Thioureido complexes of copper(I), copper(II) and copper(III). Crystal structure of the copper(I) complex [Cu[(C₆H₅)NC(S)N[(C₂H₄)₂O]]]₆

Abstract

Abstract Deprotonated N ‐phenyl, N ′, N ′‐dialkylthiourea (PhtuR 2 ) complexes of Cu(I) and Cu(II) have been isolated and the existence of a Cu(III) complex inferred from electrochemical measurements. The crystal structure of Cu(I)[(C 6 H 5 )NC(S)N[(C 2 H 4 ) 2 O]] (space group P l̄, Z = 24, a = 10.487(9), b = 28.961(8), c = 29.579(12) Å, α = 120.72(3), β = 103.69(5), γ = 83.14(4)°) revealed 4 hexameric units per unit cell. The metals form a distorted octahedron; the ligands are situated outside six of the faces of this octahedron. The copper coordination is threefold planar; a N atom is linked to one Cu and the S atoms to two Cu atoms. The Cu–Cu distances exclude strong metal‐metal interactions. ESR measurements on Cu(II)(PhtuBu 2 ) 2 suggest a planar coordination around Cu with the N atoms in trans ‐position. Cyclic voltamograms and differential pulse polarograms show the one‐electron oxidation, Cu(II)(PhtuR 2 ) 2 → Cu(III)(PhtuR 2 ) 2 + + e. The Cu(III) complex is only stable on the electrochemical time scale (scan rate 100 mV s −1 ).