Syntheses, reactivity, and crystal structures of molybdenum complexes with pyridine-2-thionate (pyS)-containing ligands (see abstract)

Article abstract of DOI:10.1021/ic020579x

The doubly bridged pyridine-2-thionate (pyS) dimolybdenum complex [Mo(η³-C₃H₅)(CO) ₂]₂(μ-η¹, η²-pyS)₂ (1) is accessible by the reaction of [Mo(η³-C₃H₅)(CO) ₂(CH₃CN)₂Br] with pySK in methanol at room temperature. Complex 1 reacts with piperidine in acetonitrile to give the complex [Mo(η³-C₃H₅)(CO) ₂(η²-pyS)(C₅H₁₀NH) (2). Treatment of 1 with 1,10-phenanthroline (phen) results in the formation of complex [Mo(η³-C₃H₅)(CO) ₂(η¹-pyS)(phen)] (3), in which the pyS ligand is coordinated to Mo through the sulfur atom. Four conformational isomers, endo,exo-complexes [Mo(η³-C₃H₅)(CO) (η²-pyS)(η²-diphos)] (diphos = dppm, 4a-4d; dppe, 5a-5d), are accessible by the reactions of 1 with dppm and dppe in refluxing acetonitrile. Homonuclear shift-correlated 2-D ³¹p{¹H}-³¹p{¹H} NMR experiments of the mixtures 4a-4d have been employed to elucidate the four stereoisomers. The reaction of 4 and pySK or [Mo(CO)₃(η¹-SC₅H₄NH) (η²-dppm)] (6) and O₂ affords allyl-displaced seven-coordinate bis(pyridine-2-thionate) complex [Mo(CO)(η²-pyS)₂(η²-dppm)] (7). All of the complexes are identified by spectroscopic methods, and complexes 1, 5d, 6, and 7 are determined by single-crystal X-ray diffraction. Complexes 1 and 5d crystallize in the orthorhombic space groups Pbcn and Pbcn with Z = 4 and 8, respectively, whereas 6 belongs to the monoclinic space group C2/c with Z = 8 and 7 belongs to the triclinic space group P1 with Z = 2. The cell dimensions are as follows: for 1, a = 8.3128(1) A, b = 16.1704(2) A, c = 16.6140(2) A; for 5d, a = 17.8309(10) A, b = 17.3324(10) A, c = 20.3716(11) A; for 6, a = 18.618(4) A, b = 16.062(2) A, c = 27.456(6) A, β = 96.31(3)°; for 7, a = 9.1660(2) A, b = 12.0854(3) A, c = 15.9478(4) A, α = 78.4811(10)°, β = 80.3894(10)°, γ = 68.7089(11)°.

Full text of DOI:10.1021/ic020579x

Inorg. Chem. 2003, 42, 1092−1100
Syntheses, Reactivity, and Crystal Structures of Molybdenum
Complexes with Pyridine-2-thionate (pyS)-Containing Ligands: Crystal
Structures of [Mo(η3-C H )(CO)2]2(µ-η1,η2-pyS)2,
3 5
exo-[Mo(η3-C H )(CO)(η2-pyS)(η2-dppe)],
3 5
[Mo(CO)3(η1-SC H NH)(η2-dppm)], and [Mo(CO)(η2-pyS)2(η2-dppm)]
5 4
,†
Kuang-Hway Yih,* Gene-Hsiang Lee,‡ and Yu Wang§
Department of Applied Cosmetology, Hung Kuang Institute of Technology, Taichung, Taiwan 433,
ROC, Instrumentation Center, College of Science, National Taiwan UniVersity, Taipei, Taiwan
106, ROC, and Department of Chemistry, National Taiwan UniVersity, Taipei, Taiwan 106, ROC
Received September 24, 2002
The doubly bridged pyridine-2-thionate (pyS) dimolybdenum complex [Mo(η3-C H )(CO)2]2(µ-η1,η2-pyS)2 (1) is
3
5
accessible by the reaction of [Mo(η3-C H )(CO)2(CH CN)2Br] with pySK in methanol at room temperature. Complex
3
5
3
1 reacts with piperidine in acetonitrile to give the complex [Mo(η3-C H )(CO)2(η2-pyS)(C H NH)] (2). Treatment of
3
5
5 10
1 with 1,10-phenanthroline (phen) results in the formation of complex [Mo(η3-C H )(CO)2(η1-pyS)(phen)] (3), in
3
5
which the pyS ligand is coordinated to Mo through the sulfur atom. Four conformational isomers, endo,exo-complexes
[Mo(η3-C H )(CO)(η2-pyS)(η2-diphos)] (diphos ) dppm, 4a−4d; dppe, 5a−5d), are accessible by the reactions of
3
5
1 with dppm and dppe in refluxing acetonitrile. Homonuclear shift-correlated 2-D 31P{1H}−31P{1H} NMR experiments
of the mixtures 4a−4d have been employed to elucidate the four stereoisomers. The reaction of 4 and pySK or
[Mo(CO)3(η1-SC H NH)(η2-dppm)] (6) and O affords allyl-displaced seven-coordinate bis(pyridine-2-thionate) complex
5
4
2
[Mo(CO)(η2-pyS)2(η2-dppm)] (7). All of the complexes are identified by spectroscopic methods, and complexes 1,
5d, 6, and 7 are determined by single-crystal X-ray diffraction. Complexes 1 and 5d crystallize in the orthorhombic
space groups Pbcn and Pbca with Z ) 4 and 8, respectively, whereas 6 belongs to the monoclinic space group
C2/c with Z ) 8 and 7 belongs to the triclinic space group P1h with Z ) 2. The cell dimensions are as follows:
for 1, a ) 8.3128(1) Å, b ) 16.1704(2) Å, c ) 16.6140(2) Å; for 5d, a ) 17.8309(10) Å, b ) 17.3324(10) Å, c
) 20.3716(11) Å; for 6, a ) 18.618(4) Å, b ) 16.062(2) Å, c ) 27.456(6) Å, â ) 96.31(3)°; for 7, a ) 9.1660(2)
Å, b ) 12.0854(3) Å, c ) 15.9478(4) Å, R ) 78.4811(10)°, â ) 80.3894(10)°, γ ) 68.7089(11)°.
Introduction
concerns the dithiocarbamate molybdenum complex [Mo-
(η3-allyl)(CO)2(py)(η2-S2CNR)] (R ) Me2, Et2), prepared by
treating [Mo(η2-BPY)(η3-allyl)(CO)2Br] with NaS2CNR in
the presence of py. More recently Shiu et al.3 used [Mo(CH3-
CN)2(η3-allyl)(CO)2Br] to react with NaS2CNR (R ) C4H8,
Et2), forming a 16-electron complex, [Mo(η3-allyl)(CO)2(η2-
S2CNR)]. Recently we prepared the 18-electron allyl dithio-
carbonate [Mo(CH3CN)(η3-allyl)(CO)2(η2-S2COEt)] com-
plex.4 The 18-electron allyl dialkyldithiophosphate complexes
A variety of allyl complexes of molybdenum(II) containing
bidentate anionic sulfur donor ligands such as dithiocarbam-
ates have been described.1 For example, an early report2
* Author to whom correspondence should be addressed. E-mail: khyih@
sunrise.hkc.edu.tw. Phone: 886-4-26318652-5308. Fax: 886-4-26321046.
† Hung Kuang Institute of Technology.
‡ College of Science, National Taiwan University.
§ Department of Chemistry, National Taiwan University.
(1) (a) Templeton, J. L.; Ward, B. C. J. Am. Chem. Soc. 1980, 102, 6568.
(b) Houchin, M. R.; Mitsios, K. Inorg. Chim. Acta 1982, 65, L147.
(c) Morrow, J. R.; Tonker, T. L.; Templeton, J. L. J. Am. Chem. Soc.
