pyrrole‐based PNP‐type pincer and aryloxy ligands were found to work as effective catalysts for the direct conversion of molecular dinitrogen into ammonia and hydrazine under mild reaction conditions. This is the first successful example of vanadium‐catalyzed dinitrogenreduction under mild reaction conditions.
Pyrrolyl-based pincer complexes of iron – Synthesis and electronic structure
作者:Nico Ehrlich、Dirk Baabe、Matthias Freytag、Peter G. Jones、Marc D. Walter
DOI:10.1016/j.poly.2017.08.024
日期:2018.3
[(tBuPNP)FeN(SiMe3)2] (4), featuring an Fe(II) high-spin state with large negative axial zero-field splitting and slow paramagnetic relaxation at low temperature, as evidenced by measurements of the solid-state magnetic susceptibility and zero-field 57Fe Mossbauer spectroscopy. Replacing the chlorido ligand in [(tBuPNP)FeCl] (3) by the bidentate acetylacetonato (acac) ligand enforces a trigonal–bipyramidal structure
We have newly prepared and characterized a series of the azaferrocene-based PNP-type pincer ligands and the corresponding molybdenum, chromium, and iron complexes. The stoichiometric and catalytic reactivity of molybdenum-dinitrogen complexes toward nitrogen fixation has been investigated in details.
Manganese Chemistry of Anionic Pyrrole-Based Pincer Ligands
作者:Ana L. Narro、Hadi D. Arman、Zachary J. Tonzetich
DOI:10.1021/acs.organomet.9b00058
日期:2019.4.22
The chemistry of the pyrrole-based pincer ligands, RPNP (PNP = anion of 2,5-bis(dialkylphosphinomethyl)pyrrole, R = Cy and t-Bu), with manganese is reported. Metallation of tBuPNP with Mn(II) halide precursors did not afford 1:1 ligand to metal complexes but rather led to the formation of the 2:1 complex, [Mn(κ2-N,P-tBuPNP)2]. Reduction of in situ generated tBuPNP-Mn(II) in the presence of 2,2′-bipyridine
报道了基于吡咯的钳形配体R PNP(PNP = 2,5-双(二烷基膦基甲基)吡咯的阴离子,R = Cy和t- Bu)与锰的化学反应。的金属化吨卜PNP与锰(II)卤化物前体没有得到1:1的配体与金属配合物,而是导致的2的形成:1络合物,[锰(κ 2 - N,P -吨卜PNP)2 ]。在2,2'-联吡啶存在下原位生成的t Bu PNP-Mn(II)的还原生成明显的高自旋Mn(I)络合物[Mn(bipy)(t Bu(PNP)],尽管从晶体学得出的度量参数表明该化合物最好被认为包含带有Bipy自由基阴离子的Mn(II)离子。Mn(I)前体[MnBr(CO)5 ]与R PNP的反应提供了[Mn(CO)n(R PNP)]类型的低旋转Mn(I)络合物(R = Cy,n = 3; R =t- Bu,n= 2)。第三当量的CO可逆地与[Mn(CO)2(t Bu PNP)]结合,但很容易丢失。用1,4-苯醌对[Mn(CO)n(R
Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands
The direct formation of ammoniafrommoleculardinitrogen under mild reaction conditions was achieved by using new cobalt dinitrogencomplexes bearing an anionic PNP‐type pincer ligand. Up to 15.9 equivalents of ammonia were produced based on the amount of catalyst together with 1.0 equivalent of hydrazine (17.9 equiv of fixed nitrogen atoms).