Ni(ii) complexes of the phosphine-oxime Ph₂PC₆H₄-2-CHNOH

Abstract

We report the solution and structural chemistry of nickel(ii) complexes of the phosphine-oxime Ph2PC6H4-2-CH[double bond, length as m-dash]NOH (PCH[double bond, length as m-dash]NOH). PCH[double bond, length as m-dash]NOH invariably binds in a bidentate manner as illustrated by cis-Ni(PCH[double bond, length as m-dash]NOH)2Cl2 and cis-[Ni(PCH[double bond, length as m-dash]NOH)2]2+ (as its BF4- salt). Treatment of PCH[double bond, length as m-dash]NOH with Ni(OAc)2(H2O)4 gave charge-neutral trans-[Ni(PCH[double bond, length as m-dash]NO)2]0. Treatment of trans-[Ni(PCH[double bond, length as m-dash]NO)2]0 with BF3 gave [Ni(PCH[double bond, length as m-dash]NO)2BF2]BF4. The cation features a planar NiP2N2 center wherein the pair of oximate groups are linked by the difluoroboryl center. The 1 : 1 complexes of the oxime and the oximate are illustrated by [Ni(PCH[double bond, length as m-dash]NOH)Cl2]2 and [Ni(C6F5)(PCH[double bond, length as m-dash]NO)]2, which feature five- and four-coordinate Ni(ii) centers, respectively. All complexes in this series hydrolyze to give the trinickel oxo-phosphine-oximate complex [Ni3(PCH[double bond, length as m-dash]NO)3O]+. One feature of the PCH[double bond, length as m-dash]NOH ligand is its wide bite angle combined with its protic OH center. These aspects are manifested in the structures of Ni(PCH[double bond, length as m-dash]NOH)2Cl2 and [Ni(PCH[double bond, length as m-dash]NOH)Cl2]2, which show intramolecular hydrogen bonding to terminal chloride ligands.

A rare example of the in situ formation of palladium nanoparticles: The emergence of catalytically active palladium nanoparticles from Pd (II) phosphine complexes in the Suzuki–Miyaura coupling reaction

“…[13][14][15] In contrast to other PN ligands, phosphino-benzaldoxime derivative ligands, where phosphines are substituted phenyl or cyclohexyl groups, are the most studied ones. [16] The phenyl substituted phosphine-oxime is the common ligand that is combined with various metals such as Pt, [17] Pd, [18] Ru, [19] and Ni [20] to form transition metal complexes. Only the palladium complex's catalytic activity on the catalytic rearrangement and dehydration of aldoximes has been studied among all of these complexes.…”

Ni(ii) and Co(ii) complexes for the selective adsorption of anionic dyes from aqueous solutions

“…The bond lengths of the Ni-N bonds of complex 1 ranged from 2.113(3) to 2.122(3) Å, which were similar to the bond lengths range of the Ni-N bonds (1.958(2) to 2.143(2) Å) reported in the literature. [33][34][35][36][37] The central metal Ni(II) was connected by the Hptim ligand along the b-axis to form an infinite onedimensional chain structure (Fig. 1c).…”