1247050-73-2Relevant academic research and scientific papers
Steric crowding effect of 1,3-diketonates on the structures and the solution behaviors of nickel(II) mixed-ligand complexes
Arakawa-Itoh, MacHiko,Shibata, Masayo,Linert, Wolfgang,Fukuda, Yutaka
, p. 790 - 798 (2010)
Seven nickel(II) mixed-ligand complexes were synthesized: Ni(dike)(diam)X, where dike is a 1,3-diketonate such as 3,5-heptanedionate (dedk) or 2,6-dimethyl-3,5-heptanedionate (dmhd), diam is an N-alkylated ethylenediamine such as N,N,N′,N′-etramethylethylenediamine (tmen) or 1,2-dipiperidinoethane (dipe), and X is BPh4 - or NO 3 -. The crystal structures were analyzed: each nitrate complex has a six-coordinated octahedral structure with a bidentate-coordinated nitrate, and each tetraphenylborate complex has a four-coordinated square-planar structure. The ligand field strength of [Ni(dike)(diam)]BPh4 in the solid state increases in the order: [Ni(dmhd)(dipe)]BPh4 4 4 = [Ni(dedk)(tmen)]BPh4. In solution, the change of the color depending on the donor/acceptor ability of the solvent, i.e., solvatochromism was observed. When dimethyl sulfoxide was added to a solution of [Ni(dike)(diam)]BPh4 in inert 1,2-dichloroethane, the adduct formation constants are in the order: [Ni(dmhd)(dipe)]-BPh4 4 [Ni(dmhd)(tmen)]BPh4 = [Ni(dedk)(tmen)]BPh4, reflecting the difference in steric hindrance of the ligands rather than the difference in ligand field strength. The steric crowding effect of 1,3-diketonates was observed in the solid state and solution when bulky dipe is used as diamine.
