Synthesis, spectral and crystal structures of two new copper(I) complexes of di-2-pyridyl ketone (DPK) containing uncoordinated N-protonated ligand; [(DPK)H][CuX 2] (X=I and NCS)

Abstract

Two new copper(I) complexes of di-2-pyridyl ketone (DPK); [(DPK)H][CuI 2] ( 1) and [(DPK)H][(Cu{NCS) 2] ( 2) have been prepared and characterized by spectroscopic and crystallographic methods. Both complexes are colored and exhibit very broad and strong MLCT bands in the visible region. The IR spectra of these complexes are measured and discussed. The structure determination of complex 1 shows that it consists of discrete [(DPK)H] + cation contains NH⋯N hydrogen bonds, and polymeric [CuI 2] − anion. In the anion, each copper atom is in a distorted tetrahedral environment with CuI bond lengths from 2.570(4) to 3.072(4) Å. The structure of complex 2, which is similar to 1, features uncoordinated N-protonated di-2-pyridyl ketone cations and corrugated layers of [Cu(NCS) 2] n , in which the copper atom is in a distorted tetrahedral CuS 2N 2 chromophore; CuN bond lengths are 1.954(2) and 1.958(2) Å, and CuS distances are 2.4120(8) and 2.4501(7) Å.