中文摘要：

采用密度泛函理论中的B3LYP／6-31G方法研究了在三乙胺存在下，从Se-CO-H2O体系中制备H2Se的详细机理．溶剂效应采用（CPCM）模式，在相同的方法与基组条件下模拟了该反应．计算结果表明，在四氢呋喃溶液中，反应通过三个能垒（分别是45．4，8．4和119．9kJ／mol）的过渡态．中间产物[（HOOCSe^-）·（Base·H^＋）]的稳定性与产物接近，可以和HSe的铵盐共存，而且，按照理论计算的结果，这种物质可以作为还原剂．

英文摘要：

A detailed mechanism for the formation of selane （H2Se） from Se-CO-H2O system in the presence of triethylamine was studied by density functional theory calculations at the B3LYP/6-31G level. The solvent effect is assessed by the CPCM method at the same level. The calculations suggest that the reaction proceeds through three transition states with energies barriers of 45.4, 8.4 and 19.9 kJ/mol in solvent tetrahydrofuran, respectively. The intermediate compound [（HOOCSe^-）·（Base·H^＋）], whose stability is close to that of the product, may coexist with amine salt of hydrogen selenide （[HSe^-]·[Base·H^＋） and works as a reductant according to the results of theoretical calculations.