Thallium complexes of meso-tetra-(p-chlorophenyl)porphyrin: Trifluoroacetato-[meso-tetra(p-chlorophenyl) porphyrinato]thallium(III) and pentafluoropropionato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III)

Article abstract of DOI:10.1016/S1387-7003(02)00715-3

The crystal structures of trifluoroacetato-[meso-tetra(p-chlorophenyl)porphyrinatolthallium(III), Tl[(p-Cl)₄tpp](O₂-CCF₃) (1), and pentafluoropropionato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III) Tl[(p-Cl)₄tpp](O₂CCF₂CF₃) (2), were determined. The coordination sphere around the Tl³⁺ ion is described as five-coordinate regular square-based pyramid (RSBP) in which the apical site is occupied by an unidentate CF₃CO₂^- ligand for 1 whereas the unidentate CF₃CF₂CO₂^- ligand occupies the axial site for 2. The plane of the four pyrrole nitrogen atoms [i.e., N(1)-N(4)] strongly bonded to Tl³⁺ is adopted as a reference plane 4N. The Tl³⁺ is moderately out of the 4N plane; its displacement of 0.58 ? (or 0.59 ?) for 1 (or 2) is in the same direction as that of the trifluoroacetate oxygen for 1 (or pentafluoropropionate oxygen for 2). The free energy of activation at the coalescence temperature T_c for the intermolecular trifluoroacetate exchange for 1 in CD₂Cl₂ is found to be ΔG₁₇₈^≠ = 36.6 kJ/mol whereas the intermolecular pentafluoropropionate exchange for 2 in CD₂Cl₂ is determined to be ΔG₂₁₃^≠ = 41.5 kJ/mol through ¹⁹F and ¹³C NMR temperature-dependent measurements.

Full text of DOI:10.1016/S1387-7003(02)00715-3

Inorganic Chemistry Communications 6 (2003) 252–258
www.elsevier.com/locate/inoche
Thallium complexes of meso-tetra-(p-chlorophenyl)porphyrin:
trifluoroacetato-[meso-tetra(p-chlorophenyl)
porphyrinato]thallium(III) and pentafluoropropionato-
[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III)
a
a,
c
Yu-Yi Lee , Jyh-Horung Chen *, Hsi-Ying Hsieh b,1, Feng-Ling Liao ,
c
d
Sue-Lein Wang , Jo-Yu Tung , Shanmugham Elango
e
a
Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan
b
Chung Hwa College of Medical Technology, Tainan 717, Taiwan
Department of Chemistry, National Tsing-Hua University, Hsin-Chu 300, Taiwan
c
d
Tzu Hui Institute of Technology, Ping Tung 92641, Taiwan
e
Shuang Bang Industrial Corporation, Nantou 540, Taiwan
Received 11 July 2002; accepted 31 October 2002
Abstract
The crystal structures of trifluoroacetato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III), Tl½ðp-ClÞ4tppŠðO2CCF3Þ (1),
and pentafluoropropionato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III) Tl½ðp-ClÞ4tppŠðO2CCF2CF3Þ (2), were deter-
mined. The coordination sphere around the Tl3þ ion is described as five-coordinate regular square-based pyramid (RSBP) in which
the apical site is occupied by an unidentate CF3COÀ2 ligand for 1 whereas the unidentate CF3CF2CO2À ligand occupies the axial site
for 2. The plane of the four pyrrole nitrogen atoms [i.e., N(1)–N(4)] strongly bonded to Tl3þ is adopted as a reference plane 4N. The
Tl3þ is moderately out of the 4N plane; its displacement of 0.58 A (or 0.59 A) for 1 (or 2) is in the same direction as that of the
trifluoroacetate oxygen for 1 (or pentafluoropropionate oxygen for 2). The free energy of activation at the coalescence temperature
ꢀ
ꢀ
¼
Tc for the intermolecular trifluoroacetate exchange for 1 in CD2Cl2 is found to be DG178 ¼ 36:6 kJ/mol whereas the intermolecular
¼
pentafluoropropionate exchange for 2 in CD2Cl2 is determined to be DG213 ¼ 41:5 kJ/mol through 19F and 13C NMR temperature-
dependent measurements.
Ó 2002 Elsevier Science B.V. All rights reserved.
Keywords: Crystal structures; Intermolecular exchange; Pentafluoropropionato complex; Thallium meso-tetra-(p-chlorophenyl)porphyrin complexes
1. Introduction
ion complexes of meso-tetra(p-chlorophenyl)porphyrin.
Our earlier work, described on the trifluoroacetate
(TFA) exchange in (meso-tetra-phenylporphyri-
nato)(trifluoroacetato)thallium(III), TlðtppÞðO2CCF3Þ
[tpp ¼ 5, 10, 15, 20-tetraphenylporphyrinate] [7]. The
electron density and the donating ability of the pyrrole
nitrogen, which is the first bonding atom toward the
thallium ion in the thallium porphyrin complex, are
considered to be lowered in the case of H2ðp-ClÞ4tpp, as
it contains electron-withdrawing chlorine atom [8].
Upon replacing tpp2- with ðp-ClÞ4tpp2À, the complex
TlðtppÞðO2CCF3Þ became trifluoroacetato-[meso-tetra
(p-chlorophenyl)porphyrinato]thallium(III), Tl½ðp-ClÞ4
The preparation and properties of various Cu(II),
Co(II), Ni(II), Pd(II), Pt(II), and Zn(II) chelates of a, b,
c, d-tetra-(p-chlorophenyl)porphyrin [H2ðp-ClÞ4tpp or
H2ðtClppÞ] were described earlier [1]. Crystal structures
of Zn(II), Fe(II), Mn(III), Sn(IV) and Os(VI) chelated
with H2ðp-ClÞ4tpp were also established [2–6]. But there
are no X-ray structural data available for thallium(III)
* Corresponding author. Fax: 422862547.
E-mail address: jyhchen@dragon.nchu.edu.tw (J.-H. Chen).
1
Also corresponding author.
1387-7003/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved.
PII: S1387-7003(02)00715-3

Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
253
Table 1
Proton chemical shifts (d), thallium–proton coupling constants (J in Hz) and the Dd in ppm for acido protons for complexes 1 (600.1 MHz), 2 (599.95
MHz) and H2ðp-ClÞ4tpp in CD2C12 at 20 °Ca
Compound
Hb (b-pyrrole)
H2;6 (ortho H
)
(meta H)
H
3;5
1
9.15
(75)
8.27
(7)b
8.07
(7)
7.80
(7)
7.75
(7)
Dd ¼ À0:29c
Dd ¼ À0:13
8.23
Dd ¼ 0:07
8.12
(7)
Dd ¼ À0:05
7.81
Dd ¼ 0
2
9.14
(73)
7.77
(7)
(7)
Dd ¼ À0:09
(7)
Dd ¼ À0:06
Dd ¼ À0:28
8.86
Dd ¼ 0:02
Dd ¼ À0:02
7.75
(7)
H2ðp-ClÞ tpp
8.14
(7)
4
a Chemical shifts in ppm relative to CD2C12 at 5.3 ppm. Values in parentheses beneath are J(T1-H) coupling constants in Hz.
b Value in parentheses beneath are 3J(H-H) coupling constants in Hz.
c Dd ¼ d (unligated) - d (ligated), the 1Hchemical shift difference between the H 2ðp-ClÞ4tpp and coordination compounds.
tppŠðO2CCF3Þ (1), and further replacement of the
O2CCF3 fragment in 1 by O2CCF2CF3 ligand, it became
pentafluoropropionato-[meso-tetra(p-chlorophenyl) por
phyrinato]thallium(III) Tl½ðp-ClÞ4tppŠ ðO2CCF2CF3Þ
(2). The TFA is bidentately coordinated to the Tl atom
in TlðtppÞðO2CCF3Þ [7]. However, the introduction of
Cl in the para position of the benzene ring of complexes
1 and 2 might cause change in the bonding of TFA to Tl
atom in 1 and that of pentafluoropropionato to the Tl
atom in 2 from the chelating bidentate type as observed
in TlðtppÞðO2CCF3Þ. In this paper, we report the X-ray
structural determination of two new porphyrin com-
plexes namely 1 and 2. Prompted by the earlier studies
on the TFA exchange of TlðtppÞðO2CCF3Þ observed
in THF-d8 and that of bis(trifluoroacetato)-(N-methyl-
meso-tetraphenylporphyrinato)thallium(III) Tl(N-Me-
tpp)(O2CCF3Þ2 [7,9] in CD2Cl2, we investigated a
similar intermolecular exchange for complexes 1 and
2 in CD2Cl2 by 19F and 13C dynamic NMR method.
