X-ray Structures and Hirshfeld Studies of Two Dinuclear Cd(II) Complexes with a s-Triazine/Pyrazolo Ligand and Pesudohalides as a Linker

Abstract

The two dinuclear Cd(II) complexes [Cd(BPMST)(SCN)]2 (1) and [Cd(BPMST)(N3)Cl]2 (2) of a s-triazine/pyrazolo ligand (BPMST) were synthesized. The preparation of both complexes was performed in a water–ethanol solvent mixture and involved the mixing of the functional ligand BPMST with CdCl2 in the presence of thiocyanate or azide as linkers, respectively. The dinuclear formula of both complexes and the involvement of the pesudohalide as a linker between the Cd(II) centers were approved by single crystal X-ray structures. The Cd(II) was hexa-coordinated and the CdN5S (1) and CdN5Cl (2) coordination environments had distorted octahedral geometry. In the [Cd(BPMST)(SCN)]2 and [Cd(BPMST)(N3)Cl]2, the BPMST acted as a pincer tridentate N-chelate. In the case of 1, the SCN¯ acted as a μ(1,3) bridging ligand between the Cd(II) centers, while the N3¯ had a μ(1,1) bridging mode in 2. As a result, the Cd…Cd distance was significantly longer in 1 (5.8033(5) Å) than in 2 (3.796(2) Å). In both complexes, the Cd(II) had distorted octahedral coordination geometry. Hirshfeld surface analysis was performed to inspect the supramolecular aspects of the two Cd(II) complexes. The C…H, N…H and S…H contacts were important in the case of [Cd(BPMST)(SCN)]2 (1). Their percentages were calculated to be 14.7, 17.0 and 13.4%, respectively. In the case of [Cd(BPMST)(N3)Cl]2 (2), the most significant contacts were the Cl…H, C…H and N…H contacts. Their contributions in the molecular packing were 16.5, 9.7 and 25.3%, respectively. The propensity of atom pairs of elements to form contacts in the crystal structure was analyzed using enrichment ratio (EXY).