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33. |
- Garding, L., et al.
(författare)
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Simple formulas for rotation averages of spectroscopic intensities
- 1979
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Ingår i: Chemical Physics. - : Elsevier BV. - 0301-0104. ; 41:3, s. 431-437
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Tidskriftsartikel (refereegranskat)abstract
- We give a self-contained exposition of the “ensemble method”, a rule for calculating rotation averages of spectroscopic absorption intensities. The rule is mathematically exact and conceptually simple and applies to rotation averages for several axes of rotation occurring in helical and superhelical symmetry. A measure of dichroism, DI, is introduced which has a simple multiplicative property relative to axes of rotation. There are several applications to linear dichroism spectroscopy.
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34. |
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35. |
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36. |
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37. |
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38. |
- Hakansson, R., et al.
(författare)
-
Magnetic circular dichroism of heterocycles: thiophene
- 1977
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 50:2, s. 305-308
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Tidskriftsartikel (refereegranskat)abstract
- The existence of two transitions with opposite MCD in the 38000–45000 cm−1 absorption of thiophene is demonstrated. The B-term for the lowest transition is negative, while it is positive for the higher one. Quantum mechanical calculations in the π-electron approximation resulted in energies, oscillator strengths and MCD terms in good agreement with the observed spectra.
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39. |
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40. |
- Havlicek, Jaroslav, et al.
(författare)
-
Partition chromatography and mass spectrometry of tetrulose and pentuloses
- 1972
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Ingår i: Acta Chemica Scandinavica. ; 26, s. 2205-2215
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Tidskriftsartikel (refereegranskat)abstract
- Partition chromatography on ion exchange resins in aqueous ethanol is an excellent tool for the separation of tetrulose and pentuloses for both analytical and preparative purposes. The analysis of complex mixtures is facilitated by the fact that the ketoses are recorded by both the orcinol and periodate-formaldehyde methods whereas under proper conditions aldoses are only recorded in the orcinol channel. In gas chromatography the trimethylsilylated 3-pentuloses gave rise to only one prominent peak which as revealed by mass spectrometry corresponded to the keto form. Tetrulose and the 2-pentuloses gave two or more peaks. The 1,2-enediol derivative obtained from tetrulose was identical with that recorded for threose.
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