C-C coupling formation using nitron complexes.

A series of RuII (1), RhIII (2), IrIII (3, 4), IrI (5) and PdII (6-9) complexes of the 'instant carbene' nitron were prepared and characterized by 1H- and 13C-NMR, FT-IR and elemental analysis. The molecular structures of complexes 1-4 and 6 were determined by X-ray diffraction studies. The catalytic activity of the complexes (1-9) was evaluated in alpha(α)-alkylation reactions of ketones with alcohol via the borrowing hydrogen strategy under mild conditions.

Field study on the factors affecting egg weight loss, early embryonic mortality, hatchability, and chick mortality with the use of classification tree technique.

The aim of this research was to study the factors affecting hatchability, percentage of egg weight loss during incubation, early embryonic mortality, and chick mortality in the first seven days of life in the field. This study was performed on 20,817,600 hatching eggs originating from 7 different breeder flocks. The factors responsible for variability of investigated traits were the following: genotype (ROSS 308, ROSS PM3), hen age (25 to 30, 31 to 45, 46 to 50, and 51 to 60 wk), egg storage time (0 to 13 d), and setter and hatcher type (Digital, Airstreamer, Vision, Focus, Biostreamer), which were determined using the classification tree technique.

Surgical management of melanoma-in-situ using a staged marginal and central excision technique.

Melanoma-in-situ (MIS) represents 45% of all melanomas. The margins of MIS are often poorly defined with extensive subclinical disease. Standard fusiform excision with 5-mm margins results in positive margins in up to a third of cases.

Stereoelectronic effects on molecular geometries and state-energy splittings of ligated monocopper dioxygen complexes.

The relative energies of side-on versus end-on binding of molecular oxygen to a supported Cu(I) species, and the singlet versus triplet nature of the ground electronic state, are sensitive to the nature of the supporting ligands and, in particular, depend upon their geometric arrangement relative to the O2 binding site. Highly correlated ab initio and density functional theory electronic structure calculations demonstrate that optimal overlap (and oxidative charge transfer) occurs for the side-on geometry, and this is promoted by ligands that raise the energy, thereby enhancing resonance, of the filled Cu dxz orbital that hybridizes with the in-plane pi* orbital of O2. Conversely, ligands that raise the energy of the filled Cu dz2 orbital foster a preference for end-on binding as this is the only mode that permits good overlap with the in-plane O2 pi*.

Computational investigation of the conrotatory and disrotatory isomerization channels of bicyclo[1.1.0]butane to buta-1,3-diene: a completely renormalized coupled-cluster study.

The conrotatory and disrotatory mechanisms of the isomerization of bicyclo[1.1.0]butane to trans-buta-1,3-diene have been computationally investigated with the CASSCF, MCQDPT2, (U)B3LYP, CCSD(T), CR-CCSD(T), and CR-CC(2,3) approaches.