Schneider, Jorg J.; Hagen, Jorg; Blaser, Dieter; Boese, Roland; De Biani, Fabrizia Fabrizi; Zanello, Piero; Kruger, Carl:

Synthesis, structure, electrochemistry, and reactivity of the bis(m-s-stannanediyl)dinickel butterfly cluster [{{(SiMe3)2CH}2Sn-Ni(h5-Cp)}2](Ni2-Sn2).

In: European Journal of Inorganic Chemistry, (1999) ; Nr. 11, S. 1987-1993
ISSN: 1434-1948
Zeitschriftenaufsatz / Fach: Chemie
Abstract:
Addn. of stannylene [{(Me3Si)2CH}2Sn:] to the unbridged homobimetallic Ni-Ni bond of [{PEt3Ni(h5-Cp)}2] (1) gives the heterobimetallic, tetranuclear [{(SiMe3)2CH}2Sn-Ni(h5-Cp)]2 (3) with a butterfly arrangement leaving the Ni-Ni bond intact. Elimination of both PEt3 ligands from 1 is obsd., probably due to steric restraints. 3 Is formally related to the hypothetical closoborane B4H42-. The Ni-Ni bond in 3 [2.454(3) .ANG.] is only slightly elongated when compared to 1 [2.41(1) .ANG.]. 3 Displays a butterfly arrangement with a hinge angle of 62.5 Deg. An alternative route to 3 is the direct reaction between nickelocene and [{(Me3Si)2CH}2Sn:] with 63% yield. Treating 3 with H2O results in the cleavage of an Ni-Sn bond and subsequent opening of the cluster cage of 3 to form trinuclear [(h5-Cp)Ni{Sn[CH(SiMe3)2]2OH}] (6) having an Sn-OH-Sn bridge. The OH proton in 6 can be exchanged by D within a few minutes, as detd. by 1H NMR, giving the monodeuterio product. 6 Is reactive towards MeCN, leading to cleavage of one Ni-Sn bond, elimination of one [{(SiMe3)2CH}2Sn:] unit, and formation of the organotin hydroxo complex [{(SiMe3)3CH}2(OH)Sn-Ni(h5-Cp)(MeCN)]. In this complex, MeCN is coordinated to Ni via its a lone pair, bearing the OH ligand in a terminal bonding mode to Sn.