Acyclic α-Phosphinoamido-Germylene: Synthesis and Characterization

Abstract

The reaction of the lithium salt of 1igand [1; (2,6-iPr2C6H3NH)(PPh2)] with GeCl2·dioxane in 1:1 stoichiometry gives a dimeric chlorogermylene, (2,6-iPr2C6H3NGeClPPh2)2 (2). Following the same synthetic route, germylene, (2,6-iPr2C6H3NPPh2)2Ge (3), was synthesized by performing the reaction of lithium salt of 1 with GeCl2·dioxane in 2:1 stoichiometry. Compounds 2 and 3 were characterized by means of X-ray diffraction studies, NMR, and mass spectrometry. Compound 2 is a dimer and forms a nonplanar six-membered ring with Ge, P, and N as the members of the ring. For a deeper understanding of the structure and bonding, DFT calculation was performed at the M06/Def2-TZVPP//BP86/Def2-TZVPP level of theory. Geometrical parameters obtained from optimized structures are in good agreement with the experimental data. At the same level of theory, population analysis was also performed to investigate the nature and composition of molecular orbitals (MOs). The analysis of electrostatic potential mapped onto constant electron density surface show that the nucleophilicity of P atom in 3 is higher than that of the Ge atom.