摘要:

Harmonic and anharmonic symmetry force constants matrices have been calculated using a stepwise coupling method for the twelve isotopic species of nitrosyl fluoride, chloride and bromide. The valence force fields derived from the above matrices were used to recalculate the normal frequencies and the potential energy distribution among force constants. The valence force fields are compared with others previously reported obtained by different methods.

ISSN:0038-7010    

DOI:10.1080/00387018808082338

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The electronic bands appearing in the region 300–330 nm were produced in a low-pressure DC are with beryllium electrodes. The bands were obtained in the atmosphere of ordinary water vapour and heavy water vapour. From isotope shift studies, experimental conditions and the similarity with the bands of isoelectronic BeF, the emitting molecules were identified as BeOH and BeOD, respectively.

ISSN:0038-7010    

DOI:10.1080/00387018808082339

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The15N NMR chemical shifts and1(15N-1H) coupling constants of a series of imidazolidine-2,4-dichalcogen (O, S) derivatives are reported.The15N NMR chemical shifts show a linear correlatlon wlth the vNH stretchlng vlbratlons. The influence of the substitution of the oxygen at C2and/or C4with the sulphur, and of the hydrogen at C5wlth the methyls and phenyls has been considered. The1J(15N-1H)'s found In thls serles of molecules agrees well with the expected values.

ISSN:0038-7010    

DOI:10.1080/00387018808082340

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The carbon chemical shifts of ethanol are measured in varied aqueous and organic solvents. We determine the hydrogen bonding effect between alcohol and bases by correcting the experimental values from anisotropy and non specific medium effects.

ISSN:0038-7010    

DOI:10.1080/00387018808082341

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The i-r. spectra of thiazole-2-carboxylic acid and thiazole-2-carboxylate ion as CsI pellets and Nujol mull as well as Raman spectrum of an aqueous solution of the salt have been investigated. Most vibrations have been assigned on the basis of group frequencies and by correlation between the spectra of both molecules. The -COOH characteristic vibrations have been assigned as vibrations of the intermolecularly associated species.

ISSN:0038-7010    

DOI:10.1080/00387018808082342

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

13C-NMR chemical shifts have been measured for some 9-aminoacridine derivatives, substituted on positions 9 and 10, in DMSO and for some related salts in D2O. The results are discussed with regard to amino/imino tautomerism, structure of the cations, and slow rotation about a formal C-N double bond.

ISSN:0038-7010    

DOI:10.1080/00387018808082343

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The Infrared spectrum of solid chlorotrifluoromethane (CF3Cl) has been studied and compared with that of matrix-isolated CF3Cl. Crystal field splitting patterns of the strongest modes ν1and ν4suggest the crystal structure to be orthorhombic with a C2vfactor group and two molecules per unit cell located on Cssites.

ISSN:0038-7010    

DOI:10.1080/00387018808082344

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The enhanced reactivity of the meta carbonyl function vis-a-vis nucleophiles in 3-substituted phthalic anhydrides is interpreted in terms of an internal steric effect. A through-space interaction between the substituent and the carbonyl function causes a displacement of electrons in the C=O bond from the oxygen to the carbon atom with simultaneous deactivation of the carbon atom toward nucleophilic attack and the oxygen atom toward complexation with a counter ion.

ISSN:0038-7010    

DOI:10.1080/00387018808082345

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

α-Pyrazinamide and its α-Pyrazinamide-d2as well as the15N-isotopic derivative were synthesized with an isotopic content of 99.4% and their Raman and infrared spectra were recorded and assigned on the basis of isotopic shifts.

ISSN:0038-7010    

DOI:10.1080/00387018808082346

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Disparities in the protonated carbon NMR chemical shift assignments of the polynuclear aromatic molecule, fluoranthene, have been noted. Using two-dimensional13C-13C double quantum coherence, the13C-NMR chemical shift assignments were reinvestigated and a set of unequivocal assignments obtained.

ISSN:0038-7010    

DOI:10.1080/00387018808082347

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor