Six-Coordinate Thallium(III) Porphyrin Inflate: Synthesis, Physiochemical Characteristics, and X-ray Crystal Structure of (Trifluoromethanesulfonato)(tetrahydrofuran)-(meso-tetraphenylporphyrinato) thallium(III) Tetrahydrofuran Solvate, [Tl(tpp)(OSO2

Full text of DOI:10.1021/ic9803199

6104
Inorg. Chem. 1998, 37, 6104-6108
-
and ionic CF3SO3 for a novel complex (trifluoromethane-
sulfonato)(tetrahydrofuran)(meso-tetraphenylporphyrinato)thal-
lium(III) tetrahydrofuran solvate, [Tl(tpp)(OSO2CF3)(THF)‚
THF] (1), in acetone-d6 can be drawn from the 13C and 19F NMR
spectroscopy studies of triflate ligand at 24 and -80 °C.
In light of above developments, this work synthesizes and
characterizes a six-coordinate thallium(III) porphyrin complex
(1) which appears to be the first complex with a transoid
geometry. The structure of this complex and comparisons with
related cisoid thallium porphyrin structures provide further
insight into the area of main group porphyrin chemistry.
Meanwhile, the 19F and 13C NMR spectra of (1) in a solid state
at 24 °C and in acetone-d6 at low temperature are examined to
Six-Coordinate Thallium(III) Porphyrin Triflate:
Synthesis, Physiochemical Characteristics, and
X-ray Crystal Structure of
(Trifluoromethanesulfonato)(tetrahydrofuran)-
(meso-tetraphenylporphyrinato)thallium(III)
Tetrahydrofuran Solvate,
[Tl(tpp)(OSO2CF3)(THF)‚THF]
Jo-Yu Tung and Jyh-Horung Chen*
Department of Chemistry, National Chung-Hsing University,
Taichung 40227, Taiwan, R.O.C
-
identify the bound triflate in a solid and the ionic CF3SO3 in
Feng-Ling Liao and Sue-Lein Wang
solution.
Department of Chemistry, National Tsing-Hua University,
Hsin-Chu 30043, Taiwan, R.O.C
Experimental Section
Lian-Pin Hwang
Preparation of [Tl(tpp)(OSO2CF3)(THF)‚THF] (1). Tetrahydro-
furan (15 mL) was added to a flask containing Tl(tpp)Cl (100 mg, 0.117
mmol) and Ag(CF3SO3) (60 mg, 0.234 mmol). The mixture was stirred
for 2 h and then filtered through Celite. The deep red filtrate was
evaporated to dryness to yield (1) (88.2 mg, 0.098 mmol, 84%). 1
was dissolved in THF-d8 (99.5% from Aldrich) for 1H NMR measure-
Department of chemistry, National Taiwan University and
Institute of Atomic and Molecular Sciences, Academia
Sinica, Taipei 10764, Taiwan, R.O.C
4
ment at 24 °C. 1H NMR, δ (ppm): 9.11 [d, â-pyrrole, J(Tl-H) )
ReceiVed March 23, 1998
88.4 Hz], 8.26 (m, o-H), 7.80 (m, m, p-H). The crystals were grown
from THF solution. MS, m/z (assignment, rel intensity): 966 ([Tl(tpp)-
(SO3CF3)]+, 11.54), 817 ([Tl(tpp)]+, 100.00), 615 (H2tpp+, 70.57). UV/
visible spectrum λ (nm) (ꢀ × 10-3 (M-1 cm-1)) in acetone (or THF):
332 (11.2), 410 (19.8), 430 (206.6), 530 (2.2), 564 (7.5), 604 (3.9).
Spectroscopy. Proton and 13C NMR spectra in acetone-d6 (99.96%
from Aldrich) or THF-d8 were recorded at 400.13 (or 600.20) and
100.61 (or 150.92) MHz, respectively, on Bruker AM-400 (or DMX-
600) spectrometer locked on solvent deuterium, and referenced to the
solvent peak. 19F NMR spectra were measured in acetone-d6 (or THF-
Introduction
As widely recognized, the trifluoromethanesulfonate anion
(CF3SO3-, triflate) is an excellent leaving group in nucleophilic
substitution reactions in organic chemistry.1 Lemke et al.2
investigated the 1H, 19F, and X-ray structure of bis(trifluo-
romethanesulfonato)(tetra-p-porphyrinato)silicon(IV), Si(tptp)-
(OSO2CF3)2, complex. Arnold et al.3 elucidated the diaquo
complex [Sn(tpp)(H2O)2](OSO2CF3)2, indicating that the triflates
were disordered in the unit cell with reasonably close O-O
contacts. Goff et al.4 closely examined the synthesis and 19F,
1H, and 13C characterization of (trifluoromethanesulfonato)-
(tetraphenylporphyrinato)iron(III), Fe(tpp)(CF3SO3). Guilard et
al.5 investigated the synthesis and 1H characterization of
(trifluoromethanesulfonato)(tetraphenylporphyrinato)gallium-
(III), Ga(tpp)(CF3SO3), and (2,3,7,8,12,13,17,18-octaethylpor-
phyrinato)(trifluoromethanesulfonato)gallium(III), Ga(oep)(CF3-
SO3). Although the triflate (CF3SO3-) of Si(tptp)(CF3SO3)2 is
unidentately coordinated to the silicon atom in solid-state,
according to a previous investigation, the complex Si(tptp)(CF3-
SO3)2 is converted into Si(tptp)(OH)2 and triflic acid (CF3SO2-
OH) when exposed to water in a solution.2 Similar to
Si(tptp)(CF3SO3)2, many metalloporphyrin complexes [M(por)-
(CF3SO3)n, n ) 1, 2] do not exist for a long time outside the
solid state and dissociate or react readily in a solution. Most
previous studies neglect the 13C and 19F NMR spectra of triflate
in the complexes. In this work, we largely focus on the
coordination of the triflate onto the thallium porphyrin com-
plexes. The distinction between the covalently bound CF3SO3
d8) at 282.40 MHz on Bruker MSL-300 spectrometer. Proton and 13
C
NMR are relative to acetone-d6 or THF-d8 at δ ) 2.04 or 3.58 (the
downfield resonance) and the center line of acetone-d6 or THF-d8 at δ
) 29.8 (CH3) or 67.4 (the downfield resonance). 19F data are externally
relative to CFCl3. Next, the temperature of the spectrometer probe
was calibrated by the shift difference of methanol resonance in the 1H
NMR spectrum. The solid-state 13C CP/MAS and 19F MAS spectra
were recorded at 24 °C at 50.33 and 470.6 MHz, respectively, on Bruker
MSL-200 and Bruker MSL-500 spectrometer. In addition, dry nitrogen
gas was used to drive the MAS rates of 3.7 kHz for 13C and 12 kHz
for 19F.
The positive-ion fast atom bombardment mass spectrum (FABMS)
was obtained in a nitrobenzyl alcohol (NBA) matrix using a JEOL JMS-
SX/SX 102A mass spectrometer. UV/visible spectra were recorded at
24 °C on a Hitachi U-3210 spectrophotometer.
Crystallography. Table 1 presents the crystal data and other
information for (1). X-ray structure was measured on a Siemens
SMART CCD diffractometer using monochromatized Mo KR radiation
(λ ) 0.710 73 Å). Absorption corrections were based on 3127
symmetry-equivalent reflections using the SHELXTL-PC program
package with (Tmin,max ) 0.647, 0.943). The structures were solved by
direct methods (SHELXTL PLUS) and refined by full-matrix least-
squares. All non-hydrogen atoms were refined with anisotropic thermal
parameters, whereas all hydrogen atom positions were calculated using
a riding model and included in the structure factor calculation. Table
2 lists selected bond distances and angles.
* To whom correspondence should be addressed.
(1) Lawrance, G. A. Chem. ReV. 1986, 86, 17.
(2) Kane, K. M.; Lemke, F. R.; Petersen, J. L. Inorg. Chem. 1995, 34,
4085.
(3) Smith, G.; Arnold, D. P.; Kennard, C. H. L.; Mak, T. C. W. Polyhedron
1991, 10, 509.
Results and Discussion
(4) Boersma A. D.; Goff, H. M. Inorg. Chem. 1982, 21, 581.
(5) Boukhris, A.; Lecomte, C.; Coutsolelos, A.; Guilard, R. J. Organomet.
Chem. 1986, 303, 151.
Molecular structure of [Tl(tpp)(OSO2CF3)(THF)‚THF]
(1). Figure 1 illustrates the skeletal framework of complex 1.
10.1021/ic9803199 CCC: $15.00 © 1998 American Chemical Society
Published on Web 10/20/1998

Notes
Inorganic Chemistry, Vol. 37, No. 23, 1998 6105
Table 1. Crystal Data for Compound
Tl(tpp)(OSO2CF3)(THF)‚THF (1)
empirical formula
fw
space group
cryst syst
cryst color, habit
a, Å
C49H36F3N4O4STl‚(C4H8O)
1110.4
Cc
monoclinic
blue, columnar
19.2967(1)
11.0937(1)
23.1386(3)
111.702(1)
4602(1)
4
b, Å
c, Å
â, deg
V, Å3
Z
D
calcd, g cm-3
1.602
36.21
1.07
µ(Μo ΚR), cm-1
S
cryst size, mm3
2θmax, deg
0.28 × 0.38 × 0.58
51.1
T, K
296
no. of reflns measd
no. of reflns obsd (I g 3.0σ(I))
Ra (%)
9817
4641
2.98
4.13
Rwb (%)
a R ) [∑||Fo| - |Fc||/∑|Fo|]. b Rw ) [∑w(||Fo| - |Fc||)2/∑w(|Fo|)2]1/2
;
2
w ) A/(σ2Fo + BFo ).
Table 2. Selected Bond Distances (Å) and Angles (deg) for
[Tl(tpp)(OSO2CF3)(THF)‚THF] (1)
Distances
Figure 1. Molecular configuration and atom labeling scheme for Tl-
(tpp)(OSO2CF3)(THF)‚THF (1). Hydrogen atoms and the free THF (or
noncoordinated THF) are omitted for clarity.
Tl(1)-O(1)
Tl(1)-O(4)
O(1)-S(1)
O(2)-S(1)
O(3)-S(1)
S(1)-C(45)
2.387(6)
2.778(7)
1.455(8)
1.42(1)
1.416(9)
1.77(2)
Tl(1)-N(1)
Tl(1)-N(2)
Tl(1)-N(3)
Tl(1)-N(4)
C(45)-F(1)
C(45)-F(2)
C(45)-F(3)
2.137(8)
2.140(7)
2.150(8)
2.153(6)
1.31(2)
1.32(3)
1.38(2)
CF3SO3- with thallium is purely unidentate, the second (or the
third) triflate oxygen i.e. O(2) [or O(3)] being 3.592 (or 4.594
Å) from the thallium atom. The triflate is monodentate both in
1 and in Si(tptp)(OSO2CF3)2.2
Angles
The displacements of the metal center from the planes of the
macrocycle atoms (C20N4) and the four porphyrin nitrogens are
labeled as ∆24 and ∆4N, respectively. The Tl atom is 0.295/
0.273 (i.e. ∆24/∆4N) out of the porphyrin or N4 plane toward
the triflate oxygen. The dihedral angles between the mean plane
(C20N4) and the plane of the phenyl group are 69.4° [C(24)],
82.7° [C(30)], 104.2° [C(36)], and 100.3° [C(42)]. The radius
of the central “hole” (Ct′‚‚‚N, the distance from the geometrical
center (Ct′) of the mean plane of the 24-atom core to the
porphyrinato-core N atoms) in 1 is 2.128 Å, which is larger
than 2.01 Å as suggested by Collin and Hoard.9 The thallium-
(III) is bonded in a highly expanded porphyrinato core (C20N4)
and the porphyrin (C20N4 and Tl) can be viewed as a MOOP
(metal out-of-plane) shape.10 Figure 2 illustrates the displace-
ment (in Å) of each atom of the porphyrin (C20N4 and Tl) from
the porphyrin mean plane (C20N4).
Tl(1)-O(1)-S(1)
O(1)-S(1)-O(2)
O(1)-S(1)-O(3)
O(1)-S(1)-C(45)
O(2)-S(1)-C(45)
O(3)-S(1)-C(45)
O(2)-S(1)-O(3)
O(4)-Tl(1)-N(1)
O(4)-Tl(1)-N(2)
O(4)-Tl(1)-N(3)
O(4)-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)
129.6(5)
113.8(5)
116.0(5)
100.7(8)
105.2(8)
104.1(7)
114.7(7)
83.0(3)
78.6(2)
81.7(3)
87.5(2)
97.2(3)
95.0(2)
98.2(3)
98.9(2)
S(1)-C(45)-F(1)
S(1)-C(45)-F(2)
S(1)-C(45)-F(3)
F(1)-C(45)-F(2)
F(1)-C(45)-F(3)
F(2)-C(45)-F(3)
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)
O(1)-Tl(1)-O(4)
Tl(1)-O(4)-C(46)
Tl(1)-O(4)-C(49)
113(1)
112(1)
108(2)
109(2)
108(1)
107(1)
89.2(3)
164.6(2)
88.2(3)
89.2(3)
166.1(2)
89.7(3)
173.6(3)
124(1)
124.7(8)
It is an octahedral complex of the porphyrin N4, one triflate
oxygen, and one THF oxygen. Bond distances are Tl(1)-O(1)
) 2.387(6) Å, Tl(1)-O(4) ) 2.778(7) Å, and the mean
Tl(1)-N ) 2.145(7) Å. The angle between the two axial
oxygen ligands is nearly linear with O(1)-Tl(1)-O(4) )
173.6(3)°. The thallium-O(4) distance of 2.778(7) Å is long,
but just within the sum of van der Waals radii of thallium and
oxygen, ∼3.5 Å. This longer Tl‚‚‚O(4) contact is described as
the effective coordination (or as “semicoordinated”).6,7 The
short Tl(1)-O(1) distance and the displacement of the thallium
atom toward the triflate are consistent with a much stronger
metal ligand bond to the triflate anion than to the THF molecule.
This type of asymmetry in bond lengths was also observed for
Fe(tpp)(OTeF5)(THF) with Fe-O(OTeF5) ) 1.967 Å and
Fe-O(THF) ) 2.334 Å.8 In compound 1, the interaction of
In general, the coodination sphere of the Tl3+ ion for the
thallium porphyrins is an approximate square-based pyramid
in which the apical site is occupied either by a bidentate group
for complexes Tl(tpp)(O2CCF3), Tl(tmpp)(C6H5CO2), and Tl-
(por)(OAc), with por ) tpp, tmpp (5,10,15,20-tetra(4-methoxy-
phenyl)porphyrinate), tpyp (5,10,15,20-tetra(4-pyridyl)porphy-
rinate), or by a monodentate group for complexes [Tl(por)X]
with the axial ligand X ) CN, Cl, CH3 and por ) tpp, tmpp,
tpyp (Table 3). These thallium porphyrins generally show ∆24
of 0.74-1.06 Å. However, the compound 1 is a distorted
octahedron with O(1) (of triflato) and O(4) (of THF) in the trans
position. To coordinate the O(1) of triflate and semicoordinate
(8) Kellett, P. J.; Pawlik, M. J.; Taylor, L. F.; Thompson, R. G.; Levstik,
M. A.; Anderson, O. P.; Strauss, S. H. Inorg. Chem. 1989, 28, 440.
(9) Collins, D. M.; Hoard, J. L. J. Am. Chem. Soc. 1970, 92, 3761.
(10) Prendergast, K.; Spiro, T. G. J. Am. Chem. Soc. 1992, 114, 3793.
(6) Deacon, G. B.; Philips, R. J. Coord. Chem. ReV. 1980, 33, 227.
(7) Scheidt, W. R.; Lee, Y. J.; Geiger, D. K.; Taylor, K.; Hatano, K. J.
Am. Chem. Soc. 1982, 104, 3367.

