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Bridged Dinuclear Tripodal Tris(amido)phosphane Complexes of Titanium and Zirconium as Diligating Building Blocks for Organometallic Polymers
Author(s) -
Han Hua,
Johnson Samuel A.
Publication year - 2008
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.200701015
Subject(s) - chemistry , protonolysis , adduct , bimetallic strip , ligand (biochemistry) , medicinal chemistry , diethyl ether , stereochemistry , zirconium , metal , catalysis , inorganic chemistry , organic chemistry , biochemistry , receptor
Abstract Appropriate bridging ligands allow for the preparation of bimetallic titanium and zirconium precursors to transition‐metal‐containing polymers using the formally trianionic P(CH 2 NAr R ) 3 ligand (where Ar R = Ph, and 3,5‐Me 2 C 6 H 3 for a and b , respectively). Lithiation of the known amidophosphane ligand precursors P(CH 2 NHAr R ) 3 ( 1a , b ) with 3 equiv. of n BuLi cleanly provided the diethyl ether adducts P(CH 2 NAr R ) 3 Li 3 (OEt 2 ) 1.5 ( 2a , b ). The THF adduct P(CH 2 NPh) 3 Li 3 (THF) 5 ( 2a‐THF ) was characterized by X‐ray crystallography. Protonolysis reactions were used to prepare the mononuclear titanium complexes P(CH 2 NAr R ) 3 TiOC 6 H 4 t Bu ( 4a , b ) and dinuclear species [P(CH 2 NPh) 3 TiNMe 2 ] 2 ‐μ‐4,4′{O[3,3′,5,5′‐(C 6 H 2 Me 2 ) 2 ]O} ( 5a ), [P(CH 2 NPh) 3 Ti] 2 (μ‐O) ( 6a ), and P(CH 2 N‐3,5‐Me 2 C 6 H 3 ) 3 Ti‐μ‐O‐Ti(NMe 2 ) 3 ( 7b ), from P(CH 2 NAr R ) 3 TiNMe 2 . The reactions of 1a , b with Zr(NEt 2 ) 4 afforded metal complexes of the type P(CH 2 NAr R ) 3 ZrNEt 2 ( 8a , b ). The chloride complexes P(CH 2 NAr R ) 3 ZrCl(THF) ( 9a , b ) were prepared by treatment of HNEt 3 Cl with 1 or 2 . The complexes 9a , b reacted with cyclopentadienyllithium (C 5 H 5 Li) to produce P(CH 2 NAr R ) 3 ZrCp ( 10a , b ), which were also prepared by the reactions of the lithium salts 2a , b with CpZrCl 3 . The dilithium salt of the fulvalene dianion (Li 2 C 10 H 8 ) reacts with 9a , b to produce the dinuclear complexes trans ‐[P(CH 2 NAr R ) 3 Zr] 2 (μ‐η 5 :η 5 ‐C 10 H 8 ) ( 10a , b ), respectively. The facile preparation of transition‐metal‐containing polymers from the bridged dinuclear complexes was illustrated by the reaction of 6a with half an equivalent of [Rh(CO) 2 (μ‐Cl)] 2 , which precipitated polymeric Cl(CO)Rh[P(CH 2 NPh) 3 Ti] 2 (μ‐O). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)