The Cannizzaro reaction ("RX C") and the benzoin reaction ("RX B") were investigated by density functional theory calculations. Reaction models (benzaldehyde)2 + X(-) + (H2O)n [for X(-) = OH(-) (RX C) n = 8, and for X(-) = CN(-) (RX B) n = 8 or n = 14] were adopted. Three transition states (TSs) were obtained for RX C, and the rate-determining step was confirmed to be the hydride shift. The sin...

We have performed ab initio CASSCF, CASPT2, and EOM-CCSD calculations on doubly deprotonated p-coumaric acid (pCA(2-)), the chromophore precursor of the photoactive yellow protein. The results of the calculations demonstrate that pCA(2-) can undergo only photoisomerization of the double bond. In contrast, the chromophore derivative with the acid replaced by a ketone (p-hydroxybenzylidene aceton...

The double bond-to-ozone reaction stoichiometry was quantified for ozonation of several environmentally relevant unsaturated fatty acids and monoterpenes in saturated hydrocarbon solvents. Olefins with initial concentrations from 30 microM to 3mM were injected in a solvent (n-hexadecane, nonane, or cyclohexane) while an ozone-oxygen mixture was slowly bubbled through the solution. The number of...

The reaction of 3,3,3-tris-(dimethyl-amino)-1-phenyl-prop-1-yne with bromine in pentane yields the title compound, C(13)H(17)N(2) (+)·Br(-). The acetyl-enic bond distance [1.197 (2) Å] is consistent with a C C triple bond. The amidinium C=N bonds [1.325 (2) and 1.330 (2) Å] have double-bond character and the positive charge is delocalized between the two dimethyl-amino groups.

Substrate activation by means of a reactive ligand is a topic of much interest. Herein we describe a stoichiometric anti-Markovnikov C-N bond formation involving ligand reactivity in multiple steps along the reaction coordinate, including ligand assisted substrate (de)protonation and C-N bond formation, as illustrated by a combined experimental, spectroscopic and computational study. This affor...

The observed V3 torsional barriers measured by microwave spectroscopy for nine methyl groups attached alpha to peptide bond linkages in five gas-phase biomimetics have been found to differ considerably from one molecule to the next and even depend on the position of substitution, being sensitive to structural changes at the other end of the peptide bond. In the search for an explanation for the...

Exo- and endocyclic double bonds of glycals and terminal double bonds of enoses were reacted with various thiols by irradiation with UV light in the presence of a cleavable photoinitiator. The photoinduced radical-mediated hydrothiolation reactions showed highly varying overall conversions depending not only on the substitution pattern and electron-density of the double bond but also on the nat...

The title compound, C(12)H(28)N(6), is located about an inversion center situated at the center of the -CH(2)-CH(2)- bond. The C-N bond lengths are 1.285 (2), 1.384 (2) and 1.395 (1) Å, indicating double- and single-bond character. The N-C-N angles are 114.1 (1), 119.3 (1) and 126.5 (1)°, showing a deviation of both CN(3) planes from an ideal trigonal-planar geometry.

In the title Schiff base, C(15)H(13)Br(2)NO, the benzene and phenyl rings form a dihedral angle of 75.18 (13)°. The N=C bond length of 1.263 (6) Å is shorter than of the N-C bond [1.476 (5) Å], indicating a double bond. In the crystal, there is some pseudosymmetry. This occurs because most of the two mol-ecules are centrosymmetrically related. The mol-ecular structure is stabilized by intra-mol...

In the title compound, C(11)H(12)N(2)O(3)·H(2)O, the water mol-ecule is a hydrogen-bond donor to the double-bond amide and the carbonyl O atoms of two acid mol-ecules; it is also a hydrogen-bond acceptor to the acid -OH and amide -NH- groups. These hydrogen-bonding inter-actions give rise to a layer structure, with the layers parallel to the ab plane.