A new class of sulfido/oxo(dithiolene)-molybdenum(IV) complexes derived from sulfido/oxo-bis(tetrasulfido)molybdenum(IV) anions

Article abstract of DOI:10.1021/ic800832a

Mono(dithiolene)sulfidomolybdenum(IV) complexes, [MoS(S₄)(bdt)] ^2- (2) and [MoS(S₄)(bdtCl₂)]^2- (3) (1,2-benzene-dithiolate = bdt, 3,6-dichloro-1,2-benzenedithiolate = bdtCl ₂), were prepared by the substitution reaction of a tetrasulfido ligand in known [MoS(S₄)₂]^2- (1) with the corresponding dithiol. Complexes 2 and 3 were irreversibly oxidized to give bis(μ-sulfido) dimolybdenum(V) species, {[MoS(bdt)]₂(μ-S) ₂}^2- (4) and {[MoS(bdtCl₂)]₂(μ-S) ₂}^2- (5), in aerobic acetonitrile. Mono(dithiolene) oxomolybdenum(IV) complexes, [MoO(S₄)(bdt)]^2- (7) and [MoO(S₄)(bdtCl₂)]^2- (8), that are oxo derivatives of 2 and 3 were also synthesized from a known [MoO(S ₄)₂]^2- (6) of an oxo derivative of 1 and the corresponding dithiol. Further, the electrophilic addition of dimethyl acetylenedicarboxylate to 7 gave [MoO(bdt)(S₂C₂(COOMe) ₂)]^2- (9), and ligand substitution of the tetrasulfido group of 7 with bdt and bdtCl₂ yielded [MoO(bdt)₂] ^2- (10) and [MoO(bdt)(bdtCl₂)]^2- (11), respectively. New sulfido/oxo molybdenum complexes were characterized by ¹H NMR, IR, ESI-MS, Raman, and UV-vis spectroscopies; cyclic voltammetry; and elemental analysis, and crystal structures of 2, 3, 5, 7, and 8 were determined by X-ray analysis.

Full text of DOI:10.1021/ic800832a

Inorg. Chem. 2008, 47, 10150-10157
A New Class of Sulfido/Oxo(dithiolene)-Molybdenum(IV) Complexes
Derived from Sulfido/Oxo-Bis(tetrasulfido)molybdenum(IV) Anions
Hideki Sugimoto,*,† Koichiro Suyama,† Kunihisa Sugimoto,‡ Hiroyuki Miyake,† Isao Takahashi,§
Shun Hirota,§ and Shinobu Itoh†
Department of Chemistry, Graduate School of Science, Osaka City UniVersity, Sumiyoshi-ku,
Osaka 558-8585, Japan, Rigaku Corporation, Akishima, Tokyo 196-8666, Japan, and Graduate
School of Materials Science, Nara Institute of Science and Technology, Ikoma, 630-0192 Japan
Received May 7, 2008
Mono(dithiolene)sulfidomolybdenum(IV) complexes, [MoS(S4)(bdt)]2- (2) and [MoS(S4)(bdtCl2)]2- (3) (1,2-benzene-
dithiolate ) bdt, 3,6-dichloro-1,2-benzenedithiolate ) bdtCl2), were prepared by the substitution reaction of a
tetrasulfido ligand in known [MoS(S4)2]2- (1) with the corresponding dithiol. Complexes 2 and 3 were irreversibly
oxidized to give bis(µ-sulfido) dimolybdenum(V) species, {[MoS(bdt)]2(µ-S)2}2- (4) and {[MoS(bdtCl2)]2(µ-S)2}2- (5),
in aerobic acetonitrile. Mono(dithiolene)oxomolybdenum(IV) complexes, [MoO(S4)(bdt)]2- (7) and [MoO(S4)(bdtCl2)]2-
(8), that are oxo derivatives of 2 and 3 were also synthesized from a known [MoO(S4)2]2- (6) of an oxo derivative
of 1 and the corresponding dithiol. Further, the electrophilic addition of dimethyl acetylenedicarboxylate to 7 gave
[MoO(bdt)(S2C2(COOMe)2)]2- (9), and ligand substitution of the tetrasulfido group of 7 with bdt and bdtCl2 yielded
[MoO(bdt)2]2- (10) and [MoO(bdt)(bdtCl2)]2- (11), respectively. New sulfido/oxo molybdenum complexes were
1
characterized by H NMR, IR, ESI-MS, Raman, and UV-vis spectroscopies; cyclic voltammetry; and elemental
analysis, and crystal structures of 2, 3, 5, 7, and 8 were determined by X-ray analysis.
Introduction
for elucidating the structure/reaction relationships.5-7 Among
the synthetic analogues, a limited number of mono(dithiolene)-
Mo complexes relating to reaction centers of the xanthine
oxidase family and sulfite oxidase family have been reported,
whereas many bis(dithiolene) complexes including MoO,5-8
MoS,9 and MoSe10 and des-oxo Mo5-7,11 functional groups
were presented as synthetic analogues of DMSO reductase
family reaction centers. In particular, significantly fewer are
a type of mono(dithiolene)MoS complex, resulting in only
In recent years, much attention has been directed toward
the synthesis of metal-dithiolene complexes. This interest
is primarily due to their utility in magnetic materials,1
superconductors,1 nonlinear optical materials,1 and lumines-
cent sensors2 as well as in supramolecular architectures.3
Molybdenum (Mo)-containing enzymes, except nitrogenase,
universally possess pyranopterindithiolene cofactors and are
classified into the xanthine oxidase family featured by
mono(dithiolene)MoS centers, the sulfite oxidase family
characterized by mono(dithiolene)MoO centers, and the
DMSO reductase family consisting of bis(dithiolene)Mo
centers,4 and this finding has given new significance to
chemistry of dithiolene complexes of Mo.4 Synthetic ana-
logues of the enzyme reaction centers have been developed
(5) McMaster, J.; Tunney, J. M.; Garner, C. D. Prog. Inorg. Chem. 2004,
52, 539, and references therein.
(6) Enemark, J. H.; Cooney, J. J. A.; Wang, J.-J.; Holm, R. H. Chem.
ReV. 2004, 104, 1175, and references therein.
(7) Sugimoto, H.; Tsukube, H. Chem. Soc. ReV. [Online] DOI: 10.1039/
B610235M and references therein.
(8) Sugimoto, H.; Harihara, M.; Shiro, M.; Sugimoto, K.; Tanaka, K.;
Miyake, H.; Tsukube, H. Inorg. Chem. 2005, 44, 6386.
(9) (a) Sugimoto, H.; Sakurai, T.; Miyake, H.; Tanaka, K.; Tsukube, H.
Inorg. Chem. 2005, 44, 6927. (b) Groysman, S.; Holm, R. H. Inorg.
Chem. 2007, 46, 4090.
(10) Tano, H.; Tajima, R.; Miyake, H.; Itoh, S.; Sugimoto, H. Inorg. Chem.
2008, 47, 7465.
(11) (a) Nagarajan, K.; Joshi, H. K.; Chaudhury, P. K.; Pal, K.; Cooney,
J. A.; Enemark, J. H.; Sarkar, S. Inorg. Chem. 2004, 43, 4532. (b)
Jiang, J.; Holm, R. H. Inorg. Chem. 2005, 44, 1068. (c) Wang, J.-J.;
Tessier, C.; Holm, R. H. Inorg. Chem. 2006, 45, 2979. (d) Majumdar,
A.; Pal, K.; Sarkar, S. Inorg. Chem. 2008, 47, 3393.
* Author to whom correspondence should be addressed. Phone: 81 6
6605 2548. Fax: 81 6 6605 2522. E-mail: sugimoto@sci.osaka-cu.ac.jp.
†
Osaka City University.
Rigaku Corporation.
Nara Institute of Science and Technology.
‡
§
(1) Faulmann, C.; Cassoux, P. Prog. Inorg. Chem. 2004, 52, 399.
(2) Cummings, S. D.; Eisenberg, R. Prog. Inorg. Chem. 2004, 52, 315.
(3) Kreickmann, T.; Hahn, F. E. Chem. Commun. 2007, 1111.
(4) Hille, R. Chem. ReV. 1996, 96, 2757.
10150 Inorganic Chemistry, Vol. 47, No. 21, 2008
10.1021/ic800832a CCC: $40.75  2008 American Chemical Society
Published on Web 10/01/2008

Sulfido/Oxo(dithiolene)-Molybdenum(IV) Complexes
Scheme 1. Preparation Procedures of 2, 3, 4, 5, 7, 8, 9, 10, and 11
one series of [Tp*MoV/IVS(dithiolene)]0/- complexes (Tp*
) hydrotris(3,5-dimethylpyrazol-1-yl)borate);12,13 this indi-
cates that the incorporation of one terminal sulfido group
into a mono(dithiolene)Mo center is a still difficult task. With
respect to mono(dithiolene)MoO complexes, some types of
the species have been synthesized with mono-,14 di-,15 or
tridentate16 coligands. Therefore, development of new syn-
thetic procedures for various types of mono(dithiolene)-
MoS/O complexes is necessary to expand the fields of
bioinorganic chemistry as well as material science.
In this study, we employ the known (Et4N)2[MoIVS(S4)2]
(1) from the literature17 to prepare novel dithiolene com-
plexes of Mo, because 1 comprises a square pyramidal Mo
center with substitutable sulfido and tetrasulfido ligands and
can be easily obtained from commercially available reagents
of MoS4 and elemental sulfur.17 Here, we describe the
2-
synthesis of (Et4N)2[MoIVS(S4)(bdt)] (2, bdt ) 1,2-benzene-
dithiolate) and (Et4N)2[MoIVS(S4)(bdtCl2)] (3, bdtCl2 ) 3,6-
dichloro-1,2-benzenedithiolate) from 1 and the corresponding
dithiol and characterizations of 2 and 3. Reaction of the oxo
analogue of 1, (Et4N)2[MoIVO(S4)2] (6),18 which is obtained
from commercially available reagents Mo7O246-, S2-, and
elemental sulfur, with H2bdt and H2bdtCl2 is also revealed
to yield oxo analogues of 2 and 3, (Et4N)2[MoIVO(S4)(bdts)]
(bdts ) bdt (7) and bdtCl2 (8)). Furthermore, the conversion
of 7 to bis(dithiolene)MoIVO complexes, (Et4N)2[MoO-
(bdt)(dithiolene)] (dithiolene ) S2C2(CO2Me)2 (9), bdt (10),
and bdtCl2 (11)) is briefly described. The complexes obtained
in this study are new members of dithiolene complexes of
Mo (Scheme 1).
(12) (a) Young, C. G.; Gable, R. W.; Hill, J. P.; Geroge, G. N. Eur. J. Inorg.
Chem. 2001, 2227. (b) Burgmayer, S. J. N.; Kim, M.; Peti, R.;
Rothkopf, A.; Kim, A.; BelHamdounia, S.; Hou, Y.; Somogyi, A.;
Habel-Rodriguez, D.; Williams, A.; Kirk, M. L. J. Inorg. Biochem.
2007, 101, 1601.
Experimental Section
General. All reagents and solvents were used as received unless
otherwise noted. Acetonitrile was dried over CaH2 and then P2O5
and distilled under dinitrogen prior to use. All reactions were carried
out under dinitrogen in a Schlenk tube. (Et4N)2[MoS(S4)2] (1) and
(Et4N)2[MoO(S4)2] (6) were prepared by following the literature
procedures.17,18
Synthesis and Characterization of Complexes. (Et4N)2[MoS-
(S4)(bdt)] (2). H2bdt (9.0 µL, 0.078 mmol) was added to 1 (50.0
mg, 0.077 mmol) suspended in acetonitrile (15 mL). Within 30
min of stirring, the suspension changed to a brown solution, which
was then concentrated to ca. 3 mL. After removal of the precipitated
(13) [Tp*MoVS(S2C2(CO2Me)2)] was obtained as a mixture with the MoO
derivative from a reaction of (Et4N)[Tp*MoS/O(S4)] and DMAD.16c
(14) (a) Lim, B. S.; Willer, M. W.; Miao, M.; Holm, R. H. J. Am. Chem.
Soc. 2001, 123, 8343. (b) Partyka, D. V.; Holm, R. H. Inorg. Chem.
2004, 43, 8609. (c) Wang, J.-J.; Holm, R. H. Inorg. Chem. 2007, 46,
11156.
(15) (a) Nicholas, K. M.; Khan, M. A. Inorg. Chem. 1987, 26, 1633. (b)
Sugimoto, H.; Siren, K.; Tsukube, H.; Tanaka, K. Eur. J. Inorg. Chem.
2003, 2633.
(16) (a) Eagle, A. A.; Young, C. G.; Tiekink, E. R. T. Polyhedron 1990,
9, 2965. (b) Cleland, W. E., Jr.; Barnhart, K. M.; Yamanouchi, K.;
Collison, D. M.; Ortega, F. E. R. B.; Enemark, J. H. Inorg. Chem.
1987, 26, 1017. (c) Sproules, S. A.; Morgan, H. T.; Doonan, C. J.;
White, J. M.; Young, C. G. Dalton Trans. 2005, 3552.
(17) Draganjac, M.; Simhon, E.; Chan, K. T.; Kanatzidis, M.; Baenziger,
N. C.; Coucouvanis, D. Inorg. Chem. 1982, 21, 3321.
(18) (a) Ansari, M. A.; Chandrasekaran, J.; Sarkar, S. Inorg. Chim. Acta
1987, 133, 133. (b) Coucouvanis, D.; Hadjikyriacou, A.; Toupadakis,
A.; Koo, S.-M.; Draganjac, I. M. Inorg. Chem. 1991, 30, 754.
Inorganic Chemistry, Vol. 47, No. 21, 2008 10151

Sugimoto et al.
1
elemental sulfur from the solution, an orange microcrystalline
powder precipitated from the solution and was collected by filtration.
Yield: 30.5 mg (60%). Anal. calcd for C22H44MoN2S7 (mol wt.
656.96): C, 40.22; H, 6.75; N, 4.26. Found: C, 40.17; H, 6.72; N;
4.31. H NMR (CD3CN, anionic part): δ 6.79 (m, 2H), 7.50 (m,
2H). UV-vis spectrum (CH3CN): λmax ) 322 (16 000), 422 nm (ε
) 3500 dm3 mol-1 cm-1). ESI-MS (CH3CN): m/z 512 {[M]2-
+
Et4N+}-. CV (CH3CN): Epa(irrev.) ) -0.05 V vs SCE. IR (KBr):
ν 662 (w), 761 (s), 781 (m), 927 (vs), 1001 (s), 1021 (m), 1091
(w), 1171 (s), 1236 (s), 1391 (vs), 1434 (vs), 1451 (s), 1483 (vs),
1547 cm-1 (w).
1
4.24. H NMR (CD3CN, anionic part): δ 6.86 (m, 2H), 7.61 (m,
2H). UV-vis spectrum (CH3CN): λmax ) 336 (ε ) 16200), 440
nm (3500 dm3 mol-1 cm-1). ESI-MS (CH3CN): m/z 528 {[M]2-
+ Et4N+}-. CV (CH3CN): Epa(irrev.) ) -0.10 V vs saturated
calomel electrode (SCE). IR (KBr): ν 500 (vs), 664 (w), 751 (s),
754 (m), 1002 (s), 1022 (m), 1172 (s), 1239 (m), 1287 (m), 1391
(vs), 1433 (vs), 1457 (vs), 1479 (vs), 1547 cm-1 (w).
Method B. To an acetonitrile solution (50 mL) of (Et4N)2-
[MoO(S4)2] (100 mg, 0.159 mmol), H2bdt (18.3 µL, 0.159 mmol)
was added. The brown solution was stirred for 3 h at 60 °C and
then concentrated to ca. 5 mL. After removal of the precipitated
elemental sulfur from the solution by filtration, diethyl ether (20
mL) was then added to the filtrate. A brown microcrystalline powder
precipitated and was collected by filtration. Yield: 77.4 mg (76%).
The UV-vis and IR spectra were identical with those of 7 prepared
by method A.
(Et4N)2[MoO(S4)(bdtCl2)] (8). As it was difficult to purify this
complex by method A for 7 on a synthetic scale, 8 was prepared
by method B for 7, except that H2bdtCl2 was used instead of H2bdt.
Yield: 81.2 mg (72%). Anal. calcd for C22H42Cl2MoN2OS6 (mol
wt. 709.83): C, 37.23; H, 5.96; N, 3.95. Found: C, 37.27; H, 5.94;
(Ph4P)2[MoS(S4)(bdt)] (2a). After the addition of Ph4PBr (64.0
mg, 0.153 mmol) to an acetonitrile solution of 2 (50.0 mg, 0.076
mmol), the resultant brown solution stood for several days to give
an orange microcrystalline powder. The powder was collected by
filtration and dried in Vacuo. Yield: 56.0 mg (68%). Anal. calcd
for C54H44MoP2S7 (mol wt. 1075.29): C, 60.32; H, 4.12. Found:
C, 60.06; H, 4.09. ESI-MS (CH3CN): m/z 737 {[M]2- + Ph4P+}-.
(Et4N)2[MoS(S4)(bdtCl2)] (3). This complex was prepared as
described above for the synthesis of 2 by using H2bdtCl2 instead
of H2bdt. Yield: 24.3 mg (43%). Anal. calcd for C22H42Cl2MoN2S7
(mol wt. 724.90): C, 36.40; H, 5.83; N, 3.86. Found: C, 36.58; H,
1
N; 3.95. H NMR (CD3CN, anionic part): δ 6.95 ppm (s, 2H).
1
5.68; N; 4.00. H NMR (CD3CN, anionic part): δ 7.01 (s, 2H).
UV-vis spectrum (CH3CN): λmax ) 329 (ε ) 9200), 429 nm (1400
dm3 mol-1 cm-1). ESI-MS (CH3CN): m/z 580 {[M]2- + Et4N+}-.
CV (CH3CN): Epa(irrev.) ) +0.05 V vs SCE. IR (KBr): ν 785 (s),
806 (s), 919 (vs), 1001 (s), 1058 (s), 1153 (s), 1171 (s), 1182 (s),
1268 (s), 1330 (s), 1395 (vs), 1457 (vs), 1477 (s), 1527 cm-1 (w).
(Et4N)2[MoO(bdt)(S2C2(COOMe)2)] (9). To an acetonitrile
solution (4 mL) of 7 (100.8 mg, 0.16 mmol), dimethyl acetylene-
dicarboxylate (28.9 µL, 0.24 mmol) was added. After stirring for
6 h, the resulting solution was concentrated to ca. 1 mL. Elemental
sulfur precipitated from the solution and was removed by filtration.
An orange powder precipitated from the resultant solution, which
was collected by filtration and recrystallized by CH3CN/diethyl
ether. Yield: 62.3 mg (55%). Anal. calcd for C28H50MoN2O5S4 (mol
wt. 718.92): C, 46.78; H, 7.01; N, 3.90. Found: C, 46.70; H, 6.95;
UV-vis spectrum (CH3CN): λmax ) 330 (sh), 423 nm (ε ) 3700
dm3 mol-1 cm-1). ESI-MS (CH3CN): m/z 596 {[M]2- + Et4N+}-.
CV (CH3CN): Epa(irrev.) ) +0.04 V vs SCE. IR (KBr): ν 502
(vs), 595 (w), 782 (s), 811 (m), 1000 (s), 1058 (vs), 1155 (s), 1170
(s), 1182 (s), 1270 (s), 1329 (s), 1394 (vs), 1453 (vs), 1477 (vs),
1521 cm-1 (w).
(Ph4P)2[MoS(S4)(bdtCl2)] (3a). This complex was prepared by
a similar method as for the preparation of 2a except that 3 (50.0
mg, 0.069 mmol) was applied instead of 2. Yield: 56.8 mg (72%).
