New boronates prepared from 2,4-pentanedione derived ligands of the NO2 and N2O2 type – comparison to the complexes obtained from the corresponding salicylaldehyde derivatives
heterocycle had been reported, it becomes apparent that there may be differences in reactivity when comparing 2,4-pentanedione and salicylaldehydederived ligands. The molecular compositions of the boron complexes prepared from acacenH2 and acacpenH2 are analogous to the corresponding salen and salpen derivatives, however, the presence of two methyl groups in the six-membered chelate rings generates some structural
B2O3/Al2O3 as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions
Boron oxide adsorbed on alumina (B2O3/Al2O3 ) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of β-enaminoketones and esters by the enamination of various primary and secondary amines with β-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts
Influence of fluorine substitution on the properties of metal chelate compounds—II copper(II) chelates of tetradentate ligands
作者:A.E. Martell、R. Linn Belford、M. Calvin
DOI:10.1016/0022-1902(58)80127-x
日期:1958.1
The ultra-violet visible, and infra-redabsorption spectra of four Schiff bases derived from β-diketones and their copper(II) chelates are described and discussed in relation to the structure of these molecules. Infra-red assignments are made where possible. The influence of fluorine substitution and ring size on the ultra-violet and visible spectra of the chelate compounds is discussed, and interrelationships
作者:Steven A. Schuetz、Mitzy A. Erdmann、Victor W. Day、Joanna L. Clark、John A. Belot
DOI:10.1016/j.ica.2004.08.005
日期:2004.11
This contribution describes the synthesis and complete characterization of dinuclear (Ln(2)(SB)(3)) and rigorously dimeric ([(SB)Ln(N(TMS)(2))](2)) lanthanide complexes bearing "saturated" tetradentate Schiff bases (SB). The molecular connectivities, nuclearity, and metal ion coordination geometries in these compounds are governed by the interplay of Schiff-base steric requirements, metal ion radius, and reaction conditions (i.e., solvent choice, concentration, and temperature); the impact of these factors will be discussed and emphasized in the context of structural similarities and notable intramolecular interactions within these related compounds. Also presented is a tetranulear Nd3+ complex exhibiting a ladder arrangement of metal ions and mu-oxo bridges; its formation occurs by the destruction of THF at elevated temperatures. All the compounds presented can be reproducibly synthesized in high yields and analytical purity. (C) 2004 Elsevier B.V. All rights reserved.
Syntheses and characterization of copper(II) complexes of bis(acetylacetone)trimethylenediimine
作者:Yue-Peng Cai、Cheng-Yong Su*、An-wu Xu、Bei-Sheng Kang、Ye-Xiang Tong、Han-Qin Liu、Sun Jie
DOI:10.1016/s0277-5387(01)00721-5
日期:2001.4
Copper(II) complexes [Cu(acactn)H2O](2) (1) and [Cu-2(acactn)(2)KClO4](2) (2), where H(2)acactn is a tetradentate Schiff base bis(acetylacetone)trimethylenediimine, have been prepared and characterized by IR, CV and X-ray single crystal structure analyses. The ligand H(2)acactn is strongly metallophilic to stabilize Cu(II) ion with a square planar N2O2 coordination environment. Complex 1 can be seen as a hydrogen-bonded dimer of building block Cu(acactn) via bridging water molecules, while complex 2 is a tetrametric adduct of [Cu(acactn)] moiety and KClO4, in which K+ and ClO4- are the bridging-groups. Electrochemical studies displayed that Cu(II)/Cu(I) is an irreversible one-electron reduction process. (C) 2001 Elsevier Science B.V. All rights reserved.