Synthesis, X-ray Diffraction Studies, and DFT Calculations on Hexacoordinated Germanium Derivatives: The Case of Germaspirobis(ocanes)
作者:Sergey S. Karlov、Elmira Kh. Lermontova、Maxim V. Zabalov、Anastasia A. Selina、Andrei V. Churakov、Judith A. K. Howard、Mikhail Yu. Antipin、Galina S. Zaitseva
DOI:10.1021/ic048165m
日期:2005.6.1
Synthesis of the title compounds, viz. [RN(CH2CHR'O)(2)](2)Ge (1, R = Me, R' = H; 2, R = Me, R' = Ph; 3, R = Ph, R' H), by the reaction of 2 equiv of corresponding dialkanolamines RN(CH2CHR'OH)(2) (4, R = Me, R' = H; 5, R Me, R' = Ph; 6, R = Ph, R' = H) with (AIkO)(4)Ge is reported. Composition and structures of all novel compounds were established by H-1 and C-13 NMR spectroscopy and mass spectrometry as well as elemental analysis data. The single-crystal X-ray diffraction of 2 has clearly indicated the presence of two transannular interactions Ge <- N in the compound. N atoms are cis-orientated. The compound 3 possesses long Ge center dot center dot center dot N distances. The structural data obtained from geometry optimizations by DFT calculations on 1-3 reproduces experimental results. Both cis- and trans-isomers were studied, and cis-configuration was found to be more thermodynamically stable for all three compounds. The transition states for possible cis <-> trans rearrangement processes in 1-3 were calculated. The properties of the Ge-O and Ge-N bonds in 1-3 were analyzed by the AIM approach. The interactions between the Ge atom and N atoms as well as 0 atoms possess predominantly ionic character.