Nitrogen reduction and functionalization by a multimetallic uranium nitride complex was written by Falcone, Marta;Chatelain, Lucile;Scopelliti, Rosario;Zivkovic, Ivica;Mazzanti, Marinella. And the article was included in Nature (London, United Kingdom) in 2017.Category: pyridine-derivatives This article mentions the following:
Mol. nitrogen (N2) is cheap and widely available, but its unreactive nature is a challenge when attempting to functionalize it under mild conditions with other widely available substrates (such as carbon monoxide, CO) to produce value-added compounds Biol. N2 fixation can do this, but the industrial Haber-Bosch process for ammonia production operates under harsh conditions (450 °C and 300 bar), even though both processes are thought to involve multimetallic catalytic sites. And although mol. complexes capable of binding and even reducing N2 under mild conditions are known, with co-operativity between metal centers considered crucial for the N2 reduction step, the multimetallic species involved are usually not well defined, and further transformation of N2-binding complexes to achieve N-H or N-C bond formation is rare. Haber noted, before an iron-based catalyst was adopted for the industrial Haber-Bosch process, that uranium and uranium nitride materials are very effective heterogeneous catalysts for ammonia production from N2. However, few examples of uranium complexes binding N2 are known, and soluble uranium complexes capable of transforming N2 into ammonia or organonitrogen compounds have not yet been identified. Here we report the four-electron reduction of N2 under ambient conditions by a fully characterized complex with two U(III) ions and three K+ centers held together by a nitride group and a flexible metalloligand framework. The addition of H2 and/or protons, or CO to the resulting N2(4-) complex results in the complete cleavage of N2 with concomitant N2 functionalization through N-H or N-C bond-forming reactions. These observations establish that a mol. uranium complex can promote the stoichiometric transformation of N2 into NH3 or cyanate, and that a flexible, electron-rich, multimetallic, nitride-bridged core unit is a promising starting point for the design of mol. complexes capable of cleaving and functionalizing N2 under mild conditions. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Category: pyridine-derivatives).
Pyridinehydrochloride (cas: 628-13-7) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Category: pyridine-derivatives