Regioselective reaction of 5,15-disubstituted porphyrins with organolithium reagents - Synthetic access to 5,10,15-trisubstituted porphyrins and directly meso-meso-linked bisporphyrins

Article abstract of DOI:10.1039/b005411i

The reaction of organolithium reagents with 5,15-disubstituted porphyrins, followed by hydrolysis of the intermediate anion to give a porphodimethene and oxidation with DDQ allows the facile preparation of 5,10,15-tri-and 5,10,15,20-tetrasubstituted porph

Full text of DOI:10.1039/b005411i

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Regioselective reaction of 5,15-disubstituted porphyrins with
organolithium reagents—synthetic access to 5,10,15-trisubstituted
porphyrins and directly meso-meso-linked bisporphyrins
1
Mathias O. Senge* and Xiangdong Feng
Institut für Chemie, Organische Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin,
Germany. E-mail: mosenge@chemie.fu-berlin.de
Received (in Cambridge, UK) 6th July 2000, Accepted 22nd August 2000
First published as an Advance Article on the web 10th October 2000
The reaction of organolithium reagents with 5,15-disubstituted porphyrins, followed by hydrolysis of the
intermediate anion to give a porphodimethene and oxidation with DDQ allows the facile preparation of
5,10,15-tri- and 5,10,15,20-tetrasubstituted porphyrins with mixed meso substituent types. Easily available
5,15-disubstituted porphyrins react almost quantitatively with sterically undemanding organolithium reagents
(PhLi, BuLi) to give the respective 5,10,15-trisubstituted porphyrins (A2B-type). When bulkier reagents are used
(e.g. Bus or But) the number and yield of side products increases considerably. Thus, the regioselectivity of the
nucleophilic attack (meso versus β) depends on the steric hindrance of the LiR reagents. The 5,10,15-trisubstituted
porphyrins can in turn be used for another cycle of nucleophilic attack, hydrolysis, and oxidation giving rise to
5,10,15,20-tetrasubstituted porphyrins of the A2B2- or A2BC-types. In contrast, reaction of 5,15-disubstituted
porphyrins with LiR and direct oxidation of the intermediate anion without a hydrolysis step gives directly linked
(5,5Ј) bisporphyrins allowing the preparation of bisporphyrins with mixed meso substituent pattern. In addition,
the crystal structures of two 5,10,15-trisubstituted porphyrins (25, 28) are reported. Both compounds exhibit
moderately nonplanar macrocycles as a result of the sterically hindered meso substituents.
(5,15-dihydroporphyrin) 10 as the sole product, that upon
Introduction
oxidation with DDQ can be converted into 11, a 5,51-didehydro-
porphodimethene with an exocyclic double bond.8a,b The
reactivity of these porphyrins is strongly governed by the
central metal and the meso substituents. For example, Callot
and coworkers showed that tetraphenylporphyrin 8 reacts
with alkyllithium reagents to give a variety of phlorins (5,22-
dihydroporphyrins) (12) and porphodimethenes (5,10-dihydro-
porphyrins) (13).9 In addition, Cb–Cb addition reactions to yield
chlorins (14–16) were observed with both free base tetraphenyl-
porphyrin 89b and the corresponding zinc() complex 9.8b
In order to expand the synthetic utility of organolithium
reagents for the synthesis of novel porphyrins and hydro-
porphyrins we have now utilized 5,15-disubstituted porphyrins
as starting materials. Using compounds like 17–19, i.e. por-
phyrins with both free meso and β positions, we intended to
investigate the regioselectivity of this reaction. Provided that
preferential attack of RLi occurs at the meso position, this
would give a convenient entry into 5,10,15-tri- and 5,10,15,20-
tetrasubstituted porphyrins. Porphyrins of this type are useful
precursors for further transformations and are accessible only
with difficulty via established routes.10
Functionalization of porphyrins via organometallic coupling
reactions has enjoyed considerable success recently.1 For
example, Heck and Suzuki coupling reactions allowed the
synthesis of various meso and β-substituted porphyrins.2
Considerable progress has also been made in the development
of syntheses for directly linked bisporphyrins3,4 and oligo/
polyporphyrins5 as novel (opto)electronic materials.6 Neverthe-
less, the increasing demand for functionalized porphyrins,
especially in the context of technical and medicinal appli-
cations,7 requires short synthetic routes with as few steps as
possible, high yields and preferably a wide substrate tolerance.
Utilizing organolithium reagents we have shown that a wide
range of meso substituted and functionalized porphyrins and
porphodimethenes is accessible without having to prepare
activated or prefunctionalized porphyrins.8
Initially we used octaethylporphyrin derivatives, e.g. 1 for
our investigation.8a The method developed utilized a reaction
sequence consisting of treatment of the porphyrin with RLi,
hydrolysis with water to yield a porphodimethene, followed
by oxidation with DDQ to give the desired porphyrin. For
example, reaction of 1 with BuLi under the conditions
described gave the respective 5-butylporphyrin 2 in quantitative
yield. This method was equally successful with alkyl- and aryl-
lithium reagents (e.g. 1 ϩ PhLi → 3) and could be used for
the modification of both metallo porphyrins and free base
porphyrins. Thus, reaction of 2,3,7,8,12,13,17,18-octaethyl-
porphyrin 4 with either BuLi or PhLi, followed by hydrolysis
and oxidation, gave the porphyrins 5 and 6, respectively. The
studies performed so far, indicate that this is a general method
that can be used for the synthesis of any meso substituted
porphyrin, provided the required LiR reagent can be prepared.
Next we turned our attention to the investigation of
5,10,15,20-tetrasubstituted porphyrins, e.g. the tetraalkyl-
porphyrin 7. Reaction with BuLi gives the porphodimethene
Results and discussion
The 5,15-disubstituted porphyrins 17–19 were chosen as
starting materials as they are easily prepared in one step and
acceptable yields from dipyrromethane and the appropriate
aldehyde.11 In addition, a quick investigation of the regio-
selectivity of the meso versus β attack should be possible. First
we used sterically undemanding organolithium reagents. For
example, reaction of the diphenylporphyrin 18 with either PhLi
or BuLi yielded a brown reaction mixture, that after hydrolysis
and oxidation turned deep red. After flash chromatographic
separation the trisubstituted porphyrins 20 or 23 were obtained
in almost quantitative yield. Similar reaction products (21 or
DOI: 10.1039/b005411i
J. Chem. Soc., Perkin Trans. 1, 2000, 3615–3621
This journal is © The Royal Society of Chemistry 2000
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Scheme 1
different red, green, and blue products (by TLC). Attempts to
separate this mixture by flash chromatography resulted in
decomposition to even more products and we were unable to
isolate the desired free base. Only the reaction of 18 with PriLi
or BusLi gave the free bases 25 and 27 in 30 and 15% yield,
respectively. Variation of the reaction conditions (temper-
ature, solvents, and concentration of RLi) did not result in a
significantly improved yield or a diminished number of side
products.
