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Synthesis, Structure, Electrochemistry and Reactivity of the Bis(μ‐σ‐stannanediyl)dinickel Butterfly Cluster [{{(SiMe 3 ) 2 CH} 2 Sn–Ni(η 5 ‐Cp)} 2 ]( Ni 2 –Sn 2 )
Author(s) -
Schneider Jörg J.,
Hagen Jörg,
Bläser Dieter,
Boese Roland,
de Biani Fabrizia Fabrizi,
Zanello Piero,
Krüger Carl
Publication year - 1999
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199911)1999:11<1987::aid-ejic1987>3.0.co;2-4
Subject(s) - chemistry , acetonitrile , deprotonation , steric effects , crystallography , ligand (biochemistry) , bond cleavage , medicinal chemistry , stereochemistry , reactivity (psychology) , nickel , organic chemistry , ion , catalysis , medicine , biochemistry , receptor , alternative medicine , pathology
Addition of stannylene [{(SiMe 3 ) 2 CH} 2 Sn : ] ( 2 ) to the unbridged homobimetallic Ni–Ni bond of [{PEt 3 Ni(η 5 ‐Cp)} 2 ] ( 1 ) gives the heterobimetallic, tetranuclear compound [{{(SiMe 3 ) 2 CH} 2 Sn–Ni(η 5 ‐Cp)} 2 ] ( 3 ) with a butterfly arrangement and leaves the Ni–Ni bond of 1 intact. Elimination of both PEt 3 ligands from the starting material 1 is observed, probably due to steric restraints. Compound 3 is formally related to the hypothetical closo ‐borane B 4 H 4 2– . 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 [{(SiMe 3 ) 2 CH} 2 Sn : ] 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 [(η 5 ‐Cp)Ni{Sn(CH(SiMe 3 ) 2 } 2 OH] ( 6 ) having an Sn–OH–Sn bridge. The hydroxy proton in 6 can be exchanged by deuterium within a few minutes, as determined by 1 H‐NMR spectroscopy, giving the monodeuterio product, [D 1 ]‐ 6 . Compound 6 is reactive towards acetonitrile, leading to cleavage of one Ni–Sn bond, elimination of one [{(SiMe 3 ) 2 CH} 2 Sn : ] unit, and formation of the organotin hydroxo complex [{(SiMe 3 ) 2 CH} 2 (OH)Sn–Ni(η 5 ‐Cp)(CH 3 CN)] ( 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.