Syntheses, crystal structures and luminescence behaviors of four neutral penta-/hexacoordinate cadmium(II) compounds containing a tridentate Schiff base: Variation in coordination numbers, nuclearities and dimensionalities by changing halides/pseudohalides

New Coordination Compounds of CuII with Schiff Base Ligands—Crystal Structure, Thermal, and Spectral Investigations

The new mono-, di- and tetranuclear coordination compounds [Cu(HL1)]·H2O (1), [Cu2(L1)(OAc)(MeOH)]·2H2O·MeOH (2), [Cu4(L2)2(OAc)2]·4MeOH (3), and [Cu4(L2)2(OAc)2]·4H2O·4MeOH (4) were synthesized by the direct reaction of 2,2′-{(2-hydroxypropane-1,3-diyl)bis[nitrilomethylidene]}bis(4-bromo-6-methoxyphenol) (H3L1) or 2,2′-{(2-hydroxypropane-1,3-diyl)bis(nitriloeth-1-yl-1-ylidene)}diphenol (H3L2) and the Cu(II) salt. They were characterized by elemental analysis, X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, simultaneous thermal analysis and differential scanning calorimetry (TG/DSC), and thermal analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) techniques and the single crystal X-ray diffraction study. In the dinuclear complex 2, the copper(II) ions are bridged by an alkoxo- and a carboxylato bridges. The tetranuclear complexes 3 and 4 are formed from dinuclear species linkage through the phenoxo oxygen atoms of the fully deprotonated H3L2. Compounds 1–4 are stable at room temperature. During heating in air, at first, the solvent molecules (water and/or methanol) are lost and after that, the organic part undergoes defragmentation and combustion. The final decomposition solid product is CuO. The main gaseous products resulting from the thermal degradation of 1–4 in a nitrogen atmosphere were: H2O, MeOH, CH3COOH, CH4, C6H5OH, CO2, CO, and NH3.

Hexnuclear Cadmium(II) Cluster Constructed from Tris(2-methylpyridyl)amine (TPA) and Azides

A novel rare hexa nuclear cadmium(II)–azide cluster, [Cd6(TPA)4(μ3-1,1,3-N3)4(μ2-1,1-N3)6](ClO4)2·2H2O (1) was isolated and structurally characterized, in which the azide ligands reveal μ-1,1,3- and μ-1,1-N3 bridging modes.