Accession Number : ADA264709


Title :   1,2-Dimethyl-1,2-Disila-Closo-Dodecaborane(12), A Silicon Analog of an Ortho-Carborane: Synthesis; X-Ray Crystal Structure; NMR, Vibrational and Photoelectron Spectra; Bonding


Descriptive Note : Technical rept.


Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY


Personal Author(s) : Seyferth, Dietmar ; Buechner, Klaus D ; Rees, Jr , William S ; Wesemann, Lars ; Davis, William M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264709.pdf


Report Date : 20 Apr 1993


Pagination or Media Count : 45


Abstract : The reaction of (CH3)2Si(NMe2)2 with BlOH14 Yields a polymer, BlOH12. Me2NSi(CH3)2NMe2n, whose pyrolysis in a stream of ammonia gives hexagonal boron nitride containing 'a' little silicon nitride. In contrast, CH3(H)Si(NMe2)2 reacts with BlOH14 to give 1,2-dimethyl-1,2-disila-closo-dodecaborane(12) (DMSB) , an air-sensitive solid, the structure of whose 1:1 benzene solvate was determined by X-ray diffraction. This compound crystallizes in the space group P ccn ( 56) with a 10.081(1) b = 10 . 666(8) A, c = 16.130(5) A, V = 1734(2)A3 and Z = 4. Final R = 0.044 and RW = 0.058. The 1H, 13C, 29Si and 11B NMR spectra and mass spectrum of DMSB are reported. Its vibrational spectrum (Raman, 5-3600 cm-1 ; IR, 200-3600 cm-1) has been measured and compared with that of ortho- carborane. A study of its He(I) photoelectron spectrum led to the conclusion that DMSB is the most electro rich cluster of type XYB1OH1O with two adjacent main group element centers known.


Descriptors :   *SYNTHESIS(CHEMISTRY) , *MOLECULAR STRUCTURE , *CARBORANES , BENZENE , CRYSTAL STRUCTURE , NUCLEAR MAGNETIC RESONANCE , SOLIDS , CHEMICAL BONDS , PYROLYSIS , PHOTOELECTRONS , SOLVATES , VIBRATIONAL SPECTRA , BORON NITRIDES , SILICON NITRIDES , BONDING , YIELD , AMMONIA , X RAY DIFFRACTION , PHYSICAL PROPERTIES , POLYMERS


Subject Categories : Organic Chemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE