Interconversion between Planar-Triangle, Trigonal-Pyramid and Tetrahedral Configurations of Boron (B(OH)3 -B(OH)4- ), Carbon (CH3+ -CH3X) and for the Group 15 Elements as Nitrogen (NH3-NH4+ ). A Modelling Description with Ab Initio Results and Pressure-Induced Experimental Evidence
Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53387#.VMBtrCzQrzE Author(s) Henk M. Buck Affiliation(s) Kasteel Twikkelerf 94, Tilburg, The Netherlands . ABSTRACT Recently a mechanistic understanding of the pressure-and/or temperature-induced coordination change of boron in a borosilicate glass has been demonstrated by Edwards et al . In situ high-pressure 11 B solid-state NMR spectroscopy has been used in combination with ab initio calculations in order to obtain insight in the molecular geometry for the pressure-induced conversion. The results indicate a deformation of the B(OH) 3 planar triangle, under isotropic stress, into a trigonal pyramid that serves as a precursor for the formation of a tetrahedral boron configuration. From our point of view, the deformation controlling the out-of-plane transition of boron accompanied with a D 3h into C 3v geometric change is an interesting ...