文摘
Using X-ray diffraction the presence of two phases of 1-fluorosilatrane (FSa) is stated and the specific features of their spatial structure are studied. Phase transition occurs at 156–158 K and is characterized by low energy. In the low-temperature phase, four crystallographically independent molecules are ordered, while in the high-temperature phase one of two independent molecules has disordered carbon β-atoms. A quantum chemical analysis of crystal packing in the low-temperature FSa phase is performed. The estimated value of the coordination N→Si bond strength in the crystal is 29.2 kcal/mol. The charge distribution indicates the localization of valence electron density around the O3SiF fragment.