Lewis-base adducts of Group 11 metal(I) compounds. Part 27. Solid-state phosphorus-31 cross-polarization magic-angle spinning nuclear magnetic resonance, far-infrared, and structural studies on the mononuclear 2 : 1 adducts of triphenylphosphine with cop

Abstract

Single - crystal X-ray diffract ion structure determi nations, high resolution solid -state crosspolarization magic-angle spinning 31P n.m.r., and far4.r. spectral data are reported for the mononuclear 2 : 1 adducts of triphenylphosphine with copper( I) and gold( I) halides, [ M (PPh,),X] . Crystal data are reported for [Cu( PPh,),CI]-0.5C6H6, [Cu( PPh,),l], [Au( PPh,),CI] (unsolvated), [Au(PPh,),Br], and [Au(PPh,),l]. In each structure the PPh, ligands adopt an eclipsed conformation about M-P with respect to M-X, with X-M-P-C(11) conformational angles ranging from 0.5 to 18.3". Within each halide series, M-P distances and P-M-P angles are independent of halogen [CuCI: 2.272(2), 2.260(2) A, 125.48(7)"; Cul: 2.273(2) A, 126.9(1)"; AuCl (unsolvated): 2.336(4), 2.31 7(4) A, 135.7(1); AuBr: 2.323(2) A, 132.45(8)"; and Aul: 2.333(2) A, 132.1 3(7)"]. Considerable asymmetry (490-560 Hz) in the solid-state 31P n.m.r. quartets obtained for M = Cu reflects the lower symmetry of the copper environment relative to four-co-ordinate tetrahedral compounds. Solid-state 31P chemical shift data for M = Au are independent of halogen (CI, 37; Br, 38; I, 36 p.p.m.). The far4.r. spectrum of [Cu( PPh,),l] reveals a strong band at 184 cm-l which is assigned to the Cul terminal stretching mode.