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

New silver(I) derivatives [Ag{HnB(btz)4 − n}(PR3)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 AgNO3 with PR3 (R = Ph, o-tolyl, m-tolyl, p-tolyl, Bns) and K[H2B(btz)2], or K[HB(btz)3] (Hbtz = 1,2,3-benzotriazole). When the reaction between K[H2B(btz)2] and AgNO3 was carried out in the presence of dppe (1,2-bis(diphenylphosphino)ethane), or dppf (1,1′-bis(diphenylphosphino)ferrocene), compounds [Ag{H2B(btz)2}]2(L) (L = dppe or dppf) formed, the diphosphine acting as a bidentate bridging P2-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}(PPh3)3] · (1/2H2O) and [Ag{H2B(btz)2}]2 (dppf) have been characterised by single crystal X-ray studies. In the former, the HB(btz)3 is unidentate in an NAgP3 coordination environment; the latter is a dimer, the dppf bridging the two silver atoms, while the H2B(btz)2 ligand, which chelates one silver, bridges to the second also, the array having 2-symmetry.

Graphical abstractNew silver(I) derivatives containing mono- and bidentate tertiary phosphines and anionic bis- or tris(1,2,3-benzotriazol-1-yl)borates have been synthesised. Adducts [AgHB(btz)3(PPh3)3] · (1/2H2O) and [Ag{H2B(btz)2}]2(dppf) have been characterised by single crystal X-ray studies. In the first, the HB(btz)3 is unidentate in an NAgP3 coordination environment; the latter is a dimer, the dppf bridging the two silver atoms, while the H2B(btz)2 ligand, which chelates one silver, bridges to the second also, the array having 2-symmetry.Figure optionsDownload full-size imageDownload as PowerPoint slide