6106 Inorganic Chemistry, Vol. 37, No. 23, 1998
Notes
Table 3. Stereochemical Parameters for Thallium(III) Porphyrin Complexes
compound
∆24 (Å)
binding of axial ligand (found)
distortion (C20N4 and Tl)
core size Ct′‚‚‚N (Å)
2.092
Tl(tpp)(O2CCF3)12
Tl(tpp)(OAc)19,20
Tl(tmpp)(OAc)24
Tl(tpyp)(OAc)25,26
Tl(tmpp)(C6H5CO2)27
Tl(tpp)(CN)28
0.741
0.842
0.808
0.858
0.811
0.908
1.027
0.86
0.825
0.900
0.737
0.82
0.826
0.85
0.979
1.059
0.975
0.295
bidentate
bidentate
bidentate
bidentate
bidentate
monodentate
domed
domed
domed
domed
domed
domed
-
2.084
-
2.096
-
Tl(tmpp)(CN)17
Tl(tpyp)(CN)29
monodentate
monodentate
domed
domed
2.085
-
Tl(tpp)Cl30
Tl(tmpp)Cl17
Tl(tpyp)Cl31
-
-
-
domed
domed
domed
-
2.095
2.091
30
Tl(tpp)CH3
-
-
domed
domed
-
-
32
Tl(tpyp)CH3
Tl(tpp)(OSO2CF3)(THF)‚THF
monodentate
MOOP
2.128
Table 4 summarizes 13C data for 1 in acetone-d6 at 24 and -80
°C. Eight major resonances with a R carbon (CR) at δ ) 149.8,
Cl at δ ) 141.3, C2,6 at δ ) 135.5, Câ at δ ) 134.1, C4 at δ )
l29.2, C3,5 at δ ) 127.9, meso carbon (Cm) at δ ) 122.7 and
the CF3SO3 carbon at δ ) 121.2 ppm were observed at -80
°C. Figure 3 shows the 13C spectrum for 1 in acetone-d6 at
-100 °C. The 13C resonance of CF3SO3 for compound 1, as
obtained by averaging over 24 and -80 °C at δ ) 121.5 ( 0.3
1
ppm with J(C-F) coupling constant 321 Hz, resembles that
of ionic CF3SO3- (or free CF3SO3-) with δ ) 120.8 ( 0.2 and
1J(C-F) ) 322 Hz at room temperature (Table 4). 19F NMR
-
spectroscopy was used to examine the binding of CF3SO3 to
Tl(tpp)+. The fluorine resonance for [Bu4N+][CF3SO3-] in
chloroform is found at -78.7 ppm (where CFCl3 is used as an
external reference) at room temperature.4 The 19F signal for
compound 1 at 24 °C is -78.7 ppm (in THF-d8) or -78.1 ppm
(in acetone-d6) resembles that in ionic CF3SO3-. Both 13C and
-
19F data indicate that only the free CF3SO3 is detected for 1
in acetone-d6. Although 1 is a THF solvate, disssolution in
acetone-d6 could produce Tl(tpp)(THF)2+, or the acetone adduct
Tl(tpp)(THF)(OC(CD3)2)+. However, when 1 is dissolved in
acetone-d6, the NMR resonances of THF downfield from Me4-
Si are observed with similar chemical shifts at 67.7 and 25.9
ppm for 13C at -100 °C (Figure 3a), at 67.9 and 26.3 ppm for
13C at 24 °C, and at 3.59 and 1.77 ppm for 1H at -100 and 24
°C. These resonances confirm that all THF is free THF. In
addition, these data do not support the exchange between a small
amount of coordinated THF and free THF for 1 in acetone-d6.
Meanwhile, the 13C and 1H NMR resonances of acetone
downfield from TMS for 1 in acetone-d6 at -100 and 24 °C
are observed with the same chemical shifts at 206.2 and 29.8
Figure 2. Diagram of the porphyrin core (C20N4 and Tl) of compound
1 showing the displacement (in Å) of the atoms from the mean plane
of the porphyrin (C20N4).
the O(4) of THF simulataneously, the T13+ atom closely
approaches the Ct′ of C20N4, resulting in the smaller ∆24 of
0.295 Å for compound 1. The displacement of the thallium
atom depends at least partially on the relative importance of
the binding of the two dissimilar axial ligands for the six-
coordinate metal porphyrin complexes.7 Some measurements
are taken of the asymmetry in axial ligand binding with respect
to the difference in axial bond lengths (∆l). Interestingly,
increasing ∆l from 0 (for the equivalent axial ligand, i.e.
