ISSN:
1434-1948
Schlagwort(e):
Cluster
;
Nickel
;
Tin
;
Bimetallic complexes
;
Electrochemistry
;
Chemistry
;
General Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Addition of stannylene [{(SiMe3)2CH}2Sn:] (2) to the unbridged homobimetallic Ni-Ni bond of [{PEt3Ni(η5-Cp)}2] (1) gives the heterobimetallic, tetranuclear compound [{{(SiMe3)2CH}2Sn-Ni(η5-Cp)}2] (3) with a butterfly arrangement and leaves the Ni-Ni bond of 1 intact. Elimination of both PEt3 ligands from the starting material 1 is observed, probably due to steric restraints. Compound 3 is formally related to the hypothetical closo-borane B4H42-. The Ni-Ni bond in 3 is only slightly elongated [2.454(3) Å] when compared to the starting material 1 [2.41(1) Å]. Compound 3 displays a butterfly arrangement with a hinge angle of 62.5°. An alternative route to 3 is by a direct reaction between nickelocene (5) and Lappert's stannylene [{(SiMe3)2CH}2Sn:] in 63% yield. Treating 3 with water results in the cleavage of an Ni-Sn bond and subsequent opening of the cluster cage of 3 to form the trinuclear compound [(η5-Cp)Ni{Sn(CH(SiMe3)2}2OH] (6) having an Sn-OH-Sn bridge. The hydroxy proton in 6 can be exchanged by deuterium within a few minutes, as determined by 1H-NMR spectroscopy, giving the monodeuterio product, [D1]-6. Compound 6 is reactive towards acetonitrile, leading to cleavage of one Ni-Sn bond, elimination of one [{(SiMe3)2CH}2Sn:] unit, and formation of the organotin hydroxo complex [{(SiMe3)2CH}2(OH)Sn-Ni(η5-Cp)(CH3CN)] (7). In this complex, acetonitrile is coordinated to Ni via its σ lone pair, bearing the OH ligand in a terminal bonding mode to tin.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
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