Reversible Switching of Electronic Ground State in a Pentacoordinated Cu(II) 1D Cationic Polymer and Structural Diversity

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• 作者：Ashok Sasmal ; Eugenio Garribba ; Corrado Rizzoli ; Samiran Mitra
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：July 7, 2014
• 年：2014
• 卷：53
• 期：13
• 页码：6665-6674
• 全文大小：569K
• ISSN：1520-510X

文摘

Two copper(II) polymeric complexes {[Cu(HPymat)(MeOH)](NO₃)}_n (1) and {[Cu₄(Pymab)₄(H₂O)₄](NO₃)₄} (2) were synthesized with the carboxylate-containing Schiff-base ligands HPymat^{鈥?/sup> and Pymab鈥?/sup> [H₂Pymat = (E)-2-(1-(pyridin-2-yl)methyleneamino)terephthalic acid, HPymab = (E)-2-((pyridine-2-yl)methyleneamino)benzoic acid]. Complex 1 is a one-dimensional Cu(II) cationic polymeric complex containing free protonated carboxylic groups and nitrate anions as counterions. Complex 2 is a zero-dimensional tetranuclear cationic Cu(II) complex containing nitrate anions as counterions. Complex 1 shows rhombic electron paramagnetic resonance (EPR) spectra in the solid state at room temperature (RT) and 77 K and tetragonal EPR spectra in dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) and 鈥渋nverse鈥?EPR spectrum in CH₃CN. Complex 2 shows rhombic EPR spectra in the solid state at RT and 77 K. But complex 2 shows tetragonal spectra in DMSO, DMF, and CH₃CN. Thermogravimetric analysis was also performed for both complexes 1 and 2. Mean-square displacement amplitude analysis was carried out to detect librational disorder along the metal鈥搇igand bonds in crystal structures.}