metal-organic compounds
whole assembly is symmetrical, with atoms Cd1 and I1 (from
the anion), as well as atoms N2, C11, C12, C15 and C16 (from
the cation), lying on the mirror plane. Fig. 2 shows the packing
diagram viewed along the c axis. Selected geometric para-
meters are collected in Table 1.
uration of the CdS4I kernel. The index parameter ꢀ (Addison
et al., 1984), conveniently describing the changes on going
from ideal square-pyramidal (ꢀ = 0.0) to ideal trigonal-bipyr-
amidal geometry (ꢀ = 1.0), calculated for the structures of four
different [Cd(S2CNEt2)2X] -type anions is 0.5 when X is Cl
and Br (Baggio et al., 1996), 0.27 when X is NCS (Baggio et al.,
1992), and 0.0 when X is I (this paper). It is unlikely that any
`special' property of homologous Cl, Br or I ligands (or even
the NCS ligand) determines the complex anion geometry.
Instead, we conclude that it is the cation and, more precisely,
its steric requirements (namely [NEt4]+ versus [PPh4]+) that
signi®cantly in¯uence the structure. In the somewhat similar
complex anion [Cd{S2P(OEt)2}2I] , when accompanied by a
very large cation such as [ꢁ3-oxo-tri-ꢁ2-sul®do-tris(diethyl-
The structure of the [NEt4]+ cation is very typical and does
not require any discussion. The most notable structural
feature of the anion is its square-pyramidal geometry, with
atoms S1, S10, S2 and S20 de®ning the basal plane (Fig. 3).
Some deviations are imposed by the bite angle of two
symmetry-related chelating dithiocarbamate ligands and the
non-equivalence of the necessarily wider S1ÐCd1ÐS10 and
S2ÐCd1ÐS20 angles. Further distortion is demonstrated by
atom Cd1 being displaced from the basal plane towards the
apical I atom of the square pyramid and the apical-to-basal
bond angles being greater than 90ꢀ. These deviations,
however, by no means favor a trigonal-bipyramidal con®g-
dithiophosphonato)(pyridine)molybdenum]+
[Cambridge
Structural Database (CSD; Version 5.27 of 2006; Allen, 2002)
refcode MAJGIN (Lu et al., 1997)], the geometry of the
central CdS4I kernel is slightly distorted, but nevertheless it
easily quali®es as trigonal-bipyramidal (ꢀ = 0.7).
The dithiocarbamate ligand in the [Cd(S2CNEt2)2X]
complex anion with X = I is bonded to cadmium much more
Ê
symmetrically (the CdÐS bond lengths differ by only 0.01 A)
Ê
than the same ligand in the cases where X = NCS (0.07 A;
Ê
Baggio et al., 1992) and X = Cl or Br (ca 0.16 A; Baggio et al.,
1996). This property seems to be related to the magnitude of
advancement of the CdS4X kernel geometry towards
trigonal-bipyramidal where the discrimination in bond lengths
formed by the same donor atoms in equatorial and axial
positions is usually observed. The mean CdÐS bond length
remains, however, the same in all complexes discussed
Ê
(2.65 A) and does not differ from that in the neutral dimeric
cadmium bis(N,N-diethyldithiocarbamate) complex (Dome-
nicano et al., 1968). Again, the data reported for [Cd-
S2P{OEt)2}2I] (Lu et al., 1997) support this conclusion (CdÐ
Ê
Seq = 2.531 and 2.545 A, although CdÐSax = 2.766 and
Ê
2.952 A).
Ê
Finally, the CdÐI bond length of 2.7919 (8) A seems
unexceptional as it falls roughly within the upper limit of CdÐ
I bond lengths reported for different complexes where non-
bridging I and S atoms are bonded to ®ve-coordinated
Figure 2
A packing diagram of (I), viewed along the c axis. H atoms have been
omitted.
Ê
cadmium (2.70±2.80 A; CSD).
Experimental
All commercially available reagents were of analytical or reagent
grade purity and were used as received. Cadmium bis(tri-tert-
butoxysilanethiolate) (0.135 g, 0.11 mmol), prepared according to a
previously reported procedure (Wojnowski et al., 1992), was dissolved
in toluene (15 ml). Sodium N,N-diethyldithiocarbamate trihydrate
(0.49 g, 0.22 mmol) and tetraethylammonium iodide (0.056 g,
0.22 mmol) were dissolved in hot water (7 ml each). The aqueous
solutions were mixed, and to the resulting mixture a solution of the
cadmium complex in toluene was added. The mixture was shaken
vigorously for ca 3 h and the layers separated. The organic layer was
washed with three 15 ml portions of water, dried over anhydrous
magnesium sulfate and ®nally evaporated to dryness. The solid was
dissolved in a minimum amount of toluene and the solution was left
for crystallization at room temperature. After a few days, the
Figure 3
The central square-pyramidal CdS4I core.
ꢁ
m96 Kropidøowska et al.
(C8H20N)[Cd(C5H10NS2)2I]
Acta Cryst. (2006). C62, m95±m97
Kropidlowska, Anna
