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Breaking and Making of Carbon–Carbon Bonds by Lanthanides and Third‐Row Transition Metals
Author(s) -
Zhou Shaodong,
Li Jilai,
Schlangen Maria,
Schwarz Helmut
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201504571
Subject(s) - lanthanide , carbon fibers , transition metal , transition (genetics) , reinforced carbon–carbon , bond , materials science , chemical physics , chemistry , catalysis , business , organic chemistry , composite material , ion , composite number , biochemistry , finance , gene
Carbon‐atom extrusion from the ipso ‐position of a halobenzene ring (C 6 H 5 X; X=F, Cl, Br, I) and its coupling with a methylene ligand to produce acetylene is not confined to [LaCH 2 ] + ; also, the third‐row transition‐metal complexes [MCH 2 ] + , M=Hf, Ta, W, Re, and Os, bring about this unusual transformation. However, substrates with substituents X=CN, NO 2 , OCH 3 , and CF 3 are either not reactive at all or give rise to different products when reacted with [LaCH 2 ] + . In the thermal gas‐phase processes of atomic Ln + with C 7 H 7 Cl substrates, only those lanthanides with a promotion energy small enough to attain a 4f n 5d 1 6s 1 configuration are reactive and form both [LnCl] + and [LnC 5 H 5 Cl] + . Branching ratios and the reaction efficiencies of the various processes seem to correlate with molecular properties, like the bond‐dissociation energies of the C−X or M + −X bonds or the promotion energies of lanthanides.