Metal complexes of N-tosylamidoporphyrin: cis-Acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III) and trans-acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III)

Article abstract of DOI:10.1021/ic9911318

The crystal structures of acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III), Tl(N-NTs-tpp)(OAc) (1), and acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III), Ga(N-NTs-tpp)(OAc) (2), were determined. The coordination sphere around the Tl³⁺ ion is a distorted square-based pyramid in which the apical site is occupied by a chelating bidentate OAc^- group, whereas for the Ga³⁺ ion, it is a distorted trigonal bipyramid with O(3), N(3), and N(5) lying in the equatorial plane. The porphyrin ring in the two complexes is distorted to a large extent. For the Tl³⁺ complex, the pyrrole ring bonded to the NTs ligand lies in a plane with a dihedral angle of 50.8°with respect to the 3N plane, which contains the three pyrrole nitrogens bonded to Tl³⁺, but for the Ga³⁺ complex, this angle is found to be only 24.5°. In the former complex, T1³⁺ and N(5) are located on the same side at 1.18 and 1.29 A from its 3N plane, but in the latter one, Ga³⁺ and N(5) are located on different sides at -0.15 and 1.31 A from its 3N plane. The free energy of activation at the coalescence temperature T(c) for the intermolecular acetate exchange process in 1 in CD₂Cl₂ solvent is found to be ΔG((+))₁₇₁ = 36.0 kJ/mol through ¹H NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl (CO) carbons of the OAc^- group in 1 are separately located at δ 18.5 [³J(Tl-(13)C) = 220 Hz] and 176.3 [²J(Tl-¹³C) = 205 Hz] at -110 °C.

Full text of DOI:10.1021/ic9911318

1106
Inorg. Chem. 2000, 39, 1106-1112
Metal Complexes of N-Tosylamidoporphyrin:
cis-Acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III) and
trans-Acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III)
Jo-Yu Tung, Jyh-Iuan Jang, Chu-Chieh Lin, and Jyh-Horung Chen*
Department of Chemistry, National Chung-Hsing University, Taichung 40227, Taiwan, R.O.C
Lian-Pin Hwang
Department of Chemistry, National Taiwan University and Institute of Atomic and Molecular Sciences,
Academia Sinica, Taipei 10764, Taiwan, R.O.C
ReceiVed September 22, 1999
The crystal structures of acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III), Tl(N-NTs-tpp)(OAc)
(1), and acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III), Ga(N-NTs-tpp)(OAc) (2), were deter-
mined. The coordination sphere around the Tl3+ ion is a distorted square-based pyramid in which the apical site
is occupied by a chelating bidentate OAc- group, whereas for the Ga3+ ion, it is a distorted trigonal bipyramid
with O(3), N(3), and N(5) lying in the equatorial plane. The porphyrin ring in the two complexes is distorted to
a large extent. For the Tl3+ complex, the pyrrole ring bonded to the NTs ligand lies in a plane with a dihedral
angle of 50.8° with respect to the 3N plane, which contains the three pyrrole nitrogens bonded to Tl3+, but for
the Ga3+ complex, this angle is found to be only 24.5°. In the former complex, Tl3+ and N(5) are located on the
same side at 1.18 and 1.29 Å from its 3N plane, but in the latter one, Ga3+ and N(5) are located on different sides
at -0.15 and 1.31 Å from its 3N plane. The free energy of activation at the coalescence temperature Tc for the
intermolecular acetate exchange process in 1 in CD2Cl2 solvent is found to be ∆Gq171 ) 36.0 kJ/mol through 1H
NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl (CO) carbons
of the OAc- group in 1 are separately located at δ 18.5 [3J(Tl-13C) ) 220 Hz] and 176.3 [2J(Tl-13C) ) 205 Hz]
at -110 °C.
Introduction
N-tosylimido-meso-tetraphenylporphyrinatonickel(II) [Ni(N-
NTs-tpp)] (NTs ) tosylimido)3 and chloro-N-tosylimido-
meso-tetraphenylporphyrinatoiron(III), Fe(N-NTs-tpp)Cl (or
Fe(TPP)(NTs)(Cl), bridged).7 The nickel in Ni(N-NTs-tpp)
is tetracoordinated to three pyrrole nitrogens and one extra
nitrogen atom from the nitrene fragment. The four pyrrole
nitrogens are approximately coplanar. The nickel atom lies out
of this four-nitrogen mean plane (4N) by 0.21 Å, and the extra
nitrogen is also in the same direction with a distance of 0.94
Å. The porphyrin macrocyclic is distorted because of the nitrene
insertion and because the perturbed pyrrole ring is oriented at
a very large dihedral angle of 40.5° with respect to the 4N plane;
the other three pyrroles are oriented at quite smaller angles of
1.8°, 4.4°, and 9.4°.3
Metalloporphyrins with a bridged structure between the
central metal and one of the four pyrrole nitrogens have drawn
much attention because it was proposed that the highly oxidized
form of some hemoproteins may contain a ferric porphyrin with
an oxygen atom inserted into an N-Fe bond.1,2 Only bridged
metalloporphyrins with metal-N-N linkages (metal ) Zn, Ni,
Fe, Hg)3-8 have so far been reported. Callot3 and Mahy7 de-
scribed the X-ray structure investigation of the metalation of
N-tosylamido-meso-tetraphenylporphyrin [N-NHTs-Htpp]
(NHTs ) tosylamido, tpp ) dianion of meso-tetraphenyl-
porphyrin, Ts ) tosyl)9 leading to mononuclear complexes of
* To whom correspondence should be addressed.
(1) Chevrier, B.; Lange, M.; Chottard, J. C.; Mansuy, D. J. Am. Chem.
Soc. 1981, 103, 2899.
(2) Setsune, J.; Ikeda, M.; Kishimoto, Y.; Ishimaru, Y.; Fukuhara, K.;
Kitao, T. Organometallics 1991, 10, 1099.
(3) Callot, H. J.; Chevrier, B.; Weiss, R. J. Am. Chem. Soc. 1978, 100,
4733.
(4) Callot, H. J. Tetrahedron 1979, 35, 1455.
(5) Ichimura, K. Bull. Chem. Soc. Jpn. 1978, 51, 1444.
(6) Mahy, J. P.; Battioni, P.; Mansuy, D. J. Am. Chem. Soc. 1986, 108,
1079.
(7) Mahy, J. P.; Battioni, P.; Bedi, G.; Mansuy, D.; Fishcher, J.; Weiss,
R.; Morgenstern-Badarau, I. Inorg. Chem. 1988, 27, 353.
(8) Callot, H. J.; Chevrier, B.; Weiss, R. J. Am. Chem. Soc. 1979, 101,
7729.
(9) Au, S. M.; Fung, W. H.; Cheng, M. C.; Che, C. M.; Peng, S. M. J.
Chem. Soc., Chem. Commun. 1997, 1655.
The iron atom in Fe(N-NTs-tpp)Cl is pentacoordinated, and
its coordination geometry is a distorted trigonal bipyramid with
an equatorial plane containing three different atoms, Cl, N(Ts),
and one pyrrole nitrogen. The porphyrin ring is also severely
distorted as the pyrrole ring bonded to the NTs ligand orients
in a dihedral angle of 29.9° with the 3N plane, which contains
the three pyrrole nitrogens bonded to the iron.7
However, until now there are no X-ray structural data
available for the diamagnetic metal ion (M(III)) complexes
of N-NHTs-Htpp with coordination number (CN) above 4
(i.e., with CN g 5). In this paper, we present the results
with the replacement of Ni(II) and Fe(III) with Ga(III) and
Tl(III), respectively. This replacement causes the coordination
10.1021/ic9911318 CCC: $19.00 © 2000 American Chemical Society
Published on Web 02/25/2000

Complexes of N-Tosylamidoporphyrin
Inorganic Chemistry, Vol. 39, No. 6, 2000 1107
number to increase from 4 for NiII(N-NTs-tpp)3 to 5
for trans-acetato-N-tosylimido-meso-tetraphenylporphyrinato-
gallium(III) Ga(N-NTs-tpp)(OAc) (2) and from 5 for coor-
dinated complex Fe(N-NTs-tpp)Cl7 to 6 for cis-acetato-N-
tosylimido-meso-tetraphenylporphyrinatothallium(III) Tl(N-
NTs-tpp)(OAc) (1). It is noted that the ionic radius increases
from 0.69 Å for both Ni2+ and Ga3+ to 0.72 Å for Fe3+ and
150.87) MHz, respectively, on a Varian VXR-300 Bruker AM-400, or
Varian Unity Inova-600 spectrometer. The temperature of the spec-
trometer probe was calibrated by the shift difference of methanol
resonance in the 1H NMR spectrum. 1H-13C COSY was used to
correlate protons and carbon through one-bond coupling and HMBC
(heteronuclear multiple bond coherence) for two- and three-bond
proton-carbon coupling.
The positive-ion fast atom bombardment mass spectrum (FAB MS)
was obtained in a nitrobenzyl alcohol (NBA) matrix using a JEOL
JMS-SX/SX 102A mass spectrometer.
Crystallography. Table 3 presents the crystal data as well as other
information for Tl(N-NTs-tpp)(OAc) (1) and Ga(N-NTs-tpp)(OAc)
(2). Measurements were taken on a Siemens R 3m/V diffractometer
for 1 and on a Siemens SMART CCD diffractometer for 2 using
monochromatized Mo KR radiation (λ ) 0.710 73 Å). Empirical
absorption corrections were made for 2. The structures were solved by
direct methods (SHELXTL IRIS for 1 and SHELXTL PLUS for 2)
and refined by the full-matrix least-squares method. All non-hydrogen
atoms were refined with anisotropic thermal parameters, whereas all
hydrogen atom positions were calculated using a riding model and were
included in the structure factor calculation. Table 4 lists selected bond
distances and angles for both complexes.
1.025 Å for Tl3+ 10 The relative positions of the OAc- and
.
N-tosyl groups coordinated to the metal atom lead to a cis
configuration in 1 and a trans configuration in 2 that might
depend on the ionic radius of the Tl3+ and Ga3+. According to
our previous report,11 the 13C chemical shift of the carbonyl
carbon of the acetato group in the diamagnetic complexes of
M(por)(OAc)n could indicate the axial binding mode. In
addition, the 13C chemical shift of the â-pyrrole carbon (Câ)
provides a complementary method for investigating the distor-
tion of the N-pyrrole ring via the insertion of the nitrene moiety
into the Tl‚‚‚‚N bond in complex 1 and Ga‚‚‚‚N bond in complex
2. This paper reports (i) an X-ray structure determination that
clearly establishes the TlIII-NTs-N structure for the Tl(N-
NTs-tpp)(OAc) complex and the GaIII-NTs-N structure for
the Ga(N-NTs-tpp)(OAc) complex and (ii) the 13C chemical
shifts of the carbonyl carbon and the â-pyrrole carbon for further
demonstration of the carboxylate coordination and the porphyrin
Results and Discussion
Molecular Structures of 1 and 2. The skeletal frameworks
are illustrated in Figure 1a for the complex Tl(N-NTs-tpp)-
(OAc)‚0.75CHCl3 with P21/c symmetry and in Figure 1b
for Ga(N-NTs-tpp)(OAc) (2) with P1h symmetry. Their
structures are a six-coordinate thallium and a five-coordinate
gallium, having three nitrogen atoms of the porphyrins and one
extra nitrogen atom of the nitrene fragment in common, but
they are different with a chelating bidentate OAc- ligand
for 1‚0.75CHCl3 and a monodentate OAc- ligand for 2. In
compounds 1 and 2 it appears that the N-tosyl moiety is inserted
into Tl-N and Ga-N bonds of acetato(meso-tetraphenyl-
porphyrinato)thallium(III), Tl(tpp)(OAc),11-13 and acetato(meso-
tetraphenylporphyrinato)gallium(III), Ga(tpp)(OAc).11,14 The
unusual bond distances from Tl(III) and Ga(III) atoms to the
ligand and the angles are summarized in Table 2. Bond distances
(Å) are Tl-N(1) ) 2.347(7), Tl-N(2) ) 2.152(7), Tl-N(3) )
2.361(7), Tl-N(5) ) 2.103(7), Tl-O(1) ) 2.401(8), Tl-O(2)
) 2.292(9), O(1)-C(21) ) 1.22(2), O(2)-C(21) ) 1.19(2), and
C(21)-C(22) ) 1.50(2) Å for 1‚0.75CHCl3; they are Ga(1)-
N(2) ) 2.031(3), Ga(1)-N(3) ) 1.911(3), Ga(1)-N(4) )
2.031(3), Ga(1)-N(5) ) 1.946(3), Ga(1)-O(3) ) 1.868(3),
O(3)-C(52) ) 1.260(5), O(4)-C(52) ) 1.218(5), and C(52)-
C(53) ) 1.515(6) Å for 2.
The geometry around Tl is a distorted square-based pyramid
in which the apical site is occupied by a chelating bidentate
OAc- group, whereas that around the Ga3+ is described as a
distorted trigonal bipyramid with O(3), N(3), and N(5) lying in
the equatorial plane. The distance between Ga(1) and O(4) is
2.865 Å. The pyrrole nitrogens N(4) and N(1) are no longer
bonded to the thallium and gallium as indicated by their longer
internuclear distances, 2.944 Å for Tl‚‚‚N(4) and 2.641 Å for
Ga(1)‚‚‚N(1). The Tl-N(2) bond trans to the N(5) position in
compound 1 is somewhat shorter than the other two Tl-N bond
distances (i.e., 2.152(7) Å for Tl-N(2) compared to 2.347(7)
Å for Tl-N(1) and 2.361(7) Å for Tl-N(3)). Likewise, the
Ga(1)-N(3) bond in compound 2 is slightly shorter than the
macrocycle distortion, respectively. In addition, the 1H and 13
C
NMR spectra of 1 in CD2Cl2 at low temperature are used to
investigate the intermolecular apical ligand (OAc-) exchange
process and in turn to determine the free energy of activation
at the coalescence temperature, ∆GqTc, for the exchange process.
Experimental Section
Preparation of Tl(N-NTs-tpp)(OAc) (1). Compound N-tosyl-
amido-meso-tetraphenylporphyrin [N-NHTs-Htpp] was prepared as
described in the literature.3 To a solution of Tl(OAc)3 (45 mg, 0.118
mmol) and NaOAc (10 mg, 0.122 mmol) in CH3OH (5 cm3) was added
N-NHTs-Htpp (100 mg, 0.118 mmol) in CHCl3 (20 cm3), and the
resulting solution was refluxed for 30 min. After the solution was
concentrated, it was dissolved in CHCl3 and collected by filtration.
Recrystallization from CHCl3/MeOH afforded 1 as a purple solid (110
mg, 0.105 mmol, 87.5%). Compound 1 was dissolved in CHCl3 and
layered with MeOH. The purple and parallelpiped shape crystals of 1
were obtained for single-crystal X-ray analysis. Tables 1 and 2
summarize the 1H and 13C NMR data. MS, m/z (assignment, rel
intensity): 1045 ([Tl(N-NTs-tpp)(OAc)]+, 27.70), 986 ([Tl(N-NTs-
tpp)]+, 31.23), 831 ([Tl(tpp) + N + H ]+, 69.66), 817 ([Tl(tpp) + H]+,
72.23), 614 (Htpp+, 50.68), 205 (205Tl+, 100), 203 (203Tl+, 85.78). UV/
visible spectrum, λ (nm) (ꢀ × 10-3 (M-1 cm-1)) in CHCl3: 446 (22.5),
558 (0.3), 602 (0.9).
Preparation of Ga(N-NTs-tpp)(OAc) (2). Free base N-NHTs-
Htpp (150 mg) and Ga2O3 (200 mg) were refluxed for 1 h in 30 cm3
of acetic acid containing sodium acetate (150 mg). After removal of
the solvent (HOAc) under reduced pressure, the residue was dissolved
in CHCl3 and then dried over Na2SO4. After filtration, the filtrate was
rotavaped, and recrystallization from CHCl3/n-hexane [1:6 (v/v)]
afforded a purple solid of 2 (139.35 mg, 0.148 mmol, 86%). The crystals
were grown by diffusion of ether vapor into a CHCl3 solution. Tables
1
1 and 2 summarize the H and 13C NMR data. MS, m/z (assignment,
rel intensity): 850 ([Ga(N-NTs-tpp)-H]+, 21.90), 696 ([Ga(tpp) +
N]+, 29.08), 681 ([Ga(tpp)]+, 100), 605 ([Ga(tpp) - C6H5 + H]+,
22.63). UV/visible spectrum, λ (nm) (ꢀ × 10-3 (M-1 cm-1)) in CHCl3:
436 (377), 544 (9.5), 587 (15.1), 635 (3.0).
Spectroscopy. Proton and 13C NMR spectra were recorded using
CDCl3 or CD2Cl2 at 300.00 (400.13 or 599.95) and 75.43 (100.61 or
(12) Chen, J. C.; Jang, H. S.; Chen, J. H.; Hwang, L. P. Polyhedron 1991,
10, 2069.
(10) Huheey, J. E.; Keiter, E. A.; Keiter, R. L. Inorganic Chemistry, 4th
ed.; Harper Collins College: New York, 1993; p 114.
(11) Lin, S. J.; Hong, T. N.; Tung, J. Y.; Chen, J. H. Inorg. Chem. 1997,
36, 3886.
(13) Suen, S. C.; Lee, W. B.; Hong, F. E.; Jong, T. T.; Chen, J. H.; Hwang,
L. P. Polyhedron 1992, 11, 3025.
(14) Hsieh, Y. Y.; Sheu, Y. H.; Liu, I. C.; Lin, C. C.; Chen, J. H.; Wang,
S. S.; Lin, H. J. J. Chem. Crystallogr. 1996, 26, 203.

Table 1. 1H NMR Data for Compounds 1, 2, N-NHTs-Htpp, and Ni(N-NTs-tpp)3 in CDCl3 at 24 °Ca
compounds
Hâ
Hâ
Hâ
φ-H
Hâ
7.90
s
tosyl-H3,5
tosyl-H2,6
tosyl-CH3
OAc
N-NHTs-Htpp
9.01
8.93
8.79
s
8.42-7.75
6.43
4.90
2.12
s
(d,3J(H-H) ) 5.2 Hz)
(d, 3J(H-H) ) 4.4 Hz)
m
(d, 3J(H-H) ) 8.0 Hz)
(d, 3J(H-H) ) 8.0 Hz)
1
9.13
Hâ(3,12)
8.98
Hâ(2,13)
8.75
8.49-7.76
m
6.99
Hâ(17,18)
s
6.96
6.26
2.31
s
0.67
s
(d, 3J(H-H) ) 7.5 Hz)
(d, 3J(H-H) ) 7.5 Hz)
b
Hâ(7,8)
(dd, 4J(Tl-H) ) 18 Hz
3J(H-H) ) 4.5 Hz)
(dd, 4J(Tl-H) ) 10 Hz
3J(H-H) ) 4.5 Hz)
(d, 4J(Tl-H) ) 75.6 Hz)
2
9.29
Hâ(9.10)
s
8.86
8.81
8.37-7.76
m
7.81
Hâ(19,20)
s
6.47
4.80
2.11
s
-1.21
s
Hâ(4,15)
Hâ(5,14)
(d, 3J(H-H) ) 7.8 Hz)
(d, 3J(H-H) ) 7.8 Hz)
(d, 3J(H-H) ) 4.8 Hz)
(d, 3J(H-H) ) 4.8 Hz)
Ni(N-NTs-tpp)
8.74
s
8.72
8.65
8.35-7.65
m
7.31
s
6.55
5.38
2.14
s
(d, 3J(H-H) ) 4.5 Hz)
(d, 3J(H-H) ) 4.5 Hz)
(d, 3J(H-H) ) 8.0 Hz)
(d, 3J(H-H) ) 8.0 Hz)
a Chemical shifts in ppm relative to CDCl3 at 7.24 ppm. s ) singlet, d ) doublet, m ) multiplet, and dd ) doublet of doublet. b Hâ(a,b) represents the two equivalent â-pyrrole protons attached to carbons
a and b, respectively.
Table 2. 13C NMR Data for Compounds 1 and 2 at 24 °Ca
tosyl
OAc
CO
φ
C1
φ
OAc
CH3
compound
CR
Câ
Cm
C4
143.2 137.5
[d, 47]c
C1
C3,5 C2,6 CH3
C
2,6, C3,5, C4
1 in CD2Cl2
(100.61 MHz)
176.6 157.5 [d, (C1,C14), 70]b 141.9 [d, 51]d
152.6 [d, (C16,C19), 72]c 141.6 [d, 48],d
136.4 [d, (C3,C12), 38]c 128.0 [s, (C15,C20)]
133.8 [s, (C2,C13)]
129.4 127.3 21.3 137.7, 137.2, 135.7, 135.2, 19.8
134.7, 134.3, 128.9,
124.4 [d, (C5,C10), 183]c
150.5 [d, (C6,C9), 51]b
[C41,C31], [C51,C61] 132.3 [d, (C7,C8), 161]c
115.6 [d, (C17,C18), 79]d
128.3, 127.2, 127.1
150.4 [d, (C4,C11), 102]b
2 in CDCl3
(150.87 MHz)
168.7 149.3 (C3,C16)
142.3
141.0 ,
135.0 (C5,C14)
133.2 (C9,C10)
123.5 (C2,C17)
122.4 (C7,C12)
141.2 135.3
128.0 124.9 21.1 137.3, 137.1, 135.7, 134.4, 19.2
128.4, 128.1, 128.0,
148.9 (C1,C18)
148.5 (C8,C11)
147.1 (C6,C13)
[C21,C39], [C27,C33] 129.8 (C4,C15)
119.7 (C19,C20)
127.1, 127.0, 126.9
b
c
d
a Chemical shifts in ppm relative to the center line of CDCl3 at 77.0 and to CD2Cl2 at 53.6 ppm. 2J(Tl-C) in Hz. 3J(Tl-C) in Hz. 4J(Tl-C) in Hz.

Complexes of N-Tosylamidoporphyrin
Inorganic Chemistry, Vol. 39, No. 6, 2000 1109
Table 3. Crystal Data for Tl(N-NTs-tpp)(OAc)‚0.75CHCl3 and
Ga(N-NTs-tpp)(OAc) (2)
empirical formula
C53.75H38.75Cl2.25N5O4STl- C53H38GaN5O4S-
(1‚0.75CHCl3)
1134.8
(2)
1110.4
fw
space group
cryst syst
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
P21/c
P1h
monoclinic
12.501(1)
22.807(2)
18.125(2)
triclinic
11.5126(8)
12.9912(9)
16.786(1)
82.661(1)
72.578(1)
73.461(1)
2293.8(3)
2
90.94(2)
5167(1)
4
F000
D
2254
1.459
940
1.319
6.97
0.834
calcd, g cm-3
µ(Μï ΚR), cm-1 33.31
S
1.20
cryst size, mm3
2θmax, deg
T, K
0.48 × 0.60 × 0.72
0.30 × 0.13 × 0.08
52.2
56.7
293
295(2)
no. reflns measd
no. reflns obsd
R,a %
10511
23483
10 396 (I > 2 σ(I))
5.43
6093 (F > 4.0 σ(F))
4.87
5.85
Rw ,b %
9.15
a R ) ∑||Fo| - |Fc||/∑|Fo|. b Rw ) [∑w(||Fo| - |Fc||)2/∑w(|Fo|)2]1/2
;
w ) A/(σ2Fo + BFo ).
2
Table 4. Selected Bond Distances (Å) and Angles (deg) for
Compounds Tl(N-NTs-tpp)(OAc)‚0.75CHCl3 and
Ga(N-NTs-tpp)(OAc) (2)
Tl(N-NTs-tpp)(OAc)‚0.75CHCl3
Distances
Tl-N(1)
Tl-N(2)
Tl-N(3)
Tl-N(5)
N(4)-N(5)
2.347(7)
2.152(7)
2.361(7)
2.103(7)
1.398(9)
Tl-O(1)
2.410(8)
2.292(9)
1.22(2)
1.19(2)
1.50(2)
1.635(7)
Tl-O(2)
O(1)-C(21)
O(2)-C(21)
C(21)-C(22)
N(5)-S
Angles
Tl-O(1)-C(21)
Tl-O(2)-C(21)
Tl-N(5)-N(4)
Tl-N(5)-S
O(1)-Tl-O(2)
O(1)-Tl-N(1)
O(1)-Tl-N(2)
O(1)-Tl-N(3)
O(1)-Tl-N(5)
87.5(7)
O(2)-Tl-N(1)
O(2)-Tl-N(2)
O(2)-Tl-N(3)
O(2)-Tl-N(5)
N(1)-Tl-N(2)
N(1)-Tl-N(3)
N(1)-Tl-N(5)
N(2)-Tl-N(3)
N(2)-Tl-N(5)
N(3)-Tl-N(5)
138.5(3)
92.1(3)
100.9(3)
115.8(3)
80.2(2)
117.7(2)
85.1(2)
80.8(3)
149.9(3)
83.0(2)
94.0(7)
112.9(5)
129.1(4)
53.8(3)
88.2(3)
Figure 1. Molecular configuration and atom-labeling scheme for (a)
Tl(N-NTs-tpp)(OAc)‚0.75CHCl3 (or 1‚0.75 CHCl3) and (b) Ga(N-
NTs-tpp)(OAc) (2), with ellipsoids drawn at 30% probability.
Hydrogen atoms for both compounds and solvents C(70)H(70a)Cl(1)-
Cl(2)Cl(3) for 1‚0.75 CHCl3 are omitted for clarity.
103.3(3)
154.1(3)
102.3(3)
Ga(N-NTs-tpp)(OAc)
Distances
(0.15 Å for 2 (Figure 2b). The tosyl amide nitrogen N(5) in 1
and 2 are located considerably far from the (4N) plane. In
complex 1, Tl3+ and N(5) are located on the same side at 1.17
and 1.27 Å from its (4N) plane, but for complex 2, Ga3+ and
N(5) are located on different sides at -0.28 and 0.96 Å from
its 4N plane (Figure 2). Apparently, chelating bidentate acetate
in 1 is cis to the N-tosyl group with O(1) and O(2) being located
separately at 3.11 and 3.04 Å out of the 4N plane, and
monodentate acetate in 2 is trans to the N-tosyl group with O(3)
located at -1.98 Å out of the 4N plane. The porphyrin
marocycle is indeed distorted because of the presence of the
N-tosyl group. Thus, the N(4) and N(1) pyrrole rings bearing
the N-tosyl group would deviate mostly from the (4N) plane
and would be oriented separately in a dihedral angle of 51.3°
and of 33.5°, whereas small angles of 6.0°, 7.4°, and 9.6° occur
with N(2), N(1), and N(3) pyrroles for compound 1 and 4.8°,
8.1°, and 10.4° with N(4), N(2), and N(3) pyrroles for compound
2 (see also Table 5 in Supporting Information). In compound
Ga(1)-N(2)
Ga(1)-N(3)
Ga(1)-N(4)
Ga(1)-N(5)
Ga(1)-O(3)
2.031(3)
C(52)-O(3)
C(52)-O(4)
C(52)-C(53)
N(1)-N(5)
N(5)-S(1)
1.260(5)
1.218(5)
1.515(6)
1.377(4)
1.610(3)
1.911(3)
2.031(3)
1.946(3)
1.868(3)
Angles
Ga(1)-O(3)-C(52) 117.3(3)
N(2)-Ga(1)-N(3)
92.9(1)
Ga(1)-N(5)-S(1)
Ga(1)-N(5)-N(1)
O(3)-Ga(1)-N(2)
O(3)-Ga(1)-N(3)
O(3)-Ga(1)-N(4)
O(3)-Ga(1)-N(5)
137.9(2)
103.9(2)
89.5(1)
128.2(1)
93.4(1)
N(2)-Ga(1)-N(4) 168.7(1)
N(2)-Ga(1)-N(5)
N(3)-Ga(1)-N(4)
83.2(1)
93.9(1)
N(3)-Ga(1)-N(5) 126.9(1)
N(4)-Ga(1)-N(5)
85.5(1)
104.8(1)
other two Ga-N distances [1.911(3) Å for Ga(1)-N(3) vs
2.031(3) Å for the two equivalent Ga(1)-N(2) and Ga(1)-N(4)
distances]. Figure 2 indicates the actual porphyrin skeleton for
1 and 2; the four pyrrole nitrogens N(1)-N(4) are approximately
coplanar (i.e., 4N plane) within (0.01 Å for 1 (Figure 2a) but

1110 Inorganic Chemistry, Vol. 39, No. 6, 2000
Tung et al.
plane in 1 compared to 0.21 Å for Ni and 0.94 Å for the nitrogen
atom of the nitrene fragment in Ni(N-NTs-tpp).3
The pyrrole ring nitrogens N(4) and N(1) are actually inclined
toward the Tl and Ga atoms in 1 and 2, respectively. These
distortions re-form the distances between opposite pyrrole
nitrogen atoms to be unusual. The normal diameter of the “hole”
in an undistorted metalloporphyrin complex has been estimated
to be 4.02 Å.15 In 1, the N(2)‚‚‚N(4) (or N(1)‚‚‚N(3)) distance
is 4.515 Å (or 4.029), and in 2 the N(1)‚‚‚N(3) (or N(2)‚‚‚N(4))
distance is 4.464 Å (or 4.042); it is caused by the large deviation
of the N(4) pyrrole and N(1) pyrrole from the 4N plane for 1
and 2, respectively. Hence, in 1 and 2, the thallium(III) and
gallium(III) atoms are all bound in an expanded porphyrinato
(4N) core. The plane (P) defined by Tl, N(5), N(4), and the
sulfur atom S, and the other plane by Ga(1), N(5), N(1), and
S(1) are almost perpendicular to the (4N) plane, 84.4° for 1
and 90.3° for 2. The tosyl group (T) (i.e., the plane T) is bonded
to N(5) so that it lies above the macrocycle, orienting in a
dihedral angle of 12.8° and 11.5° with the 4N plane in 1 and 2,
respectively (Table 5 in Supporting Information). The dihedral
angles between the mean plane of the skeleton (4N) and the
planes of the phenyl group are 55.7° (C(31)), 87.3° (C(41)),
34.7° (C(51)), and 50.1° (C(61)) for 1 and 73.0° (C(33)), 84.3°
(C(27)), 75.4° (C(21)), and 57.4° (C(39)) for 2 (Table 5 in
Supporting Information).
In comparison with a distorted trigonal bipyrimidal structure
of Fe(N-NTs-tpp)Cl,7 the individual planar pyrrole rings,
bearing respectively the N(1), N(2), N(3), and N(4) nitrogen
atoms in 2, orient in dihedral angles of 24.5°, 1.7°, 2.2°, and
6.1° with respect to the 3N plane, which contains the three
pyrrole nitrogens N(2), N(3), and N(4) bonded to the gallium
(Table 5 in Supporting Information). This distortion is, however,
smaller than that present in the Fe(N-NTs-tpp)Cl complex in
which the corresponding dihedral angles are 29.9°, 8.5°, 5.8°,
and 9.8°, respectively.7 The pyrrole nitrogen N(1), not bonded
to the gallium, lies 0.67 Å above the average plane of 3N (Figure
2b). Moreover, the gallium atom lies -0.15 Å below this plane
toward the O(3) atom. In Fe(N-NTs-tpp)Cl,7 the correspond-
ing pyrrole nitrogen N23 lies 0.44 Å above the 3N plane but
the iron atom lies -0.21 Å below this plane toward the chlorine
atom. Hence, the X-ray structure of compound 2 is quite similar
to that of Fe(N-NTs-tpp)Cl except that the latter is a para-
magnetic complex.
The distortion of the porphyrin skeleton seems to have very
little or no effect at all on the π-electron delocalization in the
porphyrinato core. By use of CR and Câ to denote the respective
R- and â-carbon atoms of a pyrrole ring, Cm for methine carbon,
and Cp for a phenyl carbon atom that is bonded to the core, the
averaged bond lengths in the porphine skeleton are N-CR )
1.39(1) (or 1.376(4)), CR-Câ ) 1.43(1) (or 1.427(5)),
Câ-Câ ) 1.35(1) (or 1.347(5)), CR-Cm ) 1.41(1) (or
1.403(5)), and Cm-Cp ) 1.50(1) Å (or 1.497(5)) for compound
1 (or 2). These distances are almost identical with those found
in nondistorted porphyrin complexes for Tl(tpp)(OAc)13 (or
Ga(tpp)(OAc)).14 This has also been observed in the previously
described porphyrin derivatives in which a nitrene moiety is
inserted into a metal-pyrrole nitrogen bond.3,7,8
Figure 2. Diagram of the porphyrinato core (C20N4, M, NTs, and
OAc-) of (a) compound 1 and (b) compound 2. The values represent
the displacements (in Å) of the atoms from the mean 3N plane (i.e.,
N(1)-N(3) for 1 and N(2)-N(4) for 2) and the parenthesized values
from the mean 4N plane (i.e., N(1)-N(4)).
1, such a large deviation from planarity for the N(4) pyrrole
(Table 2) is also reflected by observing a 16-21 ppm upfield
shift of the Câ (C17, C18) at 115.6 ppm compared to 136.4
ppm for Câ (C3, C12), 133.8 ppm for Câ (C2, C13), and 132.3
ppm for Câ (C7, C8). In compound 2, a similar deviation is
also found for the N(1) pyrrole (Table 2) by observing a 10-15
ppm upfield shift of the Câ (C19, C20) at 119.7 ppm compared
to 135.0 for Câ (C5, C14), 133.2 ppm for Câ (C9, C10), and
129.8 ppm for Câ (C4, C15). The distortion in 1 is larger than
that present in the Ni(N-NTs-tpp) complex in which the
dihedral angle between the mean plane of one pyrrole ring and
the mean plane of the four pyrrole nitrogens (4N) is as large as
40.5°. Because of the larger size of the Tl3+, the acetate ligand
is bidentately chelated to the Tl atom, while it is unidentately
coordinated to the Ga atom. Likewise, because of the same large
size of the Tl3+, Tl and N(5) lie 1.17 and 1.27 Å above the 4N
The major difference between six-coordinate (1) and five-
coordinate (2) complexes is the movement of the metal toward
the 3N (or 4N) plane in the five-coordinate complex compared
to the six-coordinate complex. In the binding to the OAc- ligand
in 2 with CN ) 5, the smaller Ga(III) ion is forced to lie below
(15) Collins, D. M.; Hoard, J. L. J. Am. Chem. Soc. 1970, 92, 3761.

Complexes of N-Tosylamidoporphyrin
Inorganic Chemistry, Vol. 39, No. 6, 2000 1111
the 3N (or 4N) plane of the macrocycle. Hence, in 2 the distance
between Ga and the 3N (or 4N) plane is only -0.15 (or -0.28)
Å, while in 1 with CN ) 6 this distance is much larger, ∼1.18
(or ∼1.17) Å for the larger Tl(III) ion.
1H and 13C for Tl(N-NTs-tpp)(OAc) (1) and Ga(N-
NTs-tpp)(OAc) (2) in CDCl3 and CD2Cl2. Complexes 1 and
2 were characterized by 1H and 13C NMR spectra. In solution,
where the phenyl, N-tosyl, and acetate groups are free to rotate,
the molecule has effective Cs symmetry with a mirror plane
running through the N(2)-Tl-N(5)-N(4) unit for 1 or the
N(3)-Ga(1)-N(5)-N(1) unit for 2. There are four distinct
â-pyrrole protons Hâ, four â-pyrrole carbons Câ, four R-pyrrole
carbons CR, two different meso carbons Cmeso, and two phenyl-
C1 carbons for both complexes (Tables 1 and 2). In compound
1, the average distance between Tl‚‚‚C(7) and Tl‚‚‚C(8), Tl‚‚‚
C(3) and Tl‚‚‚C(12), Tl‚‚‚C(2) and Tl‚‚‚C(13), and Tl‚‚‚C(17)
and Tl‚‚‚C(18) increases from 4.258, 4.294, 4.415 to 4.712 Å.
The NMR data of 1 showed four different types of Tl-H
coupling constants for Hâ (Figure 3 and Table 1). The doublet
4
at 8.75 ppm is assigned as Hâ(7,8) with J(Tl-H) ) 75.6 Hz.
The doublet of a doublet at 9.13 ppm is due to Hâ(3,12) with
3
4J(Tl-H) ) 18 Hz and J(H-H) ) 4.5 Hz. The doublet of a
4
doublet again at 8.98 ppm is due to Hâ(2,13) with J(Tl-H) )
3
10 Hz and J(H-H) ) 4.5 Hz, and the singlet at 6.99 ppm is
due to Hâ(17,18) with 5J(Tl-H) being unobserved. Likewise, there
were also four different types of Tl-13C coupling constants for
Câ (Table 2). The doublet at 132.3 ppm is due to Câ(C7, C8)
with 3J(Tl-13C) ) 161 Hz. The doublet at 136.4 ppm is due to
3
Câ(C3, C12) with J(Tl-13C) ) 38 Hz. The singlet at 133.8
ppm is due to Câ(C2, C13) with 3J(Tl-13C) being unobserved,
and the doublet at 115.6 ppm is due to Câ(C17, C18) with
1
4J(Tl-13C) ) 79 Hz. The H NMR spectra (Figure 3) reveal
that the aromatic protons of the tosyl groups appear as doublets
at 6.96 (tosyl-H3,5) and 6.26 ppm (tosyl-H2,6) for 1 and at 6.47
and 4.80 ppm for 2. All tosylimido and acetato protons are
shifted upfield compared to their counterparts on free NHTs
and OAc-. Such a shift is presumably attributed to the porphyrin
ring current effect. On the basis of the ring model,16 as the
distance between the geometrical center (Ct) of the 4N plane
and axial protons gets smaller, the shielding effect becomes
larger. The (Ct‚‚‚axial proton) distance can be estimated from
Ct to the carbons bearing the axial protons. The average
distances (in Å) for Ct‚‚‚tosyl-C2,6, Ct‚‚‚tosyl-C3,5, Ct‚‚‚tosyl-
CH3, and Ct‚‚‚CH3 (OAc) are 5.282, 6.364, 8.159, and 5.374 in
1, and 4.397, 5.424, 7.190, and 4.339 in 2. The fact that all
four bond distances in 2 are shorter than those in 1 indicates
that the ring current effect in 2 would be larger and in turn the
1H upfield shifts for the axial protons in 2 would be still higher.
This is what exactly observed: -1.21 ppm in 1 and 0.78 ppm
in 2 for OAc, 2.11 and 2.31 for tosyl-CH3, 4.80 and 6.26 for
tosyl-H2,6, and 6.47 and 6.96 for tosyl-H3,5. The above ring
current effect indicates that both the tosyl and acetate ligands
are bonded to Tl in 1 and to Ga in 2. This bonding argument is
further confirmed by the result that the tosyl-C1 (i.e., C(23)) in
Figure 3. 1H NMR spectra for (a) Tl(N-NTs-tpp)(OAc) (1) at 299.94
MHz and (b) Ga(N-NTs-tpp)(OAc) (2) at 599.95 MHz in CDCl3 at
24 °C. φ represents the phenyl protons.
