Salts of ammonium-crown ether supramolecular cation with bis(maleonitriledithiolato)copperate(II): Crystal structures, magnetic susceptibilities, single crystal EPR spectra and DFT calculation

Two salts consisting of ammonium-crown ether supramolecular cation with bis(maleonitriledithiolato)copperate (II), (NH4)2(15-crown-5)3[Cu(mnt)2] (1) and (NH4)2(benzo-15-crown-5)4[Cu(mnt)2] · 0.5H2O (2), have been synthesized and structurally characterized. The distinct structures of supramolecular cation, an unusual triple-decker dication in 1 and a sandwich dimer in 2, were observed. X-band EPR studies on the single crystals of both 1 and 2 have been carried out at room temperature, which revealed that 1 possesses a single resonance line whereas 2 shows a perfect hyperfine structure. The spin-density distribution in the anionic moiety of 2 is calculated on DFT method and compared well with the experimental data.