Syntheses, weak interactions, 3D network structures and magnetic properties of two salts based on bis(maleonitriledithiolate)copper(II) anion and substituted triphenylphosphonium cation

Abstract

Two new salts, [BzTPP]₂[Cu(mnt)₂] (1) and [4NO₂BzTPP]₂[Cu(mnt)₂] (2) (BzTPP⁺ = benzyltriphenylphosphonium and mnt²⁻ = maleonitriledithiolate) have been prepared and characterized by elemental analyses, UV, IR, molar conductivity and single-crystal X-ray diffraction. The single-crystal structure analysis shows that 1 crystallizes in the monoclinic space group P2₁/n, while 2 crystallizes in the triclinic space group P−1. The effects of weak intramolecular interactions such as C–H···O, C–H···S, C–H···N, C–H···Cu hydrogen bonds and p···π, π···π stacking interactions in the solids generate a 3D network structure. It is noted that the change in the molecular topology of the counteraction when the 4-substituted group in the benzyl ring is changed from H to NO₂ results in differences in the crystal system, space group, weak interactions and the stacking mode of the cations and anions of 1 and 2. The magnetic susceptibilities of these salts measured in the temperature range 2.0 to 300 K show weak ferromagnetic coupling features with θ = 2.05 × 10⁻² K for 1 and 5.13 × 10⁻³ K for 2.