Chemistry of cyclopentadienyl tricarbonylchromium dimer. Cleavage of bis(thiophosphinyl)disulfanes and bis(thiophosphoryl)disulfanes. Syntheses of CpCr(CO)2(S2PPh2) and CpCr(S2PPh2)2. X-ray

Article abstract of DOI:10.1016/S0022-328X(00)00209-6

The facile reaction of [CpCr(CO)₃]₂ with one mole equivalent of bis(diphenylthiophosphinyl)disulfane, Ph₂P(S)SSP(S)PPh₂ led to the isolation of dark purplish brown solids of CpCr(CO)₂(S₂PPh

Full text of DOI:10.1016/S0022-328X(00)00209-6

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 607 (2000) 64–71
Chemistry of cyclopentadienyl tricarbonylchromium dimer.
Cleavage of bis(thiophosphinyl)disulfanes and
bis(thiophosphoryl)disulfanes. Syntheses of CpCr(CO)2(S2PPh2)
and CpCr(S2PPh2)2. X-ray crystal structure of CpCr(S2PPh2)2
Lai Yoong Goh a,*, Weng Kee Leong a, Pak-Hing Leung a, Zhiqiang Weng a,
Ionel Haiduc b
a Department of Chemistry, National Uni6ersity of Singapore, Kent Ridge, Singapore 119260, Singapore
b Department of Chemistry, Babes-Bolyai Uni6ersity, RO-3400 Cluj-Napoca, Romania
Received 24 February 2000; received in revised form 16 April 2000
Dedicated to Professor Martin A. Bennett on the occasion of his retirement.
Abstract
The facile reaction of [CpCr(CO)3]2 with one mole equivalent of bis(diphenylthiophosphinyl)disulfane, Ph2P(S)SSP(S)PPh2, led
to the isolation of dark purplish brown solids of CpCr(CO)2(S2PPh2) (2) and blue solids of CpCr(S2PPh2)2 (3) in 50 and 10%
yields, respectively. Proton NMR spectral studies demonstrated that 3 is derived from 2, the primary product. IR spectral data
indicated that 2 possesses cis CO ligands and a bidentate SP(S)Ph2 ligand, whilst 3 contains both a unidentate and a bidentate
1
ligand, as confirmed by its X-ray diffraction analysis. Variable temperature H and 31P spectral studies showed the occurrence of
very rapid unidentate–bidentate exchange between the ligands in 3 in the temperature range −80–60°C. © 2000 Elsevier Science
S.A. All rights reserved.
Keywords: Chromium; Cyclopentadienylchromium; Diphenyldithiophosphinate; Phosphinodithioato; Crystal structure
had also observed for the reactions of [CpCr(CO)3]2
with diaryl dichalcogenides [4], these disulfanes are
1. Introduction
known to undergo facile SꢀS homolytic bond cleavage
in reactions with low oxidation state compounds, giving
rise to metal phosphinodithioato, MꢀS(S)PR2 and
phosphorodithioato, MꢀS(S)P(OR)2 derivatives.
Previous work from one of our laboratories has
demonstrated the extreme ease with which the
monomeric CpCr(CO)3 species cleaves the inter-element
SꢀS, PꢀP and SꢀP bonds in polyatomic chalcogen
molecules [1], pnicogen molecules [2], mixed phospho-
rus–chalcogen cages [3] and diaryl dichalcogenides [4],
and lately, also the bonds between main group metals
and sulfur in Sb2S3 [5]. The rich chemistry arising
therefrom, as described in our recent review [6], indi-
cated to us that similar investigations involving the
bis(thiophosphinyl)disulfanes, R2P(S)SSP(S)PR2, and
bis(thiophosphoryl)disulfanes, (RO)2P(S)SSP(S)P(OR)2,
would be a potentially fruitful exercise. Indeed, as we
A large number of main group metal organometallic
dithiophosphates and dithiophosphinates have been
characterized structurally [7], but to date, there are
only a few reported cases of organometallic transition
metal dialkyl or diaryl dithiophosphates; these include
some metal carbonyl derivatives [8] and some specific
compounds, e.g. (i) Cp2Nb(S2P(OR)2) from the re-
action of Cp2Nb(CH3)2 with [S2P(OR)2]2 (R=iPr, Et)
[9]; (ii) [Cp2V(S2P(OR)2)]+[S2P(OR)2)]− from the reac-
tion of Cp2V with [S2P(OR)2]2 (R=Et) [10]; (iii)
CpFe(CO)2(S2P(OR)2), derived from the reaction of
* Corresponding author. Fax: +65-7791691.
E-mail address: chmgohly@nus.edu.sg (L.Y. Goh).
[CpFe(CO)2]2
(Cp=h5-C5H5,
h5-C5Me5)
with
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(00)00209-6

L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
65
[S2P(OR)2]2 (R=iPr, Et) [11]; and (iv) CpNbCl3-
(S2P(OR)2), and
2. Results and discussion
CpNbCl(m-Cl)2Nb(S2P(OR)2)Cp
MeCpMo(CO)2(S2P(OR)2) (R=iPr) from the reaction
of HS2P(OR)2 with CpNbCl4 and [(MeCp)Mo-
(CO)3]2, respectively [12]. More recent reports have
described the reactions of specific transition metal com-
plexes with NH4(S2P(OEt)2) to yield phospho-
rodithioato compounds like (h6-arene)RuCl(S2P(OR)2)
2.1. Products isolation, characterization and reaction
pathways
A facile reaction between [CpCr(CO)3]2 (1) and one
mole equivalent of bis(diphenylthiophosphinyl)-
disulfane in toluene produced a brown solution, from
which was isolated dark purplish brown solids of
CpCr(CO)2(S2PPh2) (2) and blue solids of CpCr-
(S2PPh2)2 (3) in 50 and 10% yields, respectively.
A time-dependent proton NMR spectral study of the
reaction mixture showed that 2 was the primary
product. The reaction was observed to be complete
within 10 min. The progression of the reaction was
followed by obtaining the time-dependent relative ratio
of the integrals of the Cp resonances of 2 and 3, which
decreased from 1:0.14 (10 min) through 1:0.55 (1 h)
followed by 1:1.48 (7 h) to 1:35 (72 h), reaching com-
plete decomposition after 4 days. Indeed, the facile
degradation of 2 to 3, as monitored for a 24 mM
solution of 2 in C6D6 at ambient temperature, indicated
a half-life of conversion of ca. 3 h. This ease of degra-
dation is also reflected in the failure to observe any sign
of the molecular ion of 2 (m/z 422) in the mass spec-
trum, which only possessed the main mass fragments of
3.
i
(arene=benzene, p-cymene; R=Et, nPr, Pr, nBu or
n
i
sBu) [13a], Cp*RhCl(S2P(OR)2) (R=Et, Pr, Pr) and
Cp*Rh(S2P(OEt)2)2 (Cp*=h5-C5Me5) [13b], and allyl
complexes
of
Mo,
viz.
[{(h3-C3H5)Mo(CO)2-
(S2P(OEt)2)}2(m-NH2NH2)] [8e] and [(h3-C3H5)Mo-
(MeCN)(CO)2(S2P(OEt)2) [14].
Similar complexes of the corresponding dithiophos-
phinates are rarer; they include [Cp2V(S2P(Et)2)]+
[S2P(Et)2)]− [10]; W(CO)3(S2PR2)2 from the reaction of
W(CO)3(NCMe)3 with [SP(S)R2]2 (R=Et, Pr) [8c];
(arene)Ru(S2PR2)2 (R=Me, Ph) and (C5Me5)M-
(S2PR2)2 (M=Ru, Rh, Ir; R=Me, Ph) from the reac-
tion of [(arene)RuCl2]2 and [(C5Me5)MCl2]2 (M=Ru,
Rh, Ir), respectively, with [S2PR2]− (R=Me, Ph) [15];
(h3-C3H5)Mo(MeCN)(CO)2(S2PPh2) and [{(h3-C3H5)-
Mo(CO)2(S2PPh2)}2(m-NH2NH2)] from the reaction of
(h3-C3H5)Mo(MeCN)2(CO)2Br with NH4(S2PPh2),
followed by NH2NH2 [8e]; and the coordination com-
pound, [(dcpe)Pd(S2PR2)]+[S2PR2)]− (dcpe=1,2-bis(di-
cyclohexylphosphino)ethane)) from the reaction of
Pd2(m-dcpe)2 with [SP(S)R2]2 (R=Et, Ph) [16]. In
this paper, we report results from a study with
bis(diphenylthiophosphinyl)disulfane, Ph2P(S)SSP(S)-
PPh2.
In view of the facile dissociation of the chromium
dimer (1) (Eq. (i)) [17], it is conceivable that the reac-
tion is initiated by the homolytic attack of the 17-elec-
tron CpCr(CO).3 species on the SꢀS bond of the
bis(thiophosphinyl)disulfane, generating complex 2,
which must have undergone intermolecular association,
followed by bond dissociations to finally yield 3
(Scheme 1).
(i)
Complex 2 possesses a Cp resonance at l 4.58 (1H)
and l 95.27 (13C) in C6D6, within the range observed
for the CpCr moiety [1–5], and a 31P resonance in C6D6
at l 69.80. Its infrared spectrum in Nujol shows two PS
stretches at 642m and 569m cm−1, as compared with
641 and 550 cm−1 for (MeCpMo(CO)2(S2P(OiPr)2)
[12], consistent with the occurrence of a bidentate dithi-
olate group. In 3, the bands corresponding to w(PꢁS)
and w(PꢀS) occur at 649vs and 544m cm−1, respec-
tively, within the frequency ranges found for monoden-
tate dithiophosphate ligands [18] (compared with w
650–658vs and 540–542s for CpFe(CO)2(h1-S2P(OR)2
i
(R=Et, Pr)) [11].
The proton NMR spectra of 3 in C6D6 and C6D5CD3
at 27°C show only one broad unsymmetrical signal,
Scheme 1.

66
L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
phenyl rings of rapidly scrambling ligands as consistent
with the 31P-NMR observations described below. In
contrast, the spectrum in CD3CN shows two distinctly
separate signals, occurring at 27°C at l 7.80 (w1/2 30 Hz)
and l 10.08 (w1/2 75 Hz), assignable to the Cp and
phenyl rings, respectively, on the basis of their relative
integral ratio of ca. 1:4. In the temperature range of
−30–70°C, the Cp peak varied from l 7.74 (w1/2 23
Hz) at 70°C to ca. l 7.90 (w1/2 189 Hz) at −30°C,
whilst that of the phenyl rings varied from l 9.68 (w1/2
54 Hz) at 70°C to ca. l 10.35 (w1/2 270 Hz) at 0°C with
extensive broadening below this temperature. These
slight changes in a temperature range of 100°C pertain
only to solvent changes with temperature. The observa-
tion of a single sharp singlet in the 31P-NMR over the
temperature range −80–60°C in C6D5CD3 (l 70.86,
69.58 and 69.32 at −80, 27 and 60°C, respectively) for
two P atoms in different molecular environments pro-
vides conclusive evidence for rapid unidentate–biden-
tate exchange in the temperature range studied. In this
context, we note that in the VT 31P-NMR spectral
study of CpM(NO)(S2P(OR)2)2 (M=Mo, W) in ace-
tone-d6, the inter-ligand exchange began to freeze out at
−14°C, until at −78°C, two distinct sharp 31P signals
were observed [18]. The 13C spectrum in C6D6 shows
only two signals, viz. at l 150.86 and 138.05, pre-
sumably for the phenyl and Cp rings, respectively, in
accordance with the relative field in which they occur in
the proton spectrum. A single observed signal for the
six carbons of the phenyl ring is consistent with rapid
exchange of the ligands. Finally, we note that both the
Cp and phenyl resonances of 3 are observed in unusu-
ally low fields; this together with the broad characteris-
tics of the resonances is most probably associated with
the paramagnetic nature expected of a formally Cr(III)
center or a 15 electron count in the molecule. We have
observed before extremely low-field occurrences of Cp
and Me resonances, caused by the presence of 17-elec-
tron paramagnetic species from metalꢀmetal bond dis-
sociation in [CpCr(CO)3]2 [17c], and its permethyl Cp
analogue [17d].
Fig. 1. Molecular structure of CpCr(S2PPh2)2 (3).
Table 1
,
Selected bond lengths (A) and angles (°) for CpCr(S2PPh2)2 (3)
Bond lengths
a
Cr(1)ꢀCpc
Cr(1)ꢀS(3)
Cr(1)ꢀS(2)
Cr(1)ꢀS(1)
P(1)ꢀC(111)
P(1)ꢀC(121)
P(1)ꢀS(2)
1.847(2)
2.3756(8)
2.4233(9)
2.4104(8)
1.813(3)
1.818(3)
2.0209(11)
2.0229(10)
1.827(3)
P(1)ꢀS(1)
P(2)ꢀC(221)
P(2)ꢀC(211)
P(2)ꢀS(4)
1.834(3)
1.9688(10)
2.0537(10)
84.92(3)
P(2)ꢀS(3)
S(2)ꢀCr(1)ꢀS(1)
S(3)ꢀCr(1)ꢀS(1)
90.10(3)
Bond angles
C(111)ꢀP(1)ꢀC(121)
C(111)ꢀP(1)ꢀS(2)
C(121)ꢀP(1)ꢀS(2)
C(111)ꢀP(1)ꢀS(1)
C(121)ꢀP(1)ꢀS(1)
S(2)ꢀP(1)ꢀS(1)
C(221)ꢀP(2)ꢀC(211)
C(221)ꢀP(2)ꢀS(4)
C(211)ꢀP(2)ꢀS(4)
C(221)ꢀP(2)ꢀS(3)
C(211)ꢀP(2)ꢀS(3)
S(4)ꢀP(2)ꢀS(3)
105.38(13)
112.22(11)
110.12(10)
110.48(10)
111.09(11)
107.60(4)
103.81(12)
111.58(10)
111.70(10)
108.27(9)
104.50(9)
116.06(5)
83.50(3)
P(1)ꢀS(1)ꢀCr(1)
P(1)ꢀS(2)ꢀCr(1)
P(2)ꢀS(3)ꢀCr(1)
2.2. Crystallographic studies
83.21(3)
113.81(4)
The molecular structure of 3 is illustrated in Fig. 1.
Selected bond parameters are given in Table 1. The
structure is unique in possessing both a monodentate
and a bidentate dithiophosphinato ligand; to date only
NMR spectral evidence had been presented for the
occurrence of intramolecular unidentate–bidentate
scrambling of such dithio ligands in solution, e.g. in the
a Cpc, centroid of Cp ring.
consisting of a peak at l 9.75 (w1/2 ca. 80 Hz) sitting on
a very broad base hump, which became more promi-
nent as the temperature is raised; at 60°C in C6D5CD3,
it is clear that there exists a sharper signal (l 9.43 (w1/2
45 Hz)) sitting on a much broader signal (w1/2 ca. 375
Hz) centered at ca. l 9.9. The area relationship of the
sharper peak to the latter suggests that it belong to the
Cp ligand. The broad base signal can be assigned to the
organometallic
compounds
CpM(NO)(S2P(OR)2)2
(M=Mo, W) [18], (arene)Ru(S2PR2)2 (R=Me, Ph)
and (C5Me5)M(S2PR2)2 (M=Ru, Rh, Ir; R=Me, Ph)
[15], in the coordination compounds [Pt(S2PR2)2(PPh3)]
(R=Me, Et) and [Pd(S2PR2)2(PMe2R%)] (R=Me, Ph;

L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
67
R%=Me, Ph) [19] and in (C5Me5)Rh(S2P(OEt)2)2 [13b].
These dithiophosphinato and dithiophosphato ligands
are normally bidentate in bonding mode, as found in
the majority of examples listed in Table 2, with the
exception of the complex CpFe(CO)2(h1-S2P(OR)2) and
its (C5Me5) analogue, which contains a monodentate
thiophosphato ligand, coordinated via one of its two S
atoms to the Fe center [11]. In Table 2, some of the
significant bond parameters of 3 are compared with
their equivalents in the bidentate complexes known to
date, and the monodentate complexes CpFe(CO)2(h1-
S2P(OR)2) [11]. In general, there exists a close similarity
in the magnitudes of the equivalent bond distances and
angles between the complexes, with only a small spread
[CpCr(CO)3]2 (1) was synthesized as described by
Manning [21] from chromium hexacarbonyl (98% pu-
rity from Fluka). The bis(thiophosphinyl)disulfane,
Ph2P(S)SSP(S)PPh2 was prepared according to pub-
lished procedures [22]. All solvents were dried over
sodium–benzophenone and distilled before use. Celite
(Fluka AG), silica gel (Merck Kieselgel 60, 230-400
Mesh) were dried at 140°C overnight before chromato-
graphic use.
3.1. Reaction of [CpCr(CO)3]2 (1) with [Ph2P(S)S]2
3.1.1. Isolation of products
A deep green mixture of [CpCr(CO)3]2 (1) (201 mg,
0.50 mmol) and [Ph2P(S)S]2 (249 mg, 0.50 mmol) in
toluene (10 ml) was stirred at ambient temperature for
20 min. The resultant brown product mixture was
filtered through a disc (2×1.5 cm) of silica gel, remov-
ing some blue solids, to give a reddish–brown filtrate.
Concentration of the filtrate under vacuo to ca. 3 ml,
followed by addition of n-hexane (2 ml) and subsequent
cooling at −29°C for 30 min, gave dark microcrys-
talline solids of CpCr(CO)2(S2PPh2) (2) (212 mg, 0.50
mmol, 50.0% yield). Anal. Found: C, 53.21; H, 3.67;
Cr, 11.73; P, 6.56; S, 15.41. C19H15O2S2PCr Calc.: C,
54.02; H, 3.58; Cr, 12.31; P, 7.33; S, 15.18%. NMR
(C6D6): 1H l(Cp) 4.58; 13C l(Cp) 95.27; l(C6H5)
132.29, 130.30, 130.14 and 129.46; 31P l 69.80. NMR
,
of values. The PꢁS distance (1.9688(10) A) in the
unidentate ligand of 3 was found to be slightly longer
than the equivalent distances (1.944(2), 1.940(1) and
,
1.933(1) A) in the Fe complexes. Likewise, the SꢀPꢁS
angle (116.06(5)°) in 3 is larger than those in the Fe
complexes [11].
Attempts to obtain a good diffraction-quality crystal
of 2 was frustrated by its tendency to degrade in
solution to 3 even at −29°C. A modification of the
synthetic method, as described in Section 3.1.2, gave a
crystal which diffracted sufficiently to show the exis-
tence of a molecular structure (with two independent
molecules in the asymmetric unit), closely resembling
that of the dithiophosphato Mo complex, (MeCp-
Mo(CO)2(S2P(OiPr)2) [12]. It is seen that the Cr atom
assumes a four-legged piano-stool configuration, being
bonded to a bidentate (S,S) ligand, with its PPh2 ap-
pendage suspended from the two S atoms. As in the
case of (MeCpMo(CO)2(S2P(OiPr)2) [12], the cis-juxta-
position of the CO ligands is supported by the IR data
(w 1967vs, 1886vs cm−1) [20], while the low-frequency
stretches at 569m and 475m cm−1 indicates the pres-
ence of a bidentate ligand. Unfortunately the poor
quality of the X-ray data did not allow for meaningful
comparisons of bond parameters.
1
(CD3CN): H l(Cp) 5.17, l(C6H5) 7.73 (s, br), 7.56 (m)
and 7.17 (m); 13C l(Cp) 96.09; l(C6H5) 132.92, 129.69;
l(CO) 203.84; 31P l 74.44. IR (Nujol, cm−1): w(CO)
1967vs, 1886vs, 1862wsh; w (other bands) 1309w,
1146w, 1101m, 1060w, 999w, 825m, 742m, 707s, 696m,
642m, 580s, 569m, 515m, 490m, 475m. MS (FAB+):
shows the higher intensity mass fragments of
CpCr(S2PPh2)2 (3) given below, viz. m/z 615, 550, 365,
301, 256, 217, 181 and 148.
The mother liquor had to be subjected to a chro-
matographic separation on silica gel, on which com-
pound 2 was found to rapidly degrade; since the mother
liquor still contained some of 2, as indicated in its
proton NMR spectrum, it was stirred for a further 2 h
at ambient temperature to allow all of 2 to convert to
the complex 3 which then colored the resultant solution
blue–green. Concentration of the solution to ca. 4 ml
followed by filtration then removed a fine purple insol-
uble precipitate (15 mg) of a compound (the elemental
analysis of which possessed an empirical formula
3. Experimental
All reactions were carried out using conventional
Schlenk techniques under an inert atmosphere of nitro-
gen or under argon in an M. Braun Labmaster 130
Inert Gas System.
