| Autor: |
Potrzebowski, M.J., Tekely, P., Błaszczyk, J., Wieczorek, M.W. |
| Zdroj: |
The Journal of Peptide Research; October 2000, Vol. 56 Issue: 4 p185-194, 10p |
| Abstrakt: |
A crystalline sample of N-benzoyl-dl-phenylalanine 1 and a polycrystalline sample of N-benzoyl-l-phenylalanine 2 were studied using 13C high-resolution solid-state NMR spectroscopy. The X-ray structure of the dl form was established. Sample 1 crystallizes in a monoclinic form with a P21/c space group, a = 11.338(1) Å, b = 9.185(1) Å, c = 14.096(2) Å, β = 107.53(3)°, V = 1400(3) Å3, Z = 4 and R = 0.053. The principal elements of the 13C chemical shift tensors δii for 1 and 2, selectively 13C (99%) labeled at the carboxyl groups were calculated. On the basis of 13C δii analysis the hydrogen bonding pattern for sample 2 was deduced. Enriched samples were used to establish the intermolecular distance between chemically equivalent nuclei for 1 and spatial proximity in heterogeneous domain for 2, employing the ODESSA pulse sequence. The consistence of the complementary approach covering X-ray data, analysis of the 13C δii parameters and ODESSA results is revealed. |
| Databáze: |
Supplemental Index |
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