1985, 107, 5004. (d) Morrow, J. R.; Templeton, J. L.; Bandy, J. A.;
Bannister, C.; Prout, C. K. Inorg. Chem. 1986, 25, 1923. (e)
Armstrong, E. M.; Baker, P. K.; Flower, K. R. J. Chem. Soc., Dalton
Trans. 1990, 2535.
(2) Zhuang, B.; Huang, L.; He, L.; Yang, Y.; Lu, J. Inorg. Chim. Acta
1988, 145, 225.
(3) Shiu, K. B.; Yih, K. H.; Wang, S. L.; Liao, F. L. J. Organomet. Chem.
1991, 420, 359.
(4) Yih, K. H.; Lee, G. H.; Wang, Y. J. Chem. Soc., Dalton Trans.,
manuscript in preparation.
1092 Inorganic Chemistry, Vol. 42, No. 4, 2003
10.1021/ic020579x CCC: $25.00 © 2003 American Chemical Society
Published on Web 01/17/2003

Molybdenum Complexes with pyS-Containing Ligands
Scheme 1
[Mo(CH3CN)(η3-allyl)(CO)2{η2-S2P(OR2)}]5 (R ) Et, Ph)
and [Mo2(η3-allyl)2(CO)4{η2-S2P(OR2)}2(µ-NH2NH2)] have
also been described.5 The 16-electron allyl dithio complexes
such as [Mo(η3-allyl)(CO)2(η2-S2CNR)]6 (R ) Et, C4H8,
C5H10) and [Mo(η3-allyl)(CO)2(η2-Pz*2BR2)]7 (R ) H, Et,
Ph) containing sulfur or nitrogen bidentate ligands have also
been studied. However, no detailed information has been
presented on a mixed bidentate (N, S) ligand such as pySH.
Carlton8 and Baker9 described the preparation and char-
acterization of the alkyne pyridine-2-thionate (pyS) com-
plexes [W(CO)(pyS)(η2-MeC2Me)] and [W(CO)(NCMe)-
(pyS)(η2-MeC2Me)2][BPh4]. However, no allyl complexes
of molybdenum(II) containing pyS have been described. In
a previous paper10 we described the preparation and char-
acterization of the first doubly bridged pyS allyl dimolyb-
denum(II) complex [Mo(η3-C3H4R)(CO)2]2(µ-η1,η2-pyS)2 (1).
Herein, we report the reactions of 1 with nitrogen and
phosphine ligands as well as the characterization of four
conformational isomers of [Mo(η3-allyl)(CO)(η2-diphos)(η2-
pyS)] by 2-D 31P{1H}-31P{1H} NMR experiments.
Results and Discussion
Syntheses. The reactions of [Mo(η3-C3H5)(CO)2(CH3CN)2-
(Br)] with NaS2CNR (R ) Me2, Et2, C4H8, C5H10) or KS2-
COEt produced the 16-electron allyl dithiocarbamate com-
plex [Mo(η3-C3H5)(CO)2(η2-S2CNR)]3 or the 18-electron allyl
dithiocarbonate complex [Mo(CH3CN)(η3-C3H5)(CO)2(η2-S2-
COEt)].4 We expected that the reaction of [Mo(η3-C3H5)-
(CO)2(CH3CN)2(Br)] with pyS would produce a 16-electron
pyridine-2-thionate complex, [Mo(η3-C3H5)(CO)2(η2-pyS)],
or an 18-electron acetonitrile solvate complex, [Mo(CH3CN)-
(η3-C3H5)(CO)2(η2-pyS)]. Instead, we obtained a dimer, [Mo-
(η3-C3H5)(CO)2]2(µ-η1,η2-pyS)2 (Scheme 1). Complex [Mo-
(η3-C3H5)(CH3CN)2(CO)2Br] and pySK react in methanol at
room temperature, producing the novel doubly bridged
pyridine-2-thionate complex 1 in good yield. The air-stable
yellow complex 1 is soluble in DMSO and slightly soluble
in CH2Cl2, CH3CN, and THF.
Although the dinuclear compound 1 is held by sulfur
bridges and is thermally stable, these bridges are easily
cleaved. Thus, [Mo(η3-C3H5)(CO)2(η2-pyS)(C5H10NH)] (2)
and [Mo(η3-C3H5)(CO)2(η1-pyS)(phen)] (3) complexes were
produced by the reactions of 1 and piperidine, C5H10NH, or
1,10-phenanthroline, C12H8N2, in dichloromethane at ambient
temperature. The yellow compound 2 is slightly air-sensitive,
(5) Barrado, G.; Miguel, D.; Riera, V.; Garcia-Granda, S. J. Organomet.
Chem. 1995, 489, 129.
(6) Yih, K. H.; Lee, G. H.; Wang, Y. J. Organomet. Chem. 1999, 588,
125.
(7) (a) Cotton, F. A.; Stanislowski, A. G. J. Am. Chem. Soc. 1974, 96,
5074. (b) Lush, S. F.; Wang, S. H.; Lee, G. H.; Peng, S. M.; Wang,
S. L.; Liu, R. S. Organometallics 1990, 9, 1862.
(8) Carlton, L.; Davidson, J. L. J. Chem. Soc., Dalton Trans. 1988, 2071.
(9) Baker, P. K.; Jackson, P. D.; Drew, M. G. B. J. Chem. Soc., Dalton
Trans. 1994, 37.
(10) Yih, K. H.; Lee, G. H.; Huang, S. L.; Wang, Y. Inorg. Chem. Commun.
2003, 6, 213.
Inorganic Chemistry, Vol. 42, No. 4, 2003 1093

Yih et al.
soluble in polar solvent, and slightly soluble in n-hexane.
The air-stable red compound 3 is soluble in dichloromethane,
and insoluble in diethyl ether and n-hexane.
an octahedral geometry. Only one terminal carbonyl stretch-
ing band is found at 1807 cm-1 in 7.
We could not obtain the parent peak [M+] molecular mass
with the typical Mo isotope distribution of 1 from the FAB
mass spectrum. The FAB mass spectra of 2-5 and 6 and 7
show parent peaks with the typical Mo isotope distribution
corresponding to [M+] and [M+ - CO] molecular masses,
respectively.
The respective reactions of 1 and dppm or dppe in
refluxing acetonitrile result in the isolation of the mixtures
of four endo,exo conformational isomers, [Mo(η3-C3H5)(CO)-
(η2-pyS)(η2-diphos)] (diphos ) dppm, 4a-4d; dppe, 5a-
5d), in good yields with endo-PN:endo-PS:exo-PN:exo-PS
ratios of 3:7:11:79 and 15:35:10:40. The orientations of endo
and exo are defined to the open face of the allyl group and
carbonyl group in the same direction in the former and
opposite directions in the latter.11 The PS or PN means one
phosphorus atom of the diphos ligand and the sulfur or
nitrogen atom of the pyS ligand in the trans position of the
pseudooctahedral geometry of complexes 4 and 5. In an
attempt to synthesize 4a-4d, we treated [Mo(CO)3(η1-
pySH)(η2-dppm)] (6) with allyl bromide in the presence of
Et3N in acetonitrile at room temperature. However, at higher
temperatures only decomposition was observed.
1
NMR Spectroscopy. The room temperature H NMR
spectrum of 1 shows five allyl proton resonances at δ 1.00,
1.33, 3.06, 3.43, and 3.83 with equal intensity. The13C{1H}
NMR spectrum of 1 reveals two singlets at lowest field,
which are assigned to the carbon atoms of the four terminal
carbonyl groups (Supporting Information, spectrum A).
Similar spectroscopic observations of the carbonyl group and
1
allyl moiety in 13C{1H} and H NMR spectra lead us to
believe that complex 2 contains the same solution intramo-
lecular trigonal twist behavior as the 18-electron dithio
complexes [Mo(η3-C3H5){η2-S2P(OEt2)}(CH3CN)(CO)2],5
[Mo(η3-C3H5){η2-S2P(OEt2)}(C5H10NH)(CO)2],5 and [Mo-
(η3-C3H5)(η2-S2COEt2)(CH3CN)(CO)2].4 From the AM2X2
A number of pyridine-2-thionate complexes of group
VIIIB have been prepared,12 and the pyridine-2-thionate
ligand can be monodentate, with a metal-sulfur bond, it can
chelate to one metal, or it can bridge two or three metal
centers. Thus, the reaction of 4 with excess pySK in refluxing
acetonitrile produces a bis(pyridine-2-thionate) complex,
[Mo(CO)(η2-pyS)2(η2-dppm)] (7), in good yield. Complex
7 can also be obtained from the dichloromethane solution
of complex 6 with continuous stirring in the air for 24 h.
