Cadmium(II) and Nickel(II) Complexes of Benziporphyrins
A R T I C L E S
Pyrrole-deuterated ligands 1-d6, 2-d6, and 3-d6 were obtained using
pyrrole-d5 (Aldrich, 98% D). The observed isotopic enrichment was
ca. 50-60% D only, a result of proton-deuteron exchange during
condensation.
C); 129.1 (6,21/11,16-m-Ph); 127.8 (6,21/11,16-m-Ph); 127.8 (6,21/
11,16-p-Ph); 127.5 (6,21/11,16-p-Ph); 117.4 (11,16-C); 82.8 (22-C).
Chlorocadmium(II) 11,16-Bis(4-nitrophenyl)-6,6,21,21-tetraphen-
1
yl-meta-benzi-6,21-porphodimethene (7-CdCl). H NMR (CDCl3,
Zinc(II) Insertion (General Procedure for 5-ZnCl, 6-ZnCl,
7-ZnCl). The respective benziporphyrin (1, 2, or 3, 20 mg) and
anhydrous zinc(II) chloride (molar excess) are added to acetonitrile
(15 mL) and refluxed under nitrogen for 15 min. The reaction mixture
is then cooled and diluted with water to remove excess ZnCl2. The
product is extracted with dichloromethane, and the extracts are dried
with anhydrous sodium sulfate and evaporated to dryness. The residue
contains practically pure chlorozinc complex.
298 K): 8.27, 8.25 (4H, 2 × ∼d, 11,16-m); 7.68, 7.55 (4H, 2 × ∼d,
3
11,16-o); 7.54, 7.40, 7.23 (AB2C: 3-H, 2,4-H, 22-H, JAB ) 8.1 Hz,
4JBC ) 2.0 Hz); 7.33-7.26 (6H, m, 6,21-m,p-Ph); 7.19-7.14 (6H, m,
6,21-o-Ph, 6,21-p-Ph′); 7.06 (4H, ∼t, 6,21-m-Ph′); 6.71 (4H, ∼d, 6,21-
3
4
o-Ph′); 6.47, 6.12 (AB: 9,18-H, 8,19-H, JAB ) 4.7 Hz, JCdH ) 3.2
Hz, 4.6 Hz), 6.18 (2H, s, 13,14-H, 4JCdH ) 4.4 Hz). 13C NMR (CDCl3,
298 K): 176.5 (7,20-C); 150.3 (12,15-C); 148.0 (11,16-p); 145.9 (10,17-
C); 145.5 (11,16-i); 145.1 (1,5-C); 143.7 (6,21-i-Ph′); 142.4 (11,16-
C); 142.1 (6,21-i-Ph); 136.4 (9,18-C); 132.7 (3-C); 131.8, 131.6 (11,16-
o); 130.9 (6,21-o-Ph); 130.6 (2,4-C); 129.8 (6,21-o-Ph′); 128.3 (8,19-
C); 128.3 (6,21-m-Ph′); 128.3 (13,14-C); 128.3 (6,21-m-Ph); 127.7
(6,21-p-Ph); 126.8 (6,21-p-Ph′); 126.5 (22-C); 122.8, 122.5 (11,16-
m); 63.6 (6,21-C).
Chlorozinc(II) 6,11,16,21-Tetraphenyl-m-benziporphyrin (5-
ZnCl). 1H NMR (CDCl3, 298 K): 7.55-7.40 (m, 6,11,16,21-Ph); 7.65,
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7.12, 5.51 (AB2C: 3-H, 2,4-H, 22-H, JAB ) 7.8 Hz, JBC ) 1.7 Hz);
7.50, 6.83 (AB: 8,19-H, 9,18-H J ) 5.1 Hz), 6.99 (s, 13,14-H). 13C
3
NMR (CDCl3, 298 K): 170.5 (10,17-C); 161.0 (12,15-C); 153.4 (7,20-
C); 141.9 (6,21-C); 141.8 (6,21/11,16-i-Ph); 139.6 (6,21/11,16-i-Ph);
139.4 (1,5-C); 136.3 (8,19-C); 134.0 (13,14-C); 133.6 (6,21/11,16-o-
Ph); 132.9 (3-C); 132.5 (6,21/11,16-o-Ph); 131.9 (2,4-C); 131.8 (9,18-
C); 129.0 (6,21/11,16-m-Ph); 127.8 (6,21/11,16-m-Ph); 127.6 (6,21/
11,16-p-Ph); 127.5 (6,21/11,16-p-Ph); 116.6 (11,16-C); 85.8 (22-C).
HRMS (ESI, m/z): 688.1754 (688.1726 for C46H30N3Zn+).
