to chloro complex 9c, obtained
in 70% yield based on starting porphyrin 7b. UV-vis (MeOH, λmax
,
nm (ꢀ × 10-3)): 263 (17.08), 350 (14.41), 437 (37.28), 593 (3.80),
638 (4.07). HRMS (FAB+) m/z calcd for C52H53N556Fe [M+]: 801.3697.
1
Found 801.3775. H NMR (500 MHz, chloroform-d): δ 59.6, 50.8,
50.3, 49.0, 48.1, 44.1, 43.5, 42.9, 40.8, 38.8, 38.1 (1:1:1:2:1:1:1:1:1:
1:1, 7-, 8-, 12-, 13-, 17-, 18-â-CH2CH3), 34.8, 33.3 (gem-â-CH2CH3),
11.6 (12-azabenzo[b]fluoranthene H′), 10.7 (3-â-CH2CH3), 9.6 (12-
azabenzo[b]fluorantheno H′), 9.5 (gem-â-CH2CH3), 8.8, 8.2 (12-
azabenzo[b]fluorantheno H′), 6.7, 6.5, 5.9 (â-CH2CH3), -1.3 (gem-â-
CH2CH3), -26.7, -76.0 (meso-H).
1-(2,4-Dinitrobenzenesulfonamido)pyrene. 2,4-Dinitrobenzene-
sulfonyl chloride (1.35 mmol) in methylene chloride (4 mL) was added
slowly with stirring to a solution of 1-aminopyrene (1.4 mmol) and
pyridine (1.5 mmol) in methylene chloride (6 mL). After being stirred
for an additional 15 min, the reaction mixture was washed twice× with
water, the organic layer dried over sodium sulfate, and the solvent
evaporated under reduced pressure. The residue was flash-chromato-
graphed on silica eluted with methylene chloride. EI/MS m/z (rel
intensity): 447 (3.7) [M]+, 217 (100) [M - 2,4-dinitrobenzenesulfo-
nyl]+.
Acknowledgment. This work was supported by USEPA
Grant R825346.
Supporting Information Available: 1H NMR spectra of all metal-
free bases and Zn(II) and Fe(III) complexes and listings of crystal-
lographic details, atomic coordinates, anisotropic temperature factors,
fixed hydrogen atom positions, and bond distances and angles for
complexes 9c and 10b. This material is available free of charge via
the Internet at http://pubs.acs.org.
IC000112R