Complex 6 can be produced by the reaction of [Mo(CO)3-
(CH3CN)(η2-dppm)] and pySH in MeOH at room temper-
ature for 1 h. The air-stable red complexes 6 and 7 are soluble
in chlorinated solvents, and insoluble in diethyl ether and
n-hexane. Attempts to obtain a bisalkyne complex such as
[Mo{η2-S2P(OEt2)}2(PhCtCPh)2]15 from the reaction of 1
with PhCtCPh were unsuccessful. No reaction occurred
under the same reaction conditions. The isolated compounds
1-7 were already of good purity, but analytically pure
samples could be obtained by slow n-hexane diffusion into
a dichloromethane solution at 4 °C.
1
pattern of the allyl group in the H NMR spectra and the
equivalent resonance of the terminal carbon of the allyl group
as well as the resonance of the carbonyl group in the 13C-
{1H} NMR spectra of 3, it looks as if the geometry of 3 has
a mirror plane through the center carbon of the allyl group,
Mo, and coordinating S atom of the pyS ligand. The most
likely structure is shown with the allyl group and the η1-
pyS ligand occupying the axial sites and the 1,10-phenan-
throline ligand and the two carbonyl ligands in the equatorial
plane. This structure is different from those of [Mo(η3-
C3H5)(η1-O2CCF3)(Phen)(CO)2]13 and [Mo(CH3CN)(η3-
C5H7)(Phen)(CO)2] [BF4]14 but similar to the X-ray crystal-
lographically determined geometry of the complex [Mo(η3-
C3H5){η1-S2P(OEt)2}(Phen)(CO)2].15 Variable-temperature
1
(VT) (213-298 K) H NMR experiments were used to
confirm that there does not exist any intramolecular trigonal
twist behavior in complex 3 under low-temperature condi-
tions due to the steric hindrance of 1,10-phenanthroline and
pyS ligands.
IR and MS Spectroscopy. The IR spectrum of 1 shows
four terminal carbonyl stretching bands, which is similar to
those of other 16-electron complexes, [Mo(η3-allyl)(CO)2-
(η2-L)] (L ) Et2NCS2, C4H8NCS2, C5H10NCS2, Et2BPz2, Ph2-
BPz2), that were crystallographically characterized7a in the
case of L ) Et2BPz2. The solution-phase IR spectra of 2
and 3 show the two carbonyls with equal intensity, indicating
that the two carbonyls are mutually cis. In KBr and solution-
phase IR spectra, only one terminal carbonyl stretching band
is found in 4 and 5, although four isomers are known to be
present in different ratios. The IR spectrum of 6 shows two
terminal carbonyl stretchings at 1915 and 1806 cm-1 (A1 +
E) that reveal a typical pattern for a fac-L3M(CO)3 unit with
1
Unambiguous assignment of the H and 13C{1H} NMR
spectra of 4 and 5 are difficult because of the multiple
coupling between the diphos ligand and five protons of the
allyl group and the mixtures of the four isomers. However,
the 31P{1H} NMR spectra of 4 and 5 clearly show eight sets
of doublet resonance. Homonuclear shift-correlated 2-D 31P-
{1H}-31P{1H} NMR experiments of the mixtures 4a-4d
have been employed to elucidate the four isomers (Figure
1). From our early report,11 exo-complexes show larger JP-P
coupling constants than endo-complexes in the dithiodiphos
molybdenum complexes (dithio ) Et2NCS2, C4H8NCS2,
(EtO)2PS2, EtOCS2; diphos ) dppm, dppe, dppa). The
conformation of the CO ligand and nitrogen atom of the pyS
(11) (a) Yih, K. H.; Lee, G. H.; Wang, Y. J. Chin. Chem. Soc. 2002, 49,
479. (b) Yih, K. H.; Lee, G. H.; Huang, S. L.; Wang, Y. Organome-
tallics 2002, 21, 5767.
(12) (a) Zhang, N.; Wilson, S. R.; Shapley, P. A. Organometallics 1988,
7, 1126. (b) Ceeming, A. J.; Karim, M.; Powell, N. I.; Hardcastle, K.
I. Polyhedron 1990, 9, 623.
(13) Sjogren, M. P. T.; Frisell, H.; Akermark, B.; Norrby, P. O.; Eriksson,
L.; Vitagliano, A. Organometallics 1997, 16, 942.
(14) Lush, S. F.; Wang, S. H.; Lee, G. H.; Peng, S. M.; Wang, S. L.; Liu,
R. S. Organometallics 1990, 9, 1862.
(15) Yih, K. H.; Lee, G. H.; Huang, S. L.; Wang, Y. J. Organomet. Chem.
2002, 658, 191.
1094 Inorganic Chemistry, Vol. 42, No. 4, 2003

Molybdenum Complexes with pyS-Containing Ligands
Table 1. Crystal Data and Refinement Details for Complexes 1, 5d, 6, and 7
1
5d
6
7
empirical formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
C20H18N2O4S2Mo
606.36
orthorhombic
Pbcn
8.3128(1)
16.1704(2)
16.6140(2)
90
C35H33NOP2SMo
673.56
orthorhombic
Pbca
17.8309(10)
17.3324(10)
20.3716(11)
90
90
90
6295.9(6)
8
1.421
C33H27NO3P2SMo
675.50
monoclinic
C2/c
18.618(4)
16.062(2)
27.456(6)
90
96.31(3)
90
6149.3(21)
8
C36H30N2OP2S2Mo
728.62
triclinic
P1h
9.1660(2)
12.0854(3)
15.9478(4)
78.4811(10)
80.3894(10)
68.7089(11)
1604.23(7)
2
90
90
2233.28(5)
4
1.803
1.339
0.71073
295
Z
F
calcd, g cm-3
1.459
0.633
0.71073
293
1.508
0.672
0.71073
150
µ(Mo KR), mm-1
λ, Å
0.613
0.71073
295
T, K
θ range, deg
no. of independent rflns
no. of variables
Ra
2.45-27.50
1.92-27.50
1.49-24.97
1.83-27.50
2558
7233
5402
7357
137
0.051
0.106
1.159
370
0.036
0.090
1.030
371
0.034
0.078
1.041
398
0.043
0.098
1.087
b
Rw
Sc
a R ) ∑||Fo| - |Fc||/∑|Fo|. b Rw ) [∑w(|Fo| - | Fc|)2]1/2; w ) 1/s2(|Fo|). c Goodness of fit ) [∑w(|Fo| - |Fc|)2/(Nobsd - Nparams)]1/2
.
is possible to convert endo-[Mo(η3-C3H5)(CO)(η2-S2CNC4H8)-
(η2-dppm)] to the exo-form by allyl rotation.11b Since no other
information could be obtained, we are not in a position to
define the formative mechanism further.
1
The H NMR spectra of 6 and 7 exhibit resonances at δ
4.40 and δ 4.17 attributed to the methylene protons of the
dppm ligand, and the corresponding resonances in the 13C-
{1H} NMR spectra appear at δ 48.9 and δ 40.1, respectively.
The 31P{1H} NMR spectra of 6 and 7 show the two dppm
resonances at δ 0.4 and δ 14.6 and 15.4, respectively. The
AB pattern results from two inequivalent phosphorus atoms
in 7, and the downfield resonance relative to that of 6 shows
the lower electron density of the two phosphorus atoms due
to the high oxidation state of Mo(II).
X-ray Single-Crystal Structures of 1, exo-5d, 6, and 7.
To confirm the novel doubly bridging, chelating, and
monodentate pyS ligands, complexes 1, exo-5d, 6, and 7 were
confirmed by single-crystal X-ray diffraction studies. The
ORTEP diagrams with atom labels of complexes 1, exo-5d,
6 and 7 are shown in Figures 2-5. Bond distances, bond
angles, atomic coordinates, and equivalent isotropic displace-
ment coefficients for important atoms are listed in Tables 2
and 3. Complex 1 (Figure 2) is a dimer with each pyS unit
chelating through sulfur and nitrogen to one metal center
and bridging both the metals through sulfur. In the structure,
the coordination geometry around the molybdenum atom is
a distorted octahedron with an N atom and an S atom from
the pyS ligand, one sulfur atom from another pyS ligand,
and two carbonyl groups and the allyl group occupying the
six coordination sites. The Mo-S distances are not equal,
and the Mo2S2 ring is nonplanar with a dihedral angle of
31.15(4)° between the Mo(1)S(1)Mo(1A) and Mo(1)S(1A)-
Mo(1A) planes. The distortions from octahedral geometry
appear to be associated with the small interligand angles
64.43(12)° (SMoN angles in chelate rings) and 95.70(5)°
(SMoS angles). The structure confirms the unequivalent allyl
groups. The sulfur atom of the pyS ligand is trans to the
Figure 1. Homonuclear shift-correlated 2-D NMR spectrum for 31P nuclei
with 1H decoupling for the mixture 4a-4d in acetone-d6. “x” is the impurity.
ligand in the trans position is more stable than other isomers
because of the good π-bonding CO ligand competition for
the d orbital of the molybdenum atom. The ratio of the four
isomers endo-PN, endo-PS, exo-PN, and exo-PS is 3:7:11:
79 by integrating from the 31P{1H} NMR spectra of 4. One
can conclude that the dppm ligand improves the formation
of exo-products. To simplify the variable-temperature 1H and
31P{1H} NMR experiments, the mixtures of 4a-4d are
recrystallized to obtain the mixtures of 4a and 4c to
investigate the fluxional behavior. In the range of 213-273
1
K, the ratio was retained and no H and 31P{1H} NMR
1
spectra were changed. In the range of 273-323 K, the H
NMR resonances of 4c became broad at 288 K and the
resonances appeared decomposed at 313 K (Supporting
Information, spectrum B). We have recently shown that it
Inorganic Chemistry, Vol. 42, No. 4, 2003 1095

Yih et al.
Table 2. Selected Interatomic Distances (Å) and Angles (deg) for 1,
5d, 6, and 7
Table 3. Atomic Coordinates and Equivalent Isotropic Displacement
Coefficients for Important Atoms of 1, 5d, 6, and 7a
bond lengths
bond angles
Compound 1
atom
x
y
z
Beq
Compound 1
3473(1)
3185(1)
5386(3)
4202(3)
2145(3)
4677(4)
3902(4)
3809(4)
3076(4)
3153(5)
2168(3)
1454(3)
714(4)
Mo(1)-C(1)
Mo(1)-C(2)
Mo(1)-C(3)
Mo(1)-C(4)
Mo(1)-C(5)
Mo(1)-N(1)
Mo(1)-S(1)
Mo(1)-S(1A)
C(3)-C(4)
1.970(7)
1.948(7)
2.349(6)
2.209(6)
2.305(6)
2.253(5)
2.5669(14)
2.6184(14)
1.393(8)
1.402(9)
N(1)-Mo(1)-S(1)
C(4)-Mo(1)-S(1)
N(1)-Mo(1)-C(1)
S(1A)-Mo(1)-C(2)
S(1A)-Mo(1)-N(1)
C(1)-Mo(1)-C(2)
C(1)-Mo(1)-S(1)
C(3)-C(4)-C(5)
64.43(12)
152.60(18)
166.5(2)
159.95(18)
86.74(11)
77.9(2)
102.09(18)
116.1(7)
80.54(5)
95.70(5)
Mo(1)
S(1)
-449(1)
1969(2)
-817(6)
2117(6)
368(5)
-721(8)
1155(8)
-3066(8)
-2495(8)
-1212(9)
1569(6)
2385(8)
1926(8)
714(8)
1365(1)
2284(1)
1511(3)
215(3)
46(1)
48(1)
78(2)
83(1)
47(1)
60(2)
59(2)
69(2)
68(2)
73(2)
47(1)
60(2)
68(2)
65(2)
58(2)
O(1)
O(2)
N(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
1416(3)
1485(3)
619(4)
945(4)
S(1A)-Mo(1)-S(1)
Mo(1A)-S(1)-Mo(1)
610(4)
C(4)-C(5)
68(4)
1955(3)
2189(4)
1847(4)
1299(4)
1087(4)
Compound 5d
Mo(1)-C(1)
Mo(1)-C(2)
Mo(1)-C(3)
Mo(1)-C(4)
Mo(1)-N(1)
Mo(1)-S(1)
Mo(1)-P(1)
Mo(1)-P(2)
C(2)-C(3)
1.908(3)
2.295(3)
2.303(3)
2.328(3)
2.311(2)
2.5588(7)
2.5166(6)
2.4400(6)
1.353(5)
1.320(5)
N(1)-Mo(1)-S(1)
P(1)-Mo(1)-P(2)
N(1)-Mo(1)-C(1)
S(1)-Mo(1)-P(2)
C(3)-Mo(1)-P(1)
C(2)-C(3)-C(4)
N(1)-C(5)-S(1)
Mo(1)-C(1)-O(1)
C(3)-Mo(1)-C(1)
Mo(1)-C(1)-O(1)
63.34(5)
77.50(2)
161.44(9)
152.16(2)
169.66(11)
120.8(4)
112.40(17)
175.5(2)
83.27(13)
175.5(2)
696(4)
1418(3)
-51(8)
Compound 5d
7439(1)
6529(1)
8134(1)
8688(1)
8225(1)
6544(1)
7956(2)
6470(2)
6998(2)
7181(2)
6175(1)
5583(2)
5375(2)
5757(2)
2314(4)
1539(5)
1477(4)
Mo
2495(1)
2773(1)
2038(1)
2112(1)
4038(1)
1578(1)
3438(1)
3073(3)
2841(2)
2125(2)
1890(1)
1519(2)
815(2)
4908(1)
3956(1)
3900(1)
5347(1)
4973(1)
4657(1)
4946(1)
5486(2)
5931(2)
5982(1)
4140(1)
3812(2)
4016(2)
4538(2)
10478(2)
9960(2)
9181(2)
31(1)
42(1)
35(1)
33(1)
69(1)
38(1)
42(1)
80(1)
73(1)
57(1)
38(1)
52(1)
63(1)
57(1)
52(1)
61(1)
47(1)
S(1)
P(1)
P(2)
O(1)
N(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(3)-C(4)
Compound 6
Mo(1)-C(1)
Mo(1)-C(2)
Mo(1)-C(3)
Mo(1)-S(1)
Mo(1)-P(1)
Mo(1)-P(2)
C(1)-O(1)
C(2)-O(2)
C(3)-O(3)
1.974(4)
1.965(4)
1.944(4)
2.5806(11)
2.5350(10)
2.5115(10)
1.153(4)
1.160(4)
1.157(4)
C(1)-Mo(1)-C(2)
C(1)-Mo(1)-C(3)
C(2)-Mo(1)-C(3)
C(1)-Mo(1)-S(1)
C(1)-Mo(1)-P(1)
C(1)-Mo(1)-P(2)
S(1)-Mo(1)-C(3)
C(2)-Mo(1)-P(2)
P(1)-Mo(1)-P(2)
96.84(15)
87.4(2)
84.17(15)
94.50(11)
164.68(11)
97.62(11)
176.88(11)
163.15(11)
67.64(3)
490(2)
3710(5)
3704(6)
4636(5)
Compound 7
Mo(1)-C(1)
