摘要:

Band assignment of the infrared spectra of the anion-radicals of benzophenone-dO, -d10and18O has been given on the basis of isotopic shifts. The frequency of the νC=Oband decreases by ca. 270 cm−1with the transformation of neutral keton into anion-radical, due to the strong electron-withdrawing character of the carbonyl group; frequencies of the other modes decrease slightly, down to 30 cm−1.

ISSN:0038-7010    

DOI:10.1080/00387018508062221

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The problem of obtaining spectroscopic information from structureless electronic (luminescence or absorption) spectra of complex molecules is treated. Our previous model for the description of structureless spectral bands is extended to account for two (rather than one) optically active vibrations in the electronic tarnsition. In comparison with previous treatments more detailed data are obtained a bout the changes in the excited state geometry as well as the frequencies of zero-electronic transitions for a number of (substituted) phtalymids.

ISSN:0038-7010    

DOI:10.1080/00387018508062222

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Normal unenhanced Raman spectra (NURS) of low-polarizability CO molecules were observed for the first time on cobalt at R. T. and residual gas pressure. We assign five bands observed between 2030–2130 cm−1to linear chemisorbed CO species, while those observed between 1840–2010 cm−1have been ascribed to the 2-fold chemisorbed species. The three bands observed between 1740–1830 cm−1we believe are due to the 3-fold species. The corresponding fourteen Co-C stretches were observed and assigned. A model based upon electron backdonation is proposed for each of the three structures. NURS were also observed at R. T. for physisorbed CH4and assignments are made to the four frequencies of CH4.

ISSN:0038-7010    

DOI:10.1080/00387018508062223

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Although the mechanism of action of the nitrogenase enzyme system has been extensively studied with purified proteins, little information has been developed on the function cycles of nitrogenase within bacteroids of intact legume root nodules. Thorneleyet aland Hageman and Burris have reported data characterizing thein vitrofunction cycles of nitrogenase under controlled conditions of temperature and enzyme concentration (1, 2, 3).

ISSN:0038-7010    

DOI:10.1080/00387018508062224

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

There have been numerous reports on the quenching of chlorophylla(Chla) fluorescence by various oxidizing and reducing agents.1–10On the basis of the dependence of the quenching constants on the redox potentials of the quenchers, an electron transfer mechanism has been proposed although there is no experimental evidence for the radical ion pair formation. A survey of literature on chlorophyll fluorescence quenching shows that there have been no studies of singlet quenching of chlorophyllb(Chlb) so far. On the basis of singlet excited state halfwave potential values, Chlbwould be expected to

ISSN:0038-7010    

DOI:10.1080/00387018508062225

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

It is suggested that force fields calculated for polyatomic molecules may be presented in dimensionless coordinates, ξ (=R/Re, where R is internal coordinate and Re is the equilibrium value of corresponding bond distance or angle). Stretching force constants when presented in dimensionless coordinates show interesting trends. It is found that whereas the force constants in terms of internal coordinates, Fiivary widely for bonds with different atoms in the series Z-H (Z:C, Si, Ge), Y-H (Y:N, P, As, Sb, O, S), X-H (X:F, Cl, Br, I), X-C etc, the corresponding force constants in dimensionless coordinates, Φiiare same within the limits of experimental errors. It is felt that such force constants may have better prospects of transferability between related molecules and may be helpful in making the normal coordinate analysis easier to some extent.

ISSN:0038-7010    

DOI:10.1080/00387018508062226

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018508062220

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor