Neutron powder-profile study of chlorofluoromethane.
The crystal structure of chlorofluoromethane, CH(2)ClF, has been determined at 100 and 30 K using indexing, packing considerations and Rietveld refinement of neutron powder profiles. There is only one phase, in monoclinic space group P2(1) and with two molecules in the unit cell occupying general positions. The structure has close packing in several directions and there are weak hydrogen bonds forming zigzag chains.
Crystal structures of dibromochloromethane and bromodichloromethane
The crystal structures of CHB2C1 and CHBrC12 have been investigated using neutron powder profile techniques. These structures were found to be similar to that of CHBr3 in its lowest temperature triclinic phase. Whereas CHBr3 has three phases, both CHBr2C1 and CHBrC12 have only one. The two CHBr3 phases which are absent in these compounds require the molecules to have threefold axes. The degree of disorder of the halogen atoms has been examined and the results indicate that the Br and C1 atoms have definite preferences for some sites over others, so that the molecules on average do not have a threefold axis.
Raman and infrared spectra of crystalline fluoroform
Abstract Raman and far-infrared spectra of crystalline fluoroform at temperatures between 20 and 106 K have been recorded. There is no evidence for any solid-state phase transitions, nor for hydrogen bonding. The rich lattice spectra and crystal field splittings suggest that the unit cell is rather large, and possible structures are discussed.