Copper(i) coordination polymers and mononuclear copper(i) complexes built from poly(1,2,4-triazolyl)borate ligands and tri-organophosphines

Abstract

New copper(I) triorganophosphine derivatives [Cu(R₃P)_n{(tz)₂BH₂}] and [Cu(R₃P)_n{(tz)₃BH}] (n = 1 or 2) have been synthesised from the reaction of CuCl with PR₃ (R = phenyl, cyclohexyl, benzyl, o-, m-, or p-tolyl) or PMePh₂ and potassium dihydrobis(1,2,4-triazolyl)borate, K[H₂B(tz)₂], or potassium hydrotris(1,2,4-triazolyl)borate, K[HB(tz)₃]. The complexes obtained have been characterized by elemental analyses and FT-IR in the solid state, and by NMR (¹H and ³¹P{¹H}) spectroscopy and conductivity measurements in solution. The solution data are consistent with partial dissociation of the sterically hindered complexes by way of breaking of Cu–P and Cu–N bonds. Single crystal structural characterizations were undertaken for several of them. The structurally authenticated arrays fall into four different types: (a) discrete mononuclear [Cu(R₃P)₂{(tz)₂BH₂}] with a four-coordinate CuP₂(N₂) coordination sphere, (b) one-dimensional polynuclear [Cu(R₃P){(tz)BH₂(tz)}]_(∞/∞) with a four-coordinate CuP(N₃) coordination sphere due to coordination by way of both N(2) and N(4) in one of the heterocyclic rings, (c) discrete mononuclear [Cu(R₃P){(tz)₃BH}] with a CuP(N₃) coordination sphere, (d) one-dimensional polynuclear [Cu(R₃P)₂{(tz)BH(tz)(tz)}]_(∞/∞)with a four-coordinate CuP₂(N₂) coordination sphere in which one of the ligand tz rings is uncoordinated and the other two bridge through N(4) to successive copper atoms.