摘要:

AbstractA simple correlation between the MO bond orders and the resonance structures of a π system is proposed. Para conjugation is a resonance structure with parallel arrangement of alternating attractive and repulsive bonds. The results in C5H5−, C6H6and C77+clearly show that the para conjugation is very important comparing with the ordinary ring conjugation. The aromatic substitution reactions strongly demomstrates the effect of para conjugation in benzene, naphthalene and anthran

ISSN:0009-4536    

DOI:10.1002/jccs.197300001

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractC—O stretching frequency of inorganic carbonyl molecules is quite characteristic in the vibrational spectroscopy (the IR and Raman). Since such stretching modes are quite different from the skeletal modes, a non‐mechanical coupling model has been proposed by Cotton1). The C—O stretching force constants and their interaction constants may be calculated semiquantitatively from their characteristic frequencies. The trouble is that the number of vibrational frequencies is always less than the number of force constants, whenever a symmetry irreducible representation contains more than one frequency. Cotton suggest that the interaction constants for octahedral type molecule from thedpπ bonding point of view1‐2). Instead of this, a model of maximum interaction between M—C—O bonds is proposed in this paper. Such model not only gives better remedy to the problem of octahedral complexes, but also is useful to solve the normal modes in molecules of trigonal bipyramidal and many othe

ISSN:0009-4536    

DOI:10.1002/jccs.197300002

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractIn the photolysis of diazomethane‐methanol. mixture, the reaction of methylene with methanol gives dimethyl ether and ethanol as products. The ratio of dimethyl ether to ethanol is found to be independent to pressure and to. the composition of diazomethane‐methanol mixture. Methylene insertion into O—H bond is about 11 times faster than that into C—H bonds of methanol. The ratio decreases with increase of temperature.In the diazomethane‐ethanol system, ethylmethyl ether, propanol‐1 and propanol‐2 are found as the products of insertion reaction of methylene into ethanol. The ratios of ethylmethyl ether to propanol‐1 and to propanol‐2 are both found to be almost constant and independent to pressure and to the composition of diazomethane‐ethanol mixture. A small temperature effect on the ratios are observed. The rate of insertion of methylene into O—H bond is about 7.3 and 14.2 times faster than those into primary and secondary C—H bonds o

ISSN:0009-4536    

DOI:10.1002/jccs.197300003

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reaction of 2‐methylindole with pyruvic acid was studied. Two products are found to be depending on experimental conditions, including the 2:2 condensation adduct and the 2:1 condensation adduct. The reaction mechanism evidently involves a 1:1 adduct of 2‐hydroxy‐2‐(2‐methylindol‐3‐yl)‐propionic acid as

ISSN:0009-4536    

DOI:10.1002/jccs.197300004

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractA new type of triiodo compounds synthesized by irradiation ofp‐chlorostyrene or indene with iodoform in the inert solvent is reporte

ISSN:0009-4536    

DOI:10.1002/jccs.197300005

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractIn order to study the relationship between structure and activity of flavones, several new 4′‐phenylflavones, 4′‐phenylflavonols, and 4′‐phenylflavanones are synthesized by cyclization of corresponding 4‐phenyl‐2′‐hydroxychalcones with selenium dioxide in hot amyl alcohol, with hydrogen peroxide in cold alkalic ethanol, or with phosphoric acid in hot ethanol, respectively. The 4‐phenyl‐2′‐hydroxychalcones are synthesized by condensation ofp‐phenylbenzaldehyde with various 2′‐hydroxyacetophenones in hot methanol unde

ISSN:0009-4536    

DOI:10.1002/jccs.197300006

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY