Rational Synthesis of Dynamic Complexes of Mezzoscopic-size

1.硫醇盐/硫醚杂化配体对铁和镍离子的合理组装硫醇盐-硫在过渡金属原子上有很强的配位作用，而硫醚型硫形成弱的M-S键，通常表现出容易的缔合/解离平衡。我们利用硫醇盐/硫醚杂化配体RSCH_2CH_2S（-）（R=Et（etet），R= iPr（ptet），R=Ph（ptet））组装了铁（II）和镍（II）金属离子。例如，NiCl_2与2当量Li（etet）反应生成线型聚合物[Ni（etet）_2]n，而类似的1：2 NiCl_2/Li（ptet）反应生成环状六核[Ni_6（ptet）_<12>]。在这些中等大小的簇/聚合物中，硫醇盐-硫原子桥接Ni中心，使硫醚硫不配位。当1：用1当量的NiCl_2处理NaSCH_2CH_2SR（R=Me（mtet），R=Et（etet），或R=^iPr（^iptet））和NaS^tBu的混合物，生成了不寻常的环状十核簇合物[Ni（SCH_2CH_2SR）（S^tBu）]<10>。 关于我们 苯/THF分子被并入环的空腔中，其中R=Et，iPr.2。铁硫团簇模拟固氮酶活性中心的研究：通过Fe{N（SiMe_3）_2}_2、四甲基硫脲（tmtu）、2，4，6-三异丙基苯乙撑（HS-tip）和单质硫以8（Fe）：3（tmtu）：12（HS-tip）：1的比例反应，自组装出了还原态P-团簇（P^N）的[8 Fe-7S]无机核心结构。7（S）。由此得到的配合物RN（SiMe_3）_2}（tmtu）Fe_4S_3]_2（μ_6-S）{μ-N（SiMe_3）}_2（1）由6个Fe（II）+2个Fe（III）氧化态的铁组成，而PN由8个Fe（II）离子组成。我们还从Fe{N（SiMe_3）_2}_2、HSDmp、HSTip和元素硫的反应中分离出了另一种类型的[8 Fe-7S]簇合物：RSDmp）Fe_4S_（312）（μ_6-S）（μ-SDmP）_2（μ-STip）}（2）（主要）和[（STip）Fe_4S_3]_2（μ_6-S）（μ-SDmP）_2{μ-N（SiMe_3）}（3）（次要（8：6：10：7），它们在拓扑上类似于FeMo-co，并且具有有趣的5 Fe（II）+3Fe（III）氧化态和双重基态。簇合物2也由二铁配合物[Fe（Stip）]_2（μ-SDmp）_2与Sg. 3反应生成，产率为34%。模拟[Ni-Fe]氢化酶活性中心的双核Fe-Ni配合物：由FeBr_2（CO）_4、NaS^tBu和NiBr_2（EtOH）_4在40℃反应得到的一个四核Fe_2Ni_2配合物[（CO）_3Fe（μ-S^tBu）_3NiBr]_2，是一系列双核Fe（CO）_3-Ni配合物的方便入口。它们包括（CO）_3Fe（μ-S^tBu）_3NiBr（S=C（NMe_2）_2）、[（CO）_3Fe（S^tBu）（R-S^tBu）_2Ni{S_2（C_6H_4）}]、（CO）_3Fe（S^tBu）（R-S^tBu）_2Ni{S（CH_2）_2SMe}、（CO）_3Fe（μ-S^Bu）_3Ni（MeOH）（CO）_3Fe（S^tBu）（μ-S^tBu）_2Ni（ortho-OC_6H_4SMe）（5）、（CO）_3Fe（μ-S`tBu）_3Ni（THF）（OAc）、（CO）_3Fe（μ-S` tBu）_3Ni（SDmp）和（CO）_3Fe（S`tBu）（μ-S`tBu）_2Ni（SDmp）（CO）。此外，我们还从（PPh_4）[Fe（CO）_2（CN）_2（pdt）K]（6）与（PPh_3）NiBr（S_2CNR_2）的反应中分离到了（PPh_4）[（CO）_2（CN）_2Fe（μ-pdt）Ni（S_2CNR_2）（7），这是迄今为止报道的最佳[NiFe]氢化酶结构模型。少

1. Rational Assemblage of Iron and Nickel Ions by Thiolate/thioether Hybrid Ligands Thiolate-sulfurs are coordinated at transition metal atoms strongly, while thioether-type sulfurs form weak M-S bonds, often exhibiting a facile association/dissociation equilibration. We have utilized the thiolate/thioether hybrid ligands RSCH_2CH_2S(-) (R=Et (etet), R=^iPr (ptet), R=Ph (ptet)) to assemble iron(II) and Ni(II) metal ions. For instance, the reaction of NiCl_2 with 2 equiv of Li(etet) produced a linear polymer [Ni(etet)_2]n, while the analogous 1 : 2 NiCl_/Li(ptet) reaction resulted in formation of a cyclic hexa-nuclear [Ni_6(ptet)_<12>]. In these mezzozcopic-size clusters/polymers, thiolate-sulfur atoms