Unsymmetric Dinuclear RhI2 and RhIRhIII Complexes Supported by Tetraphosphine Ligands and Their Reactivity of Oxidative Protonation and Reductive Dechlorination
Unsymmetric Dinuclear RhI2 and RhIRhIII Complexes Supported by Tetraphosphine Ligands and Their Reactivity of Oxidative Protonation and Reductive Dechlorination
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四膦配体负载的不对称双核RhI2和RhIRhIII配合物及其氧化质子化和还原脱氯反应活性
DOI：
10.1021/acs.inorgchem.1c03278
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发表时间：
2022
期刊：
影响因子：
4.6
通讯作者：
T. Tanase
中科院分区：
文献类型：
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作者：
T. Nakajima;M. Maeda;A. Matsui;M. Nishigaki;M. Kotani;T. Tanase
两个线性四齿膦配体，meso-Ph 2 PCH 2 P（Ph）CH 2XCH 2 P（Ph）CH 2 PPh 2（X= CH 2（内消旋-dpmpp），NBn（meso-dpmppmNBn; Bn =苄基）合成了不对称双核铑配合物[Rh_2Cl_2（meso-dpmpp）（L）]（L = XylNC（1a），CO（1b））和[Rh2Cl2（meso-dpmppmNBn）（L）]（L = XylNC（1c），CO（1d）），其中30价电子的缺电子RhI→ RhI中心以不寻常的顺/反P，P配位方式被四膦配位。1a-d的Rh二聚体在空气中用HCl处理，得到32 e-的RhI→ RhIII二聚体，[Rh 2Cl 4（meso-dpmpp）（L）]（L = XylNC（4a），CO（4b））和[Rh2Cl4（内消旋-dpmppmNBn）（L）]（L = XylNC（4c），CO（4d）），通过中间氢化物络合物[{RhCl 2（μ-H）RhCl（L）}（中-民进党）]（L = XylNC（2a），CO（2b））和[{RhCl 2（μ-H）RhCl（L）}（meso-dpmppmNBn）]（L = XylNC（2c），CO（2d））和[{Rh（H）Cl2（μ-Cl）Rh（L）}（meso-dpmpp）]（L = XylNC（3a），CO（3b））和[{Rh（H）Cl 2（μ-Cl）Rh（L）}（meso-dpmppmNBn）]（L = XylNC（3c），CO（3d））。氢化物中间体2和3在氮气下用~ 1H {31 P}和~（31）P {1H} NMR技术进行了监测，揭示了依赖于末端辅助配体L的两条反应途径。此外，还原脱氯转化RhIRhIII（4 b，d）RhI 2（1b，d）是完成与CO末端配体通过反应与各种胺，作为一个电子还原剂通过内层电子转移机制。用密度泛函理论计算了1a-d和4a-d的电子结构，并估算了氢化物中间体配合物2和3的结构.
Two linear tetradentate phosphine ligands,meso-Ph2PCH2P(Ph)CH2XCH2P(Ph)CH2PPh2(X= CH2(meso-dpmppp), NBn (meso-dpmppmNBn; Bn = benzyl)) were utilized to synthesize unsymmetrical dinuclear RhIcomplexes, [Rh2Cl2(meso-dpmppp)(L)] (L = XylNC (1a), CO (1b)) and [Rh2Cl2(meso-dpmppmNBn)(L)] (L = XylNC (1c), CO (1d)), where electron-deficient RhI→ RhIcenters with 30 valence electrons are supported by a tetraphosphine in an unusualcis-/trans-P,Pcoordination mode. The RhIdimers of1a–dwere treated with HCl under air to afford the RhI→ RhIIIdimers with 32 e–, [Rh2Cl4(meso-dpmppp)(L)] (L = XylNC (4a), CO (4b)) and [Rh2Cl4(meso-dpmppmNBn)(L)] (L = XylNC (4c), CO (4d)), via intermediate hydride complexes, [{RhCl2(μ-H)RhCl(L)}(meso-dpmppp)] (L = XylNC (2a), CO (2b)) and [{RhCl2(μ-H)RhCl(L)}(meso-dpmppmNBn)] (L = XylNC (2c), CO (2d)), and [{Rh(H)Cl2(μ-Cl)Rh(L)}(meso-dpmppp)] (L = XylNC (3a), CO (3b)) and [{Rh(H)Cl2(μ-Cl)Rh(L)}(meso-dpmppmNBn)] (L = XylNC (3c), CO (3d)). The hydride intermediates2and3were monitored under nitrogen by1H{31P} and31P{1H} NMR techniques to reveal two reaction pathways depending on the terminal auxiliary ligand L. Further, the reductive dechlorination converting RhIRhIII(4b,d) to RhI2(1b,d) was accomplished with a CO terminal ligand by reacting with various amines that acted as one-electron reducing agents through an inner-sphere electron transfer mechanism. DFT calculations were performed to elucidate the electronic structures of1a–dand4a–dand to estimate the structures of the hydride intermediate complexes2and3.