Mo(1)-P(1)
Mo(1)-P(2)
Mo(1)-N(1)
Mo(1)-N(2)
Mo(1)-S(1)
Mo(1)-S(2)
C(1)-O(1)
P(1)-C(12)
P(2)-C(12)
S(1)-C(2)
1.910(4)
2.4554(8)
2.4577(8)
2.247(3)
2.307(3)
2.5692(9)
2.5125(8)
1.184(4)
1.842(3)
1.836(3)
1.732(3)
1.740(4)
N(1)-Mo(1)-S(1)
N(2)-Mo(1)-S(2)
P(1)-Mo(1)-P(2)
N(1)-Mo(1)-N(2)
S(1)-Mo(1)-S(2)
N(1)-Mo(1)-S(2)
N(2)-Mo(1)-S(1)
P(1)-Mo(1)-N(1)
P(1)-Mo(1)-S(1)
P(2)-Mo(1)-S(2)
P(2)-Mo(1)-N(2)
C(1)-Mo(1)-N(2)
63.29(8)
64.37(7)
66.20(3)
86.36(9)
140.27(3)
85.22(7)
88.73(7)
160.06(8)
136.34(3)
141.79(3)
112.95(7)
161.94(12)
Compound 6
3729(1)
3122(1)
4310(1)
5710(1)
1322(3)
3709(3)
2269(3)
4255(3)
1828(3)
1178(4)
100(4)
Mo
2209(1)
877(1)
1117(1)
1041(1)
1996(1)
1183(1)
611(1)
404(1)
1261(1)
1196(1)
805(1)
808(1)
655(2)
483(2)
457(2)
1857(1)
38(1)
53(1)
42(1)
44(1)
50(1)
48(1)
45(1)
50(1)
48(1)
62(1)
72(1)
73(1)
65(1)
66(1)
S(1)
P(1)
P(2)
N(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
2122(1)
1817(1)
1337(2)
2272(2)
2648(2)
3198(2)
784(2)
155(2)
S(2)-C(7)
142(2)
738(3)
-377(4)
allyl, S(1)-Mo(1)-C(4) ) 152.60(18)°, while the nitrogen
atom of the pyS ligand is trans to one carbonyl, N(1)-Mo-
(1)-C(1) ) 166.5(2)°. The remaining carbonyl is trans to
the sulfur atom of another pyS ligand, S(1A)-Mo(1)-C(2)
) 159.95(18)°. The molybdenum-sulfur bond (trans to
allyl), 2.5669(14) Å, is significantly shorter than the mo-
lybdenum-sulfur bond (trans to carbonyl), 2.6184(14) Å,
because of the greater trans effect induced by the CO group
than the allyl group. The S(1)-Mo(1)-N(1) angle of 64.43-
(12)° in 1 is similar to 63.6(1)° in Mo2(CO)9(pyS)16 within
experimental error. The Mo-Mo distance of 1 is 3.8446(9)
Å, indicating no significant metal-metal interaction. To our
knowledge, group VIB complexes containing M-S and
M-N bonds involving a pyS moiety as a doubly bridged
bidentate ligand have not been reported in the literature,
although groups VB17 and VIIIB12 metal complexes with pyS
ligands are known.
1326(2)
1955(3)
246(4)
5786(3)
Compound 7
2631(1)
499(1)
Mo
7155(1)
7875(1)
6835(1)
5115(1)
6099(1)
9549(3)
9149(3)
5534(3)
8646(4)
9297(4)
10470(4)
11518(5)
11384(5)
10193(4)
5562(4)
4640(4)
3710(5)
3704(6)
4636(5)
7727(1)
7378(1)
8983(1)
7370(1)
6356(1)
6600(2)
8376(2)
8907(2)
7004(2)
8063(2)
8280(2)
8821(3)
9136(3)
8904(2)
9425(2)
10220(2)
10478(2)
9960(2)
9181(2)
25(1)
37(1)
33(1)
25(1)
25(1)
40(1)
31(1)
31(1)
31(1)
33(1)
42(1)
53(1)
54(1)
40(1)
30(1)
39(1)
52(1)
61(1)
47(1)
S(1)
S(2)
P(1)
P(2)
O(1)
N(1)
N(2)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
3695(1)
4591(1)
2881(1)
3707(2)
1191(3)
2161(3)
3259(3)
202(3)
-902(3)
-950(4)
56(4)
1126(4)
2909(3)
3016(4)
2314(4)
1539(5)
1477(4)
a ESDs refer to the last digit printed.
The ORTEP plot of complex exo-5d is shown in Figure
3. The molybdenum atom is a pseudooctahedron with one
sulfur and one nitrogen atom of the pyS ligand, two
phosphorus atoms of the dppe ligand, and the carbonyl and
allyl groups occupying the six coordination sites. Clearly,
the open face of the allyl group is oriented away from the
(16) Yu, P.; Huang, L.; Zhuang, B. Acta Crystallogr. 1994, C50, 1191.
(17) Reynolds, J. G.; Sendlinger, S. C.; Murray, A. M.; Huffman, J. C.;
Christou, G. Inorg. Chem. 1995, 34, 5745.
1096 Inorganic Chemistry, Vol. 42, No. 4, 2003

Molybdenum Complexes with pyS-Containing Ligands
Figure 2. An ORTEP drawing with 30% thermal ellipsoids and atom-
numbering scheme for complex 1.
Figure 4. An ORTEP drawing with 30% thermal ellipsoids and atom-
numbering scheme for complex 6.
an equivalent dppm ligand. Two phosphorus atoms of the
dppm ligand and one sulfur atom of the thione ligand, SC5H4-
NH, are trans to three carbonyl groups: P(1)-Mo-C(1) )
164.68(11)°, P(2)-Mo-C(2) ) 163.15(11)°, and S(1)-Mo-
C(3) ) 176.88(11)°, respectively. The structure is compatible
with the 31P{1H} NMR spectra of 6 and complex [Mo(CO)3-
(CH3CN)(η2-dppm)],19 which was crystallographically char-
acterized. The Mo(1)-S(1) bond distance, 2.5806(11) Å, is
longer than those of 1, 5d, and 7 (2.5588(7)-2.5692(9) Å)
because of the thione ligand of SC5H4NH and Mo(0) of 6.
The seven-coordinate bis(pyridine-2-thionate) tungsten-
(II) complex [W(η2-pyS)2(CO)3] has been described by
Hoff20 and co-workers. A possible consequence of the pyS
ligand’s relatively small size and bite angle is that it may
favor higher coordination numbers. The crystal structure of
the seven-coordinate bis(pyridine-2-thionate) molybdenum-
(II) complex 7 is shown in Figure 5. The structure of 7 is
approximately a pentagonal bipyramid as is that of [W(η2-
pyS)3(NO)].20 The CO ligand is roughly trans to one of the
coordinating nitrogen atoms of the pyS ligand (C1-Mo-
N2 ) 161.4(7)°), and the remaining five donor atoms are
approximately planar. A planarity calculation of the five
atoms S1, N1, S2, P1, and P2 reveals an average deviation
of 0.25 Å. The molybdenum-nitrogen bond of 2.247(3) Å
(trans to the phosphorus atom of the dppm ligand) is
significantly shorter than the molybdenum-nitrogen bond
of 2.307(3) Å (trans to the carbonyl) because of the greater
trans effect induced by the CO group than the dppm group.
The Mo-P bond lengths of 5d, 6, and 7 are in the region
of 2.4400(6)-2.5350(10) Å, and appear to be normal. The
Mo-C-O angles of 1, 5d, 6, and 7 are essentially linear in
the region of 173.6(3)-178.3(3)° and similar to those found
for other terminal carbonyls contained in Mo systems. The
Mo-CO (1.908(3)-1.974(4) Å) and C-O distances are both
Figure 3. An ORTEP drawing with 30% thermal ellipsoids and atom-
numbering scheme for complex 5d.
carbonyl group, and the structure confirms the unequivalent
allyl group in exo-5d. The sulfur atom of the pyS ligand is
trans to the diphos, S(1)-Mo-P(2) ) 152.16(2)°, while the
nitrogen atom of the pyS ligand is trans to the carbonyl,
N(1)-Mo-C(1) ) 161.44(9)°, in exo-5d. The Mo-S and
Mo-allyl bond distances in 1 and exo-5d are consistent with
the values reported for MoII-S and numerous Mo-allyl
systems.18 The bond distances and intercarbon angles of the
allyl groups in 1 (1.393(8) and 1.394(7) Å and 116.1(7)°)
and exo-5d (1.353(5) and 1.320(5) Å and 120.8(4)°) are
insignificantly different and in the region of those of related
MoII-allylic compounds (1.31-1.42 Å, 115-125°).18
The coordination geometry around the molybdenum atom
of 6 (Figure 4) is approximately an octahedron with the two
phosphorus atoms, three carbonyls, and pySH group oc-
cupying the six coordination sites. The structure confirms
(18) (a) Graham, A. J.; Fenn, R. H. J. Organomet. Chem. 1969, 17, 405.
(b) Cosky, C. A.; Ganis P.; Avatabile, G. Acta Crystallogr., Sect. B
1971, B27, 1859. (c) Fenn R. H.; Graham, A. J. J. Organomet. Chem.
1972, 37, 137. (d) Cotton, F. A.; Jeremic M.; Shaver, A. Inorg. Chim.
Acta 1972, 6, 543. (e) Graham, A. J.; Akrigg D.; Sheldrick, B. Cryst.
Struct. Commun. 1976, 24, 173. (f) Cotton, F. A.; Murillo, C. A.; Stults,
B. R. Inorg. Chim. Acta 1977, 7, 503. (g) Brisdon, B. J.; Ewards, D.
A.; Paddick, K. E.; Drew, M. G. B. J. Chem. Soc., Dalton Trans.
1980, 1317. (h) Faller, J. W.; Chodosh, D. F.; Katahira, D. J.
Organomet. Chem. 1980, 187, 227. (i) Lush, S. F.; Wang, S. H.; Lee,
G. H.; Peng, S. M.; Wang, S. L.; Liu, R. S. Organometallics 1990, 9,
1862.
(19) Crystal data for [Mo(CO)3(CH3CN)(η2-dppm)]: C30H25NO3P2Mo (Mr
) 605.39), monoclinic, space group P21/c, a ) 10.930(4) Å, b )
18.516(8) Å, c ) 15.173(4) Å, V ) 2902.1(10) Å3, Z ) 4, Fcalcd
1.386 g cm-3, µ ) 0.592 mm-l, observed reflections 3772, θrange
)
)
1.80-22.50°. Data were collected with Mo KR radiation (λ ) 0.71073
Å) on an Enraf-Nonius CAD4 diffractometer at 295(2) K. The total
number of parameters was 335. R1 ) 0.047, wR2 ) 0.077, GOF )
1.001, and ∆F ) 0.473 and -0.367 e Å3.
(20) Sukcharoenphon, K.; Capps, K. B.; Abboud, K. A.; Hoff, C. D. Inorg.
Chem. 2001, 40, 2402.
Inorganic Chemistry, Vol. 42, No. 4, 2003 1097

Yih et al.
(CO)6, dppm, and dppe were purchased from Strem Chemical;
pySH, Et3N, 1,10-phenanthroline, C5H11N, and C3H5Br were
purchased from Merck.
[Mo(η3-C3H5)(CO)2]2(µ-η1,η2-pyS)2 (1). pySK (0.258 g, 2.0
mmol) was dissolved in MeOH (10 mL), and the solution was added
to a flask (100 mL) containing [Mo( η3-C3H5)(CO)2(CH3CN)2Br]
(0.714 g, 2.0 mmol) in CH2Cl2 (10 mL) at room temperature. After
2 min yellow solids were formed which were isolated by filtration
(G4), washed with n-hexane (2 × 10 mL), and subsequently dried
under vacuum, yielding 0.594 g (98%) of 1. IR (KBr, cm-1): υ-
(CO) 1937(vs), 1922(vs), 1875(vs), 1858(vs). 1H NMR (500 MHz,
DMSO-d6, 298 K): δ 1.00, 1.33 (d, JH-H ) 9.6 Hz, 2H, Hanti of
allyl), 3.06, 3.43 (br, 2H, Hsyn of allyl), 3.83 (m, 1H, CH of allyl),
6.77 (d, JH-H ) 8.1 Hz, 1H, SCCH), 6.83 (t, JH-H ) 6.3 Hz, 1H,
NCHCH), 7.39 (t, JH-H ) 7.7 Hz, 1H, SCCHCH), 7.88 (d, JH-H
)
4.6 Hz, 1H, NCH). 13C{1H} NMR (125 MHz, DMSO-d6, 298 K):
δ 51.9, 62.9 (s, CdCH2), 74.6 (s, CdCH2), 117.3 (s, 5-C of pyS),
126.2 (s, 3-C of pyS), 136.9 (s, 4-C of pyS), 146.2 (s, 6-C of pyS),
176.7 (s, 2-C of pyS), 228.9, 231.2 (s, CO). Anal. Calcd for
C20H18N2O4S2Mo2: C, 39.61; H, 2.99; N, 4.62. Found: C, 39.80;
H, 2.60; N, 4.50.
Figure 5. An ORTEP drawing with 50% thermal ellipsoids and atom-
numbering scheme for complex 7.
within the range of values reported for other molybdenum
carbonyl complexes. The N-Mo-S angles (63.29(8)-64.43-
(12)°) in complexes 1, 5d, and 7 are similar to those of
complexes [Mo2(pyS)(CO)9]16 (63.6(1)°), [W(pyS)(CO)(CH3-
CN)(MeC2Me)2]9 (63.6(5)°), [W(pyS)2(CO)3] (64.83(9)°),
[W(pyS)2(NO)2] (65.88(8)°), and [W(pyS)3(NO)]20 (65.85-
(7)°).
[Mo(η3-C3H5)(CO)2(η2-pyS)(C5H10NH)] (2). A solution of 1
(0.606 g, 1.0 mmol) in CH2Cl2 (20 mL) was treated with C5H10-
NH (0.1 mL, 1.2 mmol) at ambient temperature. Instantly, the
reaction mixture turned to bright yellow. After 10 min of stirring,
the solution was dried in vacuo. Subsequently, n-hexane (40 mL)
was added to the solution, and a yellow precipitate was formed.
The precipitate was collected by filtration (G4) and dried in vacuo
to yield 0.356 g (92%) of 2. IR (KBr, cm-1): υ(CO) 1924(vs),
Conclusion
In this paper we report the syntheses and X-ray crystal
structures of pyridine-2-thionate molybdenum complexes. In
complex 1, each pyS ligand chelates to one Mo atom through
the nitrogen and sulfur atoms, and σ-bond to the other Mo
atom through the sulfur atom, resulting in a four-membered
ring, in which the two pyS ligands act as doubly bridged
five-electron ligands. In complexes 2, 4, 5, and 7, the pyS
ligand acts as a chelating three-electron ligand. In complex
3, the pyS ligand acts as a one-electron ligand through sulfur
coordination and the thione ligand, SC5H4NH, acts as a two-
electron ligand through sulfur coordination in 6. The bis-
(pyridine-2-thionate) complex 7 is a stable saturated seven-
coordinate compound, in contrast to [Mo(η2-S2CNEt)2(CO)3]
and [W(SPh)2(phen)(CO)3], both of which readily lose CO
to form stable six-coordinate dicarbonyl complexes.
