Syntheses, crystal structures, weak interaction, magnetic and photoluminescent properties of two new organic–inorganic molecular solids with disubstituted benzyl triphenylphosphinium and tetra(isothiocyanate)cobalt(II) anion

Abstract

Two new organic–inorganic molecular solids of tetra(isothiocyanate)cobalt(II) dianion and disubstituted benzyl triphenylphosphinium, [2Cl4FBzTPP]2[Co(NCS)4] (1) and [2Cl4ClBzTPP]2[Co(NCS)4] (2) ([2Cl4FBzTPP]+=1-(2′-chloro-4′-fluorobenzyltriphenylphosphonium) and [2Cl4ClBzTPP]+=1-(2′,4′-dichlorobenzyltriphenylphosphonium), were synthesized and characterized by elemental analysis, FT-IR, UV–Vis spectra, ESI-MS and single crystal X-ray diffraction method. Compounds 1 and 2 crystallize in the monoclinic Pc and triclinic P-1, respectively. The Co(II) ion of the [Co(NCS)4]2− anion shows a distorted tetrahedral coordination geometry. The [2Cl4FBzTPP]+ cations containing P(2) atoms in 1 form a column by the Cl⋯π interactions, while the [2Cl4ClBzTPP]+ cations in 2 form two columns by the C–H⋯π and π⋯π interactions. The anion and the cation are linked by C–H⋯S hydrogen bonds and Cl⋯S interactions. Magnetic susceptibility measurement in the temperature range 2–300K shows that both 1 and 2 exhibit a weak antiferromagnetic exchange interaction as the temperature falls, and ultraviolet fluorescence emission in the solid state at room temperature.