It is known that the free topological group over the Tychonoff space X, denoted F(X), is a P space if and only if X is a P -space. This article is concerned with the question of whether one can characterize when F(X) is a weak P -space, that is, a space where all countable subsets are closed. Our main result is that F(X) is a weak P -space if and only if X is a weak P -space and every countable...

In the title compound, C(14)H(7)FN(2)OS, prepared by the reaction of 2-bromo-4-fluoro-benzoyl choride with 2-mercaptobenzimidazole, the four-membered fused-ring system is essentially planar [maximum deviation from the mean plane = 0.035 (2) Å]. The crystal packing is stabilized by weak inter-molecular π-π [minimum ring centroid-centroid separation = 3.509 (7) Å], weak C-F⋯π [F⋯centroid = 3.4464...

In the title compound, [Cu(C(18)H(15)P)(2)(H(2)O)]BF(4), the Cu(I) atom is coordinated by two P atoms from triphenyl-phosphine ligands and one water mol-ecule in a distorted trigonal geometry. In the BF(4) (-) anion, three F atoms are disordered over two sites around the B-F bond, the site-occupancy ratio being 0.67 (6):0.33 (6). The Cu⋯F distance of 2.602 (5) Å between the Cu atom and the orde...

The title compound, C19H17BF3P {alternative name: triphen-yl[(tri-fluoro-boran-yl)meth-yl]phosphanium}, was formed by the reaction of tri-phenyl-phosphine with potassium iodo-methyl-tri-fluoro-borate. The mol-ecule features a nearly staggered conformation along the P-C bond and a less than staggered conformation along the C-B bond. In the crystal, weak C-H⋯F hydrogen bonds between the meta-phen...