Reference

Activation of molecular oxygen: oxidation of cyclohexene on a heterobimetallic complex anchored to modified silica gel

Activation of molecular oxygen: oxidation of cyclohexene on a heterobimetallic complex anchored to modified silica gel. Leal, O.; Goldwasser, M. R.; Martinez, H.; Garmendia, M.; Lopez, R.; Arzoumanian, H. (Fac. Cienc., Univ. Cent. Venezuela, Caracas 47102, Venez.). J. Mol. Catal., 22(1), 117-30 (English) 1983. CODEN: JMCADS. ISSN: 0304-5102.Several substances with their cas registry numbers 107-10-8 and 72969-39-2 may be metioned in this study. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) [(Ph3P)2N]5[(NC)5CoOOMo(O)(OH2)(CN)5] was made heterogeneous by ion exchange with a silica gel having (CH2)3NH3+ Cl- groups chem. attached to its surface. Heating in a N stream at 150° releases mol. O and regeneration is obtained by exposure to an O atm. at 25°. The activated gel catalyzes the oxidn. of cyclohexene at 170° in the presence of mol. O, producing cyclohexene oxide with very high selectivity. Coordinatively unsatd. surface-anchored Mo(VI) and Co(III) are postulated as the sites for O activation. A surface Mo(VI)-Co(III) m-peroxo compd. is formed which is responsible for the selective oxidn. Cyclohexene oxide and cyclohexen-1-one are the products of the reaction. No carbon oxides were detected. .

The conformation of 1-vinylcyclohexene

The conformation of 1-vinylcyclohexene.Some chemicals with cas registry numbers like 110-83-8 and 2622-21-1 are also used. Pitea, Demetrio; Moro, Giorgio; Tantardini, Gian Franco; Todeschini, Roberto (Dep. Phys. Chem. Electrochem., Univ. Milan, Milan 20133, Italy). THEOCHEM, 14(3-4), 291-306 (English) 1983. CODEN: THEODJ. ISSN: 0166-1280. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The dipole moment, molar Kerr const. and UV of 1-vinylcyclohexene were measured at 25°. Using the mol. mechanics method, modified for diene systems, the equil. geometries of the possible conformers have been detd. The half-chair form is always more stable than the corresponding boat form. Ab initio SCF calcns. using the STO-3G basis set and the force field geometries have been performed on the rotamers of the half-chair vinylcyclohexene to est. the relative energies. The potential energy curve obtained for vinyl group rotation reveals s-trans (ab. min.) and nearly s-cis min., 0.53 kcal mol-1 apart, with a barrier of 2.5 kcal mol-1 from s-trans to s-cis. The model system cyclohexene is used to test the applicability of the previously proposed variable bond polarizabilities approach to the calcn. of the molar Kerr const.: the estd. value agrees with expt. The preferred soln.-state conformation of 1-vinylcyclohexene indicated by the anal. of exptl. and calcd. dipole moment, molar Kerr const. and UV is consistent with the theor. predictions: the s-trans form seems to be preferred but the presence of a 20-30% population of s-cis or nearly s-cis rotamers cannot be ruled out. An est. of the 1st ionization potential is also given. .