Lin Shen, Liu Shi-xiong
Department of Chemistry, Fuzhou University, Fujian Normal University, Fuzhou, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2002 Dec;22(6):959-62.
IR and UV-vis spectral properties of azametallacrown complexes containing Mn(III), Fe(III) or Co(III) were investigated. The relation between the main IR bands in 400-4,000 cm-1 and the structure of azametallacrown complexes were discussed. The absorption bands of nu(C=O), nu(NH), delta(NH) + nu(CN) and delta(NH) which existed in the IR spectra of the ligands disappeared in the IR spectra of the complexes. A strong band found at--1,600 cm-1 is assigned to [symbol: see text]C=N-N=C[symbol: see text] group. Bands at approximately 1,560 cm-1 and -1,410 cm-1 are attributed to nu(C=N) and nu(CO), respectively. These results suggest that the ligands in solid state may exit as keto form, and the ligands in the solution may first undergo isomerization to enol form and then coordinated to metal centers through deprotonation. The bands found at -204 and 220-256 nm can be assigned to pi-pi* or pi-pi* transitions of the pi conjugation in [symbol: see text]C=N-N=C[symbol: see text] framework and benzene ring. The absorption maxima at 274-350 nm could be assigned to metal-toligand charge transfer (MLCT) transition. The d-d transition band for the metal atoms was observed at -500 nm.
研究了含锰（III）、铁（III）或钴（III）的氮杂金属冠醚配合物的红外光谱和紫外可见光谱性质。讨论了400 - 4000 cm⁻¹范围内主要红外波段与氮杂金属冠醚配合物结构之间的关系。配体红外光谱中存在的ν（C = O）、ν（NH）、δ（NH）+ν（CN）和δ（NH）吸收带在配合物的红外光谱中消失。在1600 cm⁻¹处发现的强吸收带归属于[C=N - N=C]基团。大约在1560 cm⁻¹和1410 cm⁻¹处的吸收带分别归属于ν（C = N）和ν（CO）。这些结果表明，固态配体可能以酮式形式存在，溶液中的配体可能首先异构化为烯醇式，然后通过去质子化与金属中心配位。在-204和220 - 256 nm处发现的吸收带可归属于[C=N - N=C]骨架和苯环中π共轭的π - π或π - π跃迁。在274 - 350 nm处的吸收最大值可归属于金属 - 配体电荷转移（MLCT）跃迁。在500 nm处观察到了金属原子的d - d跃迁带。
