Synthesis, spectroscopy and structure of the parent furoxan (HCNO)2

The parent furoxan (1,2,5-oxadiazole 2-oxide), synthesized from glyoxime and NO(2)(g), has been investigated in the gas phase for the first time by mid-infrared and He I photoelectron spectroscopy, and in the liquid phase by Raman spectroscopy. The ground-state geometry has been obtained from quantum-chemical calculations at the B3LYP, MPn (n = 2-4), CISD, QCISD, CCSD, CCSD(T), RSPTn (n = 2,3), MRCI, and MR-AQCC levels using 6-311++G(2d,2p), cc-pVTZ, aug-cc-pVTZ, cc-pCVTZ, and cc-pVQZ basis sets. Furoxan is predicted to be planar, with a strong exocyclic and a relatively weak endocyclic N-O bond. The furoxan moiety is electron rich, indicated e.g. by a large negative NPA charge (-0.46 e). According to various aromaticity indices, furoxan is nearly as aromatic as furan and furazan. Unlike alkyl- and cyano-substituted furoxans, the parent furoxan, upon thermolysis, does not cleave to the monomer nitrile oxide, yielding only HNCO, HCN, CO(2), CO, NO, and H(2)O decomposition products.

Fatal suicide cases from 1991 to 2000 in Szeged, Hungary

The aim of this study is to analyze the fatalities due to suicide in the period of 1991-2000. The autopsy reports of 719 suicide cases during that period of the Department of Forensic Medicine, University of Szeged were reviewed retrospectively. The victim's age, sex, way of commitment, place of death, the presence of alcohol and drug influence and survival time were recorded. Five hundred and one of the (69.6%) total 719 suicide fatalities were men and 218 (30.4%) were women. The largest age groups were 41-50 in men, in women we experienced a 'double-peak' of age groups 41-50 and 71-80. The most frequent way of committal was hanging (46%). The results revealed that 38.8% of the 474 victims whose blood and/or urine alcohol concentration measurement were carried out consumed alcohol prior to the act. The presence of licit drugs in 12% of not drug-related cases were experienced.

Gas-Phase Infrared and ab Initio Study of the Unstable CF3CNO Molecule and Its Stable Furoxan Ring Dimer

The unstable trifluoroacetonitrile N-oxide molecule, CF3CNO, has been generated in high yield in the gas phase from CF3BrC=NOH and studied for the first time by gas-phase mid-infrared spectroscopy. Cold trapping of this molecule followed by slow warming forms the stable ring dimer, bis(trifluoromethyl)furoxan, also investigated by gas-phase infrared spectroscopy. The spectroscopy provides an investigation into the vibrational character of the two molecules, the assignments supported by calculations of the harmonic vibrational frequencies using in the case of CF3CNO both ab initio (CCSD(T)) and density functional theory (B3LYP) and B3LYP for the ring dimer. The ground-state structures of both molecules were investigated at the B3LYP level of theory, with CF3CNO further investigated using coupled-cluster. The CCSD(T) method suggests a slightly bent (C(s)) structure for CF3CNO, while the B3LYP method (with basis sets ranging from 6-311G(d) to cc-pVTZ) suggests a close-to-linear or linear CCNO chain. The CCN bending potential in CF3CNO was explored at the CCSD(T)(fc)/cc-pVTZ level, with the results suggesting that CF3CNO exhibits strong quasi-symmetric top behavior with a barrier to linearity of 174 cm(-1). Since both isomerization and dimerization are feasible loss processes for this unstable molecule, the relative stability of CF3CNO with respect to the known cyanate (CF3OCN), isocyanate (CF3NCO), and fulminate (CF3ONC) isomers and the mechanism of the dimerization process to the ring furoxan and other isomers were studied with density functional theory.