Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
Dalton Trans. 2023 Mar 21;52(12):3755-3768. doi: 10.1039/d3dt00039g.
To develop the structural and functional modeling chemistry of [NiFe]-Hases, a series of new biomimetics for the active site of [NiFe]-Hases have been prepared by various synthetic methods. Treatment of the mononuclear Ni complex (pnp)NiCl (pnp = (PhPCH)NPh) with (dppv)Fe(CO)(pdt) (dppv = 1,2-(PhP)CH, pdt = 1,3-propanedithiolate) and KPF gave the dicarbonyl complex (pnp)Ni(pdt)Fe(CO)(dppv) (1). Further treatment of 1 and (dppe)Ni(pdt)Fe(CO)(dppv) (dppe = 1,2-(PhP)CH) with the decarbonylation agent MeNO and pyridine afforded the novel sp C-Fe bond-containing complexes [(pnp)Ni(SCHCHCHS)Fe(CO)(dppv)]PF ([2]PF) and [(dppe)Ni(SCHCHCHS)Fe(CO)(dppv)]BF ([3]BF). More interestingly, the first -carboxylato complexes [(pnp)Ni(pdt)Fe(CO)(-OCR)(dppv)]PF ([4]PF, R = H; [5]PF, R = Me; [6]PF, R = Ph) could be prepared by reactions of [1]PF with the corresponding carboxylic acids RCOH in the presence of MeNO, whereas further reactions of [4]PF-[6]PF with aqueous HPF and 1.5 MPa H gave rise to the μ-hydride complex [(pnp)Ni(pdt)Fe(CO)(μ-H)(dppv)]PF ([7]PF). Except for H activation by -carboxylato complexes [4]PF-[6]PF to give a μ-hydride complex ([7]PF), the sp C-Fe bond-containing complex [2]PF was found to be a catalyst for proton reduction to H under CV conditions. Furthermore, the chemical reactivity of the μ-hydride complex [7]PF displayed in the e transfer reaction with FcPF in the presence of CO, the H evolution reaction with the protonic acid HCl, and the H transfer reaction with -methylacridinium hexafluorophosphate ([NMA]PF) was systematically studied. As a result, a series of the expected products such as H, ferrocene, the dicarbonyl complex 1, the μ-chloro complex [(pnp)Ni(pdt)Fe(CO)(μ-Cl)(dppv)]PF ([8]PF), the -MeCN-coordinated complex (pnp)Ni(pdt)Fe(CO)(-MeCN)(dppv) (9) and the H transfer product AcrH were produced. While all the newly prepared model complexes were structurally characterized by spectroscopic methods, the molecular structures of some of their representatives were confirmed by X-ray crystallography.
为了发展[NiFe]-氢化酶的结构和功能建模化学，通过各种合成方法制备了一系列新型生物模拟物作为[NiFe]-氢化酶的活性位点。用(dppv)Fe(CO)(pdt)(dppv=1,2-(PhP)CH，pdt=1,3-丙二硫醇)和 KPF 处理单核 Ni 配合物(pnp)NiCl(pnp=(PhPCH)NPh)，得到二羰基配合物(pnp)Ni(pdt)Fe(CO)(dppv) (1)。进一步用脱羰试剂 MeNO 和吡啶处理1和(dppe)Ni(pdt)Fe(CO)(dppv)(dppe=1,2-(PhP)CH)，得到了新型含 spC-Fe 键的配合物[(pnp)Ni(SCHCHCHS)Fe(CO)(dppv)]PF([2]PF)和[(dppe)Ni(SCHCHCHS)Fe(CO)(dppv)]BF([3]BF)。更有趣的是，[1]PF 与相应的羧酸 RCOOH 在 MeNO 的存在下反应，可以制备得到第一个 -羧酸盐配合物[(pnp)Ni(pdt)Fe(CO)(-OCR)(dppv)]PF([4]PF，R=H；[5]PF，R=Me；[6]PF，R=Ph)，而进一步用 HPF 和 1.5 MPa H 处理[4]PF-[6]PF，得到μ-氢化物配合物[(pnp)Ni(pdt)Fe(CO)(μ-H)(dppv)]PF([7]PF)。除了 -羧酸盐配合物[4]PF-[6]PF 通过 H 激活生成μ-氢化物配合物([7]PF)外，还发现含 spC-Fe 键的配合物[2]PF 在 CV 条件下是质子还原为 H 的催化剂。此外，系统研究了μ-氢化物配合物[7]PF 在 CO 存在下与 FcPF 的电子转移反应、与质子酸 HCl 的析氢反应以及与 -甲基吖啶鎓六氟磷酸盐([NMA]PF)的 H 转移反应的化学活性。结果，产生了一系列预期产物，如 H、二茂铁、二羰基配合物1、μ-氯配合物[(pnp)Ni(pdt)Fe(CO)(μ-Cl)(dppv)]PF([8]PF)、-MeCN 配位配合物(pnp)Ni(pdt)Fe(CO)(-MeCN)(dppv) (9)和 H 转移产物 AcrH。虽然所有新制备的模型配合物都通过光谱方法进行了结构表征，但其中一些代表物的分子结构通过 X 射线晶体学得到了证实。
