Crystallization of 1 : 2 mixtures of the copper(I) halides CuX, X = Cl,
Br, I, with triphenylstibine from acetonitrile yields adducts of 1 : 2
CuX/SbPh3 stoichiometry, confirmed by single-crystal
X-ray structure determinations. The three complexes are isomorphous,
monoclinic, P
21/c, a
≈ 24·3, b ≈ 14·2,
c ≈ 20 Å, β 110°,
Z = 4 dimers; conventional
R on F were 0·047,
0·044 and 0·045 for No 11247, 4673 and
10418 independent ‘observe’ (I > 3σ(I)) reflections
respectively. The complexes, also isomorphous with some related species, e.g.
1 : 2 AgBr,I/AsPh3, are dimers:
[(Ph3Sb)2Cu(µ-X)2Cu(SbPh3)2].
The chloride is also recorded as a chloroform disolvate, isomorphous with its
arsine analogue, being monoclinic, C
2/c, a 21·486(9),
b 17· 925(9), c
19·972(7) Å, β 91·31(3)°, Z
= 4 dimers, R 0·057 for
No 3756. The far-infrared spectra of
[(Ph3Sb)2Cu(µ-X)2Cu(SbPh3)2]
(X = Br, I) showed no clear v(CuX) bands, in
contrast to the situation reported previously for the corresponding
Ph3As compounds. A possible
v(CuCl) band is observed in the X = Cl complex at
219 cm-1 , but this occurs in a region where there is
also significant absorption in the other two compounds. The absence of strong
v(CuX) bands in these complexes is consistent with the
situation observed previously for the 3 : 1 compounds
[(Ph3Sb)3CuX].