Anal. calcd for C54H42Cl2MoP2S7 (mol wt. 1144.18): C, 56.69; H,
3.37. Found: C, 56.85; H, 3.54. ESI-MS (CH3CN): m/z 805 {[M]2-
+ Ph4P+}-.
(Et4N)2[MoS(bdt)]2(µ-S)2 (4). An acetonitrile solution (10 mL)
containing 2 (24.9 mg, 0.038 mmol) was exposed to the air with
stirring for 5 h at 60 °C. After concentration of the obtained brown
solution to ca. 3 mL, a brown microcrystalline powder precipitated,
which was collected by filtration and dried in the air. Yield: 19.2
1
N; 3.87%. H NMR (CD3CN, anionic part): δ 3.69 (s, 6H), 6.73
(m, 2H), 7.49 (m, 2H). ESI-MS (CH3CN): m/z 590 {M + Et4N}-,
460 {M}-. CV (CH3CN): E1/2(rev.) ) -0.24 V vs SCE. IR (KBr):
ν 753 (w), 908 (s), 1021 (s), 1234 (vs), 1435 (s), 1481 (w), 1530
(w), 1718 cm-1 (vs).
1
mg (57%). The H NMR, UV-vis, ESI-MS, and IR spectra were
identical to those reported in the literature.19
(Et4N)2[MoO(bdt)2] (10). H2bdt (9.8 µL. 0.085 mmol) was
added to an acetonitrile solution (50 mL) of 7 (50.0 mg, 0.08 mmol),
and the solution was stirred for 4 h at 40 °C. The resulting green
solution was concentrated to ca. 9 mL and then stood for 1 h. After
elemental sulfur precipitated and was removed by filtration, a pale
microcrystalline powder precipitated from the filtrate, which was
collected by filtration and washed with CS2. Yield: 16.1 mg (32%).
(Et4N)2[MoS(bdtCl2)]2(µ-S)2 (5). This complex was synthesized
by a similar method as for the preparation of 4 except that 3 (50.0
mg, 0.069 mmol) was reacted instead of 2. Yield: 35.0 mg (51%).
Anal. calcd for C28H44Cl4Mo2N2S8 (mol wt. 998.89): C, 33.67; H,
4.44; N, 2.80. Found: C, 33.63; H, 4.21; N; 2.89. 1H NMR (CD3CN,
anionic part): δ 7.16 (s, 11H). ESI-MS (CH3CN): m/z 370 {M}2-
.
CV (CH3CN): E1/2 (rev.) ) -1.58, Epc(irrev.) ) -1.93 V vs SCE.
IR (KBr): ν 451 (w), 527 (vs), 600 (w), 792 (w), 819 (m), 998
(w), 1065 (s), 1158 (s), 1267 (s), 1336 (vs), 1397 (vs), 1436 (w),
1455 (w), 1478 (w), 1525 cm-1 (w).
(Et4N)2[MoO(S4)(bdt)] (7). Method A. Water (5 mL) was
added to an acetonitrile solution (45 mL) of 2 (32.9 mg, 0.050
mmol). The resultant brown solution was stirred for 5 h and
concentrated to ca. 2 mL. An orange microcrystalline powder
precipitated from the solution, which was collected by filtration.
Yield: 21.8 mg (68%). Anal. calcd for C22H44MoN2OS6 (mol wt.
640.93): C, 41.23; H, 6.92; N, 4.37. Found: C, 41.12; H, 6.86; N;
1
The H NMR, UV-vis, ESI-MS, and IR spectra were identical
with those reported in the literature.20
(Et4N)2[MoO(bdt)(bdtCl2)] (11). This complex was prepared
as described above for the synthesis of 10 by using H2bdtCl2 instead
of H2bdt. Yield: 25.9 mg (46%). Anal. calcd for C28H48-
Cl2MoN2O2S4 (mol wt. 721.80): C, 46.59; H, 6.62; N, 3.88. Found:
1
C, 46.68; H, 6.24; N, 3.78. H NMR ((CD3)2SO, anionic part): δ
6.66 (m, 2H), 6.84 (s, 2H), 7.43 (m, 2H). UV-vis spectrum
(CH3CN): λmax ) 330 (sh), 423 nm (ε ) 3700 dm3 mol-1 cm-1).
ESI-MS (CH3CN): m/z ) 592 {[M]2- + Et4N+}-, 462 {[M]2-
-
e-}-. CV (CH3CN): E1/2(rev.) ) -0.24 V vs SCE. IR (KBr): ν
(19) Lee, C. C.; Halbert, T. R.; Pan, W.-H.; Harmer, M. A.; Wei, L.;
Leonowicz, M. E.; Dim, C. O. B.; Miller, K. F.; Bruce, A. E.;
McKenna, S.; Corbin, J. L.; Wherland, S.; Stiefel, E. I. Inorg. Chim.
Acta 1996, 243, 147.
(20) Boyde, S.; Ellis, S. R.; Garner, C. D.; Clegg, W. J. Chem. Soc., Chem.
Commun. 1986, 1541.
10152 Inorganic Chemistry, Vol. 47, No. 21, 2008

Sulfido/Oxo(dithiolene)-Molybdenum(IV) Complexes
Table 1. Crystallographic Data for 1-8a
2
2a·DMF
3a ·DMF
5
7
8a
formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
ꢀ, deg
γ, deg
V, Å3
C22H44MoN2S7
656.96
monoclinic
P21/n
9.229(2)
30.116(6)
10.893(2)
90
100.803(2)
90
2974(1)
4
C57H51MoNOP2S7
1148.34
monoclinic
P21/c
11.1008(2)
22.032(3)
21.427(4)
90
91.921(3)
90
5238(2)
4
C57H49Cl2MoNOP2S7
1217.23
C28H44Cl4 Mo2N2S8
998.84
monoclinic
P21/a
17.118(3)
13.014(3)
18.085(4)
90
92.013(4)
90
4027(1)
4
C22H44MoN2OS6
640.89
orthorhombic
Pbcn
30.103(2)
14.4075(7)
13.6530(7)
90
90
90
5921.4(5)
8
1.438
C38H42Cl2MoNOPS6
918.94
monoclinic
P21/c
16.427(2)
14.070(2)
17.529(2)
90
95.436(3)
90
4033.3(9)
4
triclinic
j
P1
10.421(1)
13.519(2)
20.424(3)
80.555(7)
88.458(7)
75.768(6)
2750.9(6)
2
Z
F, g cm-3
µ, mm-1
data
1.467
0.947
26598
1.456
0.632
52277
1.469
0.700
29465
1.648
1.325
37589
1.513
0.839
41869
0.884
40479
unique data
7021
11962
12400
9212
6413
9207
R1a
0.0446
0.1026
1.085
0.0743
0.1503
0.992
0.0723
0.1729
0.992
0.0790
0.1511
1.140
0.0627
0.1103
1.319
0.0708
0.1939
1.004
wR2 (F2)b
GOF
a R1 ) ∑(|Fo| - |Fc|)/∑|Fo|. b wR2 ) {∑(w(Fo - Fc )2)/∑w(Fo )2}1/2
.
