Synthesis and structure of dinuclear dimethylene- or 1,4-phenylene-linked bis(decamethyltitanoceneoxide) (Ti^III) complexes

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• 作者：Michal Hor&#xe1 ; č ; ek ; Ró ; bert Gyepes ; Ivana C&#xed ; sař ; ov&#xe1 ; Jiř ; &#xed ; Kubiš ; ta ; Jiř ; &#xed ; Pinkas ; Karel Mach
• 关键词：Titanium ; Titanocene ; Dinuclear complexes ; Dioxocarbyl links ; Triplet state ; ESR spectra
• 刊名：Journal of Organometallic Chemistry
• 出版年：2010
• 出版时间：1 October 2010
• 年：2010
• 卷：695
• 期：21
• 页码：2338-2344
• 全文大小：574 K

文摘

The singly tucked-in titanocene [Ti(η⁵-C₅Me₅)(η⁵:η¹-C₅Me₄CH₂)] (1) reacts smoothly with ethylene glycol or hydroquinone to give bis(titanoceneoxide) (Ti^III) complexes [CH₂OTi(η⁵-C₅Me₅)₂]₂ (2) and [(η⁵-C₅Me₅)₂TiOC₆H₄OTi(η⁵-C₅Me₅)₂] (3) containing dimethylene and 1,4-phenylene link, respectively. EPR spectra of 2 in 2-methyltetrahydrofuran glass and 3 in toluene glass revealed that the unpaired d¹ electrons are in interaction to form triplet state molecules. The Ti–Ti distance derived from the zero-field splittings D for the two conformations of 2 (7.42 Å and 7.66 Å) are in good agreement with the Ti–Ti distance of 7.2430(7) Å from the X-ray diffraction single-crystal analysis. For 3, however, the Ti–Ti distance derived from D (7.65 Å) is by 1.47 Å shorter than the crystallographic distance of 9.1230(8) Å that indicates an enhancement of the through-space dipole–dipole interaction due to the presence of a conjugated quinonide link.