metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
restricted bite angle of the ligand (Crespo et al., 1997; Jones et
al., 1994; Gimeno et al., 1994), whereas the largest angle, P1Ð
AuÐP2, is likely to arise in order to minimize steric interac-
tions between the PPh3 groups.
ISSN 0108-2701
The four-membered AuS2C ring is planar, with the
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maximum deviation from the plane being 0.018 (9) A for C37.
The Au1ÐS1 and S1ÐC37 bond lengths are longer than those
of Au1ÐS2 and S2ÐC37, respectively. The shorter AuÐS
bond length (Au1ÐS2) lies adjacent to the C37ÐS2 bond,
(Piperidine-1-carbodithioato-S,S0)-
bis(triphenylphosphine-P)gold(I)
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which is closer to the normal C S bond length of 1.69 A. This
characteristic is also found and explained in detail in the
complex [Au(S2CPh)(PPh3)2] (Lanfredi et al., 1992).
Ibrahim Abdul Razak,a S. Shanmuga Sundara Raj,a
Hoong-Kun Fun,a* Fangfang Jian,b Fengli Bei,b Xujie
Yang,b Lude Lub and Xin Wangb
The Au1ÐP1 and Au1ÐP2 distances are comparable with
those found in the complex [Au(S2COEt)(PPh3)2] (Assefa et
al., 1994), but longer than the corresponding NiÐP distances
of 2.201 (1) and 2.229 (1) A found in the Ni analogue of (I)
(Venkatachalam et al., 1996). The C37ÐN1 bond length shows
signi®cant double-bond character, but is longer than that
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800
USM, Penang, Malaysia, and bMaterial Chemistry Laboratory, Nanjing University of
Science and Technology, Nanjing 210094, People's Republic of China
Correspondence e-mail: hkfun@usm.my
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observed in the Ni analogue of (I) [2.284 (5) A; Venka-
tachalam et al., 1996]. The piperidine ring adopts a chair
Received 15 February 2000
Accepted 9 March 2000
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conformation. The total puckering amplitude QT is 0.54 (1) A
(Cremer & Pople, 1975).
In the title compound, [Au(C6H10NS2)(C18H15P)2], the Au
atom is in a distorted tetrahedral environment, with the two P
atoms of the triphenylphosphine ligands and the S atoms of
the bidentate piperidinecarbodithioate ligand occupying the
vertices. The piperidine ring adopts a chair conformation.
Comment
Dithiocarbamate anions have proved to be highly versatile
chelating agents for the separation of metals as metal chelates
by gas chromatography (Riekkola et al., 1979). Dithio-
carbamate (dtc) ligands exhibit both bidentate behaviour,
acting as S,S0-donors, and monodentate behaviour, acting as S-
donors, depending on the type of complex (Forghieri et al.,
1988). Also, there has been a growing interest in the study of
d10 metal complexes, which exhibit rich photophysical and
photochemical properties (Harvey & Gray, 1988; Vogler &
Kunkely, 1988). Of particular interest is the nature of the
lowest electronic excited states, which serves to develop a
better understanding of the luminescent properties of d10±d10
systems (Yam et al., 1990). Nevertheless, the number of reports
on gold(I) complexes containing dtc anions and neutral
ligands is quite limited. In this context, we present here the
crystal structure of the title compound, (I).
Figure 1
The structure of (I) showing 30% probability displacement ellipsoids and
the atom-numbering scheme. H atoms are omitted for clarity.
Experimental
Sodium piperidinecarbodithioate, [Na(S2CNC5H10)], was dissolved in
H2O. Gold trichloride was added at room temperature with stirring.
The brown reaction mixture was ®ltered and the ®ltrate was washed
with water and dried overnight under vacuum. The dried ®ltrate was
dissolved in EtOH and triphenylphosphine was added at 353±363 K
with stirring. The solution was then re¯uxed for 4±5 h. Upon cooling,
the light-yellow solution obtained was ®ltered and left to evaporate.
After a few days, a light-yellow solid had separated out and was
recrystallized from EtOH/CHCl3. Single crystals suitable for X-ray
analysis were obtained by slow evaporation of an EtOH solution at
room temperature (m.p. 424 K).
The structure of (I) consists of mononuclear
[Au(Pipdtc)(PPh3)2] units (Pipdtc is piperidinecarbodithio-
ate). The Au atom is in a distorted tetrahedral environment.
This coordination is formed by two S atoms from the bidentate
Pipdtc ligand, which forms a four-membered chelate ring, and
two P atoms from the triphenylphosphine ligands. The angles
around the Au atom range between 65.77 (8) and 130.86 (8)ꢁ.
The smallest angle, which is S1ÐAuÐS2, is due to the
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666 # 2000 International Union of Crystallography
Printed in Great Britain ± all rights reserved
Acta Cryst. (2000). C56, 666±667
Razak, Ibrahim Abdul