2
2
2
755 (m), 784 (w), 805 (m), 907 (s), 998 (s), 1055 (s), 1151 (s),
1172 (s), 1267 (m), 1324 (m), 1392 (s), 1433 (w), 1482 (vs), 1524
idealized positions on carbon atoms and were not refined. All
structures converted in the final stages of refinement showed no
movement in the atom positions. Calculations for 2, 2a·DMF,
3a·DMF, 5, 7, and 8a were performed using the Single-Crystal
Structure Analysis Software, version 3.8.23 The crystallographic
parameters are summarized in Table 1.
(w) cm-1
.
Physical Measurements. FT-IR spectra were recorded with a
Perkin-Elmer Spectrum One spectrometer. Resonance Raman (rR)
scattering was excited at 488 nm with an Ar+ ion laser (Spectra
Physics, 2017) and detected with a triple polychromator (Jasco,
NRS-1800) equipped with a CCD detector (Princeton Instruments).
rR spectra were measured at ambient temperature in a spinning
cell (3000 rpm). Raman shifts were calibrated with inden. Solid
FT Raman (FTR) spectra were measured with a Perkin-Elmer
Spectrum GX-Raman spectrometer. 1H NMR spectra were recorded
with a JEOL Lambda 300, and the TMS signal was adjusted to 0
ppm. ESI-MS spectra were measured with a JEOL JMS-700S.
UV-vis spectra were recorded on a HP-8453 spectrometer.
Electrochemistry. Cyclic voltammetric measurements were
performed under dinitrogen with a Hokuto Denko HZ-3000
potentiostat. A set of a glassy-carbon working electrodes with a
circle 3 mm in diameter, a SCE reference electrode, and a platinum
counter electrode were used.
Results and Discussion
Preparation and Crystal Structural Characterization
of Dithiolene Complexes of MoIVS(S4). (Et4N)2[MoIVS-
(S4)(bdt)] (2; bdt ) 1,2-benzenedithiolate) and its chlorine-
substituted analogue (Et4N)2[MoIVS(S4)(bdtCl2)] (3; 3,6-
dichloro-1,2-benzenedithiolate) were obtained in good yields
(60 and 43%) when 1 equiv of the corresponding dithiol was
added dropwise slowly to an acetonitrile solution of
(Et4N)2[MoIVS(S4)2] (1). The yields became lower (<50%
and <35%) when the dithiols were added rapidly. Meth-
athesis of 2 and 3 with 2 equiv of Ph4PBr gave the
corresponding Ph4P+ salts, 2a and 3a.
X-ray Crystallography. Single crystals of (Ph4P)2[MoS(S4)-
(bdt)] · DMF (2a · DMF) and (Ph4P)2[MoS(S4)(bdtCl2)] · DMF
(3a·DMF) were obtained by the diffusion of diethyl ether into DMF
solutions of 2 and 3 in the presence of Ph4PBr. Single crystals of
2, 5, and 7 were obtained by recrystallization from acetonitrile/
diethyl ether. A single crystal of (Et4N)(Ph4P)[MoO(S4)(bdtCl2)]
(8a) was obtained by the diffusion of diethyl ether into an
acetonitrile-H2O solution containing 3 and Ph4PBr. Each single
crystal obtained was mounted on top of glass fibers. All X-ray data
were collected by Rigaku CCD diffractometer with monochromated
Mo KR (graphite for 2a·DMF, 3a ·DMF, 7, and 8a and multilayer
mirror for 2 and 5) at -160 °C. The structures were solved by a
direct method (SIR-92)21 and expanded using DIRDIF 99.22 The
non-hydrogen atoms, except two methyl carbon atoms of the DMF
molecule in 3a·DMF, were refined anisotropically by full-matrix
least squares on F2. The hydrogen atoms, except the formamide
group of 2a·DMF and 3a·DMF, in all structures were attached at
The crystal structures of the anionic complexes of 2,
2a · DMF, and 3a · DMF are shown in Figure 1, and the
selected bond distances and angles are listed in Table 2. The
Mo1 atom of 2 is coordinated by a terminal sulfido S1, two
sulfur atoms S2 and S5 of a tetrasulfido group, and two sulfur
atoms S6 and S7 of bdt. The S2, S5, S7, and S6 atoms are
almost on the same plane, and four bond angles of
S1-Mo1-S2(108.74(3)°),-S5(108.55(3)°),-S6(108.18(4)°),
and -S7 (108.12(3)°) are very close to each other. The bond
angle of S2-Mo1-S7 (142.51(3)°) is also very close to
S5-Mo1-S6 bond angles (143.14(3)°). These observations
indicate that the Mo1 center adopts a slightly distorted square
pyramidal geometry, where the Mo1 atom is raised above
the plane toward the S1 atom by 0.75 Å. For the tetrasulfido
group, the S2, S3, S4, and S5 atoms form a zigzag structure
in which the torsion angle defined by S2-S3-S4-S5 is 47°.
The coordination environment of the Mo1 center of 2a is
similar to that of 2, and the four sulfur atoms S2, S3, S4,
(21) Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.; Burla,
M.; Polidori, G.; Camalli, M. J. Appl. Crystallogr. 1994, 27, 435.
(22) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.; de
Gelder, R.; Israel, R.; Smits, J. M. M. The DIRDIF-99 program system;
Technical Report of the Crystallography Laboratory, University of
Nijmegen: The Netherlands, 1999.
(23) Crystal Structure Analysis Package; Rigaku and Rigaku/MSC: The
Woodlands, TX, 2000-2006.
Inorganic Chemistry, Vol. 47, No. 21, 2008 10153

Sugimoto et al.
Figure 2. Crystal structure of the anionic complex of (Et4N)2[MoS(bdtCl2)](µ-
S)2 (5) shown with 50% ellipsoids. The hydrogen atoms were omitted for
clarity.
