Synthesis and characterization of transition metal complexes of dimeric N-confused porphyrin linked by an o-xylene fragment

Article abstract of DOI:10.1021/ic800591n

Insertion of nickel(II), zinc, cadmium, or silver(III) into both macrocyclic crevices of 2,2′-o-xylene-bis(5,10,15,20- tetrakis(p-tolyl)-2- aza-21-carbaporphyrin) results in homometallic dimeric complexes which were isolated and characterized by NMR, UV-v

Full text of DOI:10.1021/ic800591n

Inorg. Chem. 2009, 48, 432-445
Synthesis and Characterization of Transition Metal Complexes of
Dimeric N-Confused Porphyrin Linked by an o-Xylene Fragment
Piotr J. Chmielewski*
Department of Chemistry, UniVersity of Wrocław, 14 F. Joliot-Curie Street,
50-383 Wrocław, Poland
Received April 2, 2008
Insertion of nickel(II), zinc, cadmium, or silver(III) into both macrocyclic crevices of 2,2′-o-xylene-bis(5,10,15,20-
tetrakis(p-tolyl)-2-aza-21-carbaporphyrin) results in homometallic dimeric complexes which were isolated and
characterized by NMR, UV-vis, mass spectrometry, and cyclic voltammetry. The 1H NMR study of these systems
at low temperatures (203-233 K) allowed determination of most stable conformers with respect to a rotational
freedom around the xylene bridge. An unfolded conformation for the dicationic bis(silver(III)) complex was determined
on the basis of 2D nuclear Overhauser effect spectrometry experimentation. A mixture of nonequally populated
diastereomers is observed for bis(zinc) and bis(cadmium) complexes due to a possibility of two different orientations
of the apical anionic ligands with respect to the bridge. In a reaction of 5,10,15,20-tetrakis(p-tolyl)-2-aza-21-
carbaporphyrinato nickel(II) with 2-(o-bromoxylene)-5,10,15,20-tetrakis(p-tolyl)-2-aza-21-carbaporphyrin in the presence
of a proton scavenger, two isomeric bis(N-confused porphyrin) complexes with one subunit “empty” and the other
metalated by nickel(II) were obtained. In the product 10, the o-xylene links external nitrogens of the subunits while
product 11 consists of the xylene bridge between external nitrogen of the nonmetalated subunit and internal carbon
of the fragment containing a nickel(II) ion. The products were characterized by mass spectrometry, UV-vis, NMR,
¯
and, in the case of complex 11, also by X-ray crystallographic analysis (space group P1, a )17.007(3), b )
18.130(3), c ) 18.797(2) Å, R ) 105.856(13)°, ꢀ ) 107.447(13)°, γ ) 98.818(15)°, V ) 5141.1(15) Å3, Z ) 2).
Insertion of zinc or silver(III) into an empty crevice of 10 resulted in heterometallic zinc-nickel(II) or silver(III)-nickel(II)
complexes 12 or 13, respectively, which were characterized by NMR, UV-vis, and cyclic voltammetry. The subunits
in the bis(porphyrin) systems retain spectroscopic and redox properties typical for monomeric complexes.
Introduction
reactivity of metal complexes25 of NCP allows further
modification of the system which involves the confused
pyrrole26–36 due to its susceptibility to various types of
reaction. The free-base porphyrin also can be a subject of
derivatization that leads to the formation of many species
bearing substituents on the external nitrogen (N2),37–41
external carbon (C3),42–44 or internal carbon (C21).45,46 The
attractiveness of NCP and its complexes comes from its facile
N-confused (inverted) porphyrin (NCP) 11–3 forms variety
of stable organometallic compounds4–12 displaying multi-
modal coordination properties (see Chart 1).11–24 A peculiar
* Author to whom correspondence should be addressed. E-mail: pjc@
wchuwr.pl.
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432 Inorganic Chemistry, Vol. 48, No. 2, 2009
10.1021/ic800591n CCC: $40.75  2009 American Chemical Society
Published on Web 06/21/2008

Transition Metal Complexes of Dimeric N-Confused Porphyrin
Chart 1
these modifications, NCP can be applied instead of the
regular porphyrins in the potentially useful molecular47,48
and supramolecular systems.49–52 A built-in external coor-
dinating site of 1 or some of its derivatives, that is, the
exposed outer nitrogen of the confused pyrrole, has been
shown to be involved in formation of the coordinately linked
oligomers.15,18–20,22,33,53–55 Also, a number of covalent
dimers consisting of N-confused porphyrin subunits linked
either directly44,56 or by an alkanyl bridge27,29,38 have been
reported recently.
The present contribution is focused on the synthesis,
characterization, and dynamics of the N-confused bis-
porphyrin complexes linked by an o-xylene fragment by
using either nickel(II) complex 21 as a substrate for dimer-
ization reaction or by inserting metal ions into predefined
dimeric ligand 3, whose synthesis was described recently.38
The resulting systems, covalently linked by such a semirigid
bridge can adopt various orientations of the macrocyclic
subunits and display interaction between these subunits
depending on the way in which the fragments are connected
and arranged. In the previous report, a face-to-face arrange-
ment of the porphyrinoid subunits has been demonstrated
both in the solid state and in solution for the system where
o-xylene linked internal carbons of the confused pyrroles of
bis(nickel(II)) complex 4.57 A relatively strong interaction
between the subunits despite a lack of electronic delocal-
ization suggested a mutual through-space influence of closely
spaced porphyrinoid rings. The synthetic approaches applied
in the present paper lead to the dimer consisting of the same,
yet differently arranged, building blocks as those of 4 or
allow the preparation of heterometallic systems.
modification leading to the alteration of its coordination,
redox, optical, and acid-base properties. Considering reten-
tion of the aromatic properties of the macrocyclic ring upon
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Results and Discussion
Synthesis. The insertion of nickel(II) into dimeric ligand
3 (Scheme 1) yields symmetric diamagnetic neutral complex
5, which is isomeric with 4. Also, metalation of 3 by using
silver(I) salt proceeds smoothly under mild conditions,
leading to the formation of a first dicationic silver(III)
complex 6 (Scheme 1). The dimeric character of this species
is supported by the electrospray ionization mass spectrometry
(ESI-MS) spectrum in which two peaks can be found: the
one at m/z ) 827 amu represents the dication, while the other
at 1741 amu is attributable to the monocation that comprises
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Inorganic Chemistry, Vol. 48, No. 2, 2009 433

Chmielewski
Scheme 1
The ESI-MS spectra for both systems are identical, consisting
of one peak at m/z ) 1500 amu.
An insertion of zinc(II) or silver(III) into the “empty”
macrocyclic subunit of 10 led to the formation of the
heterometallic complexes 12 or 13, respectively (Scheme 3).
For both metals, the reaction takes place at room temperature.
However, in the case of the silver complex, a paramagnetic
species, likely containing a nickel(III) center, is formed
initially. It is due to the oxidative properties of silver(I) salt
with respect to the divalent nickel ion coordinated in the
carbaporphyrinoid crevice.9 The excess of AgBF4 can be
removed by washing the chloroform solution with a small
amount of water, which allows the separation of 13. The
ESI-MS spectra for 12 (m/z ) 1563 amu) and 13 (m/z )
1604 amu) confirm the heterometallic character of the
complexes. The apical acetate in 12a can be easily substituted
with chloride by means of aqueous NaCl, which yields 12b.
Spectroscopic Characterization. 1H and 13C NMR,
including homo- and heteronuclear 2D techniques, were
applied for characterization of the new compounds. The
NMR of the NCP and its derivatives is particularly informa-
tive due to their low symmetry.27,29,38,54 In the current
systems, methylene protons of the xylene bridge constitute
a diastereotopic probe providing additionally some informa-
tion about the dynamics of the bis(porphyrin).
Spectral characteristics of 5 or 6 (Figure 1, traces A and
B), due to their symmetric character, to some extent resemble
those of monomeric nickel(II) or silver(III) complexes of
NCP and its 2-substituted derivatives.1,4,27,37,38 However,
about a 0.5 ppm upfield shift of one of the tolyllic methyl
a tetrafluoroborate group associated with the dimer. It is
noteworthy that 6 is stable despite only dianionic character
of a coordination core in each of the linked subunits. With
two exceptions,38,58 in all known macrocyclic complexes of
the trivalent silver the coordination core was trianionic, fully
neutralizing the charge of the metal ion.4,55,59–63
The other homonuclear dimeric complexes, 7a and 8a, are
immediately formed upon combining a chloroform solution
of ligand 3 with an excess of zinc or cadmium acetate,
respectively in methanol (Scheme 1). The labile apical acetate
can be easily substituted by means of aqueous NaCl, which
results in the formation of the chloride complexes 7b and
8b. The ESI-MS spectrum of 7b consists of one peak at m/z
) 1605.9 amu that is in line with the presence of a chloride
ligand.
Two asymmetric isomeric bis(porphyrinic) systems are
formed in a reaction of nickel(II) complex 2 with an
equimolar amount of 2-bromoxylene-substituted NCP 9
(Scheme 2), whose synthesis has been reported recently.38
Aapplication of a basic catalyst (K2CO3/[18]-crown-6 system)
resulted in an approximately 70:30 mixture of 10 and 11
after about 3 h of refluxing the reaction mixture in THF.
1
signals in the H NMR spectra of both complexes suggests
a shielding influence of the aromatic ring current of the
neighboring subunit on the resonance frequency. At room
temperature, the methylene groups of the xylene bridge as
well as protons within each of the CH2 fragments are
isochronous, although the signals at about 4.5 or 5.5 ppm in
5 or 6, respectively, are significantly broadened. At temper-
atures below 233 K, the degeneracy of the methylene signals
is removed by slowing down rotation around the C(Xyl)-N2
bond. It results in splitting of the methylene resonance into
two broad signals in the spectrum of 5 (Figure 3A′) and into
two doublets (2J ) 17.8 Hz) in that of 6 (Figure 3B′),
indicating diastereotopic differentiation of the methylene
protons. Significantly, no other signal splits that is in line
with symmetric conformation of the dimers. It may be
1
inferred from the comparison of H NMR spectral data
observed for 6 with those reported for the N-unsubstituted
NCP complexes of trivalent silver that the electron density
distributions among the pyrrole protons are similar despite
the highly charged character of the bis(silver(III)) adduct.
Analysis of a nuclear Overhauser effect spectrometry
(NOESY) spectrum of 6 recorded at 203 K for a carefully
overcooled CDCl3 solution reveals an unfolded conformation
of the bis(porphyrinoid) system and allows a model to be
built that takes into account observed interprotonic contacts
between the subunits. The correlations that are most signifi-
cant for the structure elucidation of 6 are marked in the
NOESY map and on the chart presenting the model
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434 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
Scheme 2
Scheme 3
CH3 at the position 5 (cross-peak C), unequivocally indicat-
ing the way of mutual orientation of the subunits in solution.
In the case of heterometallic complex 13, the asymmetric
character of the compound is reflected by the appearance of
two sets of ꢀ-pyrrole and meso-aryl resonances observed in
1
the H NMR spectrum (CDCl3, 298 K, Figure 3C) as well
as by a lack of degeneracy of the xylene bridge signals. The
resonance positions of the respective protons in each of the
optimized by molecular mechanics in Figure 2. Among them
are dipolar interactions of the methyl group of the tolyl
substituent at position 20 with H3 (cross-peak A), with CH2
protons of the xylene bridge (cross-peaks B), and with tolyllic
Figure 1. Low-field parts of the 1H NMR spectra (500 MHz, CDCl3) of 5
(A), 6 (B), and 13 (C) taken at 298 K. The expansions of two of the
ꢀ-pyrrole resonances (components of an AB system) in trace B present
signal splitting due to proton coupling with 107,109Ag nuclei (4J ) 1.1 Hz).
Figure 2. NOESY spectrum (top, 500 MHz, overcooled CDCl3, 203 K)
and an energy-minimized model of 6 (bottom). The cross-peak assignments
in the map (A-H) indicate interprotonic interaction marked on the model
by curved arrows.
1
Insets A′, B′, and C′ show fragments of the H NMR spectra of 5, 6, and
13, respectively, recorded in overcooled CDCl3 at 203 K.
Inorganic Chemistry, Vol. 48, No. 2, 2009 435

Chmielewski
to its chirality resulting in a diastereotopic differentiation of
the methylene protons of the xylene bridge in the complexes
of both metals. Unlike in the cases of 5 and 6, where the
macrocyclic subunits are planar, the differentiation in 7 and
8 cannot be dynamically averaged by rotation, and thus it is
observed also at room temperature. Another consequence of
local chirality of the subunits is the observation of two sets
of signals in the 1H NMR spectra of 7 and 8, which is related
to the presence of diastereomers. One set of signals can be
assigned to a mixture of enantiomers which are not distin-
guishable by NMR, with the same RR or SS configurations
of both subunits, while the other set represents the meso form
consisting of heterochiral subunits. The diastereomers are
not equally populated either for zinc or for cadmium
complexes. The molar ratio of the isomers is about 1:2 for
7b and 8a and 1:4 for 8b. Clearly, there is a steric preference
for one of the stereoisomers. As expected, no equilibrium
between the diastereomers occurs. Their molar ratios do not
depend on temperature, and no chemical exchange correlation
signals between the respective protons of the isomers are
observed in the NOESY or rotating-frame Overhauser
enhancement spectroscopy (ROESY) experiments. Unlike in
the cases of 5, 6, and 13, there is no correlation of any of
the H3 with tolyllic CH3 in the NOESY spectra of 7b and
8b. It may suggest different spatial arrangement of the
subunits in the case of zinc or cadmium complexes than that
proposed for the former systems.
The conformational space analyzed for 7b and 8b by
means of molecular mechanics and the semiempirical PM3
method for these stereoisomers involves several energy
minima consisting of rotamers which differ from each other
by an orientation of the apical anion with respect to the vector
defined by the phenylene part of the xylene bridge (Scheme
4). Thus, the chloride ligands can be situated both on the
same side of the mean plane of the system as the phenylene
fragment (RuRu, SuSu, SuRu) or both on the opposite side (RdRd,
SdSd, SdRd) of the phenylene ring or can adopt alternating
directions with respect to that of the bridge (RdRu, SdSu, SdRu,
SuRd). The relative energy values for PM3 energy-optimized
models of the conformers of each stereoisomer of 8b are
presented in Scheme 4. At room temperature, rotation around
the bonds of the xylene bridge, which is fast on the NMR
time scale, averages the magnetic environment of protons,
and thus the effective symmetry of each diastereomer is
2-fold, resulting in a degeneracy of the signals of the
subunits. At lower temperatures (233-203 K), the signals
are broadened and eventually split, which reflects differentia-
tion of the resonances due to slowing down the rotation at
the bridge. In the case of bis(chlorocadmium) complex 8b,
the spectral lines of the more populated diastereomer are
sufficiently sharp to allow an analysis of the spectrum at
213 K, while signals of the minor isomer are still broad
(Figure 4A). The two sets of signals of equal intensity can
be related either to the presence of two equally populated
1
Figure 3. Fragments of H NMR spectra (CDCl3, 298 K) of 7b (A) and
8a (B). The indices x and y in the peak assignments are introduced to
distinguish signals of diastereomers. The extension of two ꢀ-pyrrole signals
in trace B and sticks in the high-field part of this spectrum present a fine
structure of the peaks with satellites due to a coupling with 111,113Cd nuclei.
subunits of 13 are similar to those observed in the symmetric
dimers 5 and 6, indicating a lack of the essential alteration
in the electronic structure of the subunits. Also, in this case,
at low temperatures, both methylene groups of the xylene
bridge are diastereotopic (203 K, overcooled CDCl3, Figure
1C′). The arrangement of the silver(III)- and nickel(II)-
containing subunits seems to be analogous to that in 6, which
can be inferred from a room-temperature NOESY spectrum
in which protons in the 3 positions (3Ag and 3Ni in Figure 1)
correlate with most upfield-shifted CH3 signals of tolyl
substituents.
The 1H NMR spectra of zinc and cadmium dimeric
complexes 7 and 8 (Figure 3) indicate the presence of a
proton bound to the internal carbon of the confused pyrrole
and a side-on coordination of the trigonal-hybridized C21.
1
A splitting of the 21-CH proton signals in the H NMR
1
spectra of 8 due to H-111,113Cd coupling is in line with a
bonding interaction between internal carbon and the metal
ion. Also, the position of the C21 signal found in the 1H-13C
HMQC maps of 7 and 8 (∼76 ppm) is strongly shifted
upfield with respect to that of the free ligand (109.1 ppm),38
suggesting changes in electron density on this carbon atom
due to the formation of a weak bond. These features are
characteristic for Zn2+ or Cd2+ coordination to carbapor-
phyrinoids.10,18,20,53,64–66 As a result of such a coordination
mode, the subunits of the dimers are nonplanar, which leads
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436 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
Scheme 4
distinguishing between these two situations. Since the
differentiation of signals at low temperatures is caused by
the slowing down of the dynamic processes (rotation), by
necessity all corresponding protons of different sets (e.g.,
H21, H3, bridging CH2) correlate in the NOESY spectrum,
giving strong chemical exchange signals (EXSs). In the case
of two different rotamers, only this type of correlation should
be observed for the respective protons of the isomers and
no NOE (i.e., correlation effect due to a spatial proximity
of protons) between them should take place, while in the
asymmetric dimer, the particular protons of its different
“halves” (e.g., protons of different methylene groups at the
xylene bridge) are close enough to each other to give a NOE
signal. The ROESY spectrum discriminates between EXS
and ROE (i.e., rotating frame Overhauser effect) through a
different phase of cross-peaks: these, due to chemical
exchange and scalar interactions, have the same phase as a
diagonal, while ROE signals have the opposite phase. All
correlations observed in the NOESY map should appear in
the ROESY experiment if interaction between protons has a
unique character (i.e., exclusively scalar, ROE, or EXS), as
is expected for the mixture of rotamers. If, however, protons
interact simultaneously by a through-space coupling and by
chemical exchange or scalar coupling, their correlation peak
may be weakened or even absent in the ROESY map, being
a result of superposition of the opposite phase effects. The
latter situation takes place in the actual ROESY experiment
performed for 8b at 213 K (Figure 4B). There is no
correlation among four signals of methylene protons of
bridging xylene, although they correlate (ROE) with H3,
bridging phenylene, or meso-aryl protons. Moreover, a scalar
coupling pattern in a correlation spectroscopy (COSY)
experiment at 213 K indicates the presence of a unique set
of xylene protons expected for an asymmetric dimer. The
magnetic nonequivalency of the subunits excludes symmetric
conformers with homochiral subunits as a major component
of the diastereomeric mixture of 8b. Also, the lack of H3
interactions with the tolyllic methyl protons, which can be
predicted on the basis of molecular models of the symmetric
conformers RuRu, SuSu, RdRd, or SdSd, for which the mean
values of the appropriate interprotonic distances are about 3
Å, is in line with the domination of one of the asymmetric
rotamers. Similarly, an absence of the expected strong
correlations between protons of the tolyl substituents in the
5 and 20 positions of different subunits excludes heterochiral
diastereomer SdRu/RdSu, though its relative energy is the
lowest according to the PM3 calculations. A pattern of the
interprotonic interaction for H3 on both subunits as well as
an about 0.6 ppm upfield shift of the methyl protons of the
20-tolyl substituents suggest the structure of asymmetric
system RuRd/SuSd and, thus, domination of the diastereomer
of homochiral subunits in the case of 8b.
“symmetric” conformers which differ in orientation with
respect to the bridge (RuRu/RdRd and enantiomeric SuSu/SdSd)
or to a magnetic inequivalence of subunits in a system of
asymmetric structure (SuRu, SdRd RdRu, SdSu, SdRu, SuRd). The
NOESY and ROESY experiments can be operative in
1
The H NMR spectra of the asymmetric systems 10 and
11 (CDCl3, 298 K, Figure 5) unify spectral features of the
appropriate 2- or 21-substituted NCP nickel(II) com-
plexes25,27–29 with those of the 2-alkylated ligand.37–39 That
includes signals of the “inner” protons of the “empty”
macrocyclic ring, that is, 21′-CH (1.79 ppm for 10 and 1.26
Figure 4. (A) The high-field fragments of the 1H NMR spectra of 8b taken
at the temperatures specified near each trace. (B) Fragments of the NOESY
and ROESY spectra recorded at 213 K for 8b. In the ROESY map, the
phase of the green cross-peaks is negative (ROE) and that of the red signals
is positive (EXS).
Inorganic Chemistry, Vol. 48, No. 2, 2009 437

Chmielewski
1
Figure 5. Fragments of the H NMR spectra (500 MHz, CDCl3) of 10 (A) and 11 (B) taken at 298 K. Inset B′ shows an upper-field part of the spectrum
of 11 recorded at 213 K.
ppm for 11), which are scalar coupled to the proton 3′ on
the external carbon of the confused pyrrole (7.35 and 6.78
ppm), and a broader resonance of 23′-NH (3.96 and 3.55
ppm, respectively). There are two singlets of the xylene
bridge CH2 groups in the spectrum of 10, reflecting the
asymmetric character of the compound, while in the case of
11, both methylene groups (i.e., the one that is bound to the
asymmetric C21 and the other that is connected with N2′)
are diastereotopic. A strong shielding effect of the aromatic
ring current is reflected by a significant high-field shift of
the 21-CH2 signal and, to a lesser extent, that of 2′-CH2, in
line with the position of the 2′-xylene-NCP fragment within
the inner sphere of the aromatic, nickel(II)-complexing
moiety. The same effect is responsible for a high-field shift
of one of the tolyllic methyl signals (1.05 ppm). The spatial
proximity of this methyl group and 21-CH2 is reflected by a
correlation observed in a NOESY spectrum recorded for 11
at 298 K. At low temperatures (213 K), the spectrum of 11
alters significantly. Due to a slowing down of the rotation
at the bridging xylene, each signal splits into two separate
resonances, indicating the presence of rotamers that are not
equally populated (40:60 from the integration of the 21-CH2
signals, Figure 5B′).
1
The H NMR spectrum of the Ni-Zn heterometallic
1
Figure 6. Fragments of the H NMR spectra (500 MHz, CDCl3) of 12a
(A, 298 K; B, 213 K) and 12b (C, 298 K; D, 213 K). The inset B′ presents
a cross-section of the NOESY map (213 K) of 12a with correlation signals
of acetate methyl protons (Meac) with meso-aryl protons. The insets contain
fragments of the NOESY map of 12b (213 K) presenting correlations
between xylene CH2 protons (D′) and chemical exchange signals between
21′-CH of the isomers (D′′).
system 12a reveals the presence of an acetate ligand
coordinated to the zinc center (Figure 6). The signal of
CH3COO- appears at room temperature as a broad singlet
shifted to 0.15 ppm (Meac in Figure 6A, 298 K, CDCl3). At
lower temperatures, the signal is sharpened and shifted even
more upfield to -0.45 ppm (213 K, Figure 6B). The
coordination of acetate, apart from the aromatic ring current
affecting the chemical shift of methyl protons, is supported
also by the through-space interaction of CH3 protons with
some aryl protons of the zinc-coordinated fragment observed
in the NOESY map of 12a (213 K, Figure 6B′). Analysis of
the interprotonic through-space interaction reveals unfolded
conformation of the dimer, similar to that observed in the
case of bis-silver complex 6. The most significant dipolar
correlations are those between protons 3 or 3′, that is, protons
attached to the external carbon of the confused pyrrole in
the nickel- or zinc-containing subunit, respectively, and
methyl fragments of the tolyl substituents.
To some extent, the room-temperature 1H NMR spectrum
of chloride complex 12b resembles that of 7b superimposed
on the spectrum of bis-nickel(II) complex 5. However, only
one set of signals for each fragment of the asymmetric system
is observed at 298 K (Figure 7C), unlike in the case of 7b.
That reflects a fast rotation around the C-N bonds. The
situation changes at lower temperatures (213 K, Figure 6D),
when the spectrum reveals the presence of two nonequally
populated (40:60) stereoisomers. Unlike in the cases of bis-
438 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
Figure 7. Optical spectra (CH2Cl2 solutions) of 5 (A, black solid line), 6
(A, red dashed), and 13 (A, blue doted); 7b (B, black solid), 8a (B, red
dashed), and 12b (B, blue doted); and 10 (C, black solid) and 11 (C, red
dashed).
Figure 8. Top: A perspective view (with 50% thermal ellipsoids) and atom
numbering scheme of 11. All hydrogens and solvent molecules are omitted.
Bottom: A wire-frame representation of the skeleton of 11 with all tolyl
substituents removed. Selected bond lengths and angles: Ni1-N23, 1.963(4);
Ni1-N22, 1.975(4); Ni1-N24, 1.982(4); Ni1-C21, 2.054(5); C21-C4,
1.446(7); C21-C1, 1.458(7); C21-C60; 1.582(7), C1-N2; 1.404(7);
N2-C3, 1.352(7); C3-C4, 1.392(7); C45-C25, 1.392(7); C45-C28,
1.399(7); N26-C27, 1.330(7); N26-C67, 1.463(6); C27-C28, 1.418(7);
N23-Ni1-N22, 92.32(17); N23-Ni1-N24, 90.67(17); N22-Ni1-N24,
174.74(16); N23-Ni1-C21, 173.11(18); N22-Ni1-C21, 87.43(18);
N24-Ni1-C21, 89.09(18); C4-C21-C1, 102.0(4); C4-C21-C60, 114.7(4);
C1-C21-C60, 117.8(4); C4-C21-Ni1, 118.3(3); C1-C21-Ni1, 115.8(3);
C60-C21-Ni1, 89.2(3); N2-C1-C21, 109.7(4); C3-N2-C1, 108.8(5);
N2-C3-C4, 108.9(4).
zinc complexes, these stereoisomers are in equilibrium, since
their xylene-CH2 or 21′-CH resonances give chemical-
exchange correlation signals in the NOESY spectrum of 12b
at 213 K (Figure 6D′ and D′′). It indicates a different origin
of the stereoisomerism in the case of homometallic com-
plexes 7 and 8 containing nonplanar subunits, for which
differentiation is permanent, being related with a mutual
orientation of apical ligands, and in the present case where
the other chirality center is induced by slowing down the
dynamic process. Interestingly, in the case of acetate complex
12a, such dynamic differentiation of the signals at low
temperatures does not occur. It may suggest that, due to steric
factors related to the presence of the acetate ligand, the
nickel-coordinated macrocyclic fragment can adopt only one
orientation with respect to that of the zinc-containing moiety.
The optical properties of the homonuclear dimeric system
do not seem to be significantly altered with respect to those
of the monomeric complexes. It indicates lack of strong
interaction between aromatic chromophores. For each of the
heterometallic complexes, the UV-vis spectrum resembles
superposition of the spectra of the appropriate homodimers
(Figure 7). It suggests that, although relatively close to each
other and covalently bound, the subunits retain their elec-
tronic properties.
X-Ray Structure of 11. The structure of 11 in the solid
state is confirmed by an X-ray diffraction analysis (Figure
8). The molecule’s topology involves two subunits of the
N-confused porphyrin 2′,21-linked by an o-xylene bridge.
The macrocyclic part in the metalated subunit is slightly
saddle-distorted but coordination core Ni1-C21-N22-
N23-N24 is essentially planar with a 0.03 Å mean deviation
Inorganic Chemistry, Vol. 48, No. 2, 2009 439

Chmielewski
Table 1. Cyclovoltammetric Data for Homo- and Heterometallic
Complexes of Xylene-Linked N-Confused bis(Porphyrins)a
complex
Eox
∆Eac(ox)
Ered
∆Eac(red)
58
5
214
59
-1592
595b
942b
826b
irreversible
irreversible
irreversible
6
-867
-1560
-1357
-1894c
-1373
-1643
-1841
-889
61
86
90
7b
12b
233
746b
189
80
irreversible
85
irreversible
59
78
78
irreversible
60
65
99
73
80
65
570b
1236
224
13
383
-1450
-1532
644b
839
irreversible
84
a Data for dichloromethane solutions referenced with ferrocene/ferroce-
nium internal standard. The values (in mV) are the average of the oxidation
and reduction peak potentials, unless stated otherwise. b Only an oxidation
peak has been observed. c Only a reduction peak has been observed.
Figure 9. Cyclic voltammograms (CH2Cl2, 0.1 M TBAP) of homo- and
heterometallic dimeric complexes: 7b (A), 12b (B), 13 (C), and 5 (D).
In the case of bis-nickel(II) adduct 5, both first reduction
and oxidation couples appear at half-wave potentials similar
to those observed for monomeric complexes of NCP and its
2-N-alkylated derivatives.9,28 In contrast to the 2,2′- or 2,21′-
methylene-linked dimeric NCP nickel(II) complexes,28,29 for
which electrostatic interaction between the redox centers
results in a splitting of the first oxidation couple, both
subunits in 5 are oxidized at the same potential. Significantly,
such electrostatic interaction, which resulted in the splitting
of both oxidation and reduction waves, has been observed
for isomeric system 4, containing the same, yet differently
arranged, moieties as complex 5.57
Bis(chlorozinc) complex 12b displays lower separation of
the first oxidation and reduction couples than that observed
in the case of 5. It is due to a more positive potential of the
first reduction wave of 12b, while first oxidation takes place
at a potential which is very similar to that observed for
bis(nickel(II)) complex 5. This similarity may suggest that,
for both complexes, a ligand-centered oxidation leads to the
formation of a cationic biradical species. However, the
observed oxidation potential of 5 is close to those reported
for the monomeric nickel(II) complexes of NCP and its 2-
or 21-alkylated derivatives, for which metal-centered chemi-
cal oxidation yielded nickel(III) species, which has been
shown by electron paramagnetic resonance (EPR).25,28
A significant alteration of redox properties with respect
to that of the monomeric unsubstituted species4 is observed
for bis(silver(III)) complex 6. A strong anodic shift of the
first reduction couple (∆E ∼ 500 mV) may reflect a change
of the reduction site from the ligand to the metal center. It
is related to the alteration of the ligand properties caused by
introduction of the substituent at the external nitrogen in 6.
As a consequence of this, the macrocyclic subunits cannot
fully neutralize the metal ion charge, making it prone to
reduction. It is well-documented that the dianionic character
of the carbaporphyrinoid ligand destabilizes trivalent metal
ions with respect to the systems possessing trianionic
coordination cores.6,28,54,55,59
from the plane. The distances between nickel and the
coordinating atoms (Ni1-C21, 2.054(5) Å; Ni1-N22,
1.975(4) Å; Ni1-N23, 1.963(4); Ni1-N24, 1.982(4)) are
similar to those observed for other 21-alkylated com-
plexes.25,54,57 The carbon-nickel bond distance as well as
a sum of the bond angles around C21 (658°) indicate σ
coordination and sp3 hybridization of this atom. Also, the
ring atoms of the nonmetallated subunit do not decline
significantly from planarity, and a mean deviation from the
plane defined by all atoms of the macrocycle is 0.17 Å. The
dihedral angle between the mean planes of the macrocyclic
subunits is 112°. The orientation of the nonmetalated subunit
with respect to the bridge allows a closeness of the methyl
group of the tolyl substituent at C44 and methylene group
C60. Such an arrangement leads to an interprotonic distance
of about 2.6 Å and is consistent with the correlation between
CH2 and CH3 protons observed in the solution NOESY
experiment.
Redox Properties. Cyclovoltammetric measurements for
the metal complexes of dimeric species were performed in
dichloromethane using a [BuN4]ClO4 supporting electrolyte
and were referenced against a ferrocene/ferrocenium internal
standard. The representative electrochemical experiments are
presented in Figure 9, and the data are collected in Table 1.
Due to a relatively long distance between the subunits and
a lack of the coupling of the aromatic systems, no interaction
of the redox centers is anticipated for homometallic 2,2′-
xylene-linked bis(porphyrin) complexes 5, 6, and 7. Indeed,
unsplit two-electron couples are observed in the cyclic
voltammograms of these complexes, indicating a simulta-
neous oxidation or reduction of both subunits. The irrevers-
ibility of most of the second sets of oxidations may be due
to the poor solubility of the highly charged species in
CH2Cl2,67 although the application of a more polar solvent
(THF or acetonitrile) does not significantly improve the shape
of the voltammograms.
In the heterometallic systems 12b and 13, each of the
subunits containing different metals retain individual redox
properties, and thus oxidation or reduction processes occur
(67) Pognon, G.; Boudon, C.; Schenk, K. J.; Bach, B.; Weiss, J. J. Am.
Chem. Soc. 2006, 128, 3488.
440 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
case are the π-bond systems of the subunits coupled. The
closeness of the two chromophores and the semirigid
character of the bridge, as well as the labile character of
the complexes containing zinc or cadmium allowing facile
exchange of an apical anion, make these systems suitable
for application in recognition of the absolute configuration
of the chiral anionic ligands by exploiting exciton cou-
pling.68–77 Some preliminary circular dichroism investigation
of the systems containing chiral ligands gave promising
results (see the Supporting Information for an example),
which will be reported in due time. Also, in heterometallic
complexes 12 and 13 and in mono(nickel(II)) systems 10
and 11, the subunits’ behavior seems not to be altered with
respect to the monomeric complexes. The presence of two
different chromophore/redox/coordination centers in one
molecule is a promising feature for further application of
these systems as electronic switches or photocatalysts.
Experimental Section
Instrumentation. Absorption spectra were recorded on a diode
array Hewlett-Packard 8453 spectrometer. Mass spectra were
recorded on a Bruker Daltonics microTOF-Q spectrometer using
the electrospray technique. NMR spectra were recorded on a Bruker
Avance 500 spectrometer. The 1D and 2D experiments (COSY,
NOESY, heteronuclear multiple-quantum coherence (HMQC), and
heteronuclear multiple-bond correlation) were performed by means
of standard experimental procedures of the Bruker library. The
peaks were referenced to the residual CHCl3 resonances in 1H and
13C NMR (7.24 and 77.2 ppm, respectively). Cyclovoltammetric
measurements were performed in dichloromethane on an EA9C
MTM apparatus with a glassy carbon disk as the working electrode,
Ag/AgCl as the reference electrode (the ferrocene reference potential
was 530 mV), and platinum wire as the auxiliary electrode.
Tetrabutylammonium perchlorate (0.1 M) was used as the support-
ing electrolyte. The X-band EPR spectra were obtained with a
Bruker ESP 300E spectrometer. The magnetic field was calibrated
with a proton magnetometer and EPR standards. Molecular model-
ing was performed using the HyperChem 6 Molecular Modeling
System (Hypercube Inc., 2000), using the MM+ force field for
the initial determination of the conformer shapes, which was
followed by the PM3/RHF semiempirical energy optimization.
Caution! The organic perchlorate salts are potentially explosiVe
and should be handled with caution and only in small quantities.
Syntheses of the Precursors. N-confused porphyrin 1 was
synthesized by the Lindsey method.3 Nickel complex 2 was
Figure 10. The frozen-solution EPR spectra of the oxidized species 5-Br2
(A), 12-Br (B), and 13-Br (C) recorded in CH2Cl2 at 77 K.
independently. As a result of this, their cyclic voltammo-
grams resemble the superposition of bis(nickel(II)) complex
5 with the voltammogram of 7b or 6, respectively
(Figure 9).
A chemical oxidation of the bis(metalated) nickel(II)-
containing complexes, 5, 12, and 13, with bromine can be
conveniently monitored by EPR. In each case, a signal
observed for the frozen solution of the oxidized species is
typical for the nickel(III) complex containing one paramag-
netic center with a bromide ligand coordinated to the metal
ion9,28 (Figure 10). The spin-Hamiltonian parameters
(gx ) 2.319, gy ) 2.186, gz ) 2.100, AzBr )144 G for 5; gx
) 2.339, gy ) 2.147, gz ) 2.103, AzBr )143 G for 12; gx )
2.328, gy ) 2.200, gz ) 2.109, AzBr )140 G for 13) are
similar for all three complexes and do not vary with the
concentration of the oxidizing agent. The similarity of the
EPR spectral parameters between complexes containing
one and two nickel(III) ions implicates a lack of magnetic
interaction between the subunits in 5-Br2, that is, for the
bis(nickel) complex in the oxidized state. This is in a sharp
contrast with the case of complex 4, for which mono- and
bis-oxidized species have been detected during the titration
with bromine and an interaction between the unpaired
electrons has been established on the basis of spin-Hamil-
tonian parameters.57
(68) Proni, F.; Pescitelli, G.; Huang, X.; Nakanishi, K.; Berova, N. J. Am.
Chem. Soc. 2003, 125, 12914.
(69) Pescitelli, G.; Gabriel, S.; Wang, Y.; Fleischhauer, J.; Woody, R.;
Berova, N. J. Am. Chem. Soc. 2003, 125, 7613.
(70) Balaz, M.; Holmes, A. E.; Banedetti, M.; Rodriguez, P. C.; Berova,
N.; Nakanishi, K.; Proni, G. J. Am. Chem. Soc. 2005, 127, 4172.
(71) Huang, X.; Rickman, B. H.; Borhan, B.; Berova, N.; Nakanishi, K.
J. Am. Chem. Soc. 1998, 120, 6185.
Conclusion
The bis(N-confused porphyrin) system 2,2′-linked by
o-xylene allows for the preparation of bis(metal) complexes,
and the coordination cores retain multimodal properties
typical of monomeric NCP ligands. The subunits, although
relatively close to each other, do not interact. That is in
contrast with the previously described system containing the
same linker joining “internal” carbon atoms. Clearly, the
mutual orientation of the subunits is of primary importance
for their electrostatic or electronic interactions since in neither
(72) Proni, G.; Pescitelli, G.; Huang, X.; Quraishi, N. Q.; Nakanishi, K.;
Berova, N. Chem. Commun. 2002, 1590.
(73) Borovkov, V. V.; Hembury, G. A.; Inoue, Y. Acc. Chem. Res. 2004,
37, 449.
(74) Borovkov, V. V.; Fujii, I.; Muranaka, A.; Hembury, G. A.; Tanaka,
T.; Ceulemans, A.; Kobayashi, N.; Inoue, Y. Angew. Chem., Int. Ed.
2004, 43, 5481.
(75) Borovkov, V. V.; Lintuluoto, J. M.; Inoue, Y. J. Am. Chem. Soc. 2001,
123, 2979.
(76) Borovkov, V. V.; Muranaka, A.; Hembury, G. A.; Origane, Y.;
Ponomarev, G. V.; Kobayashi, N.; Inoue, Y. Org. Lett. 2005, 7, 1015.
(77) Bhyrappa, P.; Borovkov, V. V.; Inoue, Y. Org. Lett. 2007, 9, 433.
Inorganic Chemistry, Vol. 48, No. 2, 2009 441

Chmielewski
obtained as described previously.1,27,28 Xylene-containing deriva-
tives 3 and 9 were synthesized with a method modified from one
reported previously.38 Freshly distilled THF instead of toluene as
the solvent and [18]-crown-6 as a phase-transfer agent for a proton
scavenger (K2CO3) were used in the present study. Under such
conditions, a molar ratio of dimeric and monomeric products (0.6:
1) is more favorable for the dimer than in the case of the formerly
described method.
125.0; 124.0; 122.5; 121.8; 116.0; 55.8; 21.5; 20.8. 11B NMR (160.5
MHz, CDCl3, 298 K): δ -1.49 (BF4-). HRMS (ESI+): m/z
1738.455 (observed); 1738.452 (calculated for [C104H78N8-
Ag2BF4]+); 826.2214 (observed); 826.2225 (calculated for
[C104H78N8Ag2]2+). Anal. calcd for C104H78N8Ag2B2F8: %C, 68.29;
%H, 4.30; %N, 6.13. Observed: %C, 68.34; %H, 4.47; %N, 5.67.
Synthesis of 2,2′-Bis(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinatozinc Chloride)-o-xylene, 7b. A sample of 3 (20
mg, 0.014 mmol) was dissolved in chloroform (20 mL), to which
zinc acetate dihydrate solution in methanol (33 mg, 0.15 mmol in
10 mL) was added, and the mixture was stirred at room temperature
for 1 h. The solvents were then removed by evaporation at room
temperature, and the solid residue was dissolved in dichloromethane
(15 mL) and filtered. Formation of the acetate bis(zinc) complex,
7a, was determined by mass spectrometry (HRMS (ESI+):
1627.532 (observed); 1627.522 (calculated for [(C104H80N8Zn2)-
(CH3CO2)]+). The filtrate volume was reduced to 5 mL, and the
solution was vigorously stirred for 1 h with an aqueous solution of
NaCl (1 M, 2 mL), after which the water layer was removed, and
the organic phase was washed with three portions of water (10 mL
each). After separation of the organic phase, the solution was
filtered, and the solvent was removed. The solid residue was dis-
solved in chloroform, and the olive-green product, 7b, was
crystallized slowly after the addition of hexane. Yield: 16 mg (70%).
Selected data for 7b. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 259
(47.9); 311 (56.2); 364 (55.7); 451 (sh); 471 (218.0); 549 (sh); 591
Synthesis of 2,2′-Bis(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinato-nickel(II))-o-xylene, 5. To a solution of 3 (20
mg, 0.014 mmol) in chloroform (30 mL) was added nickel(II)
acetate tetrahydrate (50 mg, 0.2 mmol) in ethanol (15 mL), and
the reaction mixture was refluxed for 1 h. After that, the solvents
were removed, and the complex was extracted with several 10 mL
portions of dichloromethane. The extract was passed down the silica
gel column with dichloromethane as an eluent. The fastest-migrating
green band was collected. The solution volume was reduced to about
10 mL, and the dark green product, 5, was precipitated with hexane.
Yield: 15 mg (70%).
Selected data for 5. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 242 sh;
626 (99.6); 431 (174.5); 463 (121.1); 526 sh; 562 (25.5); 595 (sh);
659 (sh); 725 (12.4); 796 (12.4). 1H NMR (500 MHz, CDCl3, 298
3
K): δ 8.29 (s, 1H); 8.08 (d, J ) 5.0 Hz, 1H); 7.87 (s, 2H); 7.83
(d, 3J ) 7.8 Hz, 2H); 7.80 (d, 3J ) 5.0 Hz, 1H); 7.68 (d, 3J ) 7.8
3
3
Hz, 2H); 7.64 (d, J ) 8.0 Hz, 2H); 7.62 (d, J ) 5.0 Hz, 1H);
3
3
3
7.46 (d, J ) 8.0 Hz, 2H); 7.44 (d, J ) 5.0 Hz, 1H); 7.37 (d, J
) 8.0 Hz, 2H); 7.32 (d, J ) 7.6 Hz, 2H); 7.08 (d, J ) 6.2 Hz,
2H); 6.94 (d, J ) 7.3 Hz, 2H); 6.72 (m, 1H); 6.29 (m, 1H); 4.45
3
3
1
(13.2); 636 (17.2); 724 (20.0); 788 (53.2). H NMR (500 MHz,
3
3
3
CDCl3, 298 K): δ 8.36 (d, JHH ) 4.8 Hz, 1Hy); 8.24 (d, JHH )
(s, 2H); 2.60 (s, 3H); 2.55 (s, 3H); 2.53 (s, 3H); 2.06 (s, 3H). 13C
NMR (126 MHz, CDCl3, 298 K): δ 154.0; 151.7; 150.9; 149.8;
148.4; 146.5; 144.6; 138.3; 137.5; 137.3; 137.1; 136.8; 136.7; 136.2;
134.7; 133.4; 133.2; 133.0; 132.9; 132.8; 132.4; 132.0; 131.4; 130.9;
130.3; 128.2; 127.8; 127.7; 127.7; 127.6; 127.4; 126.0; 124.5; 123.2;
121.2; 118.1; 117.2; 52.3; 21.4; 21.3; 20.8. MS (ESI): m/z 1556.5
(observed); 1556.2 (calculated for C104H76N8Ni2 + H+).
4.6 Hz, 1Hx); 8.10 (d, JHH ) 7.6 Hz, 2Hy); 8.03 (d, JHH ) 4.8
3
3
3
3
Hz, 1Hx); 7.96 (d, JHH ) 4.8 Hz, 1Hy); 7.88 (d, JHH ) 8.2 Hz,
2Hx); 7.87 (d, 3JHH ) 4.8 Hz, 1Hy); 7.84 (d, 3JHH ) 4.6 Hz, 1Hx +
3
3
1Hy); 7.82 (d, JHH ) 4.8 Hz, 1Hx); 7.80 (d, JHH ) 4.8 Hz, 1Hx);
3
3
7.77 (d, JHH ) 4.8 Hz, 1Hx); 7.75 (d, JHH ) 4.6 Hz, 1Hy); 7.74
(d, 3JHH ) 4.6 Hz, 1Hy); 7.70 (b, m); 7.63 (d, 3JHH ) 7.8 Hz, 2Hx);
3
3
7.53 (d, JHH ) 7.1 Hz, 2Hx); 7.45 (d, JHH ) 7.1 Hz, 2Hy); 7.42
(d, 3JHH ) 7.8 Hz, 2Hx); 7.38 (m, 2Hx + 2Hy); 7.04 (m, 1Hx); 6.94
Synthesis of 2,2′-Bis(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinato-silver(III))-o-xylene Bis(tetrafluoroborate), 6.
A solution containing 3 (20 mg, 0.014 mmol) and silver(I)
tetrafluoroborate (15 mg, 0.08 mmol) in THF (20 mL) was stirred
in darkness for 2 h at room temperature. After that, the solvent
was removed, and the olive-green solution was separated from a
gray precipitate (metallic silver) by extraction with benzene and
filtration. The filtrate was washed with two portions of water (10
mL); the solvent was then removed, and the solid was redissolved
in a minimum volume of CH2Cl2, and the product, 6, was
precipitated by the addition of hexane, collected by filtration, and
dried in the air. Yield: 16 mg (62%).
3
(b, 1Hy); 6.81 (d, JHH ) 7.8 Hz, 1Hy); 6.75 (m, 1Hx); 6.37 (s,
1Hy); 5.80 (s, 1Hx); 4.49 (d, 2JHH ) 15.8 Hz, 1Hx); 4.41 (d, 2JHH
)
17.0 Hz, 1Hy); 4.35 (d, 2JHH ) 15.8 Hz, 1Hx); 4.08 (d, 2JHH ) 17.0
Hz, 1Hy); 2.67 (s, 3Hy); 2.59 (s, 3Hx + 3Hy); 2.56 (s, 6Hx + 3Hy);
2.07 (s, 3Hx); 1.77 (s, 3Hy); -0.31 (s, 1Hx); -0.41 (s, 1Hy). 13C
NMR (126 MHz, CDCl3, 298 K): δ 162.4; 162.2; 162.1; 161.9;
158.0; 157.8; 156.3; 156.2; 153.5; 153.4; 150.8; 150.7; 139.4; 139.2;
139.1; 138.9; 138.6; 138.5; 138.4; 138.0; 137.7; 137.4; 137.0; 136.9;
136.8; 136.6; 136.3; 136.0; 135.8; 134.3; 134.1; 133.9; 133.5; 133.4;
133.3; 133.1; 133.0; 132.3; 132.0; 131.7; 131.4; 128.7; 128.5; 128.3;
127.9; 127.8; 127.7; 127.5; 124.9; 124.5; 123.7; 122.0 (3-CHy);
118.7 (3-CHx); 118.4; 116.5; 116.1; 76.6 (21-CHy); 75.0 (21-CHx);
50.6 (CH2x); 50.1 (CH2y); 21.5; 21.4; 20.8; 20.8. HRMS (ESI+):
1603.473 (observed); 1603.478 (calculated for C104H80N8ClZn2).
Anal. calcd for C104H80N8Zn2Cl2 ·H2O·hexane: %C, 75.59; %H,
5.54; %N, 6.48. Observed: %C, 75.36; %H, 5.20; %N, 6.25.
Selected data for 6. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 255 (77.6);
273 (sh); 327 (44.0); 379 (45.5); 416 (sh); 442 (sh); 458 (242.0);
532 (14.0); 575 (12.5); 644 (13.9); 696 (24.0). 1H NMR (500 MHz,
3
4
CDCl3, 298 K): δ 9.14 (s, 1H); 8.81 (dd, JHH ) 5.2 Hz, JAgH
)
1.1 Hz, 1H); 8.51 (d, 3JHH ) 5.0 Hz, 1H); 8.40 (d, 3JHH ) 5.3 Hz,
1H); 8.39 (d, JHH ) 5.3 Hz, 1H); 8.26 (d, JHH ) 5.0 Hz, 1H);
8.18 (d, 3JHH ) 8.0 Hz, 2H); 8.01 (dd, 3JHH ) 5.2 Hz, 4JAgH ) 1.1
Hz, 1H); 7.90 (d, JHH ) 7.8 Hz, 2H); 7.82 (d, JHH ) 8.0 Hz,
2H); 7.75 (d, JHH ) 7.6 Hz, 2H); 7.56 (d, JHH ) 7.6 Hz, 2H);
3
3
Syntheses of 2,2′-Bis(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinatocadmium Acetate)-o-xylene, 8a, and 2,2′-Bis-
(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-carbaporphyrinatocadmi-
um Chloride)-o-xylene, 8b. A sample of 3 (20 mg, 0.014 mmol)
was dissolved in chloroform (20 mL), to which a cadmium acetate
dihydrate solution in methanol (30 mg, 0.11 mmol in 10 mL) was
added, and the mixture was stirred at room temperature for 1 h.
The solvents were then removed by evaporation at room temper-
ature, and the solid residue was dissolved in dichloromethane (15
mL) and filtered and washed with three 5 mL portions of water.
The solvent was then removed, and the solid residue was redissolved
3
3
3
3
3
7.50 (d, JHH ) 7.6 Hz, 2H); 6.77 (m, AA′XX′, 1H); 5.96 (m,
AA′XX′, 1H); 5.49 (b, 2H); 2.73 (s, 3H); 2.67 (s, 3H); 2.63 (s,
3H); 2.09 (s, 3H). 13C NMR (126 MHz, CDCl3, 298 K): δ 152.4
(3-CH); 146.6; 145.5; 144.6; 144.5; 141.8; 139.8; 138.8; 138.7;
138.6; 136.5; 136.4; 135.1; 134.7; 134.6; 133.9; 133.7; 133.6; 133.4;
133.1; 132.9; 132.4; 132.2; 130.2; 128.9; 128.6; 128.4; 128.3; 126.5;
1
1
125.7 (d, JAgC ) 57.6 Hz 109Ag, JAgC ) 50.0 Hz 107Ag, 21-C);
442 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
2
4
in a minimum amount of chloroform and precipitated by the
addition of hexane. The dark-green product, 8a, was collected by
filtration and dried in Vacuo. Yield: 20 mg (80%). A 10 mg sample
of the acetate complex, 8a, was converted into a bis(chloride)
complex by dissolving it in 10 mL of chloroform and vigorous
stirring with an aqueous solution of NaCl (1 M, 2 mL). The water
layer was then removed, and the organic phase was washed with
three portions of water (5 mL each). After separation of the organic
phase, the solution was filtered, and the solvent was removed. The
solid residue was dissolved in chloroform, and the product, 8b,
was crystallized slowly after the addition of hexane. Yield: 8 mg
(82%).
4JHH ) 1.4 Hz, JCdH ) 12.1 Hz, 1Hx); -0.40 (d, JHH ) 1.2 Hz,
4
2
dd, JHH ) 1.2 Hz, JCdH ) 11.5 Hz, 1Hy).
Synthesis of 2-(2′-(5,10,15,20-Tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinatonickel(II))-o-xylene)-(5,10,15,20-tetrakis(p-tolyl)-
2-aza-21-carbaporphyrin, 10, and 2-(21′-(5,10,15,20-Tetrakis(p-
tolyl)-2-aza-21-carbaporphyrinatonickel(II))-o-xylene)-5,10,15,20-
tetrakis(p-tolyl)-2-aza-21-carbaporphyrin, 11. To a solution
containing 2 (25 mg, 0.07 mmol) and 9 (32 mg, 0.07 mmol) in
THF (20 mL) was added 10 mg of K2CO3 and 2 mg of [18]-crown-
6, and the mixture was stirred and refluxed under nitrogen for 3 h.
After that, the solution was filtered, the solvent was evaporated,
and the solid residue was dissolved in CH2Cl2. The solution was
passed down a silica-gel column with dichloromethane or a 1%
solution of ethanol in chloroform as the mobile phase. The fastest-
migrating band contained a small amount of unreacted 2; the second
band contained product 10, and the third contained product 11.
Solvents from the fractions containing the desired products were
evaporated, dissolved in chloroform, and precipitated with hexane.
The green product, 10, and brown product, 11, were separated from
the solution by filtration and dried in the air. Yields: 10, 25 mg
(47%); 11, 11 mg (20%).
Selected data for 8a. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 258
(44.1); 321 (64.1); 403 (sh); 456 (sh); 478 (235.1); 560 (67.0); 608
(8.3); 669 (9.7); 739 (sh); 811 (57.8). 1H NMR (500 MHz, CDCl3,
298 K): δ 8.19 (d, 3JHH ) 4.6 Hz, dd, 3JHH ) 4.6 Hz, 4JCdH ) 4.2
3
3
4
Hz, 1Hy); 8.13 (d, JHH ) 4.8 Hz, dd, JHH ) 4.8 Hz, JCdH ) 4.4
3
3
Hz, 1Hx); 7.96 (d, JHH ) 7.9 Hz, 2Hy); 7.90 (d, JHH ) 4.8 Hz,
3
3
1Hx); 7.90 (d, JHH ) 7.6 Hz, 1Hx); 7.85 (d, JHH ) 5.0 Hz, 1Hy);
7.84 (d, JHH ) 4.6 Hz, 1Hy); 7.83 (d, JHH ) 4.8 Hz, 1Hy); 7.82
3
3
3
3
(d, JHH ) 4.2 Hz, 1Hx); 7.81 (d, JHH ) 4.2 Hz, 1Hx); 7.72 (d,
3JHH ) 4.6 Hz, dd, JHH ) 4.6 Hz, JCdH ) 4.3 Hz, 1Hy); 7.69 (b,
3
4
Selected data for 10. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 253 (sh);
309 (sh); 364 (60.5); 433 (sh); 449 (100.0); 567 (14.6); 661 (10.1);
721 (11.2); 796 (5.4). 1H NMR (500 MHz, CDCl3, 298 K): δ 8.28
(s, 1H); 8.08 (d, 3JHH ) 5.0 Hz, 1H); 7.95 (d, 3JHH ) 4.8 Hz, 1H);
7.89 (d, 3JHH ) 7.8 Hz, 2H); 7.86 (s, 2H); 7.83 (d, 3JHH ) 7.8 Hz,
3
3
4
1Hy); 7.66 (d, JHH ) 5.0 Hz, dd, JHH ) 5.0 Hz, JCdH ) 3.6 Hz,
3
3
4
1Hy); 7.65 (d, JHH ) 4.8 Hz, dd, JHH ) 4.8 Hz, JCdH ) 4.4 Hz,
2Hx); 7.61 (b, 1Hy); 7.57 (d, 3JHH ) 7.1 Hz, 1Hx); 7.55 (d, 3JHH
)
3
3
7.3 Hz, 1Hx); 7.44 (d, JHH ) 7.6 Hz, 2Hx); 7.41 (d, JHH ) 7.9
Hz, 1Hy); 7.36 (m, 2Hx + 2Hy); 7.11 (m, 1Hx); 7.02 (b, 2Hy); 6.96
3
3
2H); 7.80 (d, JHH ) 5.0 Hz, 1H); 7.71 (d, JHH ) 4.4 Hz, 1H);
3
7.70 (d, 3JHH ) 5.0 Hz, 1H); 7.69 (d, 3JHH ) 5.0 Hz, 1H); 7.67 (d,
(d, JHH ) 7.3 Hz, 1Hx); 6.79 (m, 1Hy); 6.49 (m, 1Hy); 6.41 (d,
4JHH ) 1.5 Hz, 1Hy); 6.02 (b, 1Hx); 4.83 (d, 2JHH ) 16.2 Hz, 1Hx);
4.68; 4.53 (d, 2JHH ) 16.2 Hz, 1Hx); 4.32 (d, 2JHH ) 16.5 Hz, 1Hy);
2.56 (s, 3Hx + 6Hy); 2.55 (s, 6Hx + 6Hy); 2.51 (s, 3Hy); 2.09 (s,
3JHH ) 7.8 Hz, 2H); 7.64 (d, 3JHH ) 8.0 Hz, 2H); 7.62 (d, 3JHH
)
7.8 Hz, 2H); 7.60 (d, 3JHH ) 5.0 Hz, 1H); 7.53 (d, 3JHH ) 4.6 Hz,
3
3
1H); 7.49 (d, JHH ) 7.8 Hz, 2H); 7.47 (d, JHH ) 7.8 Hz, 2H);
4
7.40 (d, 3JHH ) 4.6 Hz, 1H); 7.39 (d, 3JHH ) 5.0 Hz, 1H); 7.38 (d,
3Hx); 1.12 (s, 3Hx + 3Hy, acetate); -0.47 (d, JHH ) 1.4 Hz, dd,
4JHH ) 1.4 Hz, JCdH ) 12.0 Hz, 1Hx); -0.54 (d, JHH ) 1.5 Hz,
2
4
3JHH ) 7.8 Hz, 2H); 7.36 (d, 3JHH ) 7.8 Hz, 2H); 7.35 (d, 4JHH
)
4
2
dd, JHH ) 1.5 Hz, JCdH ) 12.2 Hz, 1Hy). 13C NMR (126 MHz,
CDCl3, 298 K): δ 176.6; 163.3; 162.9; 160.2; 158.3; 154.3; 151.3;
139.2; 139.1; 138.7; 138.4; 137.8; 136.9; 136.7; 136.7; 136.4; 135.8;
134.9; 134.1; 134.1; 133.4; 133.0; 132.8; 132.2; 131.9; 131.4; 131.3;
130.9; 130.7; 129.0; 128.8; 128.9; 128.7; 128.6; 128.5; 128.4; 127.7;
127.6; 126.4; 126.2; 125.9; 122.7; 122.2 (C3y); 119.7 (C3x); 117.5;
75.3 (C21y); 73.0 (C21x); 51.0; 50.8; 29.7; 21.4; 21.4; 20.8; 21.0;
20.5. MS (ESI+): 1726.1 (observed); 1725.7 (calculated for
[(C104H80N8Cd2)(CH3CO2)]+); 833.0 (observed); 833.3 (calculated
for [C104H80N8Cd2]2+). Anal. calcd for C108H86N8Cd2O4 · CHCl3:
%C, 68.76; % H, 4.61; %N, 5.88. Observed: %C, 68.81; %H, 4.97;
%N, 5.50.
1.4 Hz, 1H); 7.34 (d, 3JHH ) 7.1 Hz, 2H); 7.32 (d, 3JHH ) 7.4 Hz,
3
3
2H); 7.31 (d, JHH ) 8.0 Hz, 2H); 7.00 (d, JHH ) 7.4 Hz, 2H);
3
3
6.82 (d, JHH ) 7.3 Hz, 1H); 6.63 (t, JHH ) 7.4 Hz, 1H); 6.5 (t,
3JHH ) 7.6 Hz, 1H); 6.23 (d, 3JHH ) 7.6 Hz, 1H); 5.71 (d, 3JHH
)
7.8 Hz, 1H); 4.41 (s, 2H); 4.37 (s, 2H); 3.91 (b, 1H); 2.61 (s, 3H);
2.55 (s, 3H); 2.52 (s, 3H); 2.51 (s, 3H); 2.12 (s, 3H); 1.99 (s, 3H);
1.81 (d, 4JHH ) 1.4 Hz, 1H). 13C NMR (126 MHz, CDCl3, 298 K):
δ 163.5; 149.9; 148.6; 144.7; 144.5; 138.7; 138.6; 138.0; 137.7;
137.4; 137.0; 136.9; 135.3; 135.2; 135.1; 134.7; 133.5; 133.0; 132.9;
132.6; 130.9; 128.1; 127.9; 127.7; 127.4; 126.0; 124.6; 121.2; 117.3;
117.0; 115.8; 115.7; 115.6; 115.5; 114.6; 114.5; 114.4; 114.3; 114.2;
113.8; 113.3; 113.1; 112.9; 112.6; 112.0; 111.2; 111.1; 111.0; 110.9;
110.8; 110.6; 108.6; 98.4 (C21); 60.5; 60.0; 40.2; 39.8. HRMS
(ESI+): m/z 1499.599 (observed); 1499.594 (calculated for
[C104H81N8Ni]+, [M+1]+). Anal. calcd for C104H80N8Ni ·
CHCl3 ·hexane: %C, 78.14; %H, 5.61; %N, 6.57. Observed: %C,
78.50; %H, 5.38; %N, 6.64.
Selected data for 11. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 251 (sh);
303 (49.2); 365 (71.3); 447 (155.2); 580 (12.0); 609 (12.8); 662
(15.3); 719 (17.2); 877 (sh). 1H NMR (500 MHz, CDCl3, 298 K):
δ 9.47 (s, 1H); 8.61 (d, JHH ) 4.6 Hz, 1H); 8.55 (d, JHH ) 5.1
Hz, 1H); 8.49 (d, JHH ) 4.2 Hz, 1H); 8.47 (d, JHH ) 4.2 Hz,
Selected data for 8b. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 321
(62.5); 362 (sh); 405 (sh); 433 (sh); 455 (sh); 478 (238.0); 560
(73.8); 605 (8.8); 667 (9.8); 743 (21.6); 807 (21.8). 1H NMR (500
3
3
MHz, CDCl3, 298 K): δ 8.25 (d, JHH ) 4.6 Hz, dd, JHH ) 4.6
4
3
3
Hz, JCdH ) 4.1 Hz, 1Hy); 8.13 (d, JHH ) 4.4 Hz, dd, JHH ) 4.4
4
3
Hz, JCdH ) 4.3 Hz, 1Hx); 8.08 (d, JHH ) 8.0 Hz, 2Hy); 7.95 (d,
3JHH ) 4.8 Hz, dd, JHH ) 4.8 Hz, JCdH ) 4.9 Hz, 1Hx); 7.90 (d,
3
4
3JHH ) 7.6 Hz, 2Hx); 7.87 (d, JHH ) 5.0 Hz, 1Hy); 7.85 (d, JHH
3
3
3
3
3
) 5.0 Hz, 1Hy); 7.84 (d, JHH ) 4.6 Hz, 1Hy); 7.80 (s, 2Hx); 7.73
(d, 3JHH ) 4.6 Hz, 1Hy); 7.68 (b, 2Hx); 7.65 (d, 3JHH ) 4.6 Hz, dd,
3JHH ) 4.6 Hz, 4JCdH ) 4.7 Hz, 1Hx); 7.64 (d, 3JHH ) 4.6 Hz, 1Hy);
7.60 (d, 3JHH ) 4.6 Hz, 1Hx); 7.54 (b, 2Hy); 7.45 (m, 1Hy + 2Hx);
7.38 (m, 2Hy + 2Hx); 7.20 (b, 1Hy); 7.16 (b, 1Hx); 7.01 (b, 2Hy);
3
3
3
3
1H); 8.46 (d, JHH ) 4.8 Hz, 1H); 8.42 (d, JHH ) 4.6 Hz, 1H);
8.00 (b, 2H); 7.90 (d, 3JHH ) 4.6 Hz, 1H); 7.88 (d, 3JHH ) 4.6 Hz,
3
3
2H); 7.83 (b, 1H); 7.79 (d, JHH ) 8.0 Hz, 1H); 7.73 (d, JHH
)
3
4
8.0 Hz, 2H); 7.69 (d, 3JHH ) 8.0 Hz, 1H); 7.68 (d, 3JHH ) 4.3 Hz,
6.82 (d, JHH ) 7.3 Hz, 1Hx); 6.50 (d, JHH ) 1.2 Hz, 1Hy); 5.88
(b, 1Hx); 4.69 (d, JHH ) 16.2 Hz, 1Hx); 4.52 (d, JHH ) 17.4 Hz,
1Hy); 4.45 (d, JHH ) 15.2 Hz, 1Hx); 4.24 (d, JHH ) 17.0 Hz,
1Hy); 2.67 (s, 3Hy); 2.57 (s, 3Hx + 6Hy); 2.55 (s, 3Hx); 2.53 (s,
3Hx); 2.00 (s, 3Hx); 1.84 (s, 3Hy); -0.20 (d, JHH ) 1.4 Hz, dd,
2
2
3
3
1H); 7.66 (d, JHH ) 8.0 Hz, 2H); 7.65 (d, JHH ) 5.0 Hz, 1H);
7.62 (d, 3JHH ) 5.0 Hz, 1H); 7.53 (d, 3JHH ) 7.8 Hz, 2H); 7.47 (d,
2
2
3JHH ) 7.8 Hz, 2H); 7.43 (d, 3JHH ) 7.8 Hz, 2H); 7.42 (d, 3JHH
)
8.0 Hz, 1H); 7.38 (d, 4JHH ) 1.4 Hz, 1H); 7.36 (d, 3JHH ) 8.0 Hz,
4
Inorganic Chemistry, Vol. 48, No. 2, 2009 443

Chmielewski
on all F2 data using the SHELXL9779 programs. All non-H atoms
were refined with anisotropic displacement parameters, except for
those in the region of the disordered solvents; hydrogen atoms were
included from the geometry of molecule. The asymmetric unit
contains one molecule of 11, two disordered molecules of n-heptane
(in four sites), and a molecule of water disordered into four sites.
A 2-fold disorder of the N-confused pyrrole of metalated subunits
of 11 was treated by the assignment of half of the nitrogen and
half of the carbon atoms to both C3 and N2 sites.
Synthesis of 2-(2′-(5,10,15,20-Tetrakis(p-tolyl)-2-aza-21-
carbaporphyrinatonickel(II))-o-xylene)-(5,10,15,20-tetrakis(p-
tolyl)-2-aza-21-carbaporphyrinatozinc) acetate, 12a, and
2-(2′-(5,10,15,20-Tetrakis(p-tolyl)-2-aza-21-carbaporphyrina-
tonickel(II))-o-xylene)-(5,10,15,20-tetrakis(p-tolyl)-2-aza-21-
carbaporphyrinatozinc) chloride, 12b. A sample of 10 (10 mg,
0.007 mmol) was dissolved in dichloromethane (10 mL), to which
a zinc acetate dihydrate solution in methanol (10 mg, 0.05 mmol
in 10 mL) was added, and the mixture was stirred at room
temperature for 1 h. The solvents were then removed by evapora-
tion, and the solid residue was dissolved in dichloromethane (15
mL) and filtered. The filtrate volume was reduced to 5 mL, and
hexane was added, causing the precipitation of a brown solid
product, 12a, that was collected by filtration and dried in the air.
Yield: 10 mg (88%). Conversion into chloride complex 12b was
done by dissolution of 12a (10 mg) in dichloromethane (10 mL)
and vigorous stirring for 1 h with an aqueous solution of NaCl (1
M, 2 mL). The water layer was then removed, and the organic phase
was washed with three portions of water (10 mL each). After
separation of the organic phase, the solution was filtered, and the
solvent was removed. The solid residue was dissolved in chloro-
form, and the dark green product, 12b, was crystallized by the
addition of hexane. Yield: 9 mg (91%).
Table 2. Crystal Data and Structure Refinement for 11
(H2O)(n-Heptane)
empirical formula
C118H113N8NiO
fw
1717.87
temp
wavelength
cryst syst
space group
100(2) K
1.54178 Å
triclinic
j
P1
unit cell dimensions
a
b
c
17.007(3) Å
18.130(3) Å
18.797(2) Å
105.856(13)°
107.447(13)°
98.818(15)°
5141.1(15) Å3
2
R
ꢀ
γ
V
Z
density (calcd) 1.114 Mg/m3
abs coeff (Cu KR)
F(000)
0.666 mm-1
1826
cryst size
cryst color and habit
diffractometer
θ range for data collection
index ranges
0.3 × 0.2 × 0.15 mm3
black prism
Oxford Diffraction Xcalibur PX
4.15-60.0°
-14 < h < 19, -19 < k < 18,
-21 < l < 21
reflns collected
39 282
ind reflns (Rint
)
14 517 (0.046)
solution method
direct
refinement method
data/restraints/params
GOF on F2
full-matrix least-squares on F2
14517/66/1181
1.071
final R indices [I > 2σ(I)]a
R indices (all data)a
largest diff peak and hole
R1 ) 0.0980, wR2 ) 0.2682
R1 ) 0.1266, wR2 ) 0.2845
1.71 and -0.37 e Å-3
a R1 ) ∑|Fo| – |Fc|/∑|Fo|, wR2 ) [∑[w(Fo – Fc )2/∑[w(Fo )2]]1/2
.
2
2
2
3
3
1H); 7.34 (d, JHH ) 7.8 Hz, 2H); 7.10 (d, JHH ) 4.8 Hz, 1H);
7.03 (d, 3JHH ) 4.8 Hz, 1H); 6.52 (t, 3JHH ) 7.6 Hz, 1H); 6.33 (b,
Selected data for 12a. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 252
(sh); 311 (sh); 363 (64.2); 433 (sh); 443 (sh); 468 (194.2); 556
(12.9); 589 (11.0); 644 (sh); 723 (20.0); 790 (34.2). 1H NMR (500
MHz, CDCl3, 298 K): δ 8.37 (d, 3JHH ) 4.8 Hz, 1H); 8.25 (s, 1H);
8.08 (d, 3JHH ) 5.0 Hz, 1H); 8.03 (d, 3JHH ) 7.8 Hz, 2H); 7.93 (d,
3
3
1H); 6.17 (t, JHH ) 7.6 Hz, 1H); 5.89 (d, JHH ) 6.8 Hz, 1H);
3
5.28 (b, 1H); 5.10 (d, JHH ) 7.8 Hz, 1H); 3.53 (b, 1H); 3.14 (d,
2JHH ) 17.1 Hz, 1H); (d, JHH ) 17.2 Hz, 1H); 2.96 (s, 3H); 2.69
2
(s, 3H); 2.66 (s, 3H); 2.65 (s, 3H); 2.58 (s, 3H); 2.57 (s, 3H); 2.54
3JHH ) 5.0 Hz, 1H); 7.90 (d, 3JHH ) 5.0 Hz, 2H); 7.88 (d, 3JHH
)
4
(s, 3H); 2.45 (s, 3H); 1.26 (d, JHH ) 1.4 Hz, 1H); 1.03 (s, 3H);
3
4.8 Hz, 1H); 7.86 (s, 2H); 7.83 (d, JHH ) 8.0 Hz, 2H); 7.80 (d,
2
2
-1.28 (d, JHH ) 14.7 Hz, 1H); -2.06 (d, JHH ) 14.7 Hz, 1H).
13C NMR (126 MHz, CDCl3, 298 K): δ 178.7; 163.0; 157.3 (C3′);
156.4; 154.1; 153.9; 153.7; 153.1; 150.0; 149.3; 147.8; 147.1; 143.4;
143.2; 138.8; 138.7; 138.7; 138.3; 138.2; 138.0; 137.9; 137.6; 137.4;
137.3; 137.0 (C3); 136.7; 136.6; 136.5; 135.9; 135.5; 135.4; 134.9;
134.9; 134.7; 134.6; 134.1; 133.8; 133.7; 133.4; 133.3; 133.0; 132.5;
132.3; 132.2; 131.6; 131.2; 130.7; 130.4; 130.4; 130.0; 129.4; 129.1;
128.9; 128.7; 128.5; 128.1; 128.0; 127.9; 127.8; 127.5; 127.1; 126.6;
126.3; 126.1; 125.7; 125.3; 124.3; 123.8; 123.6; 115.4; 115.1; 108.5
(C21); 108.2; 50.3; 30.7 (C21′); 21.6; 21.4; 21.3; 20.0. HRMS
(ESI+): m/z 1499.585 (observed); 1499.594 (calculated for
[C104H81N8Ni]+, [M+1]+).
