ISSN:
1434-1948
Keywords:
Metallocenes
;
Hydroselenide ligands
;
Selenium
;
Se coordination chemistry
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The reactions of [Cp#2NbBH4] (1) [Cp# = C5Me5 (Cp*) or C5Me4Et] and [Cp′2TaH3] (Cp′ = tBuC5H4) with elemental selenium give complexes of the general composition [Cp2MSe2H]. These exist in three isomeric forms, A-C, depending on the metal and the chalcogen. [Cp#2NbSe2H] (2) incorporates the novel η2-Se2H ligand (C), which is labile when exposed to light. Solutions of 2(Cp*) can be converted into [Cp*2NbSe2H] (3), which exists in two isomeric forms A or B, along with [Cp*2NbSe3H] (4) and [Cp*2NbO2H] (5). [Cp′2Ta(η2-Se2)H] (6) is the only isomer found for the Ta system. Se abstraction by means of P(OEt)3 gives [Cp′2Ta(=Se)H] (7). Complex 7 can be reduced with Na/Hg and subsequently hydrolysed to give [Cp′2Ta(SeH)H2] (8), which has also been observed during the formation of 6. Coordination of [W(CO)5THF] at the Se lone pair of 7 affords the heterobimetallic complex 9. All compounds have been characterized by means of 1H- and, in some cases, 77Se-NMR spectroscopy. Products 8 and 9 have also been subjected to X-ray diffraction analysis.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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