Assembly of a Series of Trinuclear Zinc(II) Compounds with N2O2 Donor Tetradentate Symmetrical Schiff Base Ligand

Self-assembly of the symmetrical tetradentate N2O2 donor Schiff base ligand, that is, bis(salicylidene)trimethylenediamine (sy-H2L3), with different zinc salts has led to six anion-dependent complexes, namely, [Zn3(sy-L3)2(μ2-Cl)Cl(C2H5OH)]·C2H5OH (1), Zn[Zn(sy-L3)(μ2-NO2)(C2H5OH)]2·2H2O (2), Zn[Zn(sy-L3)(μ2-CH3COO)]2 (3), Zn(DMF)2[Zn(sy-L3)(H2O)(SCN)]2 (4), Zn[Zn(sy-L3)(μ2-HCOO)(DMF)]2·H2O (5) and Zn[Zn(sy-L3)(μ2-HCOO)]2 (6), respectively. Six compounds were characterized by elemental analyses, IR spectra, mass spectrometry and thermogravimetric analyses, of which five structures 1, 2, 4, 5, and 6 were further determined by single-crystal X-ray diffraction analyses, and compound 3 was previously reported in the literature. It was observed that μ2-bridges in these trinuclear complexes were formed through the phenolic oxygens of the ligand or the anions in the medium. In the presence of nitrite (for 2), acetate (for 3), thiocyanate (for 4), or formate (for 5−6), μ2-bridges formed between a pair of adjacent...