Titanium Complexes of Dialkanolamine Ligands: Synthesis and Structure

Abstract

Abstract Synthesis of the title compounds, viz. [RN(CH 2 CH 2 O)(CHR 1 CR 2 R 3 O)]Ti(O i Pr) 2 ( 13 – 15 ) and [RN(CH 2 CH 2 O)(CHR 1 CR 2 R 3 O)] 2 Ti ( 18 – 28 ), by the reaction of one ortwo equivalents of the corresponding dialkanolamines RN(CH 2 CH 2 OH)(CHR 1 CR 2 R 3 OH) ( 1 – 12 ) with Ti(O i Pr) 4 is reported. Other routes to [RN(CH 2 CH 2 O)(CHR 1 CR 2 R 3 O)] 2 Ti, such as the reaction of Ti(CH 2 Ph) 4 with dialkanolamine and the reaction of TiCl 4 (THF) 2 with dialkanolamine/Et 3 N were also tested. Dimeric titanocane 16 , [PhCH 2 N(CH 2 CH 2 O) 2 Ti(OMe) 2 ] 2 , was obtained from the reaction of one equivalentof dialkanolamine 3 with CpTi(OMe) 3 . PhCH 2 N(CH 2 CH 2 O) 2 Ti(OMenth) 2 ( 17 ) was prepared from the transalkoxylation reaction of 15 with two equivalents of menthol. The composition and structures of all novel compounds were established by 1 H and 13 C NMR spectroscopy as well as elemental analysis data. The possible solution structure features of 13 – 28 are discussed. The single‐crystal X‐ray diffraction study oftitanocane 16 clearly indicates a dimeric structure for this compound in the solid state. According to X‐ray data, compounds [PhCH 2 N(CH 2 CH 2 O) 2 ] 2 Ti ( 19 ), [MeN(CH 2 CH 2 O)(CH 2 CHPhO)] 2 Ti ( 20 ), [MeN(CH 2 CH 2 O)(CH 2 CPh 2 O)] 2 Ti ( 23 ), erythro ‐[MeN(CH 2 CH 2 O)(CHPhCHPhO)] 2 Ti ( 24 ), threo ‐[MeN(CH 2 CH 2 O)(CHPhCHPhO)] 2 Ti ( 25 ), and {MeN(CH 2 CH 2 O)[CH(CH 2 ) 4 CHO]} 2 Ti ( 27 ) possess a monomeric structure with a hexacoordinate titanium atom in the solid state. Among them complexes 19 , 20 , 23 , 25 , and 27 are characterized by a cis disposition of the nitrogen atoms in the coordination environment of the Ti atom, while nitrogen atoms in 24 occupy trans positions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)