摘要:

The absorption spectrum of Mn2+ions doped in diglycine barium chloride monohydrate (DGBC) has been studied at liquid nitrogen temperature (77 K) in the region λ 6000 Å to 3000 Å. Three of the observed bands showed well resolved fine structure. The splitting of4Eg(G) band is explained as due to exciton-magnon interaction. Weak bands on either side of4A1g(G) band are assigned to phonon progressions withν = 200 cm The fine structure of the4T2g(D) band is analysed in terms of spin-orbit splitting associated with the vibrational frequency of the hydrogen bond (185 cm−1). The observed band positions are fitted with four parameters B,C, Dqand α, and the best fit is obtained with B = 810 cm−1, C = 2980 cm−1, Dq= 760 cm−1and α = 76 cm−1. justify our assumption of octahedral site symmetry for the metal ion in the crystal. From the observed absorption spectrum it is possible to determine the crystal phonons in Mn2+doped DGBC and it is found to be about 200 cm−1.

ISSN:0038-7010    

DOI:10.1080/00387018108062608

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

With the object to improve the results, of least squares refinement of force constants the authors propose an iterative procedure using the “simplex” system and the invariants of similarity. These invariants are calculated by a special way without determination of roots. This method has been applied with satisfaction to parabanic acid.

ISSN:0038-7010    

DOI:10.1080/00387018108062609

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

UV Photoelectron spectra of tertiary butylisocyanide, paratolylisocyanide, para-chlorophenylisocyanide and para-nitrophenylisocyanide are reported and assigned on the basis of He(I)/He(II) intensity differences. A comparison is made with the results from CNDO/S calculations.

ISSN:0038-7010    

DOI:10.1080/00387018108062610

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The α-heterosubstitutedN, N−diethylacetamides(1–8)cis/gaucheconformations population ratio have been estimated through the analysis of the carbonyl group stretching vibration in the carbon tetrachloride and in chloroform. The substituent steric properties determine thecis/gaucheratio which decreases as the substituent size increases. For most of the studied amides, thegaucherotamer carbonyl band exhibits larger shifts to lower frequencies than in the corresponding α-heterosubstituted propanones1, but for the α-chloro-(4) and for the α-bromo-N,N−diethylacetamide(5) a reverse trend is observed. This behavior can be related to changes in the πC=O C—X Dihedral angle, an hyperconjugative effect being sugges ted to explain the frequency shifts of thegaucherotamers.

ISSN:0038-7010    

DOI:10.1080/00387018108062611

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The direct determination of total mercury levels in human scalp hair was accomplished by atomic absorption spectroscopy at 184.9 nm through the use of a unique carbon bed atomizer. The Robinson quartz T atomizer permitted the analysis of solid hair samples, 1-cm or less in length, with no sample pretreatmant. This direct analysis eliminated both loss of volatile mercury compounds during pretreatment and contamination of the sample by added reagents. The accuracy of the determination was improved thereby. Use of the 184.9 nm line in the vacuum ultraviolet region provided increased sensitivity over the more commonly employed 253.7 nm line.

ISSN:0038-7010    

DOI:10.1080/00387018108062612

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The far-ir and Raman spectra of the tittle compound have been obtained at room and liquid nitrogen temperature. The spectra are consistent with a halogen bridged species and the vibrational modes are assigned in relation to the structure of the dimeric anionic complex. A symmetry lower than D2his proposed in agreement with preliminary X-ray diffraction results.

ISSN:0038-7010    

DOI:10.1080/00387018108062613

出版商:Taylor & Francis Group    

年代:1981

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:10.1080/00387018108062607

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor