Four 1,3-bis(1,2,4-triazol-1-yl)propane-based metal complexes tuned by competitive coordination of mixed ligands: synthesis, solid structure, and fluorescence

Four 1,3-bis(1,2,4-triazol-1-yl)propane (btp)-based transition metal complexes, {[Zn(btp)3] ⋅(ClO4)2}n (1), [Zn(btp)2(dca)2]n (2), [Zn(btp)(NCS)2] (3), and [Mn(btp)2(NCS)2]n (4), have been obtained by introducing small anionic coligands and structurally characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, thermogravimetric curves, and solid luminescence spectra. Structural determinations reveal that the polymeric triple-stranded chain for 1 without coligand is changed into 1-D double-stranded chains for 2 and 4, and discrete binuclear structure for 3. Compared with 1, the mixed-ligand complexes are moderately destabilized for 2 and 4, and slightly enhanced for 3. Additionally, the four solid complexes exhibit strong emissions, suggesting their potential applications as luminescent materials.