Silver(I) poly(1,2,3-benzotriazolyl)borate complexes containing mono- and bidentate phosphine coligands

Abstract

New silver(I) derivatives [Ag{H n B(btz) 4 − n }(PR 3) x ] ( n = 1 or 2, x ranging from 1 to 3), containing monodentate tertiary phosphines and anionic poly(benzotriazol-1-yl)borates, have been prepared from the reaction of AgNO 3 with PR 3 (R = Ph, o-tolyl, m-tolyl, p-tolyl, Bns) and K[H 2B(btz) 2], or K[HB(btz) 3] (Hbtz = 1,2,3-benzotriazole). When the reaction between K[H 2B(btz) 2] and AgNO 3 was carried out in the presence of dppe (1,2-bis(diphenylphosphino)ethane), or dppf (1,1′-bis(diphenylphosphino)ferrocene), compounds [Ag{H 2B(btz) 2}] 2(L) (L = dppe or dppf) formed, the diphosphine acting as a bidentate bridging P 2-donor. Solid state and solution properties of all complexes have been investigated through analytical and spectroscopic measurements (IR, 1H, 31P NMR), the 1H and 31P NMR spectra being interpreted in terms of equilibria that involve mono- and di-nuclear complexes. Adducts [Ag{HB(btz) 3}(PPh 3) 3] · (1/2H 2O) and [Ag{H 2B(btz) 2}] 2 (dppf) have been characterised by single crystal X-ray studies. In the former, the HB(btz) 3 is unidentate in an NAgP 3 coordination environment; the latter is a dimer, the dppf bridging the two silver atoms, while the H 2B(btz) 2 ligand, which chelates one silver, bridges to the second also, the array having 2-symmetry.