摘要:

The reactions of gamma irradiated propionamide, isobutyramide, valeramide and steaiamide with ethylene were studied by ESR spectroscopy, gas absorption, and X-ray diffraction. Some degree of polymerization of the ethylene apparently occurs in these systems. The results are discussed.

ISSN:0369-1152    

DOI:10.1080/15421406908082957

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

This Bibliography is the last of a series, of which previous issues are listed below. An outline of the energy transfer process and remarks on the scope of the Bibliographies were given in issue IV.

ISSN:0369-1152    

DOI:10.1080/15421406908082958

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

2,2,2-Trinitroethanol, 2,2-dinitropropanol and 2,2-dinitropropanediol-1,3 undergo enantiotropic transitions at 39.3°C, 9.1°C and 68.0°C, respectively. All of the high temperature forms (II) are cubic and possess properties of the plastic crystalline state. A differential scanning calorimeter was used to measure the heats of transition: 2,2,2-trinitroethanol, 4.3 kcal/mole; 2,2-dinitropropanol, 3.6 kcal/mole; and 2,2-dinitropropanediol-1,3, 5.1 keal/mole. The difference between the heat of transition of each nitroalcohol and its corresponding nitroallrane has been interpreted as a measure of hydrogen bonding energy in the low temperature form (I) of the alcohol. Hydrogen bonding energies (keal/mole) of 2,2,2-trinitroethanol-I, 2,2-dinitropropanol-I and 2,2-dinitropropanediol-1,3-I are 3.2, 0.8 and 2.3, respectively. The heats of fusion of 2,2,2-trinitroethanol and 2,2-dinitropropanol also were obtained.

ISSN:0369-1152    

DOI:10.1080/15421406908082959

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The emission spectra of solid solutions of pyrene and perylene in benzene and of mixed crystals of pyrene and perylene were investigated. The dependence of these spectra on the concentration of pyrene and perylene, on temperature and on the excitation wavelength was determined. The results for solid solutions showed clearly that there is an interaction between pyrene excimer and perylene which gives rise to a new emission spectrum. These results also helped us to interpret the emission spectra of mixed crystals of pyrene and perylene.

ISSN:0369-1152    

DOI:10.1080/15421406908082960

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Experimental studies of optical absorption and electron paramagnetic resonance of naphthalene single crystal irradiated at liquid nitrogen, dry ice and room temperatures have been made. It is found that the epr spectrum associated with the l-hydronaphthyl radical is produced at all temperatures studied. Optical absorption bands at 337, 395 and 530 nm are assigned to be associated with the l-hydronaphthyl radical. Irradiation at liquid nitrogen temperature produces a broad doublet epr spectrum as well as that associated with the l-hydronaphthyl radical; the former is considered to be caused by the naphthyl radical. Irradiation at dry ice and room temperatures produces optical absorption bands which are associated neither with the hydronaphthyl nor the naphthyl radical. It is suggested that the radiation products at higher temperature are the hydronaphthyl radical and the naphthalene dimer which is formed as the result of reaction of the naphthyl radical with a neighboring molecule.

ISSN:0369-1152    

DOI:10.1080/15421406908082961

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Studies on the photovoltaic effect in tetracene single crystals have shown that, in general, two photovoltaic mechanisms yielding signals of opposite sign can be observed. On illuminating the crystal, a fast photovoltage response is obtained which is eventually dominated by a more slowly rising photovoltage of the opposite sign. The action spectrum of the fast response is closely related to the absorption spectrum of the crystal. The slow response is more effectively induced by light in spectral regions where the crystal absorbs light weakly. Temperature higher than room temperature decrease the response time of the slow photovoltage. The results are discussed in terms of photovoltage mechanisms which involve singlet excitons and photoinduced detrapping of trapped charge.

ISSN:0369-1152    

DOI:10.1080/15421406908082962

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

It is a well established fact that transport processes in fluid substances of low molecular weight are adequately described by linear constitutive relations of the form

ISSN:0369-1152    

DOI:10.1080/15421406908082963

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

Extensive isotopic mixing in partially deuterated succinic acid single crystals brought about by moderate doses of ionizing radiation point to a radiochemical reaction occurring with very large G value and thus to a free radical chain reaction. The isotopic mixing is evident in the ESR spectrum of the free radicals produced in low concentration and also, remarkably, in the IR absorption spectrum which reveals that a considerable fraction of all of the molecules in the crystal are involved. The evidence points to the possibility that hydrogen atom vacancies in organic crystals may sometimes be mobile, and so constitute a unique type of crystal defect.

ISSN:0369-1152    

DOI:10.1080/15421406908082964

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor