Zafar Mohammad, Ramalakshmi Rongala, Rongala Ramalakshmi, Pradhan Alaka Nanda, Pathak Kriti, Roisnel Thierry, Halet Jean-François, Ghosh Sundargopal
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, F-35042 Rennes, France.
Dalton Trans. 2019 Jun 7;48(21):7413-7424. doi: 10.1039/c9dt00498j. Epub 2019 Apr 17.
The synthesis and reactivity of ruthenium complexes containing an anionic boron based ligand, supported by mercapto-benzothiazolyl heterocycles are presented. Specifically, the reaction of [(η-p-cymene)Ru{P(OMe)OR}Cl], (1a: R = Me; 1b: R = H) with [HB(mbz)] (mbz = 2-mercaptobenzothiazolyl) at room temperature afforded a series of borate complexes, namely [(L)Ru{κ-H,S,S'-HB(L)}P(O)(OMe)(HL)], 2, [Ru{κ-H,S,S'-HB(L)}], 3 and [(κ-N,S-L)P(OMe)Ru{κ-H,S,S'-HB(L)}], 4a; (L = CHNS). The pivotal feature of 2 is the coordination of the Ru centre with a phosphorus atom of secondary phosphine oxide and mercapto-benzothiazolyl ligands. On the other hand, 3 features dual RuH-B interactions between Ru and B-H bonds of [HB(mbz)]. Interestingly, along with 3, compound [(κ-N,S-L)P(OPh)Ru{κ-H,S,S'-HB(L)}], 4b (L = CHNS), was isolated upon treatment of the same borate with [(η-p-cymene)RuClP(OPh)], 1c, which is stabilized by δ-B-H interactions and one phosphite ligand. Furthermore, compound 3 promptly reacts with P(OR) to generate [(OR)PRu-{κ-S,S'-HB(L)}{κ-H,S,S'-HB(L)}], (5a: R = Me, 5b: R = Ph; L = CHNS) by breaking one of the RuH-B interactions. Upon heating, compound 5a converts into [(OMe)OPRu{κ-S,S'-HB(L)}{κ-H,S,S'-HB(L)}], 6a (L = CHNS) by release of methane gas. Compound 6a is a unique example wherein the boron atom of the borate ligand is bound to an oxygen atom of the phosphite unit. In contrast, the thermolysis of 3 with PRR' yielded [Ru{κ-H,S,S'-HB(L)}(PRR')(L)], (7a: R = Me, R' = Ph; 7b: R = Ph; R' = Me; L = CHNS), respectively, revealing the incorporation of two triphosphine ligands in the coordination sphere of ruthenium. Density functional theory (DFT) calculations were undertaken to provide an insight into the electronic structures of the complexes.
本文介绍了含阴离子硼基配体且由巯基苯并噻唑基杂环支撑的钌配合物的合成及反应活性。具体而言，[(η-对异丙基苯)Ru{P(OMe)OR}Cl]（1a：R = 甲基；1b：R = 氢）与[HB(mbz)]（mbz = 2-巯基苯并噻唑基）在室温下反应，得到了一系列硼酸盐配合物，即[(L)Ru{κ-H,S,S'-HB(L)}P(O)(OMe)(HL)]，2，[Ru{κ-H,S,S'-HB(L)}]，3和[(κ-N,S-L)P(OMe)Ru{κ-H,S,S'-HB(L)}]，4a；（L = CHNS）。配合物2的关键特征是Ru中心与仲膦氧化物的磷原子和巯基苯并噻唑基配体配位。另一方面，配合物3的特征是Ru与[HB(mbz)]的B-H键之间存在双重RuH-B相互作用。有趣的是，在使用[(η-对异丙基苯)RuClP(OPh)]，1c处理相同硼酸盐时，除了得到3之外，还分离出了化合物[(κ-N,S-L)P(OPh)Ru{κ-H,S,S'-HB(L)}]，4b（L = CHNS），它通过δ-B-H相互作用和一个亚磷酸酯配体得以稳定。此外，化合物3迅速与P(OR)反应，通过打破其中一个RuH-B相互作用生成[(OR)PRu-{κ-S,S'-HB(L)}{κ-H,S,S'-HB(L)}]，（5a：R = 甲基，5b：R = 苯基；L = CHNS）。加热时，化合物5a通过释放甲烷气体转化为[(OMe)OPRu{κ-S,S'-HB(L)}{κ-H,S,S'-HB(L)}]，6a（L = CHNS）。化合物6a是一个独特的例子，其中硼酸盐配体的硼原子与亚磷酸酯单元的一个氧原子相连。相比之下，3与PRR'进行热解反应分别生成了[Ru{κ-H,S,S'-HB(L)}(PRR')(L)]，（7a：R = 甲基，R' = 苯基；7b：R = 苯基；R' = 甲基；L = CHNS），这表明在钌的配位球中引入了两个三膦配体。进行了密度泛函理论（DFT）计算以深入了解这些配合物的电子结构。
