Synthesis and structure of trinuclear methoxy-bridged titanium(III) -magnesium complexes: [(C 5H 5− nMe n) 2Ti( μ-OMe) 2] 2Mg (n = 4 and 5)

• Published in: Journal of organometallic chemistry 1996-06, Vol.516 (1), p.177-185
• Main Authors: Gyepes, Róbert, Hiller, Jörg, Thewalt, Ulf, Polášek, Miroslav, Šindelář, Pavel, Mach, Karel
• Format: Article
• Language: English
• Subjects: EPR spectra; Methoxy-bridged; Titanium; Titanium(III)-magnesium complexes; X-ray structure
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/0022-328X(96)06126-8

The hydride complexes [(C 5Me 5) 2Ti(μ-H) 2] 2Mg ( 1) and [(C 5HMe 4) 2Ti(μ-H) 2] 2Mg ( 2) smoothly react with four equivalents of methanol to give the methoxy complexes [(C 5Me 5) 2Ti(μ-OMe) 2] 2Mg ( 3) and [(C 5HMe 4) 2Ti(μ-OMe) 2] 2Mg ( 4). The X-ray crystal analysis of 4 revealed a nearly linear arrangement of the metal atoms in an unsymmetrical molecule. The EPR spectra of the frozen toluene glass of 3 and 4 showed the triplet state spectra with very similar zero field splitting of rhombic symmetry. The distance between the unpaired electrons in 4 was estimated from the value of D = 0.00958 cm −1 to be 6.43 Å, in good agreement with the crystallographic Ti IIITi III distance of 6.329(1) Å. Complex 4 reacts with excess dibutyl magnesium to give a mixture of 2 and [(C 5HMe 4) 2Ti(μ-H]) 2Mg(μ-OMe)] 2 ( 6). A mixture of 4 and methylalumoxane (1 : 100) did not induce the polymerization of ethylene.