1
1838(vs). H NMR (500 MHz, CDCl3, 298 K): δ 1.16, 1.26 (d,
JH-H ) 8.9 Hz, 2H, Hanti of allyl), 1.64 (m, 6H, NCH2CH2CH2),
2.88 (m, 4H, NCH2), 3.20, 3.51 (br, 2H, Hsyn of allyl), 3.60 (m,
1H, CH of allyl), 3.89 (br, 1H, NH), 6.71 (t, JH-H ) 6.1 Hz, 1H,
NCHCH), 6.87 (d, JH-H ) 8.2 Hz, 1H, SCCH), 7.25 (t, JH-H
)
7.1 Hz, 1H, SCCHCH), 7.67 (br, 1H, NCH). 13C{1H} NMR (125
MHz, CDCl3, 298 K): δ 23.8 (s, NCH2CH2CH2), 25.1 (s,
NCH2CH2), 46.1 (s, NCH2), 54.2, 62.6 (s, CdCH2), 70.7 (s, Cd
CH2), 117.3 (s, 5-C of pyS), 125.0 (s, 3-C of pyS), 136.0 (s, 4-C
of pyS), 147.0 (s, 6-C of pyS), 170.3 (s, 2-C of pyS), 226.6 (s,
CO). MS (FAB, NBA, m/z): 389 [M+], 321 [M+ - CO], 293 [M+
- 2CO]. Anal. Calcd for C15H19N2O2SMo: C, 46.51; H, 4.95; N,
7.23. Found: C, 46.85; H, 5.01; N, 7.12.
[Mo(η3-C3H5)(CO)2(η2-pyS)(phen)] (3). To 1 (0.606 g, 1.0
mmol) dissolved in CH2Cl2 (20 mL) with continuous stirring under
a stream of dry nitrogen was added 1,10-phenanthroline (0.18 g,
1.0 mmol). The color of the solution changed from yellow to red
immediately, and a red precipitate formed. The precipitate was
collected by filtration (G4), washed with n-hexane (2 × 10 mL),
and then dried in vacuo to yield 0.44 g (92%) of 3. IR (KBr, cm-1):
Experimental Section
All manipulations were performed under nitrogen using vacuum-
line, drybox, and standard Schlenk techniques. NMR spectra were
recorded on a Bruker AM-500 WB FT-NMR spectrometer and are
reported in units of δ (ppm) with residual protons in the solvent as
an internal standard (CDCl3, δ 7.24; CD3CN, δ 1.93; C6D6, δ 7.15;
C2D6CO, δ 2.04). IR spectra were measured on a Nicolate Avator-
320 instrument and were referenced to a polystyrene standard, using
cells equipped with calcium fluoride windows. Mass spectra were
recorded on a JEOL SX-102A spectrometer. Solvents were dried
and deoxygenated by refluxing over the appropriate reagents before
use. n-Hexane, diethyl ether, THF, and benzene were distilled from
sodium-benzophenone. Acetonitrile and dichloromethane were
distilled from calcium hydride, and methanol was distilled from
magnesium. All other solvents and reagents were of reagent grade
and were used as received. Elemental analyses and X-ray diffraction
studies were carried out at the Regional Center of Analytical
Instrumentation located at the National Taiwan University. Mo-
1
υ(CO) 1932(vs), 1923(vs), 1845(vs), 1834(vs). H NMR (500
MHz, CDCl3, 298 K): δ 1.58 (d, JH-H ) 9.8 Hz, 2H, Hanti of allyl),
3.11 (d, JH-H ) 6.3 Hz, 2H, Hsyn of allyl), 3.66 (m, 1H, CH of
allyl), 6.00 (d, JH-H ) 8.2 Hz, 1H, SCCH), 6.45 (t, JH-H ) 4.9
Hz, 1H, NCHCH), 6.89 (t, JH-H ) 7.1 Hz, 1H, SCCHCH), 6.99
(d, JH-H ) 3.1 Hz, 1H, NCH), 7.75, 7.76 (d, JH-H ) 5.1 Hz, 2H,
3-H of phen), 7.78 (s, 2H, 5-H of phen), 8.32 (d, JH-H ) 8.1 Hz,
2H, 4-H of phen), 9.16 (d, JH-H ) 5.1 Hz, 2H, 2-H of phen). 13C-
{1H} NMR (125 MHz, CDCl3, 298 K): δ 53.4 (s, CCH2), 72.7 (s,
CCH2), 117.5 (s, 5-C of pyS), 122.2 (s, 3-C of pyS), 135.9 (s, 4-C
of pyS), 149.5 (s, 6-C of pyS), 176.7 (s, 2-C of pyS), 124.8 (s,
5,6-C of phen), 127.2 (s, 3,8-C of phen), 137.4 (s, 4,7-C of phen),
149.5 (s, 2,9-C of phen), 228.9 (s, CO). MS (FAB, NBA, m/z):
486 [M+], 458 [M+ - CO], 430 [M+ - 2CO], 389 [M+ - 2CO -
1098 Inorganic Chemistry, Vol. 42, No. 4, 2003

Molybdenum Complexes with pyS-Containing Ligands
C3H5]. Anal. Calcd for C22H17N3O2SMo: C, 54.66; H, 3.55; N,
8.70. Found: C, 54.89; H, 3.42; N, 8.75.
solution was cooled and removal of the solvent in vacuo, MeOH
(10 mL) was added to the residue, and a red precipitate was formed.
The precipitate was collected by filtration (G4), washed with
n-hexane (2 × 10 mL), and then dried in vacuo, yielding 0.49 g
(71%) of 7. IR (KBr, cm-1): υ(CO) 1807(vs). 31P{1H} NMR (202
MHz, CDCl3, 298 K): δ 15.4, 14.6 (d, 2JP-P ) 123.5 Hz). 1H NMR
(500 MHz, CDCl3, 298 K): δ 4.17 (t, 4H, CH2), 6.63-7.62 (m,
32H, Ph and SNC5H4). 13C{1H} NMR (125 MHz, CDCl3, 298 K):
[Mo(η3-C3H5)(CO)( η2-pyS)( η2-dppm)] (4a-4d). MeCN (40
mL) was added to a flask (100 mL) containing 1 (0.606 g, 1.0
mmol) and bis(diphenylphosphino)methane (dppm) (0.768 g, 2.0
mmol). The solution was refluxed for 1 h, and an IR spectrum
indicated completion of the reaction. After the solution was cooled
and removal of the solvent in vacuo, the residue was redissolved
in CH2Cl2 (10 mL). n-Hexane (20 mL) and diethyl ether (20 mL)
were added to the solution, and an orange precipitate was formed.
The precipitate was collected by filtration (G4), washed with diethyl
ether (2 × 10 mL) and n-hexane (2 × 10 mL), and then dried in
vacuo, yielding 1.16 g (88%) of 4a-4d. Further purification was
accomplished by recrystallization from 1/10 CH2Cl2/n-hexane. IR
(KBr, cm-1): υ(CO) 1794(vs). MS (FAB, NBA, m/z): 661 [M+],
633 [M+ - CO], 591 [M+ - CO - C3H5]. Anal. Calcd for C34H31-
NOP2SMo: C, 61.91; H, 4.74; N, 2.12. Found: C, 62.00; H, 4.42;
N, 2.02. 31P{1H} NMR (202 MHz, CDCl3, 298 K): (4a) δ -2.3,
2
δ 40.1 (t, JP-C ) 22.2 Hz, PCH2), 116.5, 116.8 (s, 5-C of pyS),
121.5-135.7 (m, 3-C of pyS, 4-C of pyS, Ph), 147.8, 148.0 (s,
6-C of pyS), 172.9, 176.7 (s, 2-C of pyS), 231.6 (s, CO). MS (FAB,
NBA, m/z): 702 [M+ - CO]. Anal. Calcd for C36H30N2O1P2S2-
Mo: C, 59.34; H, 4.15; N, 3.85. Found: C, 59.50; H, 3.96; N,
3.72.
Single-Crystal X-ray Diffraction Analyses of 1, 5d, 6, and 7.