Depending on the substitution pattern of the porphyrin or
the steric hindrance of RLi, phlorins, chlorins, 5,10- and 5,15-
dihydroporphyrins have been identified as possible products
from the reaction of organolithium reagents with porph-
yrins.8a,b,9 Based upon the blue color observed for several side
products, irreversible ring-opening to linear tetrapyrroles can
also occur and a further novel product was obtained from the
reaction of 18 with BusLi. As described the trisubstituted
porphyrin 27 is formed in low yield. In addition, the directly
meso–meso linked dimer 30 was isolated in 30% yield. TLC
and spectroscopic analysis indicates that formation of the
bisporphyrin occurs rapidly before the hydrolysis step.
5,10,15-Trisubstituted porphyrins 31 were subjected to the
same reaction conditions as described above. For simple
reagents like BuLi or PhLi excellent transformations to give
5,10,15,20-tetrasubstituted porphyrins of the A2B2- or A2BC-
types were observed. For example, 21 was converted to 32 with
BuLi in 88% yield, and 20 gave 33 in 93% yield. Similar results
were obtained with reagents like PhLi or other 5,10,15-
trisubstituted porphyrins and the order of introduction of the
different meso substituents is unimportant for the overall yield.
Again, complete regioselectivity for the meso position was
observed.
24) were observed when the respective free base 19 was used as
starting material. Alternatively, compounds like 22 could be
prepared from the meso-alkylporphyrin 17.4 No β-substituted
reaction products (either porphyrins or chlorins) were isolated
from any of these reactions.
A different reactivity was observed upon reaction of either
18 or 19 with sterically more demanding LiR reagents (R = Pri,
Bus, But). In general, an increasing number of reaction
products was observed depending on the steric bulk of RLi.
Using the nickel() complexes as starting material the desired
trisubstituted porphyrins 26, 28, and 29 were obtained in
acceptable yields ranging from 50 to 65%. Nevertheless, the
formation of several side products (mainly green, brown, or
blue) was observed. In contrast, the reactivity of the free bases
with sterically demanding nucleophiles is much higher. For
example, the reaction of 19 with ButLi gave more than 20
Utilization of sterically hindered nucleophiles gave similar
results as described for 5,15-disubstituted porphyrins. Here,
even use of PriLi and reaction with the free base 25 gave a
complex reaction mixture of numerous compounds that could
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Table 1 Selected bond lengths, angles, and conformational parameters
for the porphyrins studied
28
Compound
25
Molecule 1
Molecule 2
Bond lengths/Å
Ni–N21
Ni–N22
Ni–N23
Ni–N24
—
—
—
—
1.951(5)
1.940(5)
1.949(5)
1.953(5)
1.951(5)
1.937(5)
1.951(5)
1.957(5)
Bond angles/degrees
Scheme 2
C4–C5–C6
123.9(2)
125.0(2)
127.5(2)
124.9(2)
120.8(6)
121.8(6)
124.4(6)
122.3(6)
121.8(6)
122.4(6)
124.2(6)
122.6(6)
C9–C10–C11
C14–C15–C16
C19–C20–C1
not be separated chromatographically. Thus, the reaction of
5,10,15-trisubstituted porphyrins is even more susceptible to
the steric demand of the reagent than 5,15-disubstituted
porphyrins. Again, the nickel() complexes were more suitable
for transformations with hindered reagents. For example, reac-
tion of 29 with BusLi gave the tetrasubstituted porphyrin 34 in
55% yield. Presumably the different reactivity of free bases and
nickel() complexes is the result of different intermediates that
are formed as the primary product of the nucleophilic attack.
Reaction of free bases with RLi proceeds through phlorins,9
while nickel() complexes initially form porphodimethenes.4
For rhodium porphyrins a phlorin has also been postulated as
an intermediate.12 As steric interactions in porphodimethenes
are diminished this might be an explanation for the higher
yields observed for the reaction of sterically hindered nucleo-
philes with nickel() complexes compared to free bases.
Thus, it is possible to prepare 5,10,15,20-tetrasubstituted
porphyrins by successive use of two cycles of the LiR reaction.
As compounds like 31 are notoriously difficult to prepare or
require laborious chromatographic work-up of so-called mixed
condensations this method presents a considerable improve-
ment over existing methods.10 However, as we have shown that
similar products (including those with residues containing
functional groups) can easily be prepared in a one-pot
reaction using first an attack of RLi followed by reaction of the
intermediate in situ with RI,8c no further experiments were
undertaken in this area.
Conformational parameters/Å
Core size ᮏa
Core elongation Ξ b
∆24c
2.058
1.948
Ϫ0.004
1.949
Ϫ0.008
0.007
0.11
0.30
0.22
0.21
0.14
0.22
0.08
—
0.20
0.41
0.34
0.33
0.34
0.36
0.21
0.007
0.18
0.44
0.28
0.34
0.27
0.33
0.17
0
δC5d
δC10d
δC15d
δC20d
e
δCme
δCb
δNid
a The core size is defined as the geometrical center of the four nitrogen
atoms. b The core elongation parameter is defined as the difference
between the vector lengths (|N21 Ϫ N22| ϩ |N23 Ϫ N24|)/2 Ϫ (|N22 Ϫ
N23| ϩ |N21 Ϫ N24|)/2. c Deviation of the 24 macrocycle atoms from
their least squares plane. d Deviation from the 4N-plane. e Average
deviation from the 4N-plane.
Due to their limited availability tri-meso substituted por-
phyrins have not been studied much with regard to their
molecular structure and conformation.13 So far, only one study
has addressed conformational aspects of these interesting
molecules.14 Structural analysis of 5-nitro-10,20-diphenyl-
porphyrin and (5-bromo-10,20-diphenylporphyrinato)nickel()
showed the free base macrocycle to be ruffled while the nickel()
complex exhibited a planar conformation. We were able to crys-
tallize the free base 25 and the nickel() complex 28, both con-
taining one secondary alkyl residue in a meso position (Fig. 1).
A detailed conformational analysis (Fig. 2) showed that both
compounds have ruffled macrocycles. Ruffling is characterized
by rotation of the pyrrole rings against the Cb–Cb vector and
significant displacements of the meso carbon atoms (Cm) from
the mean plane of the molecule.13 With average displacements
of the Cm positions of 0.22 Å in 25 and 0.35 Å in 28 the
molecules exhibit moderate ruffling. The degree of ruffling and
thus the overall conformation is asymmetric. In addition, the
overall distortion mode has some contribution from saddle dis-
tortion, too, as evidenced by the out-of-plane tilting of some
pyrrole rings in both structures. The contribution from saddle
distortion is larger in the nickel() complex 28. The overall
measure of nonplanarity (∆24 = 0.11 to 0.2 Å) is much less
compared to highly substituted porphyrins but the local steric
influence of the meso substituents is indicated by the differ-
ence in individual Ca–Cm–Ca angles (Table 1). Substituted meso
positions generally exhibit widened Ca–Cm–Ca angles.15 The
average Ni–N bond length in 28 is 1.951(5) Å. This is only
Fig. 1 View of the molecular structure and numbering scheme of 25
(top) and 28 (bottom, only one of the two crystallographically
independent molecules shown). Hydrogen atoms and disordered
positions have been omitted for clarity.
J. Chem. Soc., Perkin Trans. 1, 2000, 3615–3621
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Fig. 2 Linear display of the skeletal deviations of the macrocycle
atoms from the 4N-plane for compounds 25 and 28 (molecule 1). The
x-axis (Å) is not to scale.
slightly shorter than that found in the triclinic A form of
(2,3,7,8,12,13,17,18-octaethylporphyrinato)nickel() (1.958(2)
Å),16 but significantly longer compared to ruffled 5,10,15,20-
tetraalkylporphyrins.17 This indicates that the observed con-
formation is mainly the result of steric interactions and not due
to a simple metal effect. As no multiple modifications have yet
been described for 5,10,15-trisubstituted porphyrins the influ-
ence of packing forces cannot be completely ruled out. Never-
theless, the structural data listed in Table 1 fit into the concepts
now established for sterically hindered porphyrins in all
respects.13 In addition, UV/VIS spectroscopy showed increasing
bathochromic shifts of the absorption bands for porphyrins
with sterically more demanding substituents. Red-shifted
absorption bands are good indicators for nonplanar macro-
cycles in solution.18 For example, the long wavelength absorp-
tion maxima for the nickel complexes 31 with R2 = Bu, Pri,
Bus, But are 556, 558, 560, and 581 nm, respectively. Relief
of steric strain is only facilitated by out-of-plane distortions;
as indicated by the small values for the core elongation factor
Ξ,13,19 no evidence for in-plane distortion was found.
Besides giving convenient access to tri- and tetra-meso-
substituted porphyrins, the reaction of 5,15-disubstituted
porphyrins with organolithium reagents has further synthetic
potential. As outlined in a communication,4 a simple switch of
the reaction conditions leads to directly linked bisporphyrins.
As described above, the reaction of porphyrins with LiR typic-
ally involves an intermediate hydrolysis step to hydrolyze excess
organolithium reagent and to protonate the intermediary anion
to a porphodimethene. Subsequent oxidation with DDQ then
gives the desired meso substituted porphyrin. We found, that
quite a different reactivity is observed upon reaction of 5,15-
disubstituted free bases 35 (R1 = Bu or Ph) with BuLi or PhLi
followed by direct addition of the oxidant DDQ without the
intermediary hydrolysis step.
Scheme 3
while reactions with BuLi and I2 resulted in diminished yields
(ca. 30%) and formation of several side products. UV light can
be used to accelerate the reaction but has to be used with care.
Normally the dimerization reaction is complete within 10–15
min. Illumination with a UV lamp leads to completion within
5 min. Longer exposure to UV light results in diminished yields
and formation of side products. This method works well with
free bases, but reaction of nickel() complexes under the same
conditions resulted in formation of the tri- and tetrasubstituted
porphyrins. While other syntheses of 5,5Ј-bisporphyrins22 often
suffer from low yields or laborious synthetic requirements, this
new method gives good yields and allows the preparation of
bisporphyrins with a mixed meso substitution pattern at C5,
C15, and C20 in one step.
In conclusion, the reaction of 5,15-disubstituted and 5,10,15-
trisubstituted porphyrins with sterically unhindered organo-
lithium reagents proceeds regioselective at the meso positions.
Only when sterically hindered reagents are used or when all
meso positions are substituted does reaction at the β-positions
become a competing reaction. Thus the reaction provides a
convenient entry into tri- and tetrasubstituted porphyrins. In
addition, simple variation of the reaction conditions provide
a route to directly meso–meso linked bisporphyrins in high
yield.
This reaction sequence yielded the meso–meso linked bis-
porphyrins 36–38 directly in yields ranging from 55 to 78%. As
side products tri- (21,22,24) and tetra-meso substituted (39–41)
porphyrins were observed. This indicates that two competing
reactions occur. Dimerization presumably proceeds via oxid-
ation of the anion to give a π stabilized radical followed by
radical dimerization. DDQ induced oxidative dimerizations are
known20 and related reactions have been described for other
tetrapyrroles.21 On the other hand, hydride abstraction to give
the neutral porphyrins 21, 22 or 24 (depending on the reagents)
can occur, which then react with a second molecule RLi to give
39–41. Other oxidants gave mixed results. With iodine the reac-
tion with PhLi proceeded well with slightly improved yields,
Experimental
General
All chemicals used were of analytical grade and purified before
3618
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3
use by distillation. The reactions of porphyrins with organo-
lithium compounds were performed under a purified argon
atmosphere by using modified Schlenk techniques and dried
and degassed solvents. Melting points are uncorrected and were
measured with a Reichert Thermovar apparatus. Neutral alu-
mina (Alfa) (usually Brockmann Grade III, i.e. deactivated
with 7.5% water) was used for column chromatography.
Analytical thin-layer chromatography (TLC) was performed on
Merck silica gel or alumina 60 (neutral, fluorescence indicator
F254) precoated plates. Proton NMR spectra were recorded at a
frequency of 250 MHz with a Bruker AC 250 instrument. All
chemical shifts are given in ppm and have been converted to the
δ scale and are referenced against the TMS signal as internal
standard. J Values are given in Hz. Electronic absorption
spectra were recorded with a Specord S10 (Carl Zeiss) spectro-
photometer using dichloromethane as solvent. Mass spectra
were obtained using a Varian MAT 711 mass spectrometer.
Calculated mass for Ni complexes refers to 58Ni. Elemental
analyses were performed with a Perkin-Elmer 240 analyzer.
CH2CH3), 5.05 (4 H, t, J 7.5, CH2CH2CH2CH3), 7.75–7.90,
8.20–8.40 (5 H, each m, HPh), 8.75–8.95, 9.25–9.35, 9.40–9.50,
9.55–9.65 (8 H, m, 8 × Hβ-pyrrole), 10.15 (1 H, s, Hmeso); m/z (EI,
80 eV): 498.2762 (Mϩ, 100%. C34H34N4 requires 498.2784), 455
(66, Mϩ Ϫ CH2CH2CH3), 412 (13, Mϩ Ϫ 2 × CH2CH2CH3),
249 (7, M2ϩ).
(10-Butyl-5,15-diphenylporphyrinato)nickel(II) 23. Chromato-
graphy eluting with ethyl acetate–n-hexane (1:100, v/v); yield
55 mg (95%) purple crystals (Found: C, 73.70; H, 4.92; N, 9.77.
C36H28N4Ni requires C, 75.16; H, 4.91; N, 9.74%. C36H28-
N4Niؒ0.5H2O requires C, 73.87; H, 5.17; N, 9.57%): mp 230 ЊC
(CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 408 (log ε/dm3 molϪ1 cmϪ1
5.16), 523 (4.00), 556 (3.17); δH (250 MHz; CDCl3; SiMe4) 1.15
(3 H, t, 3J 7.6, CH2CH2CH2CH3), 1.60–1.75 (2 H, m, CH2CH2-
CH2CH3), 2.25–2.45 (2 H, m, CH2CH2CH2CH3), 4.60 (2 H, t,
3J 7.8, CH2CH2CH2CH3), 7.55–7.65, 7.95–8.05 (10 H, each m,
HPh), 8.85 (4 H, m, 4 × Hβ-pyrrole), 9.05, 9.35 (4 H, each d, J 4.9,
4 × Hβ-pyrrole), 9.70 (1 H, s, Hmeso); m/z (EI, 80 eV): 574.1642
(Mϩ, 98%. C36H28N4Ni requires 574.1667), 531 (100, Mϩ Ϫ
CH2CH2CH3), 287 (4, M2ϩ).
General procedure for the preparation of substituted porphyrins
A Schlenk flask was charged with 0.1 mmol of the porphyrin
(ca. 50 mg) dissolved in 30–40 ml dry THF under an argon
atmosphere. The solution was cooled to Ϫ70 ЊC for RLi (R =
n-, sec-, iso-, or tert-butyl) or to 0 ЊC for reactions using phenyl-
lithium. The organolithium reagent (0.6 mmol, 0.3 ml of a 2 M
solution in cyclohexane) was added dropwise over 15 min. After
removal of the cold bath the reaction mixture was stirred for
another 15 min, followed by addition of 0.5 ml water in 5 ml
THF. After stirring for 10 min, a solution of four equivalents of
DDQ in methylene chloride (ca. 0.06 M) was added and the
reaction mixture was stirred for another 60 min at room tem-
perature. Subsequently, the mixture was filtered through neutral
alumina and subjected to column chromatography on neutral
alumina (Alfa) followed by recrystallization from CH2Cl2–
methanol.
10-Butyl-5,15-diphenylporphyrin 24. Chromatography eluting
with ethyl acetate–n-hexane (1:150, v/v); yield 47 mg (94%)
purple crystals (Found: C, 83.11; H, 5.64; N, 10.58. C36H30N4
requires C, 83.37; H, 5.83; N, 10.80%): mp 250 ЊC (CH2Cl2–
CH3OH); λmax(CH2Cl2)/nm 411 (log ε/dm3 molϪ1 cmϪ1 5.12),
509 (3.84), 543 (3.27), 584 (3.35), 641 (3.07); δH (250 MHz;
3
CDCl3; SiMe4) Ϫ3.02 (2 H, s, 2 × NH), 1.15 (3 H, t, J 7.5,
CH2CH2CH2CH3), 1.78–1.90 (2 H, m, CH2CH2CH2CH3),
2.55–2.60 (2 H, m, CH2CH2CH2CH3), 5.05 (2 H, t, 3J 7.8,
CH2CH2CH2CH3), 7.75–7.85, 8.25–8.32 (10 H, each m, 10H,
HPh), 8.95, 9.25, 9.55 (8 H, each d, J 4.9, 8 × Hβ-pyrrole),
10.07 (1 H, s, Hmeso); m/z (EI, 80 eV): 518.2441 (Mϩ, 61%.
C36H30N4 requires 518.2476), 475 (100, Mϩ Ϫ CH2CH2CH3),
259 (9, M2ϩ).
10-Isopropyl-5,15-diphenylporphyrin 25. Chromatography
eluting with ethyl acetate–n-hexane (1:100, v/v); yield 15 mg
(30%) dark purple crystals (Found: C, 82.88; H, 5.62; N, 10.48.
C35H28N4 requires C, 83.30; H, 5.59; N, 11.10%): mp 270 ЊC
(CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 412 (log ε/dm3 molϪ1 cmϪ1
5.11), 509 (3.95), 542 (3.89), 585 (3.61), 639 (3.49); δH (250
MHz; CDCl3; SiMe4) Ϫ3.01 (2 H, s, 2 × NH), 2.48 (6 H, t,
3J 7.3, CH(CH3)2), 5.76 (1 H, q, J 7.3, CH(CH3)2), 7.75–7.85,
8.25–8.32 (10 H, each m, HPh), 8.85–8.95 (4 H, m, 4 × Hβ-pyrrole),
9.22, 9.65 (4 H, each d, J 4.8, 4 × Hβ-pyrrole), 10.02 (1 H, s, Hmeso);
m/z (EI, 80 eV): 504.2354 (Mϩ, 100%. C35H28N4 requires
504.2314), 489 (72, Mϩ Ϫ CH3), 252 (12, M2ϩ).
(5,10,15-Triphenylporphyrinato)nickel(II) 20. Chromato-
graphy eluting with ethyl acetate–n-hexane (1:150, v/v); yield
55 mg (92%) purple crystals (Found: C, 72.78; H, 3.96; N, 8.60.
C38H24N4Ni requires C, 76.67; H, 4.06; N, 9.41%. C38H24N4Niؒ
0.5CH2Cl2 requires C, 72.50; H, 3.95; N, 8.78%): mp 278 ЊC
(CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 406 (log ε/dm3 molϪ1 cmϪ1
5.18), 520 (3.98), 554 (3.29); δH (250 MHz; CDCl3; SiMe4) 7.55–
7.65, 7.85–8.05 (15 H, each m, HPh), 8.75–8.78 (4 H, m, 4 ×
3
H
β-pyrrole), 8.85, 9.07 (4 H, each d, J 5.0, 8 × Hβ-pyrrole), 9.80
(1 H, s, Hmeso); m/z (EI, 80 eV): 594.1387 (Mϩ, 100%. C38H24-
N4Ni requires 594.1354), 516 (19, Mϩ Ϫ C6H5), 297 (14, M2ϩ).
5,10,15-Triphenylporphyrin 21. Chromatography eluting with
ethyl acetate–n-hexane (1:200, v/v); yield 48 mg (89%) purple
crystals (Found: C, 81.02; H, 4.92; N, 9.94. C38H26N4 requires
C, 84.73; H, 4.87; N, 10.40%. C38H26N4ؒ0.5CH2Cl2ؒ0.5CH3OH
requires C, 81.45; H, 4.94; N, 9.81%): mp 300 ЊC (CH2Cl2–
CH3OH); λmax(CH2Cl2)/nm 412 (log ε/dm3 molϪ1 cmϪ1 5.20),
508 (3.78), 543 (3.00), 584 (3.14), 638 (2.37); δH (250 MHz;
CDCl3; SiMe4) Ϫ3.05 (2 H, s, 2 × NH), 7.65–7.80, 8.15–8.35
(15 H, each m, HPh), 8.82–8.90 (4 H, m, 4 × Hβ-pyrrole), 9.05, 9.35
(4 H, each d, J 5.0, 8 × Hβ-pyrrole), 10.25 (1 H, s, Hmeso); m/z (EI,
80 eV): 538.2128 (Mϩ, 100%. C38H26N4 requires 538.2157), 461
(3, Mϩ Ϫ C6H5), 269 (16, M2ϩ).
(10-Isopropyl-5,15-diphenylporphyrinato)nickel(II)
26.
Chromatography eluting with ethyl acetate–n-hexane (1:100,
v/v); yield 30 mg (52%) purple crystals (Found: C, 75.16; H,
4.91; N, 9.74. C35H26N4Ni requires C, 74.89; H, 4.67; N, 9.98%):
mp 245 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 410 (log ε/dm3
molϪ1 cmϪ1 5.14), 527 (4.09), 558 (3.14); δH (250 MHz; CDCl3;
3
SiMe4) 2.30 (6 H, t, J 7.3, CH(CH3)2), 5.15 (1 H, q, J 7.3,
CH(CH3)2), 7.60–7.75, 7.85–8.05 (10 H, each m, HPh), 8.90
(4 H, d, J 4.8, 4 × Hβ-pyrrole), 9.05, 9.45 (4 H, each d, J 4.8,
4 × Hβ-pyrrole), 9.60 (1 H, s, Hmeso); m/z (EI, 80 eV): 560.1553
(Mϩ, 100%. C35H26N4Ni requires 560.1510), 545 (45, Mϩ Ϫ
CH3) 280 (6, M2ϩ).
5,15-Dibutyl-10-phenylporphyrin 22. Chromatography elut-
ing with ethyl acetate–n-hexane (1:150, v/v); yield 43 mg (74%)
purple crystals: mp 210 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm
413 (log ε/dm3 molϪ1 cmϪ1 5.36), 511 (4.19), 550 (3.88), 591
(3.69), 648 (3.56); δH (250 MHz; CDCl3; SiMe4) Ϫ2.75 (2 H,
10-(1-Methylpropyl)-5,15-diphenylporphyrin 27. Chromato-
graphy eluting with ethyl acetate–n-hexane (1:100, v/v); yield
8 mg (15%) purple crystals (Found: C, 82.18; H, 5.80; N, 10.04.
C36H30N4 requires C, 83.37; H, 5,83; N, 10.80%. C36H30N4ؒ
0.5H2O requires C, 81.94; H, 5.92; N, 10.62%): mp 270 ЊC
(CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 410 (log ε/dm3 molϪ1 cmϪ1
5.12), 448 (5.08), 524 (4.53), 558 (4.14), 598 (4.16), 664 (4.07);
3
s, 2 × NH), 1.10 (6 H, t, J 7.5, CH2CH2CH2CH3), 1.75–1.95
(4 H, m, CH2CH2CH2CH3), 2.45–2.65 (4 H, m, CH2CH2-
J. Chem. Soc., Perkin Trans. 1, 2000, 3615–3621
3619

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(5-Butyl-10,15,20-triphenylporphyrinato)nickel(II) 33. Chrom-
δH (250 MHz; CDCl3; SiMe4) Ϫ3.05 (2 H, s, 2 × NH), 1.15 (3 H,
3
3
t, J 7.3, CH(CH3)(CH2CH3)), 2.45 (3 H, d, J 7.4, CH(CH3)-
(CH2CH3)), 2.75–3.25 (2 H, m, CH(CH3)(CH2CH3)), 5.45–5.55
(1 H, m, CH(CH3)(CH2CH3)), 7.75–7.85, 8.15–8.35 (10 H, each
m, HPh), 8.90, 9.30, 9.65 (8 H, each d, J 4.8, 4 × Hβ-pyrrole), 10.20
(1 H, s, Hmeso); m/z (EI, 80 eV): 518.2454 (Mϩ, 100%. C36H30N4
requires 518.2470), 503 (4, Mϩ Ϫ CH3), 489 (62, Mϩ Ϫ CH2-
CH3), 259 (12, M2ϩ).
atography eluting with ethyl acetate–n-hexane (1:200, v/v);
yield 60 mg (93%) red–purple crystals (Found: C, 76.62; H,
4.98; N, 8.36. C42H32N4Ni requires C, 77.68; H, 4.66; N, 8.63%.
C42H32N4Niؒ0.5H2O requires C, 76.62; H, 4.75; N, 8.51%):
mp >300 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 415 (log
ε/dm3 molϪ1 cmϪ1 5.29), 529 (4.14), 556 (3.44); δH (250 MHz;
CDCl3; SiMe4) 1.05 (3 H, t, 3J 7.5, CH2CH2CH2CH3), 1.55–1.65
(2 H, m, CH2CH2CH2CH3), 2.25–2.40 (2 H, m, CH2CH2-
3
[10-(1-Methylpropyl)-5,15-diphenylporphyrinato]nickel(II) 28.
Chromatography eluting with ethyl acetate–n-hexane (1:100,
v/v); yield 37 mg (65%) purple crystals (Found: C, 73.92; H,
4.77; N, 9.19. C36H28N4Niؒ¹H2O requires C, 73.87; H, 5.17; N,
CH2CH3), 4.65 (2 H, t, J 7.5, CH2CH2CH2CH3), 7.55–7.70,
7.95–8.05 (15 H, each m, HPh), 8.65 (4 H, s, 4 × Hβ-pyrrole), 8.80,
9.35 (4 H, each d, J 4.8, 4 × Hβ-pyrrole); m/z (EI, 80 eV): 650.1946
(Mϩ, 100%. C42H32N4Ni requires 650.1980), 607 (94, Mϩ Ϫ
CH2CH2CH3), 325 (4, M2ϩ).
¯
²
9.57%): mp 220 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 410
(log ε/dm3 molϪ1 cmϪ1 5.24), 526 (4.15) 560 (3.29); δH (250
MHz; CDCl3; SiMe4) 0.85 (3 H, t, 3J 7.3, CH(CH3)(CH2CH3)),
2.35 (3 H, d, J 7.4, CH(CH3)(CH2CH3)), 2.55–2.80 (2 H, m,
CH(CH3)(CH2CH3)), 4.65–4.80 (1 H, m, CH(CH3)(CH2CH3)),
7.60–7.75, 7.85–8.05 (10 H, each m, HPh), 8.75–8.85 (4 H, m,
4 × Hβ-pyrrole), 9.05, 9.45 (4 H, each d, J 4.8, 4 × Hβ-pyrrole), 9.60
(1 H, s, Hmeso); m/z (EI, 80 eV): 574.1639 (Mϩ, 100%.
C36H26N4Ni requires 574.1667), 559 (4, Mϩ Ϫ CH3), 545 (63,
Mϩ Ϫ CH2CH3), 287 (5, M2ϩ).
[5-(1-Methylpropyl)-10,20-diphenyl-15-tert-butylporphyrin-
ato]nickel(II) 34. This compound was obtained from the reac-
tion of 29 with BusLi. Column chromatography on alumina
with hexane–ethyl acetate (100:1, v/v) gave 35 mg (55%) of
red–purple crystals after recrystallization (Found: C, 74.82; H,
5.56; N, 8.25. C40H36N4Ni requires C, 76.09; H, 5.75; N, 8.87%.
C40H36N4Niؒ0.5H2O requires C, 75.02; H, 5.82; N, 8.75%): mp
285 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 424 (log ε/dm3
molϪ1 cmϪ1 5.13), 551 (4.13), 580 (3.92); δH (250 MHz; CDCl3;
SiMe4) 0.85 (3 H, t, 3J 7.3, CHCH3CH2CH3), 2.15 (9 H,
s, C(CH3)3), 2.25 (3 H, d, 3J 7.4, CHCH3CH2CH3), 2.45–
2.70 (2 H, m, CHCH3CH2CH3), 4.5 (1 H, m, CHCH3CH2-
CH3), 7.65–7.75, 7.85–8.05 (10 H, each m, HPh), 8.50–8.65
(4 H, m, 4 × Hβ-pyrrole), 9.25, 9.45 (4 H, each d, 3J 4.8, 4 ×
(5,15-Diphenyl-10-tert-butylporphyrinato)nickel(II) 29. Purifi-
cation via column chromatography (hexane–ethyl acetate,
100:1, v/v) and recrystallization gave 30 mg bright purple crys-
tals in 53% yield (Found: C, 74.78; H, 4.65; N, 9.45. C36H28N4Ni
requires C, 75.16; H, 4.91; N, 9.74%): mp >300 ЊC (CH2Cl2–
CH3OH); λmax(CH2Cl2)/nm 418 (log ε/dm3 molϪ1 cmϪ1 5.17),
542 (4.05), 581 (3.25); δH (250 MHz; CDCl3; SiMe4) 2.15 (9 H, s,
C(CH3)3), 7.60–7.70, 7.80–7.95 (10 H, each m, HPh), 8.55–8.65
(4 H, m, 4 × Hβ-pyrrole), 8.95 (2 H, d, J 4.8, 2 × Hβ-pyrrole), 9.45–
9.55 (3 H, m, 2 × Hβ-pyrrole, Hmeso); m/z (EI, 80 eV) 574.1661
(Mϩ, 100%. C36H28N4Ni requires 574.1667), 559 (93, Mϩ Ϫ
CH3), 544 (9, Mϩ Ϫ 2CH3), 287 (5, M2ϩ).
H
β-pyrrole); m/z (EI, 80 eV) 630.2290 (Mϩ, 100%. C36H30N4
requires 630.2293), 615 (35, Mϩ Ϫ CH3), 601 (13, Mϩ Ϫ
CH2CH3), 315 (2, M2ϩ).
General procedure for directly linked bisporphyrins
The 5,15-disubstituted porphyrin (0.11 mmol) was dissolved in
20 ml dry THF and a solution of 0.2 ml 2 M organolithium
reagent (approx. 0.42 mmol) in cyclohexane was added at
Ϫ70 ЊC for BuLi and 0 ЊC for PhLi under stirring. After
complete addition the cold bath was removed and stirring
continued for an additional 15 min. Subsequently, a solution
of 95 mg DDQ (0.42 mmol) in 5 ml dry THF was added result-
ing in a color change from dark blue to dark brown. Stirring
was continued for 30 min, the solvent removed in vacuo, and
the residue purified by chromatography on neutral alumina
(Brockmann grade III) followed by recrystallization from
CH2Cl2–CH3OH.
15,15Ј-Bis(1-methylpropyl)-10,10Ј,20,20Ј-tetraphenyl-5,5Ј-
biporphyrin 30. This compound was obtained as one of the
products from the reaction of 19 with BusLi. Column chrom-
atography on alumina with hexane–ethyl acetate (100:1, v/v)
eluted first 27 and then 30. Final yield of 30 after recrystalliz-
ation was 15 mg (30%) of dark purple crystals (Found: C,
82.76; H, 5.38; N, 10.54. C72H58N8 requires C, 83.53; H, 5.65;
N, 10.82%. C72H58N8ؒ0.5H2O requires C, 82.81; H, 5.69; N,
10.73%): mp >300 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 406
(log ε/dm3 molϪ1 cmϪ1 5.42), 446 (4.52), 506 (4.01), 530 (3.43),
582 (3.15); δH (250 MHz; CDCl3; SiMe4) Ϫ2.25 (4 H, s.
4 × NH), 1.15 (6 H, t, 3J 7.3, 2 × CHCH3CH2CH3), 2.55 (6 H,
d, J 7.4, 2 × CHCH3CH2CH3), 2.75–3.25 (4 H, m, 2 × CHCH3-
CH2CH3), 5.40–5.55 (2 H, m, 2 × CHCH3CH2CH3), 7.60–7.75,
8.25–8.45 (20 H, each m, HPh), 8.05, 8.50, 8.95, 9.75 (16 H, each
d, 3J 4.8, 16 × Hβ-pyrrole); m/z (EI, 80 eV) 1034.4738 (Mϩ, 100%.
C72H68N8 requires 1034.4784), 1019 (10, Mϩ Ϫ CH3), 1005 (89,
Mϩ Ϫ CH2CH3), 517 (6, M2ϩ).
15,15Ј-Dibutyl-10,10Ј,20,20Ј-tetraphenyl-5,5Ј-biporphyrin 36.
Chromatography eluting with ethyl acetate–n-hexane (1:100,
v/v); yield 42 mg (75%) purple crystals (Found: C, 82.17; H,
5.94; N, 10.40. C72H58N8 requires C, 83.53; H, 5.65; N, 10.82%.
C72H58N8ؒ1H2O requires C, 82.10; H, 5.74; N, 10.64%): mp
>300 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 417 (log ε/dm3
molϪ1 cmϪ1 5.14), 448 (5.13), 523 (4.51), 561 (4.14), 597 (4.15),
664 (4.07); δH (250 MHz; CDCl3; SiMe4) Ϫ2.21 (4 H, s,
2 × NH), 1.23 (6 H, t, 3J 7.5, 2 × CH2CH2CH2CH3), 1.75–1.94
(4 H, m, 2 × CH2CH2CH2CH3), 2.45–2.65 (4 H, m, 2 × CH2-
CH2CH2CH3), 5.04 (4 H, t, 3J 7.9, 2 × CH2CH2CH2CH3), 7.64–
7.75 and 8.15–8.25 (20 H, each m, HPh), 7.95, 8.50, 8.95 and
9.65 (16 H, each d, J 4.9, 16 × Hβ-pyrrole); m/z (EI, 80 eV)
1034.4748 (Mϩ, 100%. C72H58N8 requires 1034.4784), 993 (21,
Mϩ Ϫ CH2CH2CH3), 517 (14, M2ϩ).
5-Butyl-10,15,20-triphenylporphyrin 32. Chromatography
eluting with ethyl acetate–n-hexane (1:200, v/v); yield 52 mg
(88%) purple crystals (Found: C, 79.49; H, 5.30; N, 8.80.
C42H34N4ؒ¹CH2Cl2 requires C, 80.11; H, 5.54; N, 8.79%):
¯
²
mp >300 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 417 (log ε/
dm3 molϪ1 cmϪ1 5.23), 515 (3.89), 551 (3.46), 593 (3.27), 648
(3.24); δH (250 MHz; CDCl3; SiMe4) Ϫ2.75 (2 H, s, NH), 1.10
(3 H, t, 3J 7.5, CH2CH2CH2CH3), 1.75–1.85 (2 H, m, CH2CH2-
CH2CH3), 2.45–2.60 (2 H, m, CH2CH2CH2CH3), 5.05 (2 H, t,
3J 7.5, CH2CH2CH2CH3), 7.60–7.75, 8.10–8.25 (10 H, each
m, HPh), 8.75 (4 H, s, 4 × Hβ-pyrrole), 8.90, 9.45 (4 H, each d,
J 4.9, 4 × Hβ-pyrrole); m/z (EI, 80 eV): 594.2743 (Mϩ, 100%.
C42H34N4 requires 594.2783), 551 (56, Mϩ Ϫ CH2CH2CH3),
297 (10, M2ϩ).
5,5Ј,10,10Ј,20,20Ј-Hexaphenyl-5,5Ј-biporphyrin 37. Chrom-
atography eluting with CH2Cl2–n-hexane (1:3, v/v); yield 46 mg
(79%) purple crystals (Found: C, 84.36; H, 4.49; N, 10.03.
C76H50N8 requires C, 82.06; H, 6.68; N, 11.26%. C76H50N8ؒ
¹CH3OH requires C, 84.20; H, 4.80; N, 10.27%): mp >300 ЊC
¯
²
(CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 415 (log ε/dm3 molϪ1 cmϪ1
3620
J. Chem. Soc., Perkin Trans. 1, 2000, 3615–3621

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4.99), 449 (5.04), 524 (4.39), 561 (3.81), 595 (3.89), 651 (2.53);
δH (250 MHz; CDCl3; SiMe4) Ϫ2.25 (4 H, s, 2 × NH), 7.65–
7.70, 7.75–7.82, 8.15–8.22, 8.35 (30 H, each m, HPh), 8.05, 8.60
(8 H, each d, J 4.4, 8 × Hβ-pyrrole), 8.80–8.95 (8 H, m, 8 ×
References
1 M. G. H. Vicente, in The Porphyrin Handbook, eds. K. M. Kadish
R. Guilard and K. M. Smith, Academic Press, New York, 2000,
vol. 1, p. 149; L. Jaquinod, in The Porphyrin Handbook, eds. K. M.
Kadish, R. Guilard and K. M. Smith, Academic Press, New York,
2000, vol. 1, p. 149; H. L. Anderson, Chem. Commun., 1999, 2323.
2 N. Risch, R. Gauler and R. Keuper, Tetrahedron Lett., 1999, 40,
2925; A. G. Hyslop, M. A. Kellet, P. M. Iovine and M. J. Therien,
J. Am. Chem. Soc., 1998, 120, 12676; X. A. Zhou, M. K. Tse,
T. S. M. Wan and K. S. Chan, J. Org. Chem., 1996, 61, 3590; R. W.
Wagner, T. E. Johnson, F. R. Li and J. S. Lindsey, J. Org. Chem.,
1995, 60, 5266; R. W. Boyle, C. K. Johnson and D. Dolphin,
J. Chem. Soc., Chem. Commun., 1995, 527.
3 Y. Deng, C. K. Chang and D. A. Nocera, Angew. Chem., Int. Ed.,
2000, 39, 1066; T. Ogawa, Y. Nishimoto, N. Yoshida, N. Ono and
A. Osuka, Angew. Chem., Int. Ed., 1999, 38, 176; A. Osuka and
H. Shimidzu, Angew. Chem., Int. Ed. Engl., 1997, 36, 135; R. G.
Khoury, L. Jaquinod and K. M. Smith, Chem. Commun., 1997,
1057; K. Susumu, T. Shimidzu, K. Tanaka and H. Segawa,
Tetrahedron Lett., 1996, 37, 8399.
H
β-pyrrole); m/z (EI, 80 eV): 1074.4158 (Mϩ, 100%. C76H50N8
requires 1074.4116), 537 (14, M2ϩ).
10,10Ј,20,20Ј-Tetrabutyl-15,15Ј-diphenyl-5,5Ј-biporphyrin 38.
Chromatography eluting with ethyl acetate–n-hexane (1:100,
v/v); yield 30 mg (55%) purple crystals (Found: C, 81.40; H,
6.66; N, 11.26. C68H66N8ؒ¹H2O requires C, 81.32; H, 6.72; N,
¯
²
11.16%): mp >300 ЊC (CH2Cl2–CH3OH); λmax(CH2Cl2)/nm 411
(log ε/dm3 molϪ1 cmϪ1 5.0), 451 (5.18), 526 (4.40), 562 (3.88),
6.01 (3.82), 660 (3.67); δH (250 MHz; CDCl3; SiMe4) Ϫ2.20
3
(4 H, s, 4 × NH), 1.05 (12 H, t, J 7.5, 4 × CH2CH2CH2CH3),
1.70–1.85 (8 H, m, 4 × CH2CH2CH2CH3), 2.35–2.65 (8 H, m,
4 × CH2CH2CH2CH3), 4.85 (8 H, t, 3J 8.1, 4 × CH2CH2-
CH2CH3), 7.75–7.80, 8.23–8.35 (10 H, each m, HPh), 8.02, 8.87,
9.23, 9.43 (16 H, each d, 3J 4.7, 16 × Hβ-pyrrole); m/z (EI, 80 eV):
994.5457 (Mϩ, 100%. C68H66N8 requires 994.5410).
4 M. O. Senge and X. Feng, Tetrahedron Lett., 1999, 40, 4165.
5 N. Aratani, A. Osuka, Y. H. Kim, D. H. Jeong and D. Kim, Angew.
Chem., Int. Ed., 2000, 39, 1458.
6 A. K. Burrell and M. R. Wasielewski, J. Porphyrins Phthalocyanines,
2000, 4, 401.
