Luminescent, low-toxic P,P-bischelate copper(i) complexes with N-alkylaryl-substituted 1,5-diaza-3,7-diphosphacyclooctanes

The interaction of 2-(thiophen-2′-yl)ethylphosphine, paraformaldehyde, and benzhydrylamine or 1-methylbenzylamine resulted in 1,5-diaza-3,7-diphosphacyclooctanes, which were used for the synthesis of P,P-bischelate copper( i ) complexes. The obtained compounds were characterized by NMR spectroscopy, mass spectrometry, and elemental analysis. The study of the luminescent properties of the copper( i ) complexes demonstrated that they are solid-state singlet luminophores. Their biological activity was investigated. They were shown to be inactive against gram-positive and gram-negative bacteria and exhibited a low cytotoxicity, which determined their potential use as luminescent sensors for biological applications.