Synthesis, electronic structures, and reactivity of mononuclear and dinuclear low-valent molybdenum complexes in iminopyridine and bis(imino)pyridine ligand environments
Synthesis, electronic structures, and reactivity of mononuclear and dinuclear low-valent molybdenum complexes in iminopyridine and bis(imino)pyridine ligand environments
复制标题
亚氨基吡啶和双(亚氨基)吡啶配体环境中单核和双核低价钼配合物的合成、电子结构和反应性
DOI：
10.1016/j.jinorgbio.2022.111744
复制
发表时间：
2022
影响因子：
3.9
通讯作者：
Groysman, Stanislav
中科院分区：
文献类型：
--
作者：
Dissanayake, Asanka I.;Hollingsworth, Thilini S.;Kurup, Sudheer S.;Wannipurage, Duleeka;Hamilton, Patrick N.;Lord, Richard L.;Groysman, Stanislav
钼在氧化还原非无辜的配体环境中的特点突出的生物无机系统。虽然霍尔姆和同事，沿着许多其他研究人员，已经彻底研究了正式的高氧化态钼（Mo（IV）-Mo（VI））连接的二硫代烯烃，钼在其他正式的氧化态和/或不同的氧化还原活性配体环境所知甚少。本工作主要研究了低价钼在四种不同的氧化还原非无辜氮配体类型环境（单核和双核亚氨基吡啶，单核和双核双（亚氨基）吡啶）中的反应。亚氨基吡啶N-（2，6-二异丙基苯基）-1-（吡啶-2-基）甲亚胺（L1）与Mo（CO）3（NCMe）3反应生成Mo（L1）（CO）3（NCMe）。Mo（L1）（CO）3（NCMe）经CS2处理或在二氯甲烷中长时间搅拌后转化为Mo（L1）（CO）4。开链双核双（亚氨基吡啶）配体N，N′-（2，7-二叔丁基-9，9-二甲基-9H-氧杂蒽-4，5-二基）双（1-（吡啶-2-基）甲亚胺）（L2）的反应类似地产生六羰基络合物Mo 2（L2）（CO）6（NCMe）2，其也经历转化为八羰基Mo 2（L2）（CO）8。两种配合物的螯合单元都具有反平行的几何构型。Mo（L1）（CO）3（NCMe）与I2的氧化反应生成Mo（L1）（CO）3 I2。单核化的潜在三齿双亚氨基吡啶配体（L3）（N-均三甲苯基-1-（6-（（E）-（均三甲苯基亚氨基）甲基）吡啶-2-基）甲亚胺）与Mo（CO）3（NCMe）3和Mo（CO）4（NCMe）2反应生成配合物Mo（L3）（CO）3（NCMe）和Mo（L3）（CO）4。双核大环二（双（亚氨基）吡啶）类似物（L4）的反应导致Mo 2（L4）（CO）6（NCMe）2和Mo 2（L4）（CO）8配合物的相似化学性质。Mo（L3）（CO）3（NCMe）与I2反应生成单羰基配合物Mo（L3）（CO）I2，其中Mo被氧化，L3的配位模式转变为三齿配位。采用密度泛函理论计算方法研究了亚氨基吡啶和双亚氨基吡啶配体环境中Mo（0）配合物的电子结构.
Molybdenum in redox non-innocent ligand environments features prominently in biological inorganic systems. While Holm and coworkers, along with many other researchers, have thoroughly investigated formally high-oxidation-state molybdenum (Mo(IV)-Mo(VI)) ligated by dithiolenes, less is known about molybdenum in other formal oxidation states and/or different redox-active ligand environments. This work focuses on the investigation of low-valent molybdenum in four different redox non-innocent nitrogen ligand type environments (mononucleating and dinucleating iminopyridine, mononucleating and dinucleating bis(imino)pyridine). The reaction of iminopyridine N-(2,6-diisopropylphenyl)-1-(pyridin-2-yl)methanimine (L1) with Mo(CO)3(NCMe)3produced Mo(L1)(CO)3(NCMe). Mo(L1)(CO)3(NCMe) undergoes transformation to Mo(L1)(CO)4upon treatment with CS2or prolonged stirring in dichloromethane. The reaction of the open-chain dinucleating bis(iminopyridine) ligand N,N′-(2,7-di-tert-butyl-9,9-dimethyl-9H-xanthene-4,5-diyl)bis(1-(pyridin-2-yl)methanimine) (L2) similarly produced an hexacarbonyl complex Mo2(L2)(CO)6(NCMe)2which also underwent transformation to the octacarbonyl Mo2(L2)(CO)8. Both complexes featuredanti-parallel geometry of the chelating units. The oxidation of Mo(L1)(CO)3(NCMe) with I2resulted in Mo(L1)(CO)3I2. The reaction of mononucleating potentially tridentate bis(imino)pyridine ligand (L3) (N-mesityl-1-(6-((E)-(mesitylimino)methyl)pyridin-2-yl)methanimine) with both Mo(CO)3(NCMe)3and Mo(CO)4(NCMe)2produced complexes Mo(L3)(CO)3(NCMe) and Mo(L3)(CO)4in which L3was coordinated in a bidentate fashion, with one imino sidearm unbound. The reaction of dinucleating macrocyclic di(bis(imino)pyridine) analogue (L4) led to the similar chemistry of Mo2(L4)(CO)6(NCMe)2and Mo2(L4)(CO)8complexes. Treatment of Mo(L3)(CO)3(NCMe) with I2formed a mono(carbonyl) complex Mo(L3)(CO)I2in which molybdenum was formally oxidized and L3underwent coordination mode change to tridentate. The electronic structures of formally Mo(0) complexes in iminopyridine and bis(imino)pyridine ligand environments were investigated by density functional theory calculations.