Reactions of Cu(i)Br with aziridine derivatives. Synthesis, characterization and crystal structures of monomeric, dimeric and hexameric aziridine (= az) complexes of the formal type [CuBr(az)2]n (n = 1, 2) and [CuBr(az)]6

Abstract

The first syntheses of monomeric and oligomeric aziridine complexes of copper(I) are described. Cu(I)Br (1) reacts with a series of different aziridine derivatives (C₂H₃PhNH (2), C₂H₂Me₂NH (3), C₂H₂Me₂NC₂H₂Me₂NH₂ (4)) to give the neutral dimeric complex [CuBr(C₂H₃PhNH)₂]₂ (5) and the ionic hexameric complex [Cu₆Br₅(C₂H₂Me₂NH)₆]Br (6) with terminal bound aziridine ligands as well as the neutral monomeric complex [CuBr(C₂H₂Me₂NC₂H₂Me₂NH₂)] (7) where the dimerized aziridine acts as a N,N′-chelating ligand. After purification, all of the complexes were fully characterized and their IR, ¹H and ¹³C NMR spectra are reported and discussed. The single crystal structure analysis revealed distorted tetrahedral geometry for the copper(I) centres in the complexes 5 and 6 and a trigonal planar structure for complex 7. In the oligomers the copper centres are bridged by two μ₂- (5) or two μ₃- and three μ₄-bromido ligands (6), respectively.