3
3JHH ) 4.8 Hz, 1H); 7.79 (d, JHH ) 4.8 Hz, 1H); 7.68 (b, 1H);
7.66 (d, 3JHH ) 7.6 Hz, 2H); 7.61 (d, 3JHH ) 7.6 Hz, 3H); 7.57 (d,
3
3JHH ) 5.0 Hz, 1H); 7.48 (d, JHH ) 7.1 Hz, 1H); 7.40 (b, 2H);
7.36 (d, 3JHH ) 7.8 Hz, 2H); 7.34 (d, 3JHH ) 4.9 Hz, 1H); 7.29 (d,
3
3JHH ) 7.6 Hz, 2H); 7.10 (d, JHH ) 6.2 Hz, 2H); 7.05 (b, 1H);
3
6.63 (b, 1H); 6.59 (t, JHH ) 7.0 Hz, 1H); 6.52 (b, 1H); 6.43 (s,
3
2
1H); 6.20 (d, JHH ) 8.0 Hz, 1H); 4.65 (d, JHH ) 17.4 Hz, 1H);
2
2
4.57 (b, 1H); 4.29 (d, JHH ) 16.7 Hz, 1H); 4.21 (d, JHH ) 16.4
Hz, 1H); 2.66 (s, 3H); 2.62 (s, 3H); 2.58 (s, 3H); 2.55 (s, 6H);
2.50 (s, 3H); 2.14 (s, 3H); 1.97 (s, 3H); 0.09 (b, 3H); -0.47 (s,
1H).
Selected data for 12b. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 251
(sh); 365 (79.3); 439 (111.0); 468 (182.6); 559 (18.8); 586 (19.8);
629 (19.2); 722 (16.5); 792 (33.6). H NMR (500 MHz, CDCl3,
298 K): δ 8.36 (d, 3JHH ) 4.8 Hz, 1H); 8.25 (s, 1H); 8.08 (d, 3JHH
) 5.0 Hz, 1H); 8.06 (d, JHH ) 8.0 Hz, 2H); 7.95 (d, JHH ) 5.0
X-Ray Data Collection and Refinement of 11. Crystals of
11·(H2O)(n-heptane) were prepared by the diffusion of n-heptane
into the dichloromethane solution contained in a thin tube. Data
were collected at 100 K using an Oxford Cryosystem device on an
Oxford Diffraction Xcalibur PX diffractometer with a KM4CCD
Sapphire detector. Data collection, integration, and scaling of the
reflections were performed by means of the CrysAlis suite of
programs (Oxford Diffraction, Poland). Crystal data are compiled
in Table 2. The structure was solved by direct methods with
SHELXS9778 and refined by the full-matrix least-squares method
1
3
3
3
3
Hz, 1H); 7.88 (d, JHH ) 4.8 Hz, 1H); 7.87 (d, JHH ) 4.8 Hz,
1H); 7.86 (s, 2H); 7.85 (d, 3JHH ) 5.0 Hz, 1H); 7.83 (d, 3JHH ) 7.6
3
3
Hz, 2H); 7.80 (d, JHH ) 5.0 Hz, 1H); 7.78 (d, JHH ) 5.0 Hz,
3
3
1H); 7.67 (d, JHH ) 8.0 Hz, 2H); 7.61 (d, JHH ) 7.8 Hz, 2H);
7.59 (d, 3JHH ) 7.8 Hz, 2H); 7.58 (d, 3JHH ) 5.0 Hz, 1H); 7.51 (d,
3JHH ) 7.6 Hz, 1H); 7.48 (d, 3JHH ) 7.6 Hz, 1H); 7.39 (d, 3JHH
)
(78) Sheldrick, G. M. SHELXS97 - Program for Crystal Structure Solution;
(79) Sheldrick, G. M. SHELXL97 - Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttingen, Germany , 1997.
University of Go¨ttingen: Go¨ttingen, Germany, 1997.
444 Inorganic Chemistry, Vol. 48, No. 2, 2009

Transition Metal Complexes of Dimeric N-Confused Porphyrin
5.0 Hz, 1H); 7.36 (d, 3JHH ) 7.8 Hz, 3H); 7.30 (d, 3JHH ) 8.0 Hz,
Selected data for 13. UV-vis (CH2Cl2) λ/nm (ꢀ·10-3): 253 (sh);
332 (sh); 367 (75.2); 433 (sh); 441 (149.6); 456 (202.6); 531 (21.0);
574 (19.9); 644 (15.1); 700 (21.5); 795 (7.1). 1H NMR (500 MHz,
3
3
2H); 7.13 (d, JHH ) 8.3 Hz, 1H); 7.05 (d, JHH ) 7.5 Hz, 2H);
6.93 (d, 3JHH ) 7.3 Hz, 1H); 6.81 (d, 3JHH ) 7.6 Hz, 1H); 6.76 (t,
3JHH ) 7.0 Hz, 1H); 6.65 (d, 3JHH ) 7.6 Hz, 1H); 6.63 (d, 3JHH
)
CDCl3, 298 K): δ 9.11 (s, 1H); 8.81 (d, JHH ) 5.0 Hz, 1H); 8.50
3
3
6.5 Hz, 1H); 6.46 (b, 1H); 6.37 (s, 1H); 6.17 (d, JHH ) 7.6 Hz,
(d, 3JHH ) 5.0 Hz, 1H); 8.40 (s, 2H); 8.27 (s, 1H); 8.24 (d, 3JHH
)
2
2
1H); 4.56 (d, JHH ) 17.0 Hz, 1H); 4.35 (s, 2H); 4.29 (d, JHH
)
5.0 Hz, 1H); 8.15 (d, 3JHH ) 7.6 Hz, 2H); 8.09 (d, 3JHH ) 5.0 Hz,
3
3
17.0 Hz, 1H); 2.65 (s, 3H); 2.62 (s, 3H); 2.58 (s, 3H); 2.55 (s,
6H); 2.50 (s, 3H); 2.07 (s, 3H); 1.95 (s, 3H); -0.38 (d, 4JHH ) 1.4
Hz, 1H). 13C NMR (126 MHz, CDCl3, 298 K): δ 162.6; 162.2;
158.2; 156.6; 154.3; 153.9; 152.0; 151.3; 151.1; 150.1; 151.3 (C3);
148.7; 146.8; 145.0; 139.7; 139.0; 138.9; 138.8; 138.7; 138.1; 137.8;
137.6; 137.5; 137.4; 137.3; 137.2; 137.2; 137.1; 136.8; 136.3; 134.9;
134.7; 134.4; 134.3; 134.0; 133.8; 133.7; 133.5; 133.4; 133.2; 132.7;
132.4; 132.3; 132.2; 131.7; 131.5; 131.2; 130.6; 130.4; 128.7; 128.5;
128.3; 128.2; 128.0; 127.9; 127.6; 126.3; 125.9; 124.6; 123.8; 123.7;
122.6 (C3′); 121.5; 119.3; 118.5; 117.5; 116.9; 79.0 (C21′); 52.5;
51.3; 21.9; 21.8; 21.3; 21.2. HRMS (ESI+): m/z 1593.500
(observed); 1593.497 (calculated for [C104H79N8NiZn]+, [M-Cl]+).
Synthesis of 2-(2′-(5,10,15,20-Tetrakis(p-tolyl)-2-aza-21-car-
baporphyrinatonickel(II))-o-xylene)-(5,10,15,20-tetrakis(p-tolyl)-
2-aza-21-carbaporphyrinatosilver(III)) Tetrafluoroborate, 13. A
sample of 10 (10 mg, 0.007 mmol) and silver(I) tetrafluoroborate
(5 mg, 0.03 mmol) was dissolved in THF (10 mL) and stirred in
darkness for 2 h at room temperature. The solvent was then
removed, and the olive-green product was dissolved in dichlo-
romethane and filtered. The filtrate was washed with two portions
of water (5 mL); the solvent was then removed, and the solid was
redissolved in a minimum volume of CH2Cl2 and precipitated by
the addition of hexane, collected by filtration, and dried in the air.
Yield: 8 mg (67%).
1H); 7.98 (d, JHH ) 5.0 Hz, 1H); 7.89 (d, JHH ) 7.6 Hz, 2H);
7.86 (d, 3JHH ) 5.0 Hz, 1H); 7.85 (d, 3JHH ) 5.0 Hz, 1H); 7.82 (d,
3JHH ) 5.0 Hz, 1H); 7.80 (d, 3JHH ) 7.0 Hz, 2H); 7.70 (d, 3JHH
)
8.2 Hz, 2H); 7.68 (d, 3JHH ) 8.2 Hz, 2H); 7.62 (d, 3JHH ) 7.5 Hz,
3
3
2H); 7.60 (d, JHH ) 5.0 Hz, 1H); 7.55 (d, JHH ) 7.5 Hz, 2H);
7.48 (d, 3JHH ) 6.9 Hz, 2H); 7.42 (d, 3JHH ) 4.8 Hz, 1H); 7.37 (d,
3JHH ) 7.5 Hz, 2H); 7.31 (d, 3JHH ) 7.5 Hz, 2H); 7.07 (d, 3JHH
)
7.3 Hz, 2H); 7.02 (b, 2H); 6.90 (d, 3JHH ) 6.9 Hz, 2H); 6.7 (t, 3JHH
3
3
) 7.6 Hz, 1H); 6.60 (t, JHH ) 7.6 Hz, 1H); 6.38 (d, JHH ) 7.6
Hz, 1H); 5.90 (d, JHH ) 7.6 Hz, 1H); 5.27 (s, 2H); 4.68 (s, 2H);
3
2.70 (s, 3H); 2.67 (s, 3H); 2.62 (s, 6H); 2.56 (s, 3H); 2.52 (s, 3H);
2.09 (s, 3H); 2.07 (s, 3H). HRMS (ESI+): m/z 1603.478 (observed);
1603.475 (calculated for [C104H78N8AgNi]+).
Acknowledgment. Financial support from the Ministry
of Science and Higher Education (Grant PBZ-KBN-118/T09/
2004) is kindly acknowledged.
Supporting Information Available: Crystallographic data of
11 in CIF format, optical and CD spectra of bis(zinc) complex 7b
treated with aqueous potassium mandelate. This material is available
free of charge via the Internet at http://pubs.acs.org.
IC800591N
Inorganic Chemistry, Vol. 48, No. 2, 2009 445