Three ion-pair complexes containing bis(maleonitriledithiolate) copper(II) anion and substituted 2-aminopyridinium cations: Syntheses, crystal structures, and magnetic properties

摘要

Three new ion-pair complexes, [2-CIBz-2'-NH2Py](2)[Cu(mnt)(2)](1), [2-Cl-4-ClBz-2-NH2Py](2)[Cu(mnt)(2)](2) and [2-Cl-4-BrBz-2'-NH2Py](2)[Cu(mnt)(2)]center dot C2H5OH(3) ([2-Cl-4-RBz-2'-NH2Py](+) = 1-(2'-chloro-4'-Rbenzyl)-2-aminopyridinium, R = H, Cl, Br; mnt(2-) = maleonitriledithiolate), were synthesized and characterized by elemental analyses, IR, UV-visible, single crystal X-ray diffraction and magnetic measurements. Both 1 and 2 crystallize in the monoclinic space group P2(1)/c, and the [Cu(mnt)(2)](2-) anions and the cations form a 1D network structure through the N-H center dot center dot center dot N hydrogen bonds. While the anions in 3 form a ladder-like chain through the C-H center dot center dot center dot N interactions between the [Cu(mnt)(2)](2-) anions and CH3CH2OH molecules. Some weak interactions such as pi center dot center dot center dot pi, Cu center dot center dot center dot N, Cl center dot center dot center dot C, and C-H center dot center dot center dot Cl, O-H center dot center dot center dot Cl, C-H center dot center dot center dot S, N-H center dot center dot center dot O, N-H center dot center dot center dot N and C-H center dot center dot center dot N hydrogen bonds in three molecular solids generate further a 3D network structure. The magnetic measurement reveals that 1 shows a very weak ferromagnetic interaction, and 2 exhibits a transition from ferromagnetic to antiferromagnetic coupling about 15 K, while 3 shows an antiferromagnetic coupling feature with theta = -12.51 K when the temperature is lowered. (C) 2015 Elsevier B.V. All rights reserved.