Vibrational analysis of crystalline diketopiperazine—II. Normal mode calculations
نویسندگان
چکیده
منابع مشابه
Vibrational Analysis of Crystalline Triglycine*
We have refined vibrational force fields for polypeptides that permit excellent reproduction of the normal mode frequencies of such molecules. This is demonstrated in the present study, in which 80 IR and Raman bands of crystalline triglycine between 1800 and 200 cm-’ are reproduced with an average error of 6 cm-‘. A deuterated sample is shown by normal mode analysis to have remained protonated...
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The normal-mode spectrum for the four-coordinated heme compound Fe(II) octaethylporphyrin, Fe(OEP), has been determined by refining force constants to the experimental Fe vibrational density of states measured with nuclear resonance vibrational spectroscopy (NRVS). Convergence of the calculated spectrum to the data was achieved by first imposing D4 symmetry on the model structure as well as the...
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We have found that tri-L-alanine (Ala3) can crystallize in a parallel-chain beta structure in addition to the previously known antiparallel-chain beta structure. Although the chain conformations in each structure are essentially similar, the ir and Raman spectra are distinctively different. We have calculated the normal modes of each structure, and can account in significant detail for these di...
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ژورنال
عنوان ژورنال: Spectrochimica Acta Part A: Molecular Spectroscopy
سال: 1984
ISSN: 0584-8539
DOI: 10.1016/0584-8539(84)80082-3