以（2-二甲基膦基）乙烷-1-硫醇盐和（3-二甲基膦基）丙烷-1-硫醇盐为配体的钛（IV）和钛（III）配合物的合成与表征

Syntheses and characterization of titanium(IV) and titanium(III) complexes with (2-dimethylphosphino)ethane-1-thiolate and (3-dimethylphosphino)propane-1-thiolate as ligands.

作者信息

Matsuzaki Kazutaka, Kawaguchi Hiroyuki, Voth Peter, Noda Kyoko, Itoh Sumitaka, Takagi Hideo D, Kashiwabara Kazuo, Tatsumi Kazuyuki

机构信息

Research Center for Materials Science and Department of Chemistry, Nagoya University, Nagoya 464-8602, Japan.

出版信息

Inorg Chem. 2003 Aug 25;42(17):5320-9. doi: 10.1021/ic034353l.

DOI:10.1021/ic034353l

PMID:12924904

Abstract

Reactions of Cp(2)TiCl(2) (Cp = eta(5)-cyclopentadienide) with 2 or 1 equiv of hybrid P-S ligands (L), (CH(3))(2)P(CH(2))(n)()S(-) (n = 2, dmpet; n = 3, dmppt), produced new dicyclopentadienyltitanium(IV) complexes with L, Cp(2)Ti(L-kappaS)(2) (1, L = dmpet; 2, L = dmppt) and [Cp(2)Ti(L-kappa(2)S,P)]BPh(4) (3, L = dmpet; 4, L = dmppt). The Ti(III) complexes, Cp(2)Ti(L-kappa(2)S,P) (5, L = dmpet; 6, L = dmppt), were prepared by the reaction of Cp(2)Ti(eta(3)-C(3)H(5)) with 1 equiv of L. The structures of complexes 1-6 were confirmed by X-ray diffraction analyses. It was found that complexes 3 and 5 were isostructural around Ti(IV) and Ti(III) centers: the Ti(IV)-S bond length in 3 (2.3498(9) A) is shorter by 0.14 A than Ti(III)-S in 5 (2.4877(7) A), while Ti(IV)-P (2.534(1) A) was merely 0.05 A shorter than Ti(III)-P (2.5844(7) A). The redox potential between 3 and 5 in acetonitrile was -1.14 V vs the ferricinium/ferrocene couple. A heterobimetallic complex that has the frame of complex 1, [Cp(2)Ti(dmpet)(2)Cu]PF(6) (7), was also isolated and structurally characterized: the Ti-Cu distance (2.95(1) A) was shorter than that in [Cp(2)Ti(SC(2)H(4)PPh(2))(2)Cu]BF(4), previously reported by White and Stephan. Structural characterization was also carried out for CpTi(dmpet-kappaS)(2)(dmpet-kappa(2)S,P) (8) and CpTiCl(2)(dmppt-kappa(2)S,P) (9), which were obtained by the reactions of Cp(or Cp)TiCl(3) (Cp = eta(5)-C(5)Me(5)(-)) with n equiv (n = 1-3) of L. The mutual site-exchange reaction between phosphorus atoms on a coordinated dmpet in the kappa(2)S,P mode and on two other coordinated dmpet's in the kappaS mode within complex 8 was analyzed by the variable-temperature (31)P[(1)H] dynamic NMR method. The kinetic parameters for this process, k(ex)(298) = 1.9 x 10(5) s(-)(1), DeltaH = 48 kJ mol(-)(1), and DeltaS = 17 J mol(-)(1) K(-)(1), as well as the rather long Ti(IV)-P distance (2.652(1) A), indicate the fluxional nature of the coordination geometry in complex 8.

摘要

二茂钛二氯（Cp = η⁵-环戊二烯基）与2当量或1当量的混合P-S配体（L），即(CH₃)₂P(CH₂)ₙS⁻（n = 2，dmpet；n = 3，dmppt）反应，生成了新的含L的二茂钛（IV）配合物Cp₂Ti(L-κS)₂（1，L = dmpet；2，L = dmppt）和[Cp₂Ti(L-κ²S,P)]BPh₄（3，L = dmpet；4，L = dmppt）。二茂钛（III）配合物Cp₂Ti(L-κ²S,P)（5，L = dmpet；6，L = dmppt）通过Cp₂Ti(η³-C₃H₅)与1当量的L反应制备。配合物1 - 6的结构通过X射线衍射分析得以确认。发现配合物3和5在Ti(IV)和Ti(III)中心周围具有同构结构：3中Ti(IV)-S键长（2.3498(9) Å）比5中Ti(III)-S键长短0.14 Å（2.4877(7) Å），而Ti(IV)-P（2.534(1) Å）仅比Ti(III)-P（2.5844(7) Å）短0.05 Å。在乙腈中，3和5之间的氧化还原电位相对于二茂铁鎓/二茂铁电对为 -1.14 V。还分离并对具有配合物1结构框架的异双核配合物[Cp₂Ti(dmpet)₂Cu]PF₆（7）进行了结构表征：Ti-Cu距离（2.95(1) Å）比White和Stephan先前报道的[Cp₂Ti(SC₂H₄PPh₂)₂Cu]BF₄中的短。还对通过Cp(或Cp)TiCl₃（Cp = η⁵-C₅Me₅⁻）与n当量（n = 1 - 3）的L反应得到的CpTi(dmpet-κS)₂(dmpet-κ²S,P)（8）和CpTiCl₂(dmppt-κ²S,P)（9）进行了结构表征。通过变温³¹P[(¹H)]动态核磁共振方法分析了配合物8中以κ²S,P模式配位的dmpet上的磷原子与以κS模式配位在另外两个dmpet上的磷原子之间的相互位点交换反应。该过程的动力学参数，k(ex)(298) = 1.9×10⁵ s⁻¹，ΔH = 48 kJ mol⁻¹以及ΔS = 17 J mol⁻¹ K⁻¹，以及相当长的Ti(IV)-P距离（2.652(1) Å），表明配合物8中配位几何结构具有动态性质。