Nanosecond transient absorption studies of the lifetimes (5) of several substituted 1 ,n-diphenyl-1 ,n-diyls are reported in polar and non-polar solvents. A para-bromine substituent significantly shortens r. Substitution of OH in the l-position makes the lifetime highly solvent dependent. The substituent effect and the dependence of r on biradical chain length is discussed in terms of spin-orbi...

Proton transfer equilibria in chlorobenzene between a set of di-substituted (2,3-,2,5-,2,6-, 3,5-dichloro and difluoro) benzoic acids including the corresponding mono-substituted acids and the carbinol base of crystal violet have been studied spectrophotometrically. To investigate the effect of disubstitution at orthoand/or metapositions on the strength of benzoic acid, the results have been an...

4,5-Dihydro-7H-pyrano[3,4-c]isoxazoles (II and III) with an o-chlorophenyl or p-chlorophenyl group at C-7 were synthesized and the effect of substitution at C-3 of II and III on fungicidal activity was investigated in vivo. When the substituent at C-3 of II and III was CH2Br, CH=NOMe, CH=NOEt or CH=NO-allyl, the fungicidal effect was significant and selectively high on wheat leaf rust and barle...

Employing ab initio generalized valence bond and configuration interaction theoretical methods, we calculated C-H bond energies for H3COH, H3CONa, H3COK, and H3COleading to bond energies (at 0 K) of 90.7 (the experimental value is 9 1.8 f 1.2), 80.6, 79.0, and 74.2 kcal/mol, respectively. This dramatic decrease in the adjacent bond strength due to an oxy substituent helps explain the oxy anioni...

Among the title compounds, viz. the acids C10H8ClF2NO3, (I), and C11H11F2NO3, (II), and the amides C14H14F2N2O2, (III), and C14H13ClF2N2O2, (IV), the change of substituent from Cl in (I) to methyl in (II) has a dramatic effect upon the hydrogen bonding between the molecules, which occur in layers in both cases. In the structures of (III) and (IV), hydrogen bonds connect the molecules to form ch...