259 resultados para [CO3]2-


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The 93 K X-ray crystal structure of tris(ethane-1,2-diamine)zinc(II) dinitrate is reported. As predicted by the spectroscopic studies of other workers, there is a reversible phase transition of the structure at low temperature. We have determined this temperature to be 143 K. The structure at this temperature and below resembles that of the room temperature structure, except the crystallographic D-3 symmetry of the complex cation (296 K) is lowered to C-2 ( below 144 K) by subtle changes in cation-anion hydrogen bonding. No change in the conformation of the cation or its bond lengths and angles was found.

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The crystal structure of the title compound, C12H14O2, has been determined at 150 K. Significant intermolecular non-conventional C-H...O interactions involving the terminal acetylinic H atom are observed, which result in a zigzag hydrogen-bonded chain in the b direction.

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Novel 2-amino-1,3-thiazole-5-carboxylates have been synthesised in high yield by unprecedented ultrasonic and thermally mediated nucleophilic displacement of bromide from ethyl 2-bromo-1,3-thiazole-5-carboxylate by primary, secondary and aryl amines.

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Regiospecific bromination of 2,4,4-trimethyl-cyclohex-2-enone was achieved and the X-ray crystal structure of 6-bromo-2,4,4-trimethyl-cyclohex-2-enone is presented.