NMR spectra were measured on a Bruker 300 MHz
1
FT-NMR spectrometer; for H and 13C spectra, chemi-
C14.7H15.0S1.8P0.90Cr, i.e. in the proximity of
cal shifts were referenced to residual C6H6 in C6D6,
C6D5CH2D in C6D5CD3, or CH2DCN in CD3CN; for
31P spectra, chemical shifts were referenced to external
H3PO4. IR spectra in Nujol mulls were measured in the
range 4000–200 cm−1 by means of a BioRad FTS-165
FTIR instrument. Mass spectra were run on a Finnigan
Mat 95XL-T spectrometer. Elemental analyses were
performed by the microanalytical laboratory in-house.
[CpCrS2P(C6H5)2)]n, indicative of a polymeric form of
3. The filtrate was next loaded on to a silica gel column
(1.5×20 cm) prepared in hexane. Elution gave four
fractions: (i) a greenish brown eluate in n-hexane (15
ml), which on concentration gave deep green crystals of
Cp2Cr2(CO)4S (9 mg, 0.024 mmol, 4.6% yield), iden-
tified by its color characteristics and Cp resonance in

Table 2
A comparison of selected significant bond parameters a
CpCr(S2PPh2)2 CpM(CO)2(S2P(OR)2)
[(h3-C3H5)Mo(CO)2(S2P(OEt)2)]nX b Other complexes b
n=2, X=
n=1, X=CH3CN [(h6-p-cymene) Cp*RhCl(S2P- [cy2P(CH2CH2)
(3) b,c
CpMo(CO)2-
(S2P(OiPr)2) b,d
[12]
CpFe(CO)2(S2P(OiPr)2) c
CpFe(CO)2-
(S2P(OEt)2) c (m-NH2ꢀNH2)
[14]
Ru(PPh3)
(OEt)2) [13b]
Pcy2Pd-
(S2P(Et)2)]+ e
[16]
Cp=C5H5 Cp=C5Me5 [11b]
[8e]
(S2P(OEt)2)]
BPh4 [13a]
[11b]
[11c]
/
,
Bond lengths (A)
MꢀS(1)
MꢀS(2)
MꢀS(3)
P(1)ꢀS(1)
P(1)ꢀS(2)
P(2)ꢀS(3)
P(2)ꢀS(4)
2.4104(8)
2.4233(9)
2.3756(8)
2.0229(10)
2.0209(11)
2.0537(10)
1.9688(10)
2.550(1)
2.559(1)
–
1.992(1)
1.994(1)
–
–
–
–
–
–
–
–
2.551(1)
2.642(1)
–
1.991(1)
1.988(1)
–
–
2.5648(18)
2.6377(21)
–
1.976(3)
1.973(3)
–
–
2.4312(14)
2.431(2)
–
1.989(2)
1.971(2)
–
–
2.440(2)
2.4270(13)
–
1.985(2)
1.985(2)
–
–
2.404(2)
2.398(2)
–
2.015(3)
2.016(3)
–
–
2.322(2)
–
–
2.026(2)
1.944(2)
2.311(1)
–
–
2.021(1)
1.940(1)
2.304(1)
–
–
2.018(1)
1.933(1)
Bond angles (°)
S(1)ꢀMꢀS(2)
S(1)ꢀP(1)ꢀS(2)
S(3)ꢀP(2)ꢀS(4)
P(1)ꢀS(1)ꢀM
P(1)ꢀS(2)ꢀM
P(2)ꢀS(3)ꢀM
84.92(3)
107.60(4)
116.06(5)
83.50(3)
83.21(3)
113.81(4)
76.5(1)
105.0(1)
–
89.1(1)
88.8(1)
–
–
–
–
–
–
–
77.32(5)
109.3(1)
–
87.61(6)
85.18(7)
–
75.97(7)
108.36(12)
–
88.82(8)
86.84(10)
–
80.43(5)
104.88(8)
–
83.54(7)
83.92(7)
–
80.99(5)
105.51(8)
–
86.46(6)
86.82(6)
–
83.99(7)
105.7(1)
–
84.21(9)
84.35(9)
–
112.5(1)
–
–
111.9(1)
–
–
112.1(1)
–
–
607
(
109.1(1)
112.0(1)
111.2(1)
a Cp=C5H5, unless otherwise specified.
b Containing bidentate ligand.
c Containing unidentate ligand.
d Cp=C5H4Me.
6
e cy=cyclohexyl.

L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
69
benzene-d6 at l 4.36 (1H) and 89.20 (13C) in its NMR
3.1.2. Modified procedure for growth of
diffraction-quality crystals of 2
spectra [1a,c]; (ii) a reddish–brown eluate in n-hexane–
toluene (1:1, 10 ml), from which was obtained a minute
quantity of an unidentified complex, possessing l(Cp)
4.29 and l(P) 75.54 in its proton and 31P-NMR spectra,
respectively, in benzene-d6; (iii) a dirty brown eluate in
toluene–ether (2:1, 10 ml), from which was isolated 2
mg of a black solid, presumably of Cp4Cr4S4, based on
its Cp resonance at l 4.91 in the NMR spectrum [1d];
and (iv) a prussian blue eluate in THF (15 ml), which
gave complex 3 as deep blue crystals (62 mg, 0.10
mmol, 10% yield). Anal. Found: C, 56.49; H, 4.19; Cr,
7.85; P, 9.33; S, 20.78. C29H25S4P2Cr Calc.: C, 56.57; H,
4.09; Cr, 8.44; P, 10.06; S, 20.83%. IR (Nujol, cm−1): w
1572w, 1304m, 1181w, 1158w, 1097vs, 1068w, 1025w,
998w, 825s, 756m, 742s, 706vs, 690w, 683w 665w 649vs,
628m, 608m, 567vs, 544vs, 487s. MS (FAB+): m/z 615
A deep green mixture of [CpCr(CO)3]2 (1) (10 mg,
0.025 mmol) and [Ph2P(S)S]2 (12.5 mg, 0.025 mmol) in
THF (2 ml) was stirred vigorously at ambient tempera-
ture for 6 min, and then filtered through a sintered glass
frit, removing some unreacted 1. To the resultant deep
greenish brown filtrate was added n-hexane (1.5 ml)
and the solution stood at −29°C overnight. Some
crystals of unreacted 1 was found to have fallen out of
solution; after removal of these deep green crystals by
filtration, the mother liquor yielded some purple dif-
fraction-quality needle crystals of 2 (ca. 9 mg, 42%
yield).
3.2. NMR tube reactions
3.2.1. Reaction of [CpCr(CO)3]2 with [Ph2P(S)S]2
A deep green mixture of [CpCr(CO)3]2 (1) (4 mg, 0.01
mmol) and [Ph2P(S)S]2 (5 mg, 0.01 mmol) in benzene-d6
(0.5 ml) in a 5-mm NMR tube was manually shaken up
for 10 min, and then its proton NMR spectra scanned
and subsequently monitored at intervals (1, 7, 24, 72, 96
h). The integral ratios of the Cp resonances of the
products 2 to 3 were estimated.
[CpCr(C6H5)4P2S4],
550
[Cr(C6H5)4P2S4],
365
[Cr(C6H5)2PS4], 301 [Cr(C6H5)2PS2], 256 [Cr(C6H5)PS3],
217 [(C6H5)2PS], 181 [CpCrS2], 149 [CpCrS], 148
[CpCrP]. VT-NMR spectral characteristics are pre-
sented in Section 2.1.
Table 3
Crystal and structure refinement data for 3
3.2.2. Decomposition of 2
Empirical formula
Formula weight
Temperature (K)
C29H25CrP2S4
615.67
293(2)
0.71073
Triclinic
The proton NMR of a 24 mM solution of 2 (5 mg in
0.5 ml benzene-d6) was monitored at hourly intervals up
to 6 h at ambient temperature; the change in the
integrals of the resonance of 2 gave an approximate
conversion rate from 33% at 1 h, through 62% at 4 h to
70% at 6 h; a final spectrum scanned after 24 h indi-
cated that complete decomposition had already
occurred.
,
Wavelength (A)
Crystal system
Space group
(
P1
Unit cell dimensions
,
a (A)
11.0329(2)
11.4735(1)
12.1129(2)
101.955(1)
98.373(1)
90.645(1)
1482.72(4)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3.3. Structure determinations
3
,
V (A )
Z
Owing to the unstable nature of 2 in solution, it was
not possible to obtain good quality single crystals by
conventional methods, e.g. diffusion or layering tech-
niques, even at −29°C, which invariably gave mixtures
with 3. Fortunately, a modified procedure for the isola-
tion of the primary crop of products from the reaction
of 1 with the ligand, as detailed in Section 3.1.2 above,
gave some diffraction-quality crystals.
Diffraction-quality single crystals of 3 were obtained
as blue prisms from THF, layered with hexane, after 4
days at −29°C.
The crystallographic data together with data collec-
tion details are given in Table 3. The atomic coordi-
nates and equivalent isotropic displacement parameters
are given in Table 4.
Dcalc (Mg m−3
)
1.379
0.793
634
Absorption coefficient (mm−1
F(000)
)
Crystal size (mm3)
0.30×0.18×0.13
2.23–29.19
−145h514, −145k514,
05l516
q range for data collection (°)
Index ranges
Reflections collected
11046
Independent reflections
Completeness to q (%)
Absorption correction
Max. and min. transmission
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
6921 [Rint=0.0223]
86.2 (29.19°)
SADABS
0.914549 and 0.751647
Full-matrix least-squares on F2
6921/45/340
1.021
R1=0.0443, wR2=0.0911
R1=0.0764, wR2=0.1062
The crystal of 3 were mounted on quartz fibers.
X-ray data were collected on a Siemens SMART diffrac-
tometer, equipped with a CCD detector, using Mo–Ka
Largest difference peak and hole 0.299 and −0.291
−3
,
(e A
)

70
L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
Table 4
with equal occupancies (0.5); all the CꢀC bond lengths
were restrained to be equal. All non-hydrogen atoms
were given anisotropic thermal parameters.
Atomic coordinates (×104) and equivalent isotropic displacement
2
3
a
,
parameters (A ×10 ) for 3
x
y
z
Ueq
40(1)
Cr(1)
P(1)
9036(1)
7353(1)
7516(1)
8626(1)
7587(1)
7601(1)
8734(1)
5824(2)
5067(3)
3945(4)
3563(4)
4312(4)
5445(3)
7515(3)
8435(3)
8536(4)
7749(4)
6830(4)
6711(3)
5943(2)
5596(3)
4423(3)
3595(3)
3915(3)
5091(3)
7575(2)
8337(3)
8397(4)
7712(4)
6942(4)
6868(1)
10495(1)
10934(1)
10886(1)
10416(1)
10174(1)
10916(1)
11052(1)
10688(1)
10328(1)
10469(1)
15201(1)
13345(1)
17332(1)
13084(1)
15045(1)
15565(1)
17933(1)
13029(3)
13939(4)
13678(6)
12532(6)
11615(5)
11862(4)
12316(3)
11518(3)
10779(3)
10868(4)
11653(4)
12387(3)
17481(3)
18576(3)
18734(4)
17804(4)
16719(4)
16540(3)
18216(2)
19235(3)
19857(3)
19470(4)
18473(4)
17846(2)
15841(2)
14965(2)
15395(2)
16537(2)
16813(2)
15180(2)
14992(2)
16000(2)
16812(2)
16304(2)
12552(1)
10984(1)
14612(1)
12281(1)
10815(1)
13855(1)
15977(1)
11259(2)
11595(4)
11886(5)
11836(4)
11499(4)
11202(3)
9660(3)
4. Supplementary material
42(1)
39(1)
48(1)
53(1)
43(1)
62(1)
50(1)
86(1)
121(2)
109(2)
97(2)
75(1)
49(1)
64(1)
84(1)
94(2)
93(1)
70(1)
43(1)
69(1)
81(1)
81(1)
102(2)
81(1)
44(1)
64(1)
87(1)
96(2)
84(1)
57(1)
73(3)
93(5)
90(5)
65(3)
59(3)
69(3)
58(3)
59(3)
59(3)
74(3)
P(2)
S(1)
S(2)
S(3)
Crystallographic data for the structural analysis has
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no. 140357. Copies of this infor-
mation may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK [fax: +44-1223-336033, or e-mail: de-
posit@ccdc.cam.ac.uk or www: http://www.ccdc.cam.
S(4)
C(111)
C(112)
C(113)
C(114)
C(115)
C(116)
C(121)
C(122)
C(123)
C(124)
C(125)
C(126)
C(211)
C(212)
C(213)
C(214)
C(215)
C(216)
C(221)
C(222)
C(223)
C(224)
C(225)
C(226)
C(1)
ac.uk].
6
9588(3)
8531(4)
7587(4)
7646(3)
Acknowledgements
Support from the National University of Singapore
for Academic Research Grant no. RP3972673 is grate-
fully acknowledged.
8687(3)
14930(2)
15466(3)
15741(3)
15484(4)
14961(5)
14662(4)
13526(3)
13733(3)
12873(5)
11818(5)
11608(4)
12464(2)
11712(2)
12302(2)
13464(2)
13593(2)
12510(2)
12043(2)
13146(2)
13843(2)
13170(2)
12058(2)
References
[1] (a) L.Y. Goh, T.W. Hambley, G.B. Robertson, J. Chem. Soc.
Chem. Commun. (1983) 1458. (b) L.Y. Goh, W. Chen, E. Sinn,
J. Chem. Soc. Chem. Commun. (1985) 462. (c) L.Y. Goh, T.W.
Hambley, G.B. Robertson, Organometallics 6 (1987) 1051. (d)
W. Chen, L.Y. Goh, E. Sinn, Organometallics 7 (1988) 2020.
[2] (a) L.Y. Goh, C.K. Chu, R.C.S. Wong, T.W. Hambley, J. Chem.
Soc. Dalton Trans. (1989) 1951. (b) L.Y. Goh, C.K. Chu, R.C.S.
Wong, T.W. Hambley, J. Chem. Soc. Dalton Trans. (1989) 1951.
(c) L.Y. Goh, R.C.S Wong, E. Sinn, J. Chem. Soc. Chem.
Commun. (1990) 1484. (d) L.Y. Goh, R.C.S. Wong, C.K. Chu,
J. Chem. Soc. Dalton Trans. (1990) 977. (e) L.Y. Goh, R.C.S.
Wong, W.-H. Yip, T.C.W. Mak, Organometallics 10 (1991) 875,
and references therein. (f) L.Y. Goh, R.C.S. Wong, E. Sinn,
Organometallics 12 (1993) 888.
[3] (a) L.Y. Goh, W. Chen, R.C.S. Wong, Angew. Chem. Int. Ed.
Engl. 32 (1993) 1728. (b) L.Y. Goh, W. Chen, R.C.S. Wong, K.
Karaghiosoff, Organometallics 14 (1995) 3886. (c) L.Y. Goh, W.
Chen, R.C.S. Wong, Z.-Y. Zhou, H.K. Fun, Mendeleev Com-
mun. (1995) 60. (d) L.Y. Goh, W. Chen, R.C.S. Wong, Phospho-
rus Sulphur Silicon 93–94 (1994) 209. (e) L.Y. Goh, W. Chen,
R.C.S. Wong, Organometallics 18 (1999) 306.
[4] (a) L.Y. Goh, M.S. Tay, T.C.W. Mak, R.-J. Wang,
Organometallics 11 (1992) 1711. (b) L.Y. Goh, M.S. Tay, Y.Y.
Lim, T.C.W. Mak, Z.-Y. Zhou, J. Chem. Soc. Dalton Trans.
(1992) 1239. (c) L.Y. Goh, M.S. Tay, W. Chen, Organometallics
13 (1994) 1813.
[5] L.Y. Goh, W. Chen, R.C.S. Wong, J. Chem. Soc. Chem. Com-
mun. (1999) 1481.
[6] L.Y. Goh, Coord. Chem. Rev. 185–186 (1999) 257.
