Molecular tailoring of spin-transition materials: preparation, crystal structure and magnetism of trifluoromethyl-pyridyl-1,3,2-dithiazolyl

Abstract

The α-phase of pyridyl-1,3,2-dithiazolyl, pyDTA, has previously been shown to exhibit a distorted π-stacked structure which is diamagnetic at low temperature. Unlike other π-stacked dithiazolyl radicals it does not undergo a first order phase transition to a regular π-stacked paramagnetic phase even upon warming to its melting point. Here we show that incorporation of a trifluoromethyl group destabilises the diamagnetic π*–π* dimer and the title compound (1) exhibits a spin-transition (without hysteresis) at 50 K.