Table 3. Selected Bond Distances (Å) and Angles (deg) of 5
5
Mo1-S1
2.397(2)
2.403(2)
2.336(2)
2.321(2)
2.108(2)
2.8551(9)
Mo2-S7
Mo2-S8
Mo2-S4
Mo2-S3
Mo2-S6
2.402(2)
2.400(2)
2.318(2)
2.329(2)
2.119(2)
Mo1-S2
Mo1-S3
Mo1-S4
Mo1-S5
Mo1-Mo2
S1-Mo1-S3
S2-Mo1-S4
S5-Mo1-S1
S5-Mo1-S2
S5-Mo1-S3
S5-Mo1-S4
Mo1-S3-Mo2
145.20(7)
S7-Mo2-S4
S8-Mo2-S3
S6-Mo2-S7
S6-Mo2-S8
S6-Mo2-S4
S6-Mo2-S3
Mo1-S4-Mo2
142.15(6)
144.10(7)
107.00(7)
105.55(7)
108.83(7)
109.17(7)
75.97(6)
Figure 1. Crystal structures of the anionic complexes of (Et4N)2-
[MoS(S4)(bdt)] (2, above), (Ph4P)2[MoS(S4)(bdt)]·DMF (2a·DMF, middle),
and (Ph4P)2[MoS(S4)(bdtCl2)]·DMF (3a·DMF, below) shown with 50%
ellipsoids. The hydrogen atoms were omitted for clarity.
142.20(6)
104.16(7)
106.94(7)
109.26(7)
108.98(7)
75.48(5)
Table 2. Selected Bond Distances (Å) and Angles (deg) of 2,
2a·DMF, and 3a·DMF
2
2a·DMF
3a ·DMF
110.29(6)°) are larger than those of S1-Mo1-S6 and -S7
(106.24(5) and 106.69(6)°), reflecting a lean of the Mo-S1
axis to the bdtCl2 side. A mononuclear five-coordinate MoS
structure is rare and is found in only 1,17 bis(dithiolene)-
MoIVS complexes including cyclohexene-1,2-dithiolate9a and
1,2-dimethyl-1,2-ethylenedithiolate,9b and (Et4N)2[MoS-
(CS4)2]25 in the literatures.
Mo1-S1
2.138(1)
2.126(2)
2.307(2)
2.341(2)
2.402(2)
2.391(2)
109.40(8)
107.71(7)
104.61(7)
110.08(7)
92.00(7)
83.2(1)
2.146(2)
2.314(2)
2.323(2)
2.377(1)
2.392(1)
110.05(5)
110.29(6)
106.24(5)
106.69(6)
91.57(5)
82.54(4)
142.88(6)
142.76(6)
80.53(5)
82.39(4)
Mo1-S2
2.3087(8)
2.3518(9)
2.3917(8)
2.3945(8)
Mo1-S5
Mo1-S6
Mo1-S7
S1-Mo1-S2
S1-Mo1-S5
S1-Mo1-S6
S1-Mo1-S7
S2-Mo1-S5
S2-Mo1-S6
S2-Mo1-S7
S5-Mo1-S6
S5-Mo1-S7
S6-Mo1-S7
108.74(3)
108.55(3)
108.18(4)
108.12(3)
91.37(3)
79.84(3)
142.51(3)
143.14(3)
83.35(3)
82.48(3)
Electrochemical Property of 2 and 3: Structural
Change from the [MoIVS(S4)] Unit to the [MoVS]2(µ-S)2
Unit. Complexes 2 and 3 exhibited an irreversible oxidation
wave at -0.10 V and + 0.04 V versus SCE in acetonitrile,
respectively. The potential difference is an indication of the
stronger bdt f MoIV donation compared with the bdtCl2 f
MoIV donation. Upon oxidizing 2 and 3 by air in acetonitrile,
black-brown microcrystalline powders were obtained. IR,
UV-vis, and ESI-MS spectra of the black-brown species
derived from 2 were identical with those of known (Et4N)2-
[MoVS(bdt)]2(µ-S)2 (4) prepared from (NH4)2[MoVS(S2)2]2(µ-
S)2 and 2 equiv of H2bdt.19 The powder derived from 3 was
140.19(7)
147.03(6)
80.87(7)
82.16(6)
and S5 adopt a zigzag form having a torsion angle of 46°.
In 2a, however, somewhat larger bond angles of S1-Mo1-S2
and -S7 (mean 110°) and S5-Mo1-S6 (147.03(6)°) than
thoseofS1-Mo1-S5and-S6(mean106°)andS2-Mo1-S7
(140.19(7)°), respectively, suggest that a small amount of a
trigonal bipyramidal geometry having the S5-Mo1-S6 bond
as the axis is involved in the stereochemistry of the Mo1
center, reflecting a ca. 10 times larger τ value of 2a (0.1117)
compared with 2 (τ ) 0.0105), in which τ describes a
parameter used to measure the distortion of geometries
between square pyramid and trigonal bipyramid.24 Packing
forces are considered to be responsible for these minor
differences between 2 and 2a.
The coordination environment of the Mo1 center of 3a
with a τ value of 0.00183 is similar to that of 2 rather than
2a and is described as a square pyramid with the Mo center
displaced 0.75 Å from the 4S equatorial plane. A torsion
angle of 46° comprising four sulfur atoms of the tetrasulfido
group is almost the same as those values for 2 and 2a. The
bond angles of S1-Mo1-S2 and -S5 (110.05(5) and
1
characterized as (Et4N)2[MoVS(bdtCl2)]2(µ-S)2 (5) by H
NMR, IR, and ESI-MS spectra and elemental analysis.
Although a crystal structure of the dinuclear complex 4 of
bdt has not been determined yet, that of bdtCl2 complex 5
was determined in this study. Table 3 lists the selected bond
distances and angles. As indicated in Figure 2, the anion
consists of two [MoS(bdtCl2)]+ units bridged by two sulfido
groups. The two terminal sulfido groups are located in syn
configuration. The bond angle of S1-Mo1-S3 (145.20(7)°)
is close to that of S2-Mo1-S4 (142.20(6)°), indicating that
the Mo1 atom possesses a square-pyramidal geometry. The
bond angles of S1-Mo1-S5 and S2-Mo1-S5 (mean 106°)
are smaller than those of S3-Mo1-S5 and S4-Mo1-S5
(mean 109°) due to electronic repulsions between two
terminal sulfido groups, S5 and S6. The stereochemistry of
(24) Addison, A. W.; Rao, T. N.; Reedijk, J.; Rijn, J.; Verschoor, G. C.
J. Chem. Soc., Dalton Trans. 1984, 1349.
(25) Coucouvanis, D.; Draganjac, M. J. Am. Chem. Soc. 1982, 104, 6820.
10154 Inorganic Chemistry, Vol. 47, No. 21, 2008

Sulfido/Oxo(dithiolene)-Molybdenum(IV) Complexes
from 450 to 550 cm-1.27 In that region, 2 showed one IR
peak at 500 cm-1 and two FTR peaks at 498 and 518 cm-1.
