机构地区: 中南大学化学化工学院
出 处: 《中国有色金属学报》 2005年第10期1636-1641,共6页
摘 要: 乙氧羰基硫代氨基甲酸酯(EECTC)最高占据分子轨道(HOMO)主要由硫代羰基中硫原子的px和py轨道组成;最低未占据分子轨道(LUMO)由官能团—O—C(O)—N—C(S)—O—中各原子的pz轨道组成,为共轭π键,具有接受和分散电子对的能力。Cu+离子的电子结构为t6e4,具有反馈d电子对的能力。因此,当EE-CTC与Cu+离子反应时,EECTC可向Cu+离子提供其硫代羰基中硫原子的电子对,形成σ键,而得到电子的Cu+离子也可向EECTC的LUMO提供d轨道电子,形成反馈π键。EECTC及其与Cu+离子的反应产物Cu(EE-CTC′)在HF/3-21G(D)和B3PW91/6-31G(D)水平的量子化学计算和FTIR光谱数据结果表明,EECTC通过其C S硫原子和C O氧原子与Cu+离子结合,生成六员环螯合物,同时N—H键断裂,释放出H+离子。 The highest occupied molecular orbit (HOMO) of ethoxylcarbonyl thionocarbamate (EECTC) is composed by Px and Py orbits of thiol sulfur atom. And its lowest unoccupied molecular orbit(LUMO)which can easily accept and delocalize electrons is constituted by p, orbits of every atoms in the conjugate of -O-C(≠0)-N-C(=S)-O- group. The t^6e^4 configuration of Cu^+ ion can easily donate d-orbital electrons(feedback electrons). As a result, the interaction between EECTC and Cu^+ ion is potentially involved in forming σ bond(EECTC offers electrons of thiol sulfur atom to Cu^+ ion ) and feedback π bond(Cu^+ ion donates d-orbital electrons to the LUMO of EECTC). The results of FTIR analysis and quantum chemistry calculation at the HF/3-21G(D) and B3PWg1/6-31G (D) levels for EECTC and Cu(EECTC') which is the reactive product for EECTC and Cu^+ ion in aqueous solution show that EECTC acts as a bidentate ligand, bonding with the Cu^+ ion through the thiol sulfur and carbonyl oxygen atoms to form a six membered ring structure as in which the N-H bond is shown to dissociate.
关 键 词: 乙氧羰基硫代氨基甲酸酯 离子 量子化学计算