Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| Synthesis, characterization and computational study of heterobimetallic CoFe complexes for mimicking hydrogenase | |
| Gao, Hui1; Huang, Jing1; Chen, Limin2; Liu, Ruliang1; Chen, Jinzhu1,3 | |
| 2013 | |
| Source Publication | RSC ADVANCES
 |
| Volume | 3Issue:11Pages:3557-3565 |
| Abstract | A mixture of [CpCo(CO)(2)] (Cp = cyclopentadienyl) and [Fe(pdt)(CO)(2)(dppe)] (pdt = S(CH2)(3)S; dppe = Ph2PCH2CH2PPh2) was stirred in refluxing toluene to give a heterobimetallic complex [CpCo(mu-pdt)Fe(CO)(dppe)] (2). The protonation of 2 with HBAr4F (bis-etherate of tetrakis[3,5-bis(trifiuoromethyl) phenyl] boric acid) in CD2Cl2 affords the mu-hydrido cation [CpCo(mu-pdt)(mu-H)Fe(CO)(dppe)](+) ([2 mu-H](+)) at room temperature. However, the low-temperature protonation reaction of 2 reveals a terminal hydride intermediate [Cp(H)Co(mu-pdt)Fe(CO)(dppe)](+) ([2H](+)), as confirmed by H-1 and P-31{H-1} NMR spectroscopy. The detailed process of the protonation of 2, including the relevant intermediate species, the structural and electronic properties of the bimetallic cofactors and the key factors responsible for protonation, has been revealed by a density functional theory (DFT) investigation from both a thermodynamics and kinetics perspective. Three pathways have been explored: path I has protonation at the terminal position on the Co taking place via a transition state TS1(ba-ba) (7.3 kcal mol(-1)) with the terminal hydride as the initial product [2H](+)(ba-ba) (1.2 kcal mol(-1)), which is the kinetic product, which then proceeds via an isomerization transition state TSiso (22.2 kcal mol(-1)) to form the bridging hydride [2 mu- H](+)(ba- ba) (-14.4 kcal mol(-1)); path II has protonation occurring on the Co- Fe bond via a transition state TS2(ba-ba) (21.8 kcal mol(-1)) directly producing the bridging hydride [2 mu- H](+)(ba-ba) with good thermodynamic stability; path III is another protonation process which proceeds via a transition state TS3(ba-ap) (18.1 kcal mol(-1)) to form a bridging hydride [2 mu-H](+)(ba-ap) (-7.9 kcal mol(-1)). Calculations indicate that the highest energy species of all the proposed pathways are close and have energies that are not difficult to overcome (lower than 22.2 kcal mol(-1)), which provides important insight into the process of the hindrance of the spontaneous isomerization of terminal species to produce to bridging species via the consideration of the electronic and steric factors for protonation regiochemistry. Agreement of the calculated and experimental data suggests that the proposed pathways are possible and the whole reaction is determined by the thermodynamic product [2 mu-H](+ba-ba) at room temperature. The work reported here has implications for the mechanistic interpretation of dinuclear metal-complex assisted protonation, which is helpful for the future design of new non-noble metal complexes for catalyzed hydrogen generation. |
| Subtype | Article |
| WOS Headings | Science & Technology ; Physical Sciences |
| DOI | 10.1039/c2ra22388k |
| WOS Subject Extended | Chemistry |
| WOS Keyword | FE-ONLY HYDROGENASES ; ACTIVE-SITE MODELS ; CRYSTAL-STRUCTURE ; H-2 ACTIVATION ; CATALYTIC MECHANISM ; COORDINATION SPHERE ; NIFE HYDROGENASES ; PROTON REDUCTION ; TERMINAL HYDRIDE ; MIXED-VALENT |
| Indexed By | SCI |
| Language | 英语 |
| WOS Subject | Chemistry, Multidisciplinary |
| WOS ID | WOS:000314973800015 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/10070 |
| Collection | 中国科学院广州能源研究所 |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Energy Convers, Key Lab Renewable Energy & Nat Gas Hydrate, Guangzhou 510640, Guangdong, Peoples R China 2.S China Univ Technol, Coll Environm Sci & Engn, Guangzhou 510006, Guangdong, Peoples R China 3.Nankai Univ, State Key Lab Elementoorgan Chem, Tianjin 300071, Peoples R China |
| Recommended Citation GB/T 7714 | Gao, Hui,Huang, Jing,Chen, Limin,et al. Synthesis, characterization and computational study of heterobimetallic CoFe complexes for mimicking hydrogenase[J]. RSC ADVANCES,2013,3(11):3557-3565. |
| APA | Gao, Hui,Huang, Jing,Chen, Limin,Liu, Ruliang,&Chen, Jinzhu.(2013).Synthesis, characterization and computational study of heterobimetallic CoFe complexes for mimicking hydrogenase.RSC ADVANCES,3(11),3557-3565. |
| MLA | Gao, Hui,et al."Synthesis, characterization and computational study of heterobimetallic CoFe complexes for mimicking hydrogenase".RSC ADVANCES 3.11(2013):3557-3565. |
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