Among these, the peaks at 500 (IR) and 498 (FTR) cm-1
are tentatively assigned to the ν(ModS) stretching band
because 6 with no ModS bond did not exhibit such a strong
IR peak near 500 cm-1 and ν(ModS) stretching bands are
IR- and Raman-active.27 The remaining peak at 518 cm-1
(FTR) of 2 is assignable to the ν(S-S) stretching band, as
6 with a S4 group has a peak at 513 cm-1. This tentative
2-
assignment is further supported by the IR and FTR spectra
of 7, which is a simple oxo derivative of 2 (2 (bdt)MoS(S4)
vs 7 (bdt)MoO(S4)), where no strong peak appeared near
500 cm-1, but a weak peak was observed at 509 cm-1 instead
(see below). Similarly, for 3, the peaks observed at 502 (IR)
and 500 (FTR) cm-1 and the FTR peak appearing at 517
cm-1 are tentatively assigned to the ν(ModS) and the
ν(S-S) stretching bands, respectively, on the basis of a
comparison with IR and FTR spectra of 6 with no ModS
bond and 8 being a simple oxo derivative of 3. In the rR
spectrum of an acetonitrile solution of 2,28,29 bands at 534
and 511 cm-1 are assignable to the ν(S-S) and ν(ModS)
stretchings, respectively, referring to the rR spectrum of 6
in acetonitrile (Figure 3). This tentative assignment can be
also explained by comparing the rR spectrum of 2 with that
of 7, being an oxo derivative of 2 (vide infra). Similarly,
bands at 527 and 514 cm-1 in the rR spectrum of 3 in
acetonitrile are tentatively assigned to the ν(S-S) and
ν(ModS) stretchings, respectively.
Preparation and Characterization of Dithiolene Com-
plexes of MoIVO(S4). Because 1 was revealed to be a good
precursor for mono(dithiolene)MoS complexes, its oxo
derivative, (Et4N)2[MoO(S4)2] (6), was treated with H2bdt
and H2bdtCl2, and (Et4N)2[MoIVO(S4)(bdt)] (7) and
(Et4N)2[MoO(S4)(bdtCl2)] (8) were isolated in 76 and 72%,
respectively. Complexes 7 and 8 were also derived from 2
and 3 in H2O-CH3CN or excess phenol containing
H2O-CH3CN. The crystal structure of 7 is shown in Figure
4, and the selected bond distances and angles are listed in
Table 4. The Mo1 atom is coordinated by a terminal oxo
group O1, two sulfur atoms S3 and S6 of the tetrasulfido
group, and two sulfur atoms S1 and S2 of bdt. The bond
angle of S1-Mo1-S3 (143.54(4)°) is close to that of
S2-Mo1-S6 (145.15(3)°), and four bond angles of O1-
Mo1-S (1, 2, 3, and 6) are almost same, indicating that the
Mo1 center adopts a square pyramidal stereochemistry with
a τ value of 0.0265. The crystal structure of (Et4N)(Ph4P)-
[MoO(S4)(bdtCl2)] (8a) was determined. As shown in Figure
4, the Mo1 atom possesses a square-pyramidal stereochem-
istry with a τ value of 0.0535, and bond distances and angles
around the Mo1 are also close to those of 7 (Table 4).
Whereas the Mo1dO1 distance at 1.730(4) Å of 7 is
somewhat longer than those of (Et4N)2[MoIVO(S4)2] (1.685(7)
Å)17 and (Et4N)2[MoIVO(bdt)2] (1.699(6) Å),20 the ν(ModO)
Figure 3. IR spectra (left above) and FT Raman (FTR) spectra (left, below)
of (Et4N)2[MoS(S4)(bdt)] (2), (Et4N)2[MoS(S4)(bdtCl2)] (3), and (Et4N)2-
[MoO(S4)2] (6) and rR spectra (right) of acetonitrile solutions of 2 (5.1 ×
10-4 M), 3 (6.4 × 10-4 M), and 6 (1.7 × 10-3 M) using an Ar+ ion laser
with excitation at 488 nm.
Mo2 is almost the same as that of Mo1. The syn-[MoVS](µ-
S)2 core structure is precedented in thiomolybdate sys-
tems.17,25
FT- and Resonance-Raman Spectroscopic Charac-
terization of 2 and 3. IR and FTR spectra of solid samples
of 2 and 3 in a region from 400 to 950 cm-1 are presented
in Figure 3 together with that of a known complex of
(Et4N)2[MoO(S4)2] (6).18,26 The FTR spectra in a region from
300 to 2000 cm-1 are indicated in Figure S1 (Supporting
Information). It is well-known that stretchings of MdS and
S-S bonds in coordination compounds appear in a region
(27) Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coor-
dination Compounds, 5th ed.; John Wiley & Sons: New York, 1997.
(28) The solubility of 2, 3, and 6 into acetonitrile was not sufficient enough
to measure their FT Raman spectra of the solutions.
(26) In spite of our great efforts, measurements of resonance Raman spectra
of solid samples of 2 and 3 were unsuccessful because of decomposi-
tion of the compounds by photo-irradiation.
(29) The complexes exhibit a shoulder peak at 488 nm with ε values larger
than 800 M-1 cm-1
.
Inorganic Chemistry, Vol. 47, No. 21, 2008 10155

Sugimoto et al.
Figure 4. Crystal structures of the anionic complexes of (Et4N)2-
[MoO(S4)(bdt)] (7, above) and (Et4N)(Ph4P)[MoO(S4)(bdtCl2)] (8a, below)
shown with 50% ellipsoids. The hydrogen atoms were omitted for clarity.
Table 4. Selected Bond Distances (Å) and Angles (deg) of 7 and 8a
7
8a
Mo1-O1
1.730(4)
2.406(1)
2.397(1)
2.361(1)
2.337(1)
143.54(4)
145.15(3)
106.73(9)
106.25(9)
109.34(9)
107.96(9)
1.732(4)
2.405(2)
2.388(3)
2.363(2)
2.335(2)
145.08(6)
141.87(6)
107.6(2)
107.3(2)
106.9(2)
110.6(2)
Mo1-S1
Mo1-S2
Mo1-S3
Figure 5. IR spectra (left above) and FT Raman (FTR) spectra (left, below)
of (Et4N)2[MoO(S4)(bdt)] (7) and (Et4N)2[MoO(S4)(bdtCl2)] (8) and rR
spectra (right) of acetonitrile solutions of 7 (4.2 × 10-3 M) and 8 (4.4 ×
10-3 M) using an Ar+ ion laser with an excitation at 488 nm.
Mo1-S6
S1-Mo1-S3
S2-Mo1-S6
O1-Mo1-S1
O1-Mo1-S2
O1-Mo1-S3
O1-Mo1-S6
in the lower-energy region can be attributable to the
ν(Mo-S) stretching, referring to the assignment of Raman
spectra of dithiolene complexes of Mo.33
stretching value of 7 (IR: 927 cm-1) is close to that of the
former (932 cm-1)17 and significantly larger than that of
(Et4N)2[MoIVO(bdt)2] (IR: 905 cm-1).20 In contrast, the
ν(ModO) stretching value of 8 (IR: 919 cm-1) is almost
equal to an average value (921 cm-1) of those of
(Et4N)2[MoO(S4)2] (IR: 932 cm-1)17 and (Et4N)2[MoIVO-
(bdtCl2)2] (IR: 910 cm-1).30,31 Complexes 7 and 8 exhibited
an irreversible oxidation wave at -0.05 and +0.05 V versus
SCE, respectively, in acetonitrile. As in the case of their
sulfido derivatives 2 and 3, the irreversible oxidation process
may be ascribed to dimerization of the (Et4N)[MoVO(bdts)]
species, giving the (Et4N)2[MoVO(bdts)]2(µ-S)2 species. A
comparison of the ν(ModO) stretching values of 7; 8; and
the MoIVO complexes of bis(S4), bis(bdt), and bis(bdtCl2)
suggests that bdt presents an electronic effect similar to that
of the tetrasulfido ligand, but bdtCl2 provides a different
electronic effect from it. IR and FTR spectra of solid 7 and
8 and rR spectra of acetonitrile solutions of 7 and 8 are shown
in Figure 5. The FTR spectra in a region from 300 to 2000
cm-1 are indicated in Figure S2 (Supporting Information).
When the spectra of 7 and 8 are compared with those of 2,
3, and 6, the peaks observed at 509 (FTR) and 536 cm-1
(rR) for 7 and the peaks appearing at 516 (FTR) and 536
cm-1 (rR) for 8 are tentatively assigned to the ν(S-S)
stretching band. In the FTR spectra, several peaks appearing
Formation of Bis(dithiolene) MoIVO Complex from
7. Referring to the established methods of preparing various
(dithiolene)Mo complexes from (polysulfido)Mo complexes
and activated alkynes,12b,16c,18,34 new [Mo(S/O)(S4)(bdt)]2-
complexes were treated with dimethyl acetylenedicarboxylate
(DMAD). In the case of 2, the treatment with DMAD did
not give [MoIVS(bdt)(S2C2(COOMe)2)]2- but rather a mixture
comprising (Et4N)2[MoIV(bdt)(S2C2(COOMe)2)2] and unre-
acted 2 in a 1:1 ratio. The reaction of 7 with DMAD gave
a pale brown solid in 55% yield, which was identified as
(Et4N)2[MoIVO(bdt)(S2C2(COOMe)2)] (9). Attempts to syn-
thesize (Et4N)2[MoIVS(bdts)2] complexes by the reaction of
2 or 3 with an equal amount of H2bdt or H2bdtCl2 were
unsuccessful, yielding a 1:1 mixture of (Et4N)2[MoIV(1,2-
benzenedithiolates)3]35,36 and the unreacted precursor. How-
ever, the reactions of 7 with H2bdt and H2bdtCl2 were found
to give the known (Et4N)2[MoIVO(bdt)2] (10)8 and the new
(Et4N)2[MoIVO(bdt)(bdtCl2)] (11) in 32 and 46% yields,
respectively. New complexes 9 and 11 were characterized
by 1H NMR, UV-vis, and ESI-MS spectra; CV; and
elemental analysis (see the Experimental Section). Because
(33) Johnson, M. L. Prog. Inorg. Chem. 2004, 52, 213, and references
therein.
(34) (a) Halbert, T. R.; Pan, W.-H.; Stiefel, E. I. J. Am. Chem. Soc. 1983,
105, 5476. (b) Soricelli, C. L.; Szalai, V. A.; Burgmayer, S. J. N.
J. Am. Chem. Soc. 1991, 113, 9877. (c) Rauchfuss, T. B. Prog. Inorg.
Chem. 2004, 52, 1, and references therein.
(35) Isfort, C.; Pape, T.; Hahn, F. E. Eur. J. Inorg. Chem. 2005, 2607.
(36) Sugimoto, H.; Furukawa, Y.; Tarumizu, M.; Miyake, H.; Tanaka, K.;
Tsukube, H. Eur. J. Inorg. Chem. 2005, 3088.
(30) Sugimoto, H.; Tarumizu, M.; Miyake, H.; Tsukube, H. Dalton Trans.
2005, 3558.
(31) The crystal structure of (Et4N)2[MoIVO(bdtCl2)2] has not been deter-
mined.30,32
(32) Sugimoto, H.; Tarumizu, M.; Miyake, H.; Tsukube, H. Eur. J. Inorg.
Chem. 2006, 4494.
10156 Inorganic Chemistry, Vol. 47, No. 21, 2008

Sulfido/Oxo(dithiolene)-Molybdenum(IV) Complexes
only two examples of (Et4N)2[MoO(mnt)(S2C2H2)]37 and
(Et4N)2[MoO(bdt)(S2C2(CF3)2)]38 include two different dithi-
olene ligands in bis(dithiolene)MoO complexes in the
literature, 7 was also revealed to be a precursor opening an
alternative route to MoO complexes including two different
dithiolenes.
11, including two different dithiolenes. New complexes
prepared, excluding the bis(dithiolene)MoIVO species, were
crystallographically characterized. The new and convenient
methods in this report will allow for an introduction to other,
more biologically relevant ligands to further expand model
complexes.
Conclusions
Acknowledgment. This work was partly supported by a
grant for Scientific Research (No. 20550067 to H.S.) from
the Japan Society for Promotion of Science and by the Joint
Studies Program (2008) of the Institute for Molecular
Science. The authors are grateful to Professor Koji Tanaka
and Dr. Tohru Wada for measurements of FT Raman spectra.
Measurement of rR spectra was partly supported by Kyoto-
Advanced Nanotechnology Network.
The present study provided a synthetic method starting
from the bis(tetrasulfido)MoIVS complex, 1. Mono(dithiolene)-
MoIVS complexes, 2 and 3, were synthesized from precursor
1 and 1,2-benzenedithiols. One-electron oxidation of the
obtained complexes gave dinuclear MoVS complexes, 4 and
5, bridged by two sulfido groups. The MoIVO species were
also prepared by the substitution of one tetrasulfide group
of the bis(tetrasulfido)MoIVO complex, 6, with 1,2-benzene-
dithiols. The reactions of DMAD and H2bdtCl2 with the
derived MoIVO species, 7, gave MoIVO complexes, 9 and
Supporting Information Available: The FT Raman spectra in
a region from 300 to 2000 cm-1 of solid 2, 3, 6, 7, and 8 (Figures
S1 and S2). CIF files of 2, 3, 5, 7, and 8. This material is available
free of charge via the Internet at http://pubs.acs.org.
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