885665-84-9

Upstream product

• 110370-69-9 N²,N⁶-bis(diphenylphosphino)pyridine-2,6-diamine 
• 13462-88-9 nickel dibromide 

Relevant academic research and scientific papers

Electrocatalytic H2 Generation from Water Relying on Cooperative Ligand Electron Transfer in “PN3P” Pincer-Supported NiII Complexes

Water is the most sustainable source for H2 production, and the efficient electrocatalytic production of H2 from mixed water/acetonitrile solutions by using two new air-stable nickel(II) pincer complexes, [Ni(κ3-2,6-{Ph2PNR}2(NC5H3)Br2] (R=H I, Me II) is reported. Hydrogen generation from H2O/CH3CN solutions is initiated at ?2 V against Fc+/0, and bulk electrocatalysis studies showed that the catalyst functions with an excellent Faradaic efficiency and a turnover frequency of 160 s?1. A DFT computational investigation of the reduction behavior of I and II revealed a correlation of H2 formation with charge donation from electrons originating in a reduced ligand-localized orbital. As a result, these catalysts are proposed to proceed by a novel mechanism involving electron/proton transfer between a Ni0I species bonded to an anionic PN3P ligand (“L?/Ni0I”) and a NiI-hydride (“Ni?H”). Furthermore, these catalysts are able to reduce phenol and acetic acid, more active proton sources, at lower potentials that correlate with the substrate pKa.

Achiral and chiral transition metal complexes with modularly designed tridentate PNP pincer-type ligands based on N-heterocyclic diamines

The synthesis and characterization of a series of molybdenum, iron, ruthenium, nickel, palladium, and platinum complexes containing new achiral and chiral PNP pincer-type ligands based on the N-heterocyclic diamines 2,6-diaminopyridine, N,N′-di-10-undecenyl-2,6-diaminopyridine, N,N′-dihexyl-2,6-diaminopyridine, and 2,6-diamino-4-phenyl-1,3,5-triazine are reported. The new PNP ligands are prepared conveniently in high yield by treatment of the respective N-heterocyclic diamines with 2 equiv of a variety of achiral and chiral R2PCl compounds in the presence of base. Molybdenum PNP complexes of the type [Mo(PNP)(CO)3PNP] are obtained by treatment of [Mo(CO)3(CH3CN)3] with 1 equiv of the respective PNP ligand. They were found to react with I2 to give novel seven-coordinate pincer complexes of the types [Mo(PNP)(CO) 3I]+ and [Mo(PNP)(CO)2(CH3CN)I] + depending of whether the reaction is carried out in CH 2Cl2 or CH3CN. With [Fe(H2O) 6](BF4)2 and 1 equiv of PNP ligand in acetonitrile dicationic complexes of the type [Fe(PNP)(CH3CN) 3](BF4)2 are obtained. The cis and trans dichloride complexes [Ru(PNP)(PPh3)Cl2] are prepared by a ligand exchange reaction of [RuCl2(PPh3)3] with a stoichiometric amount of the respective PNP ligand. Cationic PNP complexes of Ni(II), [Ni(PNP)Br]Br, were synthesized by the reaction of [NiBr2(DME)] with 1 equiv of PNP ligand. In similar fashion, treatment of [M(COD)X2] (M = Pd, Pt; X = C1, Br) with 1 equiv of PNP ligand yields the cationic square-planar complexes [M(PNP)X]X. If the reaction is carried out in the presence of the halide scavenger KCF3SO 3, complexes of the type [M(PNP)X]CF3SO3 are obtained, which are better soluble in nonpolar solvents than the analogous halide compounds. X-ray structures of representative Mo, Fe, Ru, Ni, and Pd PNP complexes have been determined. Finally, the use of the palladium complexes as catalysts for the Suzuki - Miyaura coupling of some aryl bromides and phenyl boronic acid has been examined.