2. Experimental
2.1. Preparation of Tl½ðp À ClÞ tppŠðO2CCF3Þ ð1Þ
4
A mixture of H2½ðp-ClÞ4tppŠ [10] (0.1 g, 1:33 ꢀ 10À4
mol) in CH2Cl2 (50 ml) and TlðCF3COOÞ3 (0.21 g,
3:99 ꢀ 10À4 mol) in MeOH(10 ml) was refluxed for 1 h.
After concentrating, the residue was dissolved in CH2Cl2,
dried over anhydrous Na2SO4 and filtered. The filtrate
was layered with MeOHtoaffordpurple crystals of 1(0.13
g, 83%) for single-crystal X-ray analysis. 2 Tables 1 and 2
3
summarize the 1H, 13C and 19F NMR data.
MS, m=z (assignment, rel. intensity): 955
ð½Tlðp-ClÞ tppŠþ, 31.75), 752 ð½H2ðp-ClÞ tppŠþ, 13.83),
4
4
751 ð½Hðp-ClÞ4tppŠþ, 10.25). UV/Vis spectrum, k (nm)
½e ꢀ 10À4ðMÀ1cmÀ1ފ in CH2Cl2: 327 (9.8), 432 (197),
564 (9.1), 603 (4.1).
2.2. Preparation of Tl½ðp-ClÞ4 tppŠðO2CCF2CF3Þ ð2Þ
A mixture of H2½ðp-ClÞ4tppŠ (0.1 g, 1:33 ꢀ 10À4 mol) in
CH2Cl2 (50 ml) and TlðOAcÞ3 (0.15 g, 3:99 ꢀ 10À4 mol) in
MeOH(10 ml) was refluxed for 1 h. After concentrating,
the residue was dissolved in CH2Cl2 and layered with
MeOHto afford purple crystals of Tl ½ðp-ClÞ4tppŠðOAcÞ
(0.135 g, 90%) and these crystals dissolved in CH2Cl2 was
passed down a column of alumina (40 g, neutral, activity
I). The major purple band eluting with CH2Cl2 was col-
lected and concentrated. The residue was redissolved in
CH2Cl2 and layered with MeOHto afford pure purple
crystals of Tl½ðp-ClÞ4tppŠCl (0.1 g, 84.7%). A mixture of
2
Crystal data for 1 ꢁ CHCl3: C47H25Cl7F3N4O2Tl, Mr ¼ 1187:23,
ꢀ
ꢀ
ꢀ
triclinic, P1, a ¼ 10:7454ð5Þ A, b ¼ 14:6045ð6Þ A, c ¼ 15:8047ð7Þ A,
ꢀ3
a ¼ 67:556ð1Þ°, b ¼ 75:674ð1Þ°, c ¼ 83:291ð1Þ°, V ¼ 2220:4ð2Þ A ,
Z ¼ 2, Dc ¼ 1:776 g cmÀ3
,
lðMo-KaÞ ¼ 4:116 mmÀ1
, 1:43 < h <
28:29°, GOF on F 2 ¼ 1:027, R1½I > 2rðIފ ¼ 0:0264, xR2½I > 2rðIފ
¼ 0:0664. Crystal data for 2: C47H24Cl4F5N4O2Tl, Mr ¼ 1117:87,
ꢀ
ꢀ
ꢀ
ꢀ3
triclinic, P1, a ¼ 9:3766ð5Þ A, b ¼ 16:2677ð9Þ A, c ¼ 16:7537ð9Þ A,
a ¼ 115:830ð1Þ°, b ¼ 103:629ð1Þ°, c ¼ 95:806ð1Þ°, V ¼ 2173:9ð2Þ A ,
Z ¼ 2, Dc ¼ 1:708 gcmÀ3
,
lðMo-KaÞ ¼ 4:027 mmÀ1
, 1:42 < h <
28:27°, GOF on F 2 ¼ 0:974, R1½I > 2rðIފ ¼ 0:0437, xR2½I > 2rðIފ
¼ 0:0962. Data collection for both structures were taken at 294(2) K
on a Brucker SMART CCD diffractometer using monochromatized
3
Proton and 13C NMR spectra in CD2Cl2 (99.6% from Aldrich)
were recorded at 599.95 (or 600.1) and 150.87 (or 150.91) MHz,
respectively, on Varian Unity Inova-600 (or Bruker DMX-600)
spectrometers. The 19F spectra were measured in CD2Cl2 at 564.48
MHz in a Varian Unity Inova-600 spectrometer. 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. UV/Vis spectra were recorded at 25 °C on a
HITACHI U-3210 spectrophotometer.
