The Chemistry of 1,3,5‐Triazacyclohexane Complexes, 4. Strained 1,3,5‐Triazacyclohexane Complexes of Copper(I) and Copper(II)

In this paper we report on the synthesis and the crystallographic characterization of η3‐1,3,5‐triazacyclohexane (R3TAC) complexes of copper(I) and copper(II). The complexes [{Me3TAC)CuCl2}2] (1), [(iPr3TAC)CuCl2] (2), [{(PhCH2)3TAC}Cu(PPh3)](BF4) (3), and [(iPr3TAC)Cu(PPh3)]‐(BF4) (4) were characterized by X‐ray crystallography. The highly strained and bent Cu–N bonds are longer than in the corresponding complexes of other amine ligands. One methylene carbon atom of the ring comes close to the copper atom (2.55–2.65 Å). However, investigation of the ring deuterated complexes by IR and X‐ray crystallography ([D6]2) showed no clear evidence for attractive C–H–Cu interactions.