Chemistry of Copper(I) Complexes Based on Formamidinate Ligands; Synthesis, Structures and Luminescent Properties

• Main Authors: Chih-Tung Yang, 楊之棟
• Other Authors: Jhy-Der Chen
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/46my57

碩士 === 中原大學 === 化學研究所 === 106 === This thesis discuss the structures and properties of Cu(I) polynuclear complexes and coordination polymers supported by the formamidinate ligands, which is divided into two parts. Part 1: Reactions of N,N’-bis(pyrimidyl-2-yl)formamidine (Hpmf), N,N''-bis(4,6-dimethylpyrimidin-2-yl)formimidamide (Hdmpmf) and N,N''-bis(4-methoxy-6-methylpyrimidin-2-yl)formimidamide (Hmmpmf) with CuX (X = Cl, Br, and I) afforded cyclic complex [Cu4(pmf)4], 1, linear copper chain {[Cu3(dmpmf)3]·CH2Cl2}, 2, cyclic complex [Cu4(mmpmf)4], 3, and compound 4 in which the structure was estimated by luminescence; complexes 1 - 3 were structurally identified by X-ray crystallography. All of the compounds follow the principle of cuprophilicity, where the distance of copper ions effect the luminescence properties. Therefore, one assumption has been proposed to estimate the structure of Cu(I) complexes that contain formamidinate ligands. The emission spectra of 1, 3, and 4 exhibit broad bands in 533 - 545 nm upon the excitation at 370 nm while the linear metal chain 2 exhibits emission at 590 upon the same excitation wavelength. Time-dependent Density function theory (TD-DFT) calculation suggests that the emissions of 1 - 4 are mainly due to metal to ligand 3dσ*/δ*→pπ*charge transfer. Part 2: One-pot hydrothermal reactions of 2-aminopyridine and triethylorthoformate and sodium hydroxide with CuX (X = Br, and I) in dimethylformamide (DMF), tetrahydrofuran (THF), and methanol (MeOH) afforded 1D extended metal atoms chain, {[Cu4(Dpyf)2Br2]･DMF}n, 5, {[Cu4(Dpyf)2Br2]･THF}n, 6, and {[Cu4(Dpyf)2I2]}n, 7, respectively, which were structurally identified by X-ray crystallography. Complexes 5 - 7 present closed-shell Cu(I)---Cu(I) interactions that are supported by formamidinate ligands. Furthermore, reversible crystal-to-crystal transformation were found in complex 5 upon the solvent exchange. The effect of cuprophilicity strongly influence the emission of compounds 5 and 7 where a board emission at 570 nm upon the excitation at 370 nm was observed for 5, while a broad emission at 549 by the excitation wavelength at 370 nm was observed for 7. Density function theory (DFT) implies that the emissions of 5 and 7 are due to metal to ligand 3dσ*/δ*→pπ*charge transfer.