bridge Ni centers, leaving thioether sufurs uncoordinated. When the 1 : 1 mixture of NaSCH_2CH_2SR (R=Me (mtet), R=Et (etet), or R=^iPr (^iptet)) and NaS^tBu was treated with 1 equiv of NiCl_2, unusual cyclic deca-nuclear clusters [Ni(SCH_2CH_2SR)(S^tBu)_<10> were formed, where a solvent … More benzene/THF molecule was incorporated in the cavity of the ring for R=Et, ^iPr.2. Toward Better Iron-Sulfur Clusters Modeling the Nitrogenase Active Sites : The unusual [8Fe-7S] inorganic core structure of the reduced form of P-cluster (P^N) was self-assembled by the reaction of Fe{N(SiMe_3)_2}_2, tetramethylthiourea (tmtu), 2, 4, 6-triiso-propylbenzenethiol(HS-tip), and elemental sulfur in the ratio of 8(Fe) : 3(tmtu) : 12(HS-tip) : 7(S). The complex RN(SiMe_3)_2}(tmtu)Fe_4S_3]_2(μ_6-S){μ-N(SiMe_3)}_2 (1), obtained therefrom, consists of irons with a 6Fe(II)+2Fe(III) oxidation state, while PN consists of 8 Fe(II) ions. We have also isolated yet another type of [8Fe-7S] clusters, RSDmp)Fe4S312(μ_6-S)(μ-SDmP)_2 (μ-STip)} (2) (major) and [(STip)Fe_4S_3]_2(μ_6-S)(μ-SDmP)_2{μ-N(SiMe3)} (3) (minor), from the reaction of Fe{N(SiMe_3)_2}_2, HSDmp, HSTip, and elemental sulfur (8 : 6 : 10 : 7), which are topologically analogous to FeMo-co and have an intriguing 5Fe(II)+3Fe(III) oxidation state with a doublet ground state. Cluster 2 was also generated in 34% yield from the reaction of the di-iron complex [Fe(Stip)]_2(μ-SDmp)_2 with Sg.3. Dinuclear Fe-Ni complexes modelling the active site of [Ni-Fe] Hydrogenase : A tetranuclear Fe2Ni_2 complex, [(CO)_3Fe(μ-S^tBu)_3NiBr]_2, obtained from the reaction of FeBr_2(CO)_4, NaS^tBu, and NiBr_2(EtOH)_4 at 40℃, was found to serve as a convenient entry into a series of dinuclear Fe(CO)_3-Ni complexes. They include (CO)_3Fe(μ-S^tBu)_3NiBr(S=C(NMe_2)_2), [(CO)_3Fe(S^tBu)(R-S^tBu)_2Ni{S_2(C_6H_4)}], (CO)_3Fe(S^tBu) (R-S^tBu)_2Ni{S(CH_2)_2SMe}, (CO)_3Fe(μ-S^Bu)_3Ni(MeOH)(ortho-OC6_H4_SMe) (4), (CO)_3Fe(S^TBu)(μ-S^tBu)_2Ni (ortho-OC_6H_4SMe) (5), (CO)_3Fe(μ-S`tBu)_3Ni(THF)(OAc), (CO)_3Fe(μ-S`tBu)_3Ni(SDmp), and (CO)_3Fe (S`tBu)(μ-S`tBu)_2Ni(SDmp)(CO). Furthermore, we isolated (PPh_4)[(CO)_2(CN)_2Fe(μ-pdt)Ni(S_2CNR_2) (7) from the reaction of (PPh_4)[Fe(CO)_2(CN)_2(pdt)K] (6) with (PPh_3)NiBr(S_2CNR_2), which is the best structural model of [NiFe] hydrogenase reported so far. Less