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Synthesis and mutagenicity of 3-halogenated and 3,3',5,5'-tetrahalogenated benzidines.

3-Fluorobenzidine (FBz), 3-chlorobenzidine (ClBz), 3-bromobenzidine (BrBz), 3,3',5,5'-tetrafluorobenzidine (F4Bz), and 3,3',5,5'-tetrachlorobenzidine (Cl4Bz) were synthesized and tested for their ability to revert Salmonella typhimurium. F4Bz was the only compound to show direct-acting mutagenicity and was equally potent in strain TA98 and the acetylase-deficient strain TA98/1,8-DNP6. In the presence of hamster liver S9, all compounds except Cl4Bz were mutagenic. The relative mutagenicities in TA98 were FBz greater than ClBz greater than BrBz greater than F4Bz greater than Bz greater than Cl4Bz = 0. In TA98/1,8-DNP6 the trend was F4Bz approximately BrBz approximately ClBz greater than FBz greater than Bz greater than Cl4Bz = 0.

Animals↗

Structure of a synthetic halogen sulfosalt, Cu3Bi2S3I3.

Cu(3)Bi(2)S(3)I(3) was crystallized during an attempt to synthesize Cu-Pb-Bi sulfosalts with iodine as the transport medium. The crystal structure was solved from a black needle-like crystal on a four-circle diffractometer with a CCD detector. The solution was obtained by direct methods and subsequent difference-Fourier syntheses. S and I atoms are arranged in a systematically distorted cubic eutaxy (close packing). Bi atoms have monocapped trigonal prismatic coordinations, while Cu atoms occupy coordination sites which vary from trigonal planar to distorted tetrahedral. A prominent feature is the distribution of Cu atoms over many closely spaced sites in the structure, the majority of them being only partly occupied, which strengthens the case for mobile Cu atoms during crystal growth at elevated temperatures. In this respect, Cu(3)Bi(2)S(3)I(3) represents an extreme example of a statistical distribution of Cu in the structure; a frequently observed property of this element in sulfosalts.

Bismuth↗

In situ high-pressure crystallization and compression of halogen contacts in dichloromethane.

The structure of dichloromethane, CH2Cl2, crystallized in situ in a diamond-anvil cell, has been determined by single-crystal X-ray diffraction at 1.33 and 1.63 GPa. The pressure-frozen crystal was determined to be orthorhombic, with the space group Pbcn, and isostructural with the low-temperature phase at 0.1 MPa. The CH2Cl2 molecules are located on one set of crystallographic twofold axes. The characteristics determined for the CH2Cl2 crystal (compression of the close intermolecular contacts, molecular association and the crystal habit of dichloromethane) suggest that the crystal cohesion forces are dominated by H...Cl interactions rather than by Cl...Cl attractions.

Crystallography, X-Ray↗