Crystal and molecular structure of the isobacteriochlorin: (2,3,7,8-tetrahydro-5,10,15,20-tetraphenylporphinato)(pyridine)zinc(II) benzene solvate
| Autor: | L. D. Spaulding, Jack Fajer, K. M. Barkigia, G. J. B. Williams |
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| Rok vydání: | 1981 |
| Předmět: | |
| Zdroj: | Journal of the American Chemical Society. 103:176-181 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja00391a031 |
| Popis: | The structure of the isobacteriochlorin, (2,3,7,8-tetrahydro-5,10,15,20-tetraphenylporphinato)(pyridine)zinc(II) benzene solvate, has been determined by three-dimensional x-ray diffraction. The compound crystallizes with one molecule each of benzene and reduced porphyrin per asymmetric unit in the triclinic space group P anti 1 with a = 11.452 (5) A, b = 13.332 (4) A, c = 14.718 (6) A, ..cap alpha.. = 99.05 (2)/sup 0/, ..beta.. = 94.37 (4)/sup 0/, and ..gamma.. = 104.88 (4)/sup 0/. It is isomorphous with the corresponding chlorin, (2,3-dihydrotetraphenylporphinato)(pyridine)zinc(II) benzene solvate. The structure has been refined by least squares in three matrix blocks to R/sub F/ = 0.073, on the basis of 6217 reflections with F/sub 0/ > 0. The results unambiguously confirm the structure, previously deduced by spectroscopic techniques, for the general class of isobacteriochlorins (and for siroheme, the prosthetic group of nitrite and sulfite reductases) as prophyrins in which two adjacent pyrrole rings are reduced. In addition, the data indicate that successive saturation of the pyrrole rings in prophyrins, chlorins, and isobacteriochlorins exerts no major effect on the stereochemistry of the macrocycles and suggest that the geometric details of high spin iron siroheme will not deviate substantially from those of iron(III) porphyrins. |
| Databáze: | OpenAIRE |
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