ꢀ
Mo-Ka radiation (k ¼ 0:71073 A). The empirical absorption correc-
tions were made for 1 ꢁ CHCl3 and 2. The structures were solved by
direct methods (SHELXTL PLUS) 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.

254
Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
Tl½ðp-ClÞ4tppŠCl (0.1 g, 10À4 mol) in CH2Cl2 (50 ml) and
C2F5CO2Ag (0.027 g, 10À4 mol) in MeOH(10 ml) was
stirred at room temperature for 1 h. After the removal of
AgCl and the unreacted C2F5CO2Ag by filtration, the
solution was dried over Na2SO4 and filtered. The filtrate
was concentrated to yield a purple solid of 2 which was
redissolved in CH2Cl2 and layered with MeOHat 4 °C in
closed system for 4–7 days to obtain the purple crystals
(0.083 g, 74%) for single-crystal X-ray analysis. 2 Tables 1
3
and 2 summarize the 1H, 13C, and 19F NMR data.
MS, m=z (assignment, rel. intensity): 1118 (Mþ,
16.07), 955 ð½Tlðp-ClÞ tppŠþ, 43.77), 752 ð½H2ðp-ClÞ
4
4
tppŠþ, 8.19), 750 (½ðp-ClÞ4tppŠþ, 5.50), 205 ð205Tlþ, 100),
203 (203Tlþ, 55.45). UV/Vis spectrum, k (nm) ½eꢀ
10À4ðMÀ1cmÀ1ފ in CH2Cl2: 328 (12), 432 (199), 563
(11), 604 (5.2).
3. Results and Discussion
3.1. Molecular structures of 1ꢁCHCl3 and 2
Fig. 1 illustrates the skeletal frameworks of com-
plexes 1 ꢁ CHCl3 and 2. Both the five-coordinate struc-
tures have bonding with four nitrogen atoms of the
porphyrin in common, but they are different with an
apical trifluoroacetate ligand for 1 ꢁ CHCl3 and a pen-
tafluoropropionate ligand in the axial site for 2. The
bond distances from Tl(III) to the ligand and the angles
are summarized in Table 3. The corresponding bond
ꢀ
distances (A) are Tl(1)–O(1) ¼ 2.219(3) for 1 ꢁ CHCl3
and Tl(1)–O(1) ¼ 2.249(6) for 2. Both the trifluoroace-
tate and pentafluoropropionate ligands interact with
thallium in an unidentate fashion. The similar kind of
unidentate interaction for trifluoroacetate was previ-
ously observed for Tl(N-Me-tpp)(O2CCF3Þ2 also [9].
The O(2) atom is no longer bonded to the thallium as
ꢀ
indicated by their longer internuclear distances, 3.140 A
ꢀ
for Tlð1Þ ꢁ ꢁ ꢁ Oð2Þ in 1 ꢁ CHCl3 and 3.028 A for the same
Tlð1Þ ꢁ ꢁ ꢁ Oð2Þ distance in 2.
