The catenation of a singlet diradical dication and modulation of diradical character by metal coordination

A singlet bis(triarylamine) diradical dication and its zigzag 1D magnetic chain catenated by silver cations were isolated and characterized by single-crystal X-ray crystallography, EPR spectroscopy, SQUID measurements, cyclic voltammetry, and UV-Vis-NIR absorption spectroscopy in conjunction with DFT calculations. The ΔEOS-T has significantly changed due to the coordination of carbonyls (Lewis base) with Ag+ (Lewis acid), revealing that the diradical character can be modulated by Lewis acid-base coordination and interchain intermolecular coupling interactions.