Crystal structure determinations
7 K. M. Kadish, R. Guilard and K. M. Smith (eds.), The Porphyrin
Handbook, Academic Press, New York, 2000, vol. 6.
8 (a) W. W. Kalisch and M. O. Senge, Angew. Chem., Int. Ed. Engl.,
1998, 38, 176; (b) M. O. Senge, W. W. Kalisch and I. Bischoff, Chem.
Eur. J., 2000, 6, 2721; (c) X. Feng and M. O. Senge, Tetrahedron,
2000, 56, 587.
9 (a) B. Krattinger and H. J. Callot, Tetrahedron Lett., 1996, 37, 7699;
(b) B. Krattinger and H. J. Callot, Tetrahedron Lett., 1998, 39, 1165;
B. Krattinger and H. J. Callot, Eur. J. Org. Chem., 1999, 1857.
10 J. S. Lindsey, in The Porphyrin Handbook, eds. K. M. Kadish,
R. Guilard and K. M. Smith, Academic Press, New York, 2000,
vol. 1, p. 45.
11 C. Brückner, J. J. Posakony, C. K. Johnson, R. W. Boyle, B. R. James
and D. Dolphin, J. Porphyrins Phthalocyanines, 1998, 2, 455.
12 J. Setsune, T. Yazawa, H. Ogoshi and Z. Yoshida, J. Chem. Soc.,
Perkin Trans. 1, 1980, 1641.
13 M. O. Senge, in The Porphyrin Handbook, eds. K. M. Kadish,
R. Guilard and K. M. Smith, Academic Press, New York, 2000,
vol. 1, p. 239.
14 D. P. Arnold, R. C. Bott, H. Eldridge, F. M. Elms, G. Smith and
M. Zojaji, Aust. J. Chem., 1997, 50, 495.
15 W. R. Scheidt and Y. J. Lee, Struct. Bonding (Berlin), 1987, 64, 1.
16 D. L. Cullen and E. F. Meyer, Jr., J. Am. Chem. Soc., 1974, 96, 2095.
17 M. O. Senge, I. Bischoff, N. Y. Nelson and K. M. Smith,
J. Porphyrins Phthalocyanines, 1999, 3, 99.
18 K. M. Barkigia, L. Chantranupong, K. M. Smith and J. Fajer,
J. Am. Chem. Soc., 1988, 110, 7566; M. O. Senge, M. W. Renner,
W. W. Kalisch and J. Fajer, J. Chem. Soc., Dalton Trans., 2000, 381.
19 M. O. Senge, C. J. Medforth, T. P. Forsyth, D. A. Lee, M. M.
Olmstead, W. Jentzen, R. K. Pandey, J. A. Shelnutt and K. M.
Smith, Inorg. Chem., 1997, 36, 1149.
Suitable single crystals were immersed in hydrocarbon oil
(Paraton N), a single crystal selected, mounted on a glass fiber
and placed in the low-temperature N2 stream.23 Intensity data
were collected at 130 K using a Siemens P4 diffractometer
equipped with a rotating anode and low temperature device
using Cu-Kα radiation (λ = 1.54178 Å). The intensities were
corrected for Lorentz, polarization and absorption effects
(XABS2);24 extinction effects were disregarded. The structures
were solved via Direct Methods using the SHELXS program.25
Refinements were carried out by full-matrix least squares on |F2|
using SHELXL-97.26
Crystal data for compound 25. C35H28N4, M = 504.61, mono-
clinic, a = 12.157(5), b = 18.255(10), c = 13.045(6) Å, β =
116.75(3)Њ, U = 2585(2) Å3 , T = 130 K, space group P21/n,
Z = 4, µ(Cu-Kα) = 0.597 mmϪ1, 3746 reflections measured,
3415 unique (Rint = 0.051), 2885 reflections with I > 2.0σ(I), 354
parameters, ∆/ρmax = 0.315 e ÅϪ3, R1 [I > 2σ(I)] = 0.0418, R1 (all
data) = 0.0514, wR2 (all data) = 0.1182.
Crystal data for compound 28. C36H28N4Ni, M = 575.33,
monoclinic, a = 12.738(6), b = 14.973(8), c = 28.374(15) Å,
β = 93.06(4)Њ, U = 5404(5) Å3 , T = 130 K, space group P21/n,
Z = 8 (2 indep. Molecules), µ(Cu-Kα) = 1.289 mmϪ1, 7578
reflections measured, 7123 unique (Rint = 0.091), 4789 reflec-
tions with I > 2.0σ(I), 570 parameters, ∆/ρmax = 0.940 e ÅϪ3, R1
[I > 2σ(I)] = 0.0786, R1 (all data) = 0.1170, wR2 (all data) =
0.2365. Disorder in the methyl-propyl side chain of one of the
two independent molecules. All phenyl rings were refined as
rigid hexagons with isotropic thermal parameters.
20 H.-D. Becker, J. Org. Chem., 1965, 30, 983; H.-D. Becker, J. Org.
Chem., 1965, 30, 989.
21 J.-H. Fuhrhop, E. Baumgarten and H. Bauer, J. Am. Chem. Soc.,
1981, 103, 5854; A. L. Balch, B. C. Noll, S. L. Phillips, S. M. Reid
and E. P. Zovinka, Inorg. Chem., 1993, 32, 4730; R. G. Khoury,
L. Jaquinod, D. J. Nurco, R, K. Pandey, M. O. Senge and K. M.
Smith, Angew. Chem., Int. Ed. Engl., 1996, 35, 2496; B. Krattinger,
D. J. Nurco and K. M. Smith, Chem. Commun., 1998, 757.
22 N. Yoshida, H. Shimidzu and A. Osuka, Chem. Lett., 1998, 55;
R. G. Khoury, L. Jaquionod and K. M. Smith, Chem. Commun.,
1997, 1057.
CCDC reference number 207/478. See http://www.rsc.org/
suppdata/p1/b0/b005411i/ for crystallographic files in .cif
format.
Acknowledgements
23 H. Hope, Progr. Inorg. Chem., 1994, 41, 1.
24 S. R. Parkin, B. Moezzi and H. Hope, J. Appl. Crystallogr., 1995, 28,
53.
25 G. M. Sheldrick, SHELXS-97, Program for Crystal Structure
Solution, Universität Göttingen, 1990.
26 G. M. Sheldrick, SHELXL-97, Program for Crystal Structure
Refinement, Universität Göttingen, 1997.
This work was generously supported by grants from the
Deutsche Forschungsgemeinschaft (Se543/2-5 and Heisenberg
Fellowship Se543/3-2) and the Fonds der Chemischen
Industrie. We are indebted to the Schering AG (Berlin) and
to the UC Davis crystallographic facility (M. M. Olmstead,
director) for their support.
J. Chem. Soc., Perkin Trans. 1, 2000, 3615–3621
3621