Diffraction Studies of Photoexcited Crystals: Metastable Nitrosyl-Linkage Isomers of Sodium Nitroprusside
| Autor: | Michael D. Carducci, M. R. Pressprich, Philip Coppens |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Journal of the American Chemical Society. 119:2669-2678 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja9625743 |
| Popis: | The geometries of two known metastable states of sodium nitroprusside dihydrate, Na2[Fe(CN)5NO]·2H2O, and that of the ground state have been analyzed by X-ray diffraction at 50 K, a temperature at which no decay of metastable-state concentration with time is observed. Data were collected on two laser-excited crystals containing populations of ∼37% of metastable state I (MS1) and ∼10% of metastable state II (MS2), respectively, using imaging plates and a rotating anode source. For MS1 the apparent geometry changes upon excitation, determined earlier at 138 K (Pressprich, M. R.; White, M. A.; Vekhter, Y.; Coppens, P. J. Am. Chem. Soc. 1994, 116, 5233−5238), are confirmed. However, reinterpretation of the diffraction data points to a linear, oxygen-bound isonitrosyl geometry of this species with Fe−O and N−O distances of 1.715(5) and 1.140(7) A, respectively. The diffraction evidence points to a geometry for the MS2 species in which NO is sideways bound (η2), with Fe−N, Fe−O, and N−O distances of 1.89(2), 2.... |
| Databáze: | OpenAIRE |
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