| Autor: |
Potrzebowski, M., Grossmann, G., Ganicz, K., Olejniczak, Z., Ciesielski, W., Koziol, A., Wawrzycka, I., Bujacz, G., Haeberlen, U., Schmitt, H. |
| Jazyk: |
angličtina |
| Rok vydání: |
2002 |
| Zdroj: |
Chemistry-A European Journal |
| Popis: |
Bis[6-O,6-O′-(1,2:3,4-diisopropylidene-α-D-galactopyranosyl)thiophosphoryl] disulfide shows a strong tendency to form inclusion compounds. The crystal and molecular structure of eight different solvates was established by X-ray analysis. The results indicate three different types of disulfide arrangements in the crystal lattice. By means of 31P CP/MAS NMR experiments the principal values δ11, δ22, and δ33 of the 31P chemical shift tensor were obtained for each form. The orientation of its principal axes with respect to a molecular frame was investigated by means of 31P CP and single-crystal NMR for the complex with propan-2-ol. The principal axis 1 of both chemically equivalent phosphorus atoms is nearly parallel to the P[BOND]S bond and the principal axis 3 is very close to the P[DOUBLE BOND]S bond. DFT GIAO calculations of the model compound (EtO)2(S)P1SSP2(S)(OEt)2 allowed assignment of the experimental chemical shift curves to the magnetically nonequivalent atoms P1 and P2. The maximum difference between calculated angles (∢ i[BOND]P[BOND]X)calcd and experimental angles (∢ i[BOND]P[BOND]X)exptl is 8.3° and the rms distance 3.8° (i=principal axes 1, 2, 3; X=S, -S-, -O1-, -O2-). The influence of C[BOND]H⋅⋅⋅S weak hydrogen bonding on phosphorus shielding was tested theoretically (31P DFT GIAO) employing the dimethoxythiophosphoryl disulfide⋅CH4 complex as a model compound. The sensitivity of 31P δii parameters to intermolecular forces is demonstrated. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
