Cu+離子作用的量子化學(xué)計算和FTIR光譜
(中南大學(xué) 化學(xué)化工學(xué)院， 長沙 410083)
摘 要: 乙氧羰基硫代氨基甲酸酯（EECTC）最高占據(jù)分子軌道（HOMO）主要由硫代羰基中硫原子的px和py軌道組成； 最低未占據(jù)分子軌道（LUMO）由官能團(tuán)—O—C(—O)—N—C(—S)—O—中各原子的pz軌道組成， 為共軛π鍵，具有接受和分散電子對的能力。 Cu+離子的電子結(jié)構(gòu)為t6e4，具有反饋d電子對的能力。 因此， 當(dāng)EECTC與Cu+離子反應(yīng)時， EECTC可向Cu+離子提供其硫代羰基中硫原子的電子對， 形成σ鍵， 而得到電子的Cu+離子也可向EECTC的LUMO提供d軌道電子， 形成反饋π鍵。 EECTC及其與Cu+離子的反應(yīng)產(chǎn)物Cu(EECTC′)在HF/3-21G(D)和B3PW91/6-31G(D)水平的量子化學(xué)計算和FTIR光譜數(shù)據(jù)結(jié)果表明， EECTC通過其C—S硫原子和C—O氧原子與Cu+離子結(jié)合，生成六員環(huán)螯合物， 同時N—H鍵斷裂， 釋放出H+離子。
關(guān)鍵字: 乙氧羰基硫代氨基甲酸酯; Cu+離子; 量子化學(xué)計算
（ School of Chemistry and Chemical Engineering，
Central South University， Changsha 410083, China）
Abstract: 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 pz orbits of every atoms in the conjugate of —O—C(—O)—N—C(—S)—O— group. The t6e4 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 B3PW91/6-31G(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.
Key words: ethoxylcarbonyl thionocarbamate; cuprous ion; quantum chemistry calculation