[Fe(oep)(THF)2]+ClO4-)11 and 0.367 (for Fe(tpp)(OTeF5)(THF))8
to 0.391 Å (Tl(tpp)(OSO2CF3)(THF)) causes an increase of the
∆24 from 0 and 0.20 to 0.295 Å.
1
ppm for 13C (Figure 3a) and at 2.04 ppm for H, respectively.
These latter resonances indicate that all the acetone-d6 is free
deuterated acetone. Notably, all THF and acetone-d6 are free
when 1 is dissolved in acetone-d6, implying that the cationic
thallium species Tl(tpp)+ is four-coordinate. The results above
support the proposed dissociation of compound 1 in acetone-d6
as shown in eq 1.
Solid-State CP/MAS 13C and MAS 19F for Compound (1).
Table 4 presents the solid-state 13C CP/MAS data of compound
1 at 24 °C. Five major resonances with CR at δ ) 150.5, C1 at
141.2, C2,6 and Câ at δ ) 133.5, C4 and C3,5 at 128.6, and Cm
and CF3SO3 at 121.2-122.7 ppm were observed. Due to the
overlap of CF3SO3 with Cm, the unambiguous assignment of
the carbon chemical shift for a coordinated triflate is impossible.
However, the 19F chemical shifts of the triflate ions are detected
13C and 19F for Tl(tpp)(OSO2CF3)(THF)‚THF (1) in
Acetone-d6. Results obtained from the 13C NMR studies of 1
in acetone-d6 indicate that 1 ionizes completely and simply Via
acetone-d6
Tl(tpp)(OSO2CF3)(THF)‚THF
8
Tl(tpp)+ + CF3SO3- + 2THF... (1)
(11) Masuda, H.; Taga, T.; Osaki, K.; Sugimoto, H.; Yoshida, Z.; Ogoshi,
H. Bull. Chem. Soc. Jpn. 1982, 55, 3891.

Notes
Inorganic Chemistry, Vol. 37, No. 23, 1998 6107
Table 4. 19F and 13C Chemical Shifts (δ) and Tl-13C Coupling Constant (J in Hz) for Tl(tpp)(OSO2CF3)(THF)‚THF (1) in Acetone-d6
a
solvent
compound
Tl(tpp)(OSO2CF3)(THF)‚THF (1) acetone-d6
(100.61 MHz)
(carbon freq.) T (°C) CR
C1
150.5 141.9 135.5; 135.4 133.7 129.2 127.9 123.2
(7) (19) (170) (166)
134.1 129.2 127.9 122.7
C2,6
Câ
C4
C3,5
Cm
CF3SO3
121.7
19F
24
-78.1
(320)b -78.7c
acetone-d6
(150.89 MHz)
solid
(50.33 MHz)
DMSO-d6
-80
24
149.8 141.3 135.5
150.5 141.2
121.2
-78.4
-74.0d
-
(179)
(166)
122.7-121.1
(321)b
(1)
133.5
128.6
-
(m)
CF3SO3-Na+
Bu4N+CF3SO3
room
temp
room
temp
-
-
-
-
-
-
-
-
-
-
-
120.633
(322)
121.033 -78.74
-
CDCl3
-
-
(321)
a Chemical shifts in ppm relative to the methyl carbon of acetone-d6 at δ ) 29.8. Values in parentheses beneath are J(Tl-13C) coupling constants
in Hz unless specified. 19F was measured at 282.40 MHz unless specified. b 1J(C-F) coupling constant. c It was measured in THF-d8. d Solid-state
19F was measured at 470.6 MHz.
a typical 4J(Tl-F) value of ∼29.2 ( 0.6 Hz,12 for a coordinated
triflate. This is despite the fact that the CF3 group in 1 lies
within the shielding region of 1, which normally leads to upfield
shifts. However, the downfield shift of ∼4.7 ppm for F in the
solid-state NMR is due to the shift of 19F in 1 being controlled
by the paramagnetic term,13-16 not by the ring current effect.
