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Reduktion von (Cyclobutadien)(cyclopentadienyl)‐ und (1,5‐Cyclooctadien)‐ (cyclopentadienyl)nickel‐Kationen
Author(s) -
Kölle Ulrich,
TingZhen Ding,
Keller Hubert,
Ramakrishna B. L.,
Raabe Eleonore,
Krüger Carl,
Raabe Gerhad,
Fleischhauer Jörg
Publication year - 1990
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19901230202
Subject(s) - chemistry , cyclopentadienyl complex , nickel , cyclobutadiene , dimer , cyclopentadiene , cyclic voltammetry , sandwich compound , electron paramagnetic resonance , 1,5 cyclooctadiene , medicinal chemistry , crystallography , crystal structure , cationic polymerization , stereochemistry , x ray crystallography , molecule , polymer chemistry , electrochemistry , nuclear magnetic resonance , catalysis , organic chemistry , physics , electrode , diffraction , optics
Reduction of (Cyclobutadiene)(cyclopentadienyl)‐ and (1,5‐Cyclooctadiene)(cyclopentadienyl)nickel Cations Cyclic voltammetry of the four cationic Ni sandwich complexes [Ni(C 5 R 5 )(C 4 R 4 ')] + ( 2 : R = H, R' = Ph; 3 : R = H, R' = Me; 4 ; R = Me, R' = Ph; 5 : R = R' = Me) shows reversible one‐electron reductions for the phenyl derivatives 2 and 4 and a peak pattern characteristic of reductive dimerization/oxidative monomerization for the methyl derivatives 3 and 5 . The product of the reduction of 3 was isolated and characterized analytically and by an X‐ray structure determination as the dimer 6 of 3 , linked through cyclobutenyl rings, the first example for a dimerization of an electron‐rich sandwich complex at a substituted C atom. EPR spectra of the neutral complexes 2 and 4 are compared to those of (1,5‐cyclooctadiene)(cyclopentadienyl)nickel ( 7 ) and are interpreted in terms of a substantial static Jahn‐Teller distortion.