[7] (a) I. Haiduc, D.B. Sowerby, S.F. Lu, Polyhedron 14 (1995)
3389. (b) I. Haiduc, D.B. Sowerby, Polyhedron 15 (1996) 2469
and references cited therein.
C(2)
C(3)
C(4)
C(5)
C(11)
C(12)
C(13)
C(14)
C(15)
a Ueq is defined as one third of the trace of the orthogonalized Uij
tensor.
radiation at ambient temperature (298 K). An exposure
time of 10 s was employed.
The data was corrected for Lorentz and polarization
effects with the SMART suite of programs [23] and for
absorption effects with SADABS [24]. The final cell
parameters were obtained by least-squares on 5245
strong reflections. Structure solution and refinement
were carried out with the SHELXTL suite of programs
[25]. The structure was solved by direct methods to
locate the heavy atoms, followed by difference maps for
the light, non-hydrogen atoms. The Cp and Ph hydro-
gens were placed in calculated positions. There was
disorder of the Cp ring, which was modeled as two sites
[8] (a) H. Keck, W. Kuchen, J. Mathow, B. Meyer, D. Mootz, H.
Wunderlich, Angew. Chem. Int. Ed. Engl. 20 (1981) 975. (b) E.
Lindner, K.-M. Matejcek, J. Organomet. Chem. 29 (1971) 283.
(c) H. Diller, H. Keck, A. Kruse, W. Kuchen, D. Mootz, R.

L.Y. Goh et al. / Journal of Organometallic Chemistry 607 (2000) 64–71
71
Wiskemann, Z. Naturforsch. 48b (1993) 548. (d) G. Barrado, D.
Miguel, J.A. Pe´rez-Martinez, V. Riera, S. Garc´ıa-Granda, J.
Organomet. Chem. 463 (1993) 127; ibid. 466 (1994) 147. (e) G.
Barrado, D. Miguel, V. Riera, S. Garc´ıa-Granda, J. Organomet.
Chem. 489 (1995) 129.
[17] (a) M.C. Baird, Chem. Rev. 88 (1988) 1217 (review) and refer-
ences cited therein. (b) S.J. McLain, J. Am. Chem. Soc. 110
(1988) 643. (c) L.Y. Goh, Y.Y. Lim, J. Organomet. Chem. 402
(1991) 209. (d) L.Y. Goh, S.K. Khoo, Y.Y. Lim, J. Organomet.
Chem. 399 (1990) 115.
[9] J. Sala-Pala, J.-L. Migot, J.E. Guerchais, L. Le Gall, F.
Grosjean, J. Organomet. Chem. 248 (1983) 299.
[18] W. De Oliveira, J.-L. Migot, M.B.G. De Lima, J. Sala-Pala,
J.-E. Guerchais, J.-Y. Le Gall, J. Organomet. Chem. 284 (1985)
313.
[19] (a) D.F. Steele, T.A. Stephenson, J. Chem. Soc. Dalton Trans.
(1973) 2124. (b) J.M.C. Alison, T.A. Stephenson, R.O. Gould, J.
Chem. Soc. (A) (1971) 3690.
[20] F.A. Cotton, G. Wilkinson, Advanced Inorganic Chemistry, fifth
ed., Wiley-Interscience, New York, 1988, pp. 1034–1040.
[21] A.R. Manning, P. Hackett, R. Birdwhistell, P. Soye, Inorg.
Synth. 28 (1990) 148.
[10] M. Mora´n, I. Cuadrado, J. Organomet. Chem. 311 (1986) 333.
[11] (a) M. Mora´n, I. Cuadrado, J. Organomet. Chem. 295 (1985)
353. (b) J. Sanz-Aparicio, S. Mart´ınez-Carrera, S. Garc´ıa-
Blanco, Acta Crystallogr. Sect. C 42 (1986) 1121; C 43 (1987)
2009. (c) J. Sanz-Aparicio, S. Mart´ınez-Carrera, S. Garc´ıa-
Blanco, Z. Krisallogr. 175 (1986) 195.
[12] S. Woodward, U. Riaz, M.D. Curtis, B.S. Haggerty, A.L. Rhein-
gold, Organometallics 9 (1990) 2703.
[13] (a) V.K. Jain, V.S. Jakkal, J. Organomet. Chem. 515 (1996) 81.
(b) V.K. Jain, B. Varghese, J. Organomet. Chem. 584 (1999) 159.
[14] K.W. Yih, G.H. Lee, Y. Wang, J. Organomet. Chem. 588 (1999)
125.
[15] D.R. Robertson, T.A. Stephenson, J. Chem. Soc. Dalton Trans.
(1978) 486.
[22] (a) W. Kuchen, H. Mayatepek, Chem. Ber. 101 (1968) 3454. (b)
W.A. Higgins, P.W. Vogel, W.G. Craig, J. Am. Chem. Soc. 77
(1955) 1864.
[23] SMART version 4.05, Siemens Energy and Automation Inc.,
Madison, WI, USA.
[24] G.M. Sheldrick, SADABS, 1996.
[16] R. Landtiser, J.T. Mague, M.J. Fink, C. Silvestru, I. Haiduc,
Inorg. Chem. 34 (1995) 6141 and references cited therein.
[25] SHELXTL version 5.03, Siemens Energy and Automation Inc.,
Madison, WI, USA.
.