摘要:

We have recently reported numerous abnormally high IR frequencies (up to 1760 cm−1) in the solid state for the carbonyl of semicarbazones (R1R2C˭N-NH-CO-NH2) of a series of aldehydes and ketones (Kolb et al., J Org. Chem. 54, 2431 (1989)). We are now proposing that these high frequencies are induced by an exceptionally strong vibrational coupling of the C˭O in the centrosymmetric solid-state H-bonded structure. Raman spectroscopy was used in conjunction with IR to detect this vibrational coupling. Theoretical AM1 analysis for the exceptional strength of this coupling has been performed.

ISSN:1058-725X    

DOI:10.1080/10587259208025840

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The kinetic features of photoinduced nitroxide formation from 2-methyl-2-nitroso-propane in a number of plastic crystals (PC: cyclohexane, cyclohexanone, cyclohexanol, 1,1,1-trichlore thane, tert-butylchloride, tert-butylamine) and liquid crystals (LC: 5CB;50CB;70CB;80CB) have been studied by ESR at low temperatures.

ISSN:1058-725X    

DOI:10.1080/10587259208025841

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The role of polymorphism in controlling the properties of organic photoconductors is central to the design of such materials. Insights into this problem may be gleaned through molecular modelling. This paper describes studies aimed at modelling crystal structures for a series of perylene photoactive pigments with the DREIDING force field. Extensions of this method to understanding polymorphism of these photogenerators are also discussed.

ISSN:1058-725X    

DOI:10.1080/10587259208025842

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Deuteration of solid 4-tert-butylcyclohexanone is studied to clarify solid state hydrogenation mechanisms of phenolic compounds. The deuterium incorporation in the carbonyl linkage and in the alicyclic ring, followed by a statistical method, allows one to consider in the solid state the existence of two types of carbonyl intermediates. Ketonic and or enolic forms are involved in the solid state hydrogenation and deuteration.

ISSN:1058-725X    

DOI:10.1080/10587259208025843

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Methyl-substituted derivatives of 1,3,5-tris(diphenylamino)benzene are found to constitute a novel class of amorphous molecular materials, as characterized by differential scanning calorimetry and X-ray diffraction. These compounds readily form stable amorphous glasses having glass-transition temperatures of ca. 50 °C on cooling from the melt. The methyl substituent exerts a great influence on the formation of the glassy state.

ISSN:1058-725X    

DOI:10.1080/10587259208025844

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

It was shown that for the interpre-tation of results in the samples made by co-condensation of reagents from a gaseous phase on a cold surface, the molecular organization of system, its nonequilibricity and energetic, kinetic, thermodynamic inequivalence should be taken into account.

ISSN:1058-725X    

DOI:10.1080/10587259208025845

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Past critical processes are investigated in co-condensates of chemically active substances formed at low temperatures. The connection of mechanical state of co-condensate films and parameters of critical processes is discussed. An approach to understanding critical effects is proposed.

ISSN:1058-725X    

DOI:10.1080/10587259208025846

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1058-725X    

DOI:10.1080/10587259208025799

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor