Synthesis, Structure, and Properties of Copper(II) Bromide Complexes with N-Disubstituted Thiocarbamoyl-N'-cyclohexylsulfenamides

Abstract

The [CuLBr₂] complexes, where L is RRN–C(=S)–S–NHC₆H₁₁ and RR = (C₂H₅)₂, (CH₂)₅, or (CH₂)₂O(CH₂)₂, have been synthesized by reacting equimolar amounts of CuBr₂ in methanol and L in diethyl ether. The compounds have been studied by elemental analysis, IR spectroscopy, EPR, X-ray absorption spectroscopy, conductometry, magnetochemistry, and thermal analysis. According to IR spectroscopy data, the ligands in the complexes are bidentately coordinated to Cu(II) through the thione sulfur sulfenamide and nitrogen atoms. Exact structural parameters of the nearest environment of Cu(II) have been determined from analysis of Cu and Br K-edge EXAFS spectra. The Cu–N, Cu–S, and Cu–Br bond lengths are within 2.06–2.08, 2.24–2.49, and 2.33–2.38 Å, respectively. The EPR spectra of the complexes in a DMF solution at 293 K are described by the isotropic spin Hamiltonian with spin S = 1/2, including hyperfine coupling to the nuclear spin of the central copper atom and additional hyperfine coupling to the nuclear spins of two equivalent bromine atoms and one nitrogen atom.