7266-80-0Relevant academic research and scientific papers
Boron-nitrogen polymers. 3. Nitrogen- and oxygen-bridged compounds
Paciorek,Kratzer,Kimble,Nakahara,Wynne,Day
, p. 2432 - 2436 (2008/10/08)
Iminobis{[bis(trimethylsilyl)amino] [(trimethylsilyl)amino]borane} (2) and oxybis{[bis(trimethylsilyl)amino] [(trimethylsilyl)-amino]borane} (3) were prepared by interaction of [bis(trimethylsilyl)amino][(trimethylsilyl)amino]chloroborane with amino-[bis(trimethylsilyl)amino][(trimethylsilyl)amino]borane and with wet triethylamine, respectively. 2 and 3 exhibited essentially identical infrared spectra; the DSC scans were also similar with two endotherms at temperatures lower than the melting points. Mass spectral breakdown patterns were closely corresponding, differing by one unit in the majority of the prominent peaks. From the metastables, the breakdown paths were established. 2 and 3 crystallize isomorphously in the monoclinic space group P21/n . For 2, a = 12.876 (2) ?, b = 14.828 (3) ?, c = 18.628 (4) ?, β = 97.07 (2)°, V = 3529 (1) ?3, Z = 4, Mr = 533.8, and the calculated density is 1.005 g/cm3. Refinement led to RF = 4.1% and RwF = 4.2% for 5093 independent reflections. The structure of 2 confirms the presence of a central N2BNBN2 framework that is essentially planar with a B(1)-N(1)-B(2) angle of 135.9 (2)°. The shortest B-N bonds, B(2)-N(5) = 1.405 (3) ? and B(1)-N(3) = 1.423 (3) ?, are to nitrogens bonded to one silicon, while the longest B-N bonds, B(2)-N(4) = 1.485 (3) ? and B(1)-N(2) = 1.487 (3) ?, are to nitrogens bonded to two silicons For 3, a = 12.826 (3) ?, b = 14.822 (4) ?, c = 18.557 (4) ?, β = 95.98 (2)°, V= 3509 (1) ?3, Z = 4, Mr = 534.8, and the calculated density is 1.012 g/cm3. Refinement led to RF = 4.3% and RwF = 4.0% for 4458 independent reflections. Structure 3 differs from 2 only in the existence of a central B-O-B unit, wherein the boron-oxygen distances B(1)-O(1) = 1.380 (3) ? and B(2)-O(1) = 1.389 (3) ? are somewhat shorter than the corresponding B-N distances for 2, B(1)-N(1) = 1.428 (3) ? and B(2)-N(1) = 1.446 (3) ?.