This paramagnetic contribution is a shift toward the lower field,
which is the largest for covalent bonds of CF3SO3 in 1. Our
earlier work observed a similar downfield shift of ∼3 ppm [from
-78.07 (obtained from CF3COOH) to -75.09 ppm] for 19F in
a 0.02 M solution of Tl(tmpp)(O2CCF3) in CD2Cl2 at -70 °C.12
UV/Visible Absorption Spectra for Compound 1. The
electronic spectrum of 1 in acetone (or THF) and the cisoid
six-coordinate thallium porphyrin complexes (e.g. Tl(tpp)(O2-
CCF3) and Tl(tpp)(OAc)) closely resemble with electronic
absorption at 430 (B(0,0)), 564 (Q(1,0)), and 604 (Q (0,0)) for
1 versus 432, 566, and 606 nm for Tl(tpp)(O2CCF3)12,17 and
433, 567, and 607 nm for Tl(tpp)(OAc).18-20 This finding is
due to the former spectrum being the spectrum of Tl(tpp)+.
Notably, the four-coordinate Tl(tpp)+ and the cisoid six-
coordinate thallium porphyrin complexes belongs to regular (or
“normal”) metalloporphyrins containing closed-shell Tl3+ ions
(d10), in which the dπ (dxz, dyz) metal-based orbitals are relatively
low in energy.21,22 These low-energy orbitals only slightly
influence the porphyrin π-to-π* energy gap in porphyrin
electronic spectra. In contrast to most transition metal com-
plexes, their color is due to absorption within the porphyrin
ligand involving the excitation of electrons from π-to-π*
porphyrin ring orbitals. When Tl binds to the porphyrin in
Tl(tpp)+ or in cisoid six-coordinate thallium porphyrin com-
plexes, the absorption spectrum changes due to symmetric
effects. However, the π-to-π* energy gap is negligibly affected
(12) Chou, L. F.; Chen, J. H. J. Chem. Soc., Dalton Trans. 1996, 3787.
(13) Carrington, A.; McLachlan, A. D. Introduction to Magnetic Resonance;
Harper and Row: New York, 1967; p 57.
(14) Pople, J. A.; Schneider, W. G.; Bernstein, H. J. High-Resolution
Nuclear Magnetic Resonance; McGraw-Hill: New York, 1959; p 172.
(15) Eaton, D. R. In Physical Methods in AdVanced Inorganic Chemistry;
Hill, H. A. O., Day, H. Ed.; Wiley: New York, 1967; p 472.
Figure 3. 13C broad band NMR spectra for Tl(tpp)(OSO2CF3)(THF)‚
(16) Yoder, C. H.; Schaeffer, C. D. Introduction to Multinuclear NMR;
Benjamin/Cummings: Reading, MA, 1987; p 85.
(17) Senge, M. O.; Senge, K. R.; Regli, K. J.; Smith, K. M. J. Chem. Soc.,
Dalton Trans. 1993, 3519.
(18) Abraham, R. J.; Barnett, G. H.; Smith, K. M. J. Chem. Soc., Perkin
THF (1) in acetone-d6 (150.92 MHz) at -100 °C: (a) entire spectrum;
(b) expansion the region of 115-155 ppm in (a). TMS is used as
internal reference.
Trans. 1 1973, 2142.
(19) Chen, J. C.; Jang, H. S.; Chen, J. H.; Hwang, L. P. Polyhedron 1991,
when they are coordinated by the solid state 19F NMR
measurement. The resonance of the solid 19F of compound 1
10, 2069.
(20) Suen, S. C.; Lee, W. B.; Hong, F. E.; Jong, T. T.; Chen, J. H.; Hwang,
L. P. Polyhedron 1992, 11, 3025.
(21) Gouterman, M. In The Porphyrins; Dolphin, D., Ed.; Academic: New
York, 1978; Vol. 3, Chapter 1.
(22) Marsh, D. F.; Mink, L. M. J. Chem. Educ. 1996, 73, 1188.
occurs as a broad singlet (line width 1700 Hz, ∼3.6 ppm) at
-74.0 ppm at 24 °C, which is ∼4.7 ppm downfield of the
fluorine resonance for [Bu4N+][CF3SO3-]. Moreover, we
cannot resolve the long-range coupling of 19F to thallium, with

6108 Inorganic Chemistry, Vol. 37, No. 23, 1998
Notes
and a regular metallorporphyrin spectrum results. This phe-
nomenon accounts for why variations of the axial ligand in
Tl(tpp)+ or in cisoid six-coordinate thallium complexes do not
significantly affect the electronic spectra, although minor change
are apparent.18
The typical thallium(III) porphyrin is cisoid five- or six-
coordinate with a large thallium atom displacement (0.74-1.06
Å) from a modestly domed porphyrinato core (with an average
Ct′‚‚‚N of 2.091 Å). The complex 1 studied herein is the first
structurally characterized transoid six-coordinate thallium(III)
porphyrin complex with the thallium atom locating (0.295 Å)
slightly out of the plane toward OSO2CF3- and having a radially
expanded core (with an average Ct′‚‚‚N of 2.128 Å). 1H, 13C,
and 19F of the triflate and THF for compound 1 in acetone-d6
(THF-d8) at -80 and 24 °C confirm that complex 1 ionizes
Conclusions
This investigation synthesizes and characterizes a new
thallium(III) porphyrin complex Tl(tpp)(OSO2CF3)(THF)‚THF
(1). Metathesis reaction of Tl(tpp)Cl with Ag(CF3SO3) in THF
solvent provides the convenient route to Tl(tpp)(OSO2-
CF3)(THF):
-
completely to Tl(tpp)+ and ionic CF3SO3 in acetone-d6 (or
THF-d8).
Acknowledgment. Financial support from the National
Research Council of the R.O.C. under Grant NSC 87-2113-
M-005-001 is gratefully acknowledged.
Tl(tpp)Cl + Ag(CF3SO3) THF8
AgCl(s) + Tl(tpp)(OSO2CF3)(THF)... (2)
Supporting Information Available: Tables of structure determi-
nation summary, atomic coordinates, bond lengths, bond angles,
anisotropic displacement, and H-atom coordinates coefficients and
ORTEP diagrams for compound 1 (14 pages). An X-ray crystal-
lographic file, in CIF format, for compound 1 is also available on the
Internet only. Ordering and access information is given on any current
masthead page.
Tl(tpp)(OSO2CF3)(THF) is formed by eq 2 and dissociates by
eq 1. This compound has little or no stability outside the crystal
lattice; its existence is directly attributed to the solid-state lattice
effects.23
IC9803199
(23) Scheidt, W. R.; Mondal, J. U.; Eigenbrot, C. W.; Adler, A.;
Radonovich, L. J.; Hoard, J. L. Inorg. Chem. 1986, 25, 795.
(24) Sheu, Y. H.; Hong, T. N.; Lin, C. C.; Chen, J. H.; Wang, S. S.
Polyhedron 1997, 16, 681.
(25) Fuh, J. J.; Tang, S. S.; Lin, Y. H.; Chen, J. H.; Liu, T. S.; Wang, S.
S.; Lin, J. C. Polyhedron 1994, 13, 3031.
(26) Tang, S. S.; Lin, Y. H.; Sheu, M. T.; Lin, C. C.; Chen, J. H.; Wang,
S. S. Polyhedron 1995, 14, 1241.
(27) Sheu, Y. H.; Hong, T. N.; Chen, J. H.; Liao, F. L.; Wang, S. L.; Wang,
S. S.; Yang, T. C. Polyhedron 1997, 16, 1621.
(29) Cheng, T. W.; Chen, Y. J.; Hong, F. E.; Chen, J. H.; Hwang, L. P.
Polyhedron 1994, 13, 403.
(30) Henrick, K.; Matthews, R. W.; Tasker, P. A. Inorg. Chem. 1977, 16,
3293.
(31) Tang, S. S.; Liu, I. C.; Lin, C. C.; Chen, J. H.; Wang, S. S. Polyhedron
1996, 15, 37.
(32) Tang, S. S.; Sheu, M. T.; Lin, Y. H.; Liu, I. C.; Chen, J. H.; Wang,
S. S. Polyhedron 1995, 14, 301.
(33) Pouchert, C. J.; Behnke, J. The Aldrich Library of 13C and 1H FT
NMR Spectra, 1st ed.; Aldrich: Milwaukee, WI, 1993; Vol. 1, P1431-
(A, B).
(28) Lee, W. B.; Suen, S. C.; Jong, T. T.; Hong, F. E.; Chen, J. H.; Lin, H.
J.; Hwang, L. P. J. Organomet. Chem. 1993, 450, 63.