6,11,16,21-Tetraphenyl-m-benziporphyrin, Mercury Complexes
(5-HgCl, 5-HgOAc, 5-HgOOCCF3). These complexes are gener-
ated in situ by shaking a chloroform solution of 1 with an appropriate
Hg(II) salt (HgCl2, Hg(OAc)2, Hg(OOCCF3)2) or by titrating with a
MeCN solution of the same Hg(II) salt. Progress of the reaction can
be monitored by means of NMR or UV-vis spectroscopy. Complexes
1
5-HgX have limited stability and tend to hydrolyze. H NMR (5-
Chlorozinc(II) 5,10,15,20-Tetraphenyl-p-benziporphyrin (6-
ZnCl). 1H NMR (CDCl3, 298 K): 8.66, 8.31 (AB: 7,18-H, 8,17-H, 3J
) 4.8 Hz); 8.38, 1.33 (AA′BB′: 2,3-H, 21,22-H, 3JAA′ ≈ 7.5 Hz, 4JAB
≈ 2.0 Hz); 8.14 (b, 4H, 5,20-o-Ph); 8.27 (s, 2H, 12,13-H); 8.10, 7.87
(2 × m, 4H, 10,15-o-Ph); 7.74 (∼t, 4H, 5,20-m-Ph); 7.70-7.69 (m,
8-H, 5,20-p-Ph, 10,15-m,p-Ph). 13C NMR (CDCl3, 298 K): 158.8 (9,16-
C); 155.8 (1,4-C); 155.1 (6,19-C); 154.4 (11,14-C); 144.3 (5,20-C);
142.3 (10,15-i-Ph); 140.2 (5,20-i-Ph); 136.5 (5,20-o-Ph); 134.9 (7,18-
C); 134.7 (8,17-C); 134.6 (10,15-o-Ph); 134.0 (12,13-C); 133.4 (10,-
15-o-Ph); 133.1 (21,22-C); 131.1 (2,3-C); 128.8 (m/p-Ph); 128.3 (m/
p-Ph); 128.3 (m/p-Ph); 127.6 (m/p-Ph); 126.9 (m/p-Ph); 126.7 (m/p-
Ph); 119.7 (10,15-C). UV-vis (CH2Cl2, λmax [nm] (log ꢀ)): 332 (4.29),
444 (4.85), 457 (4.86), 636 (4.28), 669 (4.36). HRMS (ESI, m/z):
688.1757 (688.1726 for C46H30N3Zn+).
HgCl, CDCl3, 298 K): 7.51-7.40 (m, 6,11,16,21-Ph); 7.62, 7.17, 5.80
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4
(AB2C: 3-H, 2,4-H, 22-H, JAB ) 7.7 Hz, JBC ) 1.7 Hz); 7.44, 6.70
(AB: 8,19-H, 9,18-H, 3J ) 4.9 Hz), 7.06 (s, 13,14-H). 13C NMR (5-
HgCl, CDCl3, 298 K): 171.4 (10,17-C); 163.1 (12,15-C); 153.6 (7,20-
C); 142.1 (6,21/11,16-i-Ph); 141.0 (6,21-C); 139.9 (6,21/11,16-i-Ph);
138.3 (1,5-C); 136.2 (8,19-C); 134.5 (13,14-C); 133.5 (6,21/11,16-o-
Ph); 133.0 (3-C); 132.5 (9,18-C); 132.5 (6,21/11,16-o-Ph); 132.3 (2,4-
C); 129.0 (6,21/11,16-m-Ph); 127.9 (6,21/11,16-m-Ph); 127.6 (6,21/
11,16-p-Ph); 127.5 (6,21/11,16-i-Ph); 117.5 (11,16-C); 89.2 (22-C).
UV-vis (5-HgOAc, CH2Cl2, λmax [nm] (log ꢀ)): 321 (4.46); 433
(4.74); 868 (4.21). MS (ESI, m/z): 824.0 (824.2 for C46H30N3200Hg+).
Nickel(II) 6,11,16,21-Tetraphenyl-m-benziporphyrin (8-Ni). Ben-
ziporphyrin (1, 15 mg) and NiCl2 (5 mg, 1.6 equiv) are added to dry
MeCN (20 mL) and refluxed for 4 h (reaction time can be shortened
by adding a small amount of anhydrous K2CO3). The mixture is
evaporated, yielding a solid residue, which is redissolved in a small
volume of CH2Cl2 and evaporated again (this step is repeated up to
three times to remove traces of MeCN). The product is finally dissolved
in CH2Cl2 and filtered through a Teflon disk. One crystallization
(CH2Cl2/MeOH) affords analytically pure 8-Ni. Yield: 10 mg (60%).
Chlorozinc(II) 11,16-Bis(4-nitrophenyl)-6,6,21,21-tetraphenyl-
meta-benzi-6,21-porphodimethene (7-ZnCl). 1H NMR (CDCl3, 298
K): 8.26 (4H, m, 11,16-m); 7.65, 7.58 (4H, 2 × b, 11,16-o); 7.45,
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7.34, 7.28 (ABC2: 3-H, 22-H, 2,4-H, JAC ) 8.1 Hz, JBC ≈ 1.8 Hz);
7.31-6.25 (10H, m, 6,21-o,m,p-Ph); 7.17, 7.07, 6.75 (AB2C2, 6,21-p-
3
3
Ph′, 6,21-m-Ph′, 6,21-o-Ph′, JAB ≈ JBC ≈ 7.5 Hz); 6.51, 6.22 (AB:
3
9,18-H, 8,19-H JAB ) 4.8 Hz); 6.16 (2H, s, 13,14-H). 13C NMR
3
1H NMR (CDCl3, 298 K): 7.81, 7.10 (A2B: 2,4-H, 3-H, JAB ) 7.6
(CDCl3, 298 K): 178.0 (7,20-C); 148.8 (12,15-C); 148.0 (11,16-p);
146.1 (10,17-C); 145.0 (1,5-C); 144.9 (11,16-i); 144.8 (6,21-i-Ph′);
142.4 (6,21-i-Ph); 141.3 (11,16-C); 136.3 (8,19/9,18-C); 132.0 (3-C);
131.8, 131.5 (11,16-o); 131.1 (6,21-o-Ph); 129.7 (6,21-o-Ph′); 129.3
(2,4-C); 128.4 (6,21-m-Ph′); 128.3 (8,19/9,18-C); 128.2 (6,21-m-Ph);
128.1 (22-C); 127.6 (6,21-p-Ph); 127.4 (13,14-C); 126.6 (6,21-p-Ph′);
122.8 (11,16-m); 63.5 (6,21-C).
Hz); 7.55-7.38 (m, 24H, 6,11,16,21-Ph); 7.31 (s, 2H, 13,14-H); 7.14,
6.87 (AB: 8,19-H, 9,18-H, 3JAB ) 5.2 Hz). 13C NMR (CDCl3, 298 K):
159.2 (10,17-C); 151.6 (12,15-C); 149.1 (22-C); 146.7 (7,20-C); 142.8
(2,4-C); 140.8 (6,21-i-Ph); 138.8 (11,16-i-Ph); 137.7 (1,5-C); 135.8
(8,19-C); 133.6 (13,14-C); 132.2, 132.1 (6,21/11,16-o-Ph); 129.9 (9,18-
C); 127.6 (×2, 6,21-m-Ph, 11,16-m-Ph); 126.6 ( × 2, 6,21-o-Ph, 11,16-
o-Ph); 124.9 (3-C); 117.2 (11,16-C). UV-vis (CH2Cl2, λmax [nm] (log
ꢀ)): 364 (4.48), 435 (4.57), 695 (3.68), 816 (3.61), 912 (3.53). HRMS
(ESI, m/z): 682.1809 (682.1788 for C46H29N358Ni + H+)
Chloronickel(II) 22-H-6,11,16,21-tetraphenyl-m-benziporphyrin
(5-NiCl) is obtained quantitatively by flushing a CHCl3 solution of
the diamagnetic 8-Ni with gaseous HCl. UV-vis (CH2Cl2, λmax [nm]
(log ꢀ)): 316 (4.48), 429 (4.70), 806 (4.17).
Cadmium(II) Insertion (General Procedure for 5-CdCl and
7-CdCl). A benziporphyrin (1 or 3, 2-20 mg) and anhydrous CdCl2
(molar excess) are refluxed in CHCl3/MeCN (10 mL + 10 mL, up to
2 h, depending on the ligand). The reaction can be monitored by means
of UV-vis spectroscopy. The reaction mixture is then filtered and
evaporated to dryness, yielding quantitatively the pure Cd complex.
Chlorocadmium(II) 6,11,16,21-Tetraphenyl-m-benziporphyrin
(5-CdCl). 1H NMR (CDCl3, 298 K): 7.53-7.40 (m, 6,11,16,21-Ph);
7.71, 7.26, 5.46 (AB2C: 3-H, 2,4-H, 22-H, 4JAC ) 1.7 Hz, 3JAB ) 7.8
Hz); 7.49, 6.79 (AB: 8,19-H, 9,18-H, 3J ) 5.0 Hz), 7.02 (s, 13,14-H).
13C NMR (CDCl3, 298 K): 170.8 (10,17-C); 163.1 (12,15-C); 153.5
(7,20-C); 141.8 (i-Ph/6,21-C); 140.0 (i-Ph/6,21-C); 139.6 (1,5-C); 139.5
(i-Ph/6,21-C); 135.6 (8,19-C); 134.8 (13,14-C); 133.9 (3-C); 133.4
(9,18-C); 133.4 (6,21/11,16-o-Ph); 132.6 (6,21/11,16-o-Ph); 131.8 (2,4-
Chloronickel(II) 5,10,15,20-Tetraphenyl-p-benziporphyrin (6-
NiCl). p-Benziporphyrin (2, 5 mg) and NiCl2 (5 mg) are refluxed in a
CHCl3/MeCN mixture for 6 h (progress of the reaction can be monitored
with UV-vis spectroscopy). The solution is evaporated, and the
remaining MeCN was removed by adding small portions of CH2Cl2 to
the residue and evaporating to dryness. The resulting solid is dissolved
in a small volume of CH2Cl2, filtered, and evaporated again. The product
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J. AM. CHEM. SOC. VOL. 126, NO. 14, 2004 4579