Single crystals of 1, 5d, 6, and 7 suitable for X-ray diffraction
analyses were grown by recrystallization from 20/1 n-hexane/CH2-
Cl2. The diffraction data were collected at room temperature on an
Enraf-Nonius CAD4 diffractometer equipped with graphite-mono-
chromated Mo KR (λ ) 0.71073 Å) radiation. The raw intensity
data were converted to structure factor amplitudes and their ESDs
after corrections for scan speed, background, Lorentz, and polariza-
tion effects. An empirical absorption correction, based on the
azimuthal scan data, was applied to the data. Crystallographic
computations were carried out on a Microvax III computer using
the NRCC-SDP-VAX structure determination package.21
A suitable single crystal of 1 was mounted on the top of a glass
fiber with glue. Initial lattice parameters were determined from 24
accurately centered reflections with θ values in the range from 2.45°
to 27.50°. Cell constants and other pertinent data were collected
and are recorded in Table 1. Reflection data were collected using
the θ/2θ scan method. The final scan speed for each reflection was
determined from the net intensity gathered during an initial prescan
and ranged from 2.06 to 8.24° min-1. The θ scan angle was
determined for each reflection according to the equation 0.70 (
0.35 tan θ. Three check reflections were measured every 30 min
throughout the data collection and showed no apparent decay. The
merging of equivalent and duplicate reflections gave a total of 14552
unique measured data, 2558 reflections of which with I > 2σ(I)
were considered observed. The first step of the structure solution
used the heavy-atom method (Patterson synthesis), which revealed
the positions of the metal atoms. The remaining atoms were found
in a series of alternating difference Fourier maps and least-squares
refinements. The quantity minimized by the least-squares program
was w(|Fo| - |Fc|)2, where w is the weight of a given operation.
The analytical forms of the scattering factor tables for the neutral
atoms were used.22 The non-hydrogen atoms were refined aniso-
tropically. Hydrogen atoms were included in the structure factor
calculations in their expected positions on the basis of idealized
bonding geometry but were not refined in least squares. All
hydrogens were assigned isotropic thermal parameters 1-2 Å2
larger than the equivalent Biso value of the atom to which they were
bonded. The final residuals of this refinement were R ) 0.051 and
Rw ) 0.106.
2
2
30.8 (d, JP-P ) 37.5 Hz), (4b) δ -27.1, 26.3 (d, JP-P ) 51.2
2
Hz), (4c) δ 0.3, 33.1 (d, JP-P ) 58.3 Hz), (4d) δ -3.5, 27.6 (d,
2JP-P ) 65.0 Hz). 1H NMR (500 MHz, CDCl3, 298 K, 4d): δ 1.72,
2
1.84 (d, JH-H ) 11.2 Hz, 2H, Hanti of allyl), 2.85, 4.36 (m, 2H,
Hsyn of allyl), 3.85 (dt, 2H, PCH2CH2, JH-H ) 15.1 JP-H ) 10.1
Hz), 4.24 (m, 2H, PCH2CH2), 5.26 (m, 1H, CH of allyl), 6.38-
7.79 (m, 28H, Ph and pyS). 13C{1H} NMR (125 MHz, CDCl3, 298
K): δ 39.9 (t, 2JP-C ) 19.6 Hz, PCH2), 54.8, 74.2 (d, 2JP-C ) 9.4,
13.8 Hz, CdCH2), 98.3 (s, CdCH2), 115.0 (s, 5-C of pyS), 121.5-
136.3 (m, 3-C of pyS, 4-C of pyS, Ph), 147.4 (s, 6-C of pyS), 177.6
2
(s, 2-C of pyS), 231.8 (t, JP-C ) 12.2 Hz, CO).
[Mo(η3-C3H5)(CO)(η2-pyS)(η2-dppe)] (5a-5d). The synthesis
and workup were similar to those used in the preparation of complex
4. Complex 5 was isolated in 92% yield as a red-orange microc-
rystalline solid. IR (KBr, cm-1): υ(CO) 1793(vs). MS (FAB, NBA,
m/z): 675 [M+], 647 [M+ - CO], 605 [M+ - CO - C3H5]. Anal.
Calcd for C35H33NOP2SMo: C, 62.41; H, 4.94; N, 2.08. Found:
C, 62.80; H, 4.45; N, 1.75. 31P{1H} NMR (202 MHz, CDCl3, 298
K): (5a) δ 59.4, 85.8 (d, 2JP-P ) 22.8 Hz), (5b) δ 52.5, 79.6 (br),
2
2
(5c) δ 85.0, 88.5 (d, JP-P ) 67.3 Hz), (5d) δ 64.6, 88.8 (d, JP-P
) 42.7 Hz).
[Mo(CO)3(η1-SC5H4NH)(η2-dppm)] (6). MeOH (20 mL) was
added to a flask (100 mL) containing [Mo(CH3CN)( η2-dppm)-
(CO)3] (0.605 g, 1.0 mmol) and pySH (0.111 g, 1.0 mmol) at room
temperature. After 1 h red solids were formed which were isolated
by filtration (G4), washed with n-hexane (2 × 10 mL), and
subsequently dried under vacuum, yielding 0.66 g (98%) of 6. IR
(KBr, cm-1): υ(CO) 1915(vs), 1806(vs). 31P{1H} NMR (202 MHz,
1
CD3CN, 298 K): δ 0.4. H NMR (500 MHz, CD3CN, 298 K): δ
4.40 (m, 2H, PCH2), 6.63-7.62 (m, 24H, Ph and pyS), 12.7 (br,
1H, NH). 13C{1H} NMR (125 MHz, CD3CN, 298 K): δ 48.9 (t,
2JP-C ) 18.9 Hz, PCH2), 116.3 (s, 5-C of pyS), 121.5-136.3 (m,
3-C of pyS, 4-C of pyS, Ph), 148.9 (s, 6-C of pyS), 179.8 (s, 2-C
2
2
of pyS), 210.4 (t, JP-C ) 8.68 Hz, trans-CO), 218.9 (t, JP-C
)
15.22 Hz, cis-CO). MS (FAB, NBA, m/z): 649 [M+ - CO], 621
[M+ - 2CO], 592 [M+ - 3CO]. Anal. Calcd for C33H26NO3P2-
SMo: C, 58.76; H, 3.89; N, 2.08. Found: C, 58.90; H, 3.76; N,
1.94.
The procedures for 5d, 6, and 7 were similar to those for 1. The
final residuals of this refinement were R ) 0.036 and Rw ) 0.09
for 5d, R ) 0.034 and Rw ) 0.078 for 6, and R ) 0.043 and Rw )
0.098 for 7. Selected bond distances and angles and selected final
atomic coordinates are listed in Tables 2 and 3.
[Mo(CO)(η2-pyS)2(η2-dppm)] (7). Method A. CH2Cl2 (40 mL)
was added to a flask (100 mL) containing 6 (0.675 g, 1.0 mmol),
and the solution was stirred in air at room temperature. After 24 h
red solids were formed which were isolated by filtration (G4),
washed with n-hexane (2 × 10 mL), and subsequently dried under
vacuum, yielding 0.28 g (38%) of 7.
(21) Gabe, E. J.; Lee, F. L.; Lepage, Y. In Crystallographic Computing 3;
Sheldrick, G. M., Kruger, C., Goddard, R., Eds.; Clarendon Press:
Oxford, England, 1985; p 167.
(22) International Tables for X-ray Crystallography; Reidel: Dordrecht,
The Netherlands; Boston, 1974; Vol. IV. (b) LePage, Y.; Gabe, E. J.
Appl. Crystallogr. 1990, 23, 406.
Method B. Complex 4 (0.659 g, 1.0 mmol) and pySK (0.202 g,
2.0 mmol) was reacted in refluxing CH3CN for 2 h. After the
Inorganic Chemistry, Vol. 42, No. 4, 2003 1099

Yih et al.
files, in CIF format, for the structures of complexes 1, 5d, 6, and
7. This material is available free of charge via the Internet at
http://pubs.acs.org.
Acknowledgment. We thank the National Science Coun-
cil of the Republic of China for support.
Supporting Information Available: 13C{1H}, 1H-1H COSY,
1
and H-13C HMQC NMR spectra of 1 in DMSO, 31P{1H}, 31P-
{1H} VT, and 1H VT spectra of 4a-4d, and X-ray crystallographic
IC020579X
1100 Inorganic Chemistry, Vol. 42, No. 4, 2003