Mol-ecules of the title macrocycle, C(36)H(22)N(4)O(4), are located on an inversion center. The porphyrin ring shows a wave-like conformation with adjacent pyrrole rings tilted above the porphyrin plane and the inter-porphyrin distance is 3.584 (3) Å. The dihedral angles between the meso-furyl groups and the porphyrin plane are 38.87 (7) and 48.29 (7)°; these are much smaller than those observe...

In the title mol-ecule (systematic name: methane-tetra-yltetra-methyl-ene tetra-p-toluene-sulfonate), C(33)H(36)O(12)S(4), the central C atom and the S atoms exhibit distorted tetra-hedral configurations. The aromatic rings in opposite arms are nearly parallel to each other, with a dihedral angle of 10.26 (8) or 3.45 (9)°. The mol-ecules are linked into a two-dimensional network parallel to the...

During the last decade several standards for Mobile telecommunications have been developed. The best known is without any doubt the Global Standard for Mobile Communications (GSM) which is operational in many countries, both within and outside Europe. It is now the most successful standard for mobile communications. Also the Digital Enhanced Cordless Telecommunications (DECT) was successfully i...

B ernd W rackm eyer* , H eid i E. M aisei, Jü rgen Süß, W olfgang M ilius Laboratorium für Anorganische Chemie der Universität Bayreuth. D-95440 Bayreuth Z. Naturforsch. 51b, 1320-1324 (1996); received March 14, 1996 Tetra-l-alkynylsilanes, 1,1-Organoboration, Siloles, X-Ray Tetra-l-alkynylsilanes, Si(CsCR*)4 with R 1 = 'Bu (1) and SiMe3 (2) react with triethylborane, E t3B. by intermolecular 1...

The title compound, C12H8BCl3O2·C4H8O, crystallizes as a tetra-hydro-furan monosolvate. The boronic acid group adopts a syn-anti conformation and is significantly twisted along the carbon-boron bond by 69.2 (1)°, due to considerable steric hindrance from the 2',6'-di-chloro-phenyl group that is located ortho to the boronic acid substituent. The phenyl rings of the biphenyl are almost perpendicu...

Current evaluation Conclusion from the previous Monograph: Tetrachloroethylene (Perc) is probably carcinogenic to humans (Group 2A) with the working group finding limited evidence in humans for the carcinogenicity of Perc and sufficient evidence in experimental animals for the carcinogenicity of Perc. In making the overall evaluation, the Working Group considered the following evidence: (i) Alt...

A newborn was noticed lying unattended in the hospital campus. It had complete absence of all four limbs, deformed ears, facial cleft, proptosis, hydrocephalus, corneal opacity, absent nipples, anterior abdominal wall defect with exstrophy bladder, absent external genitalia, and sacral spina bifida (Fig.1 A & B). The child died after few hours due to aspiration pneumonitis. These features are p...