The displacements of the metal center from the planes
of the four porphyrin nitrogens [i.e., N(1)–N(4)] and the
macrocycle atoms (C20N4) are labeled as D4N and D24,
ꢀ
respectively. The Tl atom is 0.58 A (i.e., D4N) out of the
4N plane toward the trifluoroacetate oxygen in 1 ꢁ CHCl3
ꢀ
and the similar kind of displacement was 0.59 A toward
the pentafluoropropionate oxygen in 2. The dihedral an-
gles between the mean plane of 4N and the planes of the
phenyl groups are 51.8° [C(24)], 50.9° [C(30)], 70.8°
[C(36)], and 69.4° [C(42)] for 1 ꢁ CHCl3 and the corre-
sponding angles are 48.2° [C(24)], 80.7° [C(30)], 64.0°
[C(36)], and 51.0° [C(42)] for 2. The radii of the central
‘‘hole’’ [Ct ꢁ ꢁ ꢁ ꢁ N, the distance from the geometrical cen-
ter (Ct) of the mean plane of the 4N-atom core to the
ꢀ
porphyrinato-core N atoms] are 2.102 A for 1 ꢁ CHCl3
ꢀ
and 2.107 A for 2, which are in the normal range of values

Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
255
Table 3
ꢀ
Selected bond lengths (A) and angles (°) for compounds 1 ꢁ CHCl3 and 2
Compound 1 ꢁ CHCl3
Tl(1)–O(1)
Tl(1)ꢁ ꢁ ꢁO(2)
2.219(3)
3.140
O(1)–C(45)
O(2)–C(45)
C(46)–F(1)
C(46)–F(2)
C(46)–F(3)
1.233(4)
1.225(4)
1.303(5)
1.307(5)
1.303(5)
Tl(1)–N(1)
Tl(1)–N(2)
2.182(2)
2.173(2)
2.198(2)
2.168(2)
111.8(1)
98.9(1)
Tl(1)–N(3)
Tl(1)–N(4)
O(1)–Tl(1)–N(1)
O(1)–Tl(1)–N(2)
O(1)–Tl(1)–N(3)
O(1)–Tl(1)–N(4)
Tl(1)–O(1)–C(45)
O(1)–C(45)–O(2)
N(1)–Tl(1)–N(2)
N(1)–Tl(1)–N(3)
N(1)–Tl(1)–N(4)
N(2)–Tl(1)–N(3)
N(2)–Tl(1)–N(4)
N(3)–Tl(1)–N(4)
85.93(8)
149.0(1)
86.52(9)
85.68(9)
149.6(1)
85.81(9)
98.9(1)
111.3(1)
115.1(2)
129.4(3)
Compound 2
Tl(1)–O(1)
Tl(1)ꢁ ꢁ ꢁO(2)
Tl(1)–N(1)
Tl(1)–N(2)
Tl(1)–N(3)
Tl(1)–N(4)
C(47)–F(4)
2.249(6)
3.028
O(1)–C(45)
O(2)–C(45)
1.13(1)
1.23(1)
1.29(1)
1.29(2)
1.519(2)
1.283(2)
1.321(2)
1.52(1)
85.7(2)
148.8(2)
85.4(2)
86.7(2)
148.6(2)
85.5(2)
112(1)
2.181(4)
2.183(4)
2.180(4)
2.208(4)
1.340(2)
C(46)–F(1)
C(46)–F(2)
C(46)–C(47)
C(47)–F(3)
C(47)–F(5)
C(45)–C(46)
O(1)–Tl(1)–N(1)
O(1)–Tl(1)–N(2)
O(1)–Tl(1)–N(3)
O(1)–Tl(1)–N(4)
Tl(1)–O(1)–C(45)
O(1)–C(45)–O(2)
O(1)–C(45)–C(46)
C(46)–C(47)–F(3)
C(46)–C(47)–F(4)
C(46)–C(47)–F(5)
117.1(2)
118.1(2)
93.0(2)
92.7(2)
114.6(7)
127(1)
N(1)–Tl(1)–N(2)
N(1)–Tl(1)–N(3)
N(1)–Tl(1)–N(4)
N(2)–Tl(1)–N(3)
N(2)–Tl(1)–N(4)
N(3)–Tl(1)–N(4)
C(45)–C(46)–F(1)
C(45)–C(46)–F(2)
C(47)–C(46)–F(1)
C(46)–C(46)–F(2)
117(1)
105.3(9)
102.1(2)
97(1)
116.0(9)
102(1)
108(1)
for Ct-N as suggested by Collins and Hoard [11]. The large
diamagnetic thallium(III) ions cannot fit well into the
porphyrin core, but just sit out-of-plane in cisoid five- or
six-coordinate thallium(III) porphyrin complexes. In
general, the coodination sphere of the Tl3þ ion for thal-
lium porphyrins is an approximate square-based pyramid
in which the apical site is occupied either by a bidentate
group or by an unidentate ligand [12]. These thallium
porphyrins generally show a large thallium atom dis-
defined as s ¼ ðb À aÞ=60 [15], where b is the largest and
a the second largest of the Lbasal–M–Lbasal angles. The
limiting values are s ¼ 0 for an ideal tetragonal geom-
etry and s ¼ 1 for an ideal trigonal-bipyramid. In the
present case, we find b ¼ 149:6ð1Þ° [N(4)–Tl(1)–N(2)]
and a ¼ 149:0ð1Þ° [N(1)–Tl(1)–N(3)] for 1 ꢁ CHCl3, and
b ¼ 148:8ð2Þ° [N(3)–Tl(1)–N(1)] and a ¼ 148:6ð2Þ°
[N(2)–Tl(1)–N(4)] for 2. Thus the value, s ¼ 0:01 is
obtained for 1 ꢁ CHCl3 and s ¼ 0 for 2. Hence the ge-
ometries around Tl(III) for both compounds are best
described as regular square-based pyramids (RSBP) [16]
with N(1)–N(4) lying in the equatorial plane.
ꢀ
placement with D24 of 0.74–1.06 A. The complexes 1 and
2 studied here are the cisoid five-coordinate thallium (III)
porphyrin complex with the thallium atom locating (0.55)
ꢀ
ꢀ
A for 1 and 0.57 A for 2 modestly out of the 4N plane
toward oxygen atom. The structure of 1 is quite different
from that of TlðtppÞðO2CCF3Þ [7]. In 1, the O2CCFÀ3 li-
gand is unidentately coordinated to the Tl atom whereas
in TlðtppÞðO2CCF3Þ, it is asymmetrical and bidentate [7].
Such difference in structure can be explained, that the
tetra(p-chloro)-substitution favors the unidentate coor-
dination either in 1 or in 2. Similar observation is made for
the OAcÀ ligand being unidentately coordinated to the In
atom in In½ðp-ClÞ4tppŠðOAcÞ [13] whereas in Intpp(OAc)
it is chelating bidentate [14].
3.2. Dynamic NMR of 1 and 2 in CD2Cl2
On cooling a solution of 1 in CD2Cl2, the 19F signals
of CF3COÀ2 being a single peak at 20 °C ( d ¼ À74:6
ppm), first broadened (coalescence temperature
Tc ¼ À95 °C) and then split into doublet at d ¼ À74:4
ppm at )102 °C with 4J(Tl-F) ¼ 31 Hz at a frequency of
564.49 MHz. This doublet is due to Tl½ðp-ClÞ4tppŠ
ðO2CCF3Þ (1).
The 19F NMR spectrum for the pentafluoropropio-
nate of 2 in CD2Cl2 displays a singlet for CF3 at
d ¼ À85:1 ppm with Dm1=2 ¼ 5 Hz and a singlet for CF2
The distortion in these five-coordinate complexes can
be quantified by the ‘‘degree of trigonality’’ which is

256
Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
Fig. 1. Molecular configuration and atom-labeling scheme for (a) 1 ꢁ CHCl3 and (b) Tl½ðp-ClÞ4tppŠðO2CCF2CF3Þ (2), with ellipsoids drawn at 30%
probability. Hydrogen atom for both compounds and solvent CHCl3 for 1 ꢁ CHCl3 are omitted for clarity.
at d ¼ À121:7 ppm with Dm1=2 ¼ 6 H z at 10°C, but the
ðXÀ ¼ CF3COÀ for 1; CF3CF2COÀ for 2Þwith a small
2
2
3
small coupling of J(F-F) ¼ cal 1.5-2 Hz is not observed
dissociation constant. Such a scenario would lead to the
change in the chemical shift with temperature and no
for the fluorine in CF2 and CF3 [17–19]. Upon further
cooling, the fluorine signals of CF2 became a broad
singlet at d ¼ À122:0 ppm with Dm1=2 ¼ 28 Hz at )114
°C, and the singlet signals of CF3 are observed at
d ¼ À84:4 ppm with Dm1=2 ¼ 16 Hz at the same tem-
perature.
The most likely cause of loss of coupling is due to
reversible dissociation of trifluoroacetate for 1 and of
pentafluoropropionate for 2
þ
detectable free XÀ and Tl½ðp-ClÞ tppŠ at low tempera-
4
ture, but would lead to the loss of coupling between X
and thallium at higher temperature [20]. The chemical
shift in the high temperature limit is the average of the
two species [i.e., Tl½ðp-ClÞ tppŠX and XÀ] in Eq. (1) as
4
weighted by their concentration. A comparison of ob-
served and computed spectra yields DG178 ¼ 36:6 kJ/mol
¼
for 1.
Due to poor solubility, signals of carbonyl and CF3
carbons for 1 and those of carbonyl, CF3, and CF2 car-
Tl½ðp-ClÞ tppŠ ꢀ Tl½ðp-ClÞ tppŠþ þ XÀ
ð1Þ
4
4

Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
257
Fig. 2. The 13C (150.87 MHz) broad-band NMR spectra for 2 in CD2Cl2: (a) at 20 °C, (b) entire spectrum at )110 °C, (c) expansion the CO, CF2, and
CF3 of (b).

258
Y.-Y. Lee et al. / Inorganic Chemistry Communications 6 (2003) 252–258
bons for 2 at 20 °C shown in Fig. 2(a) have not been found.
At low temperature, the rate of intermolecular exchange
of CF3COÀ2 for 1 and of CF3CF2COÀ2 for 2 in CD2Cl2 are
slow. Hence, at )110 °C the CO, CF3, and CF2 Carbons of
CF3CF2COÀ2 in 2 shown in Figs. 2(b) and (c) are observed
as two triplets at 156.7 ppm [with 2J(Tl-C) ¼ 128 Hz and
2J(C-F) ¼ 26 Hz], eight triplets at 115.5 ppm [with 4J(Tl-
C) ¼ 10 Hz, 1J(C-F) ¼ 286 Hz, and 2J(C-F) ¼ 35 Hz] and
six quartets at 104.3 ppm [with 3J(Tl-C) ¼ 166 Hz, 1J(C-
F) ¼ 265 Hz and 2J(C-F) ¼ 38 Hz], respectively. Simi-
larly, at )102 °C the CO and CF3 carbons of CF3COÀ2 for
1 in CD2Cl2 are observed as two quartets at 156.2 ppm
crystallographic method. Dynamic 13C and 19F NMR
spectra for the trifluoroacetato group of 1 and the
pentafluoropropionato group of 2 in CD2Cl2 reveal that
these two groups undergo intermolecular exchange with
¼
a free enegy of activation, DG178 ¼ 36:6 kJ/mol, for 1
¼
and, DG213 ¼ 41:5 kJ/mol, for 2.
Supplementary material
Crystallographic data in CIF format for 1 and 2 have
been deposited with Cambridge Data Centre as CCDC
186200 and 186201.
2
2
[with J(Tl-C) ¼ 124 Hz and J(C-F) ¼ 38 Hz] and four
doublets at 113.8 ppm [with 3J(Tl-C) ¼ 235 Hz and 1J(C-
F) ¼ 291 Hz], respectively. Since the fluorine atom has
stronger electron-withdrawing ability than the CF3
group, the fluorine atom of CF3 lower the electron density
on the carbon of the CF3 fragment in 1 more than the CF3
group does in the CF2CF3 fragment of 2. The electron
density around carbon is reduced, but this results in an
increased effective nuclear charge (Zeff ) for the carbon
nucleus. Hence the Zeff of the carbon increases from Cb of
the porphyrin ring in 1 compared to CF2 in 2, and then to
CF3 in 1, this augments the 3J(Tl-C) coupling from 134 Hz
for Cb in 1 to 166 Hz for CF2 in 2, and then to 235 Hz for
CF3 in 1. This increase in coupling constant is due to the
Acknowledgements
Financial support from the National Research
Council of the R.O.C. under Grant NSC 91-2113-M-
005-015 is gratefully acknowledged.
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1
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Due to the electronic effect of the thallium(III) center,
the downfield shifts for the 1Hresonances of the b-pyrrole
protons are 0.28–0.29 ppm for complexes 1 and 2 (Table
1) whereas that effect is small for phenyl protons in the
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In conclusion, this work describes two new thallium
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