Two mechanisms of Os^IVCl₆²⁻ photolysis were studied by means of quantum chemical calculations in gas and aqueous phases. The difference between these mechanisms is in the nature of the possible Os(IV) key intermediates (KI). According to calculations, the intermediate is an Os^IVCl₅⁻ complex of square pyramidal coordination geometry. The calculations do not give an opportunity to make an unambiguous choice between the triplet and quintet multiplicities of Os^IVCl₅⁻. The calculated CASSCF/IMCP-SR1 transition energies for ⁵Os^IVCl₅⁻ are lower than for ³Os^IVCl₅⁻, while the calculated XMC-QDPT2/SBKJC spectra for the triplet state are in better agreement with the experimental absorption spectrum of the KI than for the quintet state.

中文翻译：

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水溶液中OsCl ₆ ^2-络合物光化学中的短寿命中间体

通过在气相和水相中的量子化学计算，研究了Os ^IV Cl ₆ ^2-的光解的两种机理。这些机制之间的差异在于可能的Os（IV）关键中间体（KI）的性质。根据计算，在中间是一Os ^IV氯₅ ^-复杂方锥体协调的几何形状。该计算不给一个机会，使O的三重和五重奏多重性之间的明确选择^IV氯₅ ^- 。计算出的⁵ Os ^IV Cl ₅ ^−的CASSCF / IMCP-SR1跃迁能比对于较低³ O的^IV氯₅ ^- ，而所计算的XMC-QDPT2 / SBKJC光谱三重态都与比用于五重峰状态KI的实验吸收光谱更好的协议。