Synthesis, crystal structure and spectroscopic studies of a cobalt(III) Schiff base complex and its use as a heterogeneous catalyst for the oxidation reaction under mild condition
摘要:
A new Schiff base oriented Co(III) complex, (CoL)Cl center dot 4H(2)O (L = Schiff base), has been synthesized by careful design of the Schiff base ligand thorough oxidation of Co(II) to Co(III) during the reaction process. The complex has been characterized by single-crystal X-ray structure analysis and various spectral analyses. Structure analysis reveals that this monomeric complex crystallizes in triclinic P-1 space group. Supramolecular hydrogen bonding interactions among the guest water Molecules and counter anion chloride leads to the formation of 1D water-chloride chain. A polymer anchored heterogeneous cobalt complex has been synthesized, characterized by various physicochemical techniques and successfully used for the oxidation of alkenes and sulfides using H2O2 as oxygen source. The influence of the various reaction parameters has been studied. The heterogeneous cobalt complex can be reused seven times without any significant loss in its catalytic activity. (C) 2013 Elsevier B.V. All rights reserved.
The synthesis of iron(III) and cobalt (III) complexes of facultative hexadentate ligands. The X-ray crystal structure of [Fe{(NC4H3-2-CHNHH2CH2NHCH2)2}]PF6
作者:Anne S. Rothin、Hilary J. Banbery、Frank J. Berry、Thomas A. Hamor、Christopher J. Jones、Jon A. McCleverty
DOI:10.1016/s0277-5387(00)80747-0
日期:1989.1
2-hydroxybenzophenone or pyrrole-2-aldehyde, and from 3-methoxysalicylaldehyde with tris(2-aminoethyl)amine. Their ability to encapsulate cobalt(III) and iron(III) in complexes of 1 : 1 ligand—metal stoichiometry is reduced by the incorporation of sulphur donor atoms, or by the replacement of the terminal six-membered chelate rings of the salicylaldehyde derivatives by a five-membered ring in the pyrrole—aldehyde
Mono and bimetallic CoIII Schiff base complexes: Coordination induced ligand imidazolidine ring cleavage and stabilization
作者:Supriti Paul、Wing-Tak Wong、Debashis Ray
DOI:10.1016/j.ica.2011.03.058
日期:2011.6
2-(2'-Hydroxyphenyl) imidazoline ring grafted dinucleating diimine-diamine-tris-phenol ligand (H(3)aeas) has been obtained from a two-step reaction of 2-hydroxy acetophenone, N,N'-bis-(2-aminoethyl)ethylenediamine and 2-hydroxy benzaldehyde. Reaction of the ligand with Co(ClO4)(2)center dot 6H(2)O and NEt3 in MeOH-DCM solvent mixture yielded the monometallic complex [Co(aea)]ClO4 center dot H2O (1) of imidazolidine ring hydrolyzed hexadentate proligand H(2)aea. Any solvent derived MeO bridged Co-2 complex could not be obtained due to facile cobalt coordination assisted hydrolytic cleavage of substituted imidazolidine ring. When the reaction is carried out with Co(NO3)(2)center dot 4H(2)O and CoCl2 center dot 6H(2)O in presence of NH4NCS and NaN3 in MeOH-DCM and MeOH under aerobic conditions, preassembly of bimetallic [Co-2(mu-OMe)](5+) and [Co-2(mu-N-3)](5+) cores takes place on the solvent derived methoxido and azido clips through non-hydrolytic pathways in [(SCN)(2)Co-2(mu-OMe)(mu-aeas)]center dot DMF (2), and cocrystals of [(N-3)(2)Co-2(mu-OMe)(mu-aeas)] (3a) and [(N-3)(2)Co-2(mu-N-3)(mu-aeas)] (3b), respectively. Crown Copyright (C) 2011 Published by Elsevier B. V. All rights reserved.
A Novel μ<sub>4</sub>-Oxo Bridged Copper Tetrahedron Derived by Self-Assembly: First Example of Double Helical Bis(Tridentate) Coordination of a Hexadentate Amine