1-(3-Chloro-4-fluoro­phen­yl)-5-(2-diazo­acet­yl)-4-phenyl­pyrrolidin-2-one

In the title compound, C18H13ClFN3O2, the pyrrolidine ring adopts an envelope conformation and the planar part is rotated by 4.3 (6)° from the plane of the benzene ring and is almost perperdicular both to the diazo­acetyl unit [dihedral angle = 78.93 (7)°] and the phenyl ring [dihedral angle = 86.07 (7)°]. In the crystal, mol­ecules are linked into a three-dimensional framework by C—H⋯O inter­actions. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond

Diethyl 1-(4-methylphenyl)-3-phenyl-5-oxopyrrolidine-2,2-dicarboxylate

In the title compound, C23H25NO5, the lactam ring adopts an envelope conformation and both ethoxycarbonyl side chains show an s-cis conformation: one is nearly planar, the dihedral angle between CO2 and OCH2CH3 groups being 7.95 (14)° and the other is almost orthogonal, the C—O—C—C torsion angle being 85.33 (9)°. Dimers related by inversion symmetry are stabilized by C—H...O hydrogen bonds. The crystal structure is consolidated by weak intermolecular C—H...O interactions. Weak intramolecular interactions of the same kind also occur

On the Low-Lying Excited States of sym-Triazine-Based Herbicides

We report a joint computational and luminescence study on the low-lying excited states of sym-triazines, namely, 1,3,5-triazine (1) and the ubiquitous herbicides atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (2)] and ametryn [6-methylthio-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (3)]. Geometrical structures, energetics, and transition and state properties of 1 and 2 were computed at the TD-DFT, CASSCF, and CASPT2 levels of theory. The fluorescence and phosphorescence emission spectra, lifetimes, and fluorescence quantum yields were measured for the three compounds, and from these, the energies of the lowest excited states and their corresponding radiative rates were determined. The predictions from CASPT2 calculations are in good agreement with the experimental results obtained from the luminescence studies and allow the interpretation of different absorption and emission features

Acidities of closo -1-COOH-1,7-C2B10H11 and amino acids based on icosahedral carbaboranes

Carborane clusters are not found in Nature and are exclusively man-made. In this work we study, both experimentally and computationally, the gas-phase acidity (measured GA = 1325 kJ·mol-1, computed GA = 1321 kJ·mol-1) and liquid-phase acidity (measured pKa = 2.00, computed pKa = 1.88) of the carborane acid closo-1-COOH-1,7- C2B10H11. The experimental gas-phase acidity was determined with electrospray tandem mass spectrometry (ESI/MS), by using the extended Cooks kinetic method (EKM). Given the similar spatial requirements of the title icosahedral cage and benzene and the known importance of aminoacids as a whole, such a study is extended, within an acid-base context, to corresponding ortho, meta, and para amino acids derived from icosahedral carborane cages, 1-COOH-n-NH2-1, n-R with {R = C2B 10H10, n = 2, 7, 12}, and from benzene {R = C 6H4, n = 2, 3, 4}. A remarkable difference is found between the proportion of neutral versus zwitterion structures in water for glycine and the carborane derived amino acids. © 2014 American Chemical Society.Peer Reviewe

Reaction pathways and mechanisms of photodegradation of pesticides

The photodegradation of pesticides is reviewed, with particular reference to the studies that describe the mechanisms of the processes involved, the nature of reactive intermediates and final products. Potential use of photochemical processes in advanced oxidation methods for water treatment is also discussed. Processes considered include direct photolysis leading to homolysis or heterolysis of the pesticide, photosensitized photodegradation by singlet oxygen and a variety of metal complexes, photolysis in heterogeneous media and degradation by reaction with intermediates generated by photolytic or radiolytic means.http://www.sciencedirect.com/science/article/B6TH0-45G0043-1/1/46ea2e05c23dd9de81f3094356ba708