LEWIS-BASE ADDUCTS OF GROUP-11 METAL(I) COMPOUNDS .64. SYNTHESES, SPECTROSCOPY AND STRUCTURES OF SOME 1 4-ADDUCTS OF COPPER(I) AND SILVER(I) PERCHLORATES WITH TRIPHENYLARSINE AND TRIPHENYLSTIBINE/

Syntheses and room-temperature single crystal X-ray structure determin ations are recorded for adducts [M(EPh3)(4)](ClO4), M = Cu, E = As (1) , Sb (2); M = Ag, E = As (3), Sb (4), enabling comparison with analogo us, previously studied MP4 and MN4 environments. The four complexes so characterized all crystallize in the familiar rhombohedral <R(3)over bar> array (a approximate to 14.4, c approximate to 52 Angstrom, hexag onal setting) with the metal and chlorine atoms located on crystallogr aphic threefold axes. In these arrays Cu-E (axial, off axis) are 2.493 (2), 2.533(1) for (1), and 2.572(1), 2.577(1) Angstrom for (2), the di sparity in the two independent M-E distances being diminished relative to those of previously studied phosphorus analogues, perhaps in conse quence of increasing E size. In (3) and (4), some cation disorder is e vident in respect of the ligand pnictide atom (E); for the major compo nents Ag-E are 2.652(3), 2.680(2) in (3); 2.732(2), 2.7295(8) Angstrom in (4). Problems associated in defining the metal atom environment ge ometries in the latter are, nevertheless, more satisfactorily overcome in two further determinations of nitrate salts: [Ag(SbPh3)(4)](NO3) ( 5) is of the rhombohedral family with no cation core disorder, Ag-E (a xial, off axis) being 2.720(4), 2.725(2) Angstrom, while the structura l characterization of a 1:4 triphenylarsine adduct of silver nitrate i s recorded as its tetraethanol solvate, namely [Ag(AsPh3)(4)](NO3).sim ilar to 4C(2)H(5)OH (6), monoclinic, C2/c, a 18.373(4), b 20.786(5), c 21.070(8) Angstrom, beta 108.18(3)degrees, Z = 4f.u. The silver atom of the [Ag(AsPh3)(4)](+) cation unusually lies on a crystallographic 4 ? (rather than a 3) axis of the incipiently 23 (T) array, with Ag-As 2 .649(2), 2.650(2) Angstrom and As-Ag-As ranging from 108.22(4) to 111. 41(6)degrees. The structure determination of a chloroform solvate of ( 2), denoted (2a), of low precision, is noted, together with the struct ure of an interesting artefact, isomorphous with the rhombohedral oxoa nion array, modelled as [Ag(PPh3)(4)](2) (SiF6).py (7). Bands in the f ar-infrared spectra of [M(AsPh3)(4)](ClO4) are assigned to v(MAs) vibr ations at 119 (M = Cu) and 103 cm(-1) (M = Ag); this produces a more c onsistent picture of the Variation in the wavenumbers of the v(ME) mod es in [M(EPh3)(4)](+) compounds than was available previously.