4
coupling of J(Tl-H) rather than a chemical shift difference.
The most likely cause of loss of coupling is reversible
dissociation of acetate
Tl(N-NTs-tpp)(OAc) h Tl(N-NTs-tpp)+ + OAc- (1)
3
1 was observed at 137.5 ppm with J(Tl-C) ) 47 Hz.
Dynamical NMR of 1 in CD2Cl2. When a 0.02 M solution
of Tl(N-NTs-tpp)(OAc) (1) in CD2Cl2 (Figure 4) was recorded
at low temperature, the methyl protons of OAc- appeared as a
single peak at 24 °C (δ ) 0.67 ppm). At -110 °C the singlet
first broadened (coalescence temperature Tc ) -102 °C) and
then split into two peaks with a separation of 16.2 Hz. Since
the exchange of OAc- within 1 is reversible, the results observed
at 599.95 MHz confirm that the separation results from a
with a small dissociation constant but reasonable rate at room
temperature.17 Such a scenario would lead to little change in
the chemical shift with temperature and no detectable free OAc-
and Tl(N-NTs-tpp)+ at low temperature but would result in
the loss of coupling between acetate and thallium at higher
temperatures. The chemical shift observed at high temperature
(17) Jenson, J. P.; Muetterties, E. L. In Dynamic Nuclear Magnetic
Resonance Spectroscopy; Jackman, L. M., Cotton, F. A., Eds.;
Academic Press: New York, 1975; pp 299-304.
(16) Johnson, C. E.; Bovey, F. A. J. Chem. Phys. 1958, 29, 1012.

1112 Inorganic Chemistry, Vol. 39, No. 6, 2000
Tung et al.
value of 175.2 ( 1.6 ppm) for 1 and at 168.7 (within the range
of 168.2 ( 1.7 ppm) for 2 at 24 °C also confirm that the OAc-
group is bidentately chelated to the Tl atom but unidentately
coordinated to the Ga atom.
UV/Visible Absorption Spectra of 1 and 2. The electronic
spectrum of 1 in CHCl3 has three λmax at 446 (B(0,0)), 558
(Q(1,0)), and 602 (Q(0,0)) that are comparable to those of 433,
567, and 607 nm found for Tl(tpp)(OAc),18,19 a cisoid six-
coordinate thallium(III) porphyrin complex. On the other hand,
the electronic spectrum of 2 has three λmax at 436 (B(0,0)), 544
(Q(1,0)), and 587 (B(0,0)), which are also quite closer to those
of 420, 552, and 586 for Ga(tpp)(OAc),20 a typical five-
coordinate gallium(III) porphyrin complex.
Conclusions
We have investigated two novel diamagnetic, mononuclear,
and bridged metal complexes of N-tosylamidoporphyrin having
an MIII-NTs-N linkage, and their X-ray structures are studied.
The 13C chemical shifts of the carbonyl carbon are used to
identify the coordinate mode of the acetato group. Dynamical
1H and 13C NMR spectra of the acetato group in 1 reveal that
this group undergoes an intermolecular exchange with a free
Figure 4. The 599.95 MHz 1H NMR spectra for the axial acetato
protons of Tl(N-NTs-tpp)(OAc) (1) in CD2Cl2 at various tempera-
tures.
energy of activation, ∆Gq ) 36.0 kJ/mol.
171
Acknowledgment. The financial support from the National
Research Council of the R.O.C. under Grant NSC 89-2113-M-
005-014 is gratefully acknowledged. The NMR instrument
(Varian Unity Inova-600) is funded in part by the National
Science Council and by the Chung-Cheng Agriculture Science
& Social Welfare Foundation.
is the average of two species (i.e., Tl(N-NTs-tpp)(OAc) and
OAc-) in eq 1 weighted by their concentration. A comparison
of observed and computed spectra yields ∆Gq ) 36.0 kJ/
171
mol. At 24 °C, intermolecular exchange of the OAc- group is
rapid, indicated by singlet signals due to carbonyl carbons at
176.4 ppm and methyl carbons at 19.1 ppm. At -110 °C, the
rate of intermolecular exchange of OAc- for 1 in CD2Cl2 is
slow. Hence, at this temperature, the methyl and carbonyl
Supporting Information Available: Table 5 giving least-squares
mean planes and the dihedral angles between planes for compounds 1
and 2. X-ray crystallographic files for compounds 1 and 2 are available
in CIF format. This material is available free of charge via the Internet
at http://pubs.acs.org.
3
carbons of OAc- are observed at 18.5 ppm [with J(Tl-C) )
220 Hz] and 176.3 ppm [with 2J(Tl-C) ) 205 Hz], respectively.
These 13C resonances are quite close to the Tl(tpp)(OAc)
case in which the two corresponding carbons were observed,
in CD2Cl2 at -90 °C, at 18.8 ppm [with 3J(Tl-C) ) 280 Hz],
and 174.9 ppm [with 2J(Tl-C) ) 235 Hz].12,13 For 2 in CDCl3
at 24 and -50 °C, the corresponding carbons were observed at
19.2 and 168.7, close to those of 20.4 ppm (CH3) and 168.8
ppm (CO) in Ga(tpp)(OAc).14 On the basis of our previous
report,11 the carbonyl chemical shifts at 176.4 ppm (within the
IC9911318
(18) Abraham, R. J.; Barnett, G. H.; Smith, K. M. J. Chem. Soc., Perkin
Trans. 1 1973, 2142.
(19) Tung, J. Y.; Chen, J. H.; Liao, F. L.; Wang, S. L.; Hwang, L. P. Inorg.
Chem. 1998, 37, 6104.
(20) Yang, F. L.; Li, P.; Lin, X. Q.; Wang, E. K. Chin. Chem. Lett. 1993,
4, 119.