摘要:

AbstractThe thermometric titration of titanium(III) chloride with oxalic acid was carried out at 25°C. The molar ratio of titanium (III): oxalate was found to be 1:2, which indicates the formation of Ti(C2O4)2−ion in acid media. The limiting value of the heat of reaction between Ti(III) ion and oxalic acid in hydrochloric acid solution was found to be −1.5Kcal mole−1a

ISSN:0009-4536    

DOI:10.1002/jccs.197200001

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe polarized Raman spectra of naphthalene single crystal are recorded with a laser Raman spectrometer. Relative intensites of Raman lines in various polarizations are accurately measured by photon‐counting technique. All the strong lines are polarized in the c′c′ and bb polarizations, and the polarization data alone are not sufficient to decide the symmetry of a Raman active vibration. The oriented gas model is found not adequate to fully understand the results. The polarization data have to be interpreted in terms of the electronic spectrum of naphth

ISSN:0009-4536    

DOI:10.1002/jccs.197200002

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractZero differential overlap (ZDO) approximation1,2)and the consideration of long range (meta and para bonds etc) bonding are applied in this semiempirical LCAO‐SCF MO method. Effective Huckel type formulation and diagonalization procedure of symmetry adapted analysis simplify the computational procedure as well as give a clear and intuitive localized bonding behavior of the carbocyclic molecules. The long range repulsive bonds are defined and discussed between aromatic and non‐aromatic cases. Such bonds are closely correlated to the rigidity and distortion of ring systems. Benzene is the most stable species among the 6π electron systems, and there will be some new explanation of Dewar resonance structures due to the consideration of long range para repulsive bonds in this

ISSN:0009-4536    

DOI:10.1002/jccs.197200003

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractZirconium (IV) ions form violet red complex with 4,5‐dihydroxyfluorescein in fairly strong mineral acid medium. The reagent has been successfully applied as a metal indicator in the direct EDTA titration of zirconium.The complex formed by 4,5‐dihydroxyfluorescein and zirconium ions has been studied spectrophotometrically in 0.1MHCl solution. It is found that when an excess of metal ion is present, a violet red colored complex with metal‐ligand ratio of 1:1, (MR) is formed and when an excess of 4,5‐dihydroxyfluorescein is present a 1:2 complex (MR2) may be predominant. The 1:1 complex has maximum absorption at 510mμ and the 1:2 complex has very low solubility and tends to precipitate out from the solution. Job's method, log‐ratio method and gravimetric method were used to establish the composition of complexes. The apparent stability constant of the 1:1 complex is found to be logKh= 4.46 orKh= 2.9

ISSN:0009-4536    

DOI:10.1002/jccs.197200004

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractSix alkaloids have been isolated fromCorydalis tashirolMakino and four of these were identified as palmatine(I), dl‐tetrahydropalmatine(III), I‐tetrahydropalmatine(III) and protopine

ISSN:0009-4536    

DOI:10.1002/jccs.197200005

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractIn order to study the relationship between structure and activity of chalcones, several now 4‐phenyl and 4′‐phenyl chalcones are synthesized by condensation ofp‐phenylbenzaldehyde with, various acetophenones and ofp‐phenylacetophenone with various aldehydes, respectively, in ethanol under the presence of sodium hydroxide or potassium hydroxide as

ISSN:0009-4536    

DOI:10.1002/jccs.197200006

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY