Homoleptic Carbonyls of the Second-Row Transition Metals: Evaluation of Hartree-Fock and Density Functional Theory Methods

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• 作者：Xuejun Feng ; Jiande Gu ; Yaoming Xie ; R. Bruce King ; Henry F. Schaefer III
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2007
• 出版时间：July 2007
• 年：2007
• 卷：3
• 期：4
• 页码：1580 - 1587
• 全文大小：368K
• 年卷期：v.3,no.4(July 2007)
• ISSN：1549-9626

文摘

The homoleptic mono- and multinuclear carbonyls for Mo, Tc, Ru, and Rh, namely,Mo(CO)₆, Ru(CO)₅, Tc₂(CO)₁₀, Ru₃(CO)₁₂, Rh₄(CO)₁₂, and Rh₆(CO)₁₆, are investigated theoretically by the Hartree-Fock method and three density functional theory (DFT) methods, i.e., BP86,B3LYP, and MPW1PW91, along with the SDD ECP basis sets. The results predicted by all themethods are basically in agreement with each other. The MPW1PW91 and BP86 methods predictgeometric parameters and vibrational spectra, respectively, closest to the experimental values.For Ru₃(CO)₁₂ the relative energies of the D_3h isomer with only terminal CO groups and the C_2visomer with two bridging CO groups are within 3 kcal/mol of each other with the lower energyisomer depending upon the computational method used. For Rh₄(CO)₁₂ the global minimum ispredicted to have C_3v symmetry, with three bridging and nine terminal carbonyls, in accord withexperiment. The Rh₆(CO)₁₆ structure has T_d symmetry and satisfies the Wade-Mingos rules foran octahedral cluster. Using the MPW1PW91 method the Rh-Rh distances in Rh₄(CO)₁₂ arefound to be 2.692 Å and 2.750 Å and those in Rh₆(CO)₁₆ to be 2.785 Å.