Copper(II) solvatochromic complexes [Cu(acac)(N^N)(ligand)]BPh4 with various axial ligands. Correlation between coordination geometries and d–d transition energies (acac=acetylacetonato, N^N=1,10-phenanthoroline, 2,2′-bipyridyl)

Abstract

A series of copper(II) solvatochromic complexes [Cu(acac)(N^N)(ligand)]BPh 4 (acac = acetylacetonato; N^N = 1,10-phenanthoroline (1), 2,2-bipyridyl (2); ligand = HMPA, pyridine, DMSO, DMF, MeOH, acetone, and MeCN) have been synthesized and their coordination geometries were crystallographically investigated. The solvent-coordinated cations, adopting a five-coordinate square-pyramidal structure, formed head-to-tail dimers via π•••π interactions. Solid-state absorption studies revealed that their d-d transition energies are correlated with the donor number of the axial ligands. A linear correlation was found between the d-d transition

Naked-eye detection and thermochromic properties of Cu(ii)-3,3′-thiodipropionate complexes with benzimidazole

“…In the coordination complexes, color change of material can occur as a result of interaction of solvent and compound or changing of coordination geometry around the metal center 3,4,6 . Therefore, the studies with respect to determination of the reason of color change are important.…”

Solvatochromic CuII‐Containing Ionic Liquids with Ether Side Chains: Control of Solvent Response through Intramolecular Coordination

“…Considering the smaller DN of Tf 2 N -(DN Tf2N = 5.4 [13] ) compared with ether, it is reasonable that the Cu-O distance is longer than that in [1] In the formation of six-coordinate complexes from the fourcoordinate solvatochromic Cu II complexes by solvent addition, the first ligand coordinates more strongly to the metal center than the second. [12] This feature accounts for the different coordination modes in the salts in the present study. The side chain coordinates to the metal center in [1] The d-d transition energies of the salts in various solvents were determined from the UV/Vis spectra ( Figure S4), as summarized in Table 2.…”

“…This linear response is common in solvatochromic mixed-ligand complexes. [12] The deviation of acetonitrile and benzonitrile solutions from the linear trend is also observed in other solvatochromic complexes. [15] The deviation in CH 2 Cl 2 is due to the effect of anion coordination, as discussed later.…”

Metal acetylacetonate–amine and metal nitrate–amine complexes as low‐emission catalysts for rigid polyurethane foam preparation

“…There are reports on the X‐ray structures of copper complexes of the type [Cu(acac)(NN)X], where NN is an amine and X is an anion, for example, [Cu(acac)(phen)(NO 3 )]·H 2 O and [Cu(acac)(dmph)(NO 3 )], where acac = acetylacetonate, phen = 1,10‐phenanthroline, and dmph = 2,9‐dimethyl‐1,10‐phenanthroline . Copper atom in both complexes has an approximate square pyramidal coordination geometry with two nitrogen atoms (both from phen or dmph) and three oxygen atoms (two from acac and one from as counter ion).…”