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Imines in the Titanium Coordination Sphere: η 1 ‐Imine Complexes as Sources of Azavinylidenes and Four‐Membered Imine–Amido‐ N , N′ Chelates
Author(s) -
Loose Florian,
Schmidtmann Marc,
Saak Wolfgang,
Beckhaus Rüdiger
Publication year - 2016
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/ejic.201600995
Subject(s) - imine , chemistry , coordination sphere , denticity , ligand (biochemistry) , lone pair , titanium , context (archaeology) , catalysis , photochemistry , medicinal chemistry , inorganic chemistry , crystallography , polymer chemistry , organic chemistry , crystal structure , molecule , paleontology , biochemistry , receptor , biology
In titanium imine complexes the ligand can exhibit several bonding modes. While η 2 ‐imine complexes are intermediates in several catalytic transformations and well investigated, the potential of imines to coordinate through the lone pair of electrons of the nitrogen atom by a dative bond to the titanium center is studied herein. The formation of several bis‐η 1 complexes by the reaction of Schiff bases with titanium(IV) chloride was observed. Depending on the substitution pattern of the imine, also complexes with 1:1 stoichiometry are formed. Particular attention is paid to the reaction of imines bearing an SiMe 3 group at the nitrogen atom. Titanium complexes of such imines open access to a remarkable N , N′ ‐bidentate ligand system ( 4 ), which can only be obtained in the coordination sphere of the metal atom and cannot be formed by conventional organic synthesis. In this context, imines 2d and 2i were also treated with [CpTiCl 3 ] to yield titanaazavinylidenes 6a and 6b , which may be useful for further modifications.