Departamento de Química--Grupo de Síntesis Química de La Rioja, UA-CSIC, Universidad de La Rioja, 26006, Logroño, Spain.
Inorg Chem. 2010 Dec 20;49(24):11606-18. doi: 10.1021/ic102000s. Epub 2010 Nov 17.
A series of heteropolynuclear Pt-Tl-Fe complexes have been synthesized and structurally characterized. The final structures strongly depend on the geometry of the precursor and the Pt/Tl ratio used. Thus, the anionic heteroleptic cis-configured cis-Pt(C(6)F(5))(2)(C≡CFc)(2) and Pt(bzq)(C≡CFc)(2) (Fc = ferrocenyl) complexes react with Tl(+) to form discrete octanuclear (PPh(3)Me)(2)[{trans,cis,cis-PtTl(C(6)F(5))(2)(C≡CFc)(2)}(2)] (1), PtTl(bzq)(C≡CFc)(2) (5; bzq = benzoquinolate), and decanuclear trans,cis,cis-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2) (3) derivatives, stabilized by both Pt(II)···Tl(I) and Tl(I)···η(2)(alkynyl) bonds. By contrast, Q(2)[trans-Pt(C(6)F(5))(2)(C≡CFc)(2)] (Q = NBu(4)) reacts with Tl(+) to give the one-dimensional (1-D) anionic (NBu(4)){trans,trans,trans-PtTl(C(6)F(5))(2)(C≡CFc)(2)} (2) and neutral trans,trans,trans-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2) (4) polymeric chains based on PtFc(2) platinate fragments and Tl(+) (2) or Tl···Tl (4) units, respectively, connected by Pt(II)···Tl(I) and secondary weak κ-η(1) (2) or η(2) (4) alkynyl···Tl(I) bonding. The formation of 1-4 is reversible, and thus treatment of neutral 3 and 4 with PPh(3)MeBr causes the precipitation of TlBr, returning toward the formation of the anionic 1 and 2' (Q = PPh(3)Me). Two slightly different pseudopolymorphs were found for 2', depending on the crystallization solvent. Finally, the reaction of the homoleptic Pt(C≡CFc)(4) with 2 equiv of Tl(+) affords the tetradecanuclear sandwich type complex [Pt(2)Tl(4)(C≡CFc)(8)] (6). Electrochemical, spectroelectrochemical, and theoretical studies have been carried out to elucidate the effect produced by the interaction of the Tl(+) with the Pt-C≡CFc fragments. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) of 1-5 reveal that, in general, neutralization of the anionic fragments increases the stability of the fully oxidized species and gives higher E(1/2) (Fc) values than those observed in their precursors, increasing with the number of Pt-Tl bonding interactions. However, the electronic communication between Fc groups is reduced or even lost upon Tl(+) coordination, as confirmed by electrochemical (CVs and DPVs voltammograms, 1-5) and spectroelectrochemical (UV-vis-NIR, 2-4) studies. Complexes 2 and 4 still display some electronic interaction between the Fc groups, supported by the presence of an IVCT band in their UV-vis-NIR spectra of oxidized species and additional comparative DFT calculations with the precursor trans-Pt(C(6)F(5))(2)(C≡CFc)(2) and complex 3.
一系列杂核多金属 Pt-Tl-Fe 配合物已被合成并进行了结构表征。最终的结构强烈依赖于前体的几何形状和使用的 Pt/Tl 比。因此，阴离子杂配位顺式构型 cis-Pt(C(6)F(5))(2)(C≡CFc)(2) 和 Pt(bzq)(C≡CFc)(2)（Fc = 二茂铁基）配合物与 Tl(+) 反应，形成离散的八核（PPh(3)Me)(2)[{trans,cis,cis-PtTl(C(6)F(5))(2)(C≡CFc)(2)}(2)]（1）、PtTl(bzq)(C≡CFc)(2)（5；bzq = 苯醌）和十核 trans,cis,cis-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)（3）衍生物，通过 Pt(II)···Tl(I) 和 Tl(I)···η(2)(alkynyl) 键稳定。相比之下，Q(2)[trans-Pt(C(6)F(5))(2)(C≡CFc)(2)]（Q = NBu(4)) 与 Tl(+) 反应生成一维（1-D）阴离子 (NBu(4)){trans,trans,trans-PtTl(C(6)F(5))(2)(C≡CFc)(2)}（2）和中性 trans,trans,trans-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)（4）聚合物链，基于 PtFc(2) platinate 片段和 Tl(+)（2）或 Tl···Tl（4）单元，分别通过 Pt(II)···Tl(I) 和二级弱 κ-η(1)（2）或 η(2)（4）炔基···Tl(I) 键连接。1-4 的形成是可逆的，因此用 PPh(3)MeBr 处理中性 3 和 4 会导致 TlBr 的沉淀，从而重新形成阴离子 1 和 2'（Q = PPh(3)Me）。2' 发现了两种略有不同的假多晶型物，这取决于结晶溶剂。最后，Pt(C≡CFc)(4) 与 2 当量的 Tl(+) 反应得到十四核夹心型配合物 [Pt(2)Tl(4)(C≡CFc)(8)]（6）。进行了电化学、光谱电化学和理论研究，以阐明 Tl(+) 与 Pt-C≡CFc 片段相互作用产生的影响。1-5 的循环伏安法（CV）和差分脉冲伏安法（DPV）表明，一般来说，阴离子片段的中和会增加完全氧化物种的稳定性，并给出比其前体观察到的更高的 E(1/2)（Fc）值，随着 Pt-Tl 键合相互作用的增加而增加。然而，电化学（CVs 和 DPVs 伏安图，1-5）和光谱电化学（UV-vis-NIR，2-4）研究证实，Tl(+) 配位后，Fc 基团之间的电子通讯减少甚至丢失。复合物 2 和 4 仍然显示出 Fc 基团之间的一些电子相互作用，这得到了它们氧化物种的 UV-vis-NIR 光谱中存在 IVCT 带以及与前体 trans-Pt(C(6)F(5))(2)(C≡CFc)(2) 和配合物 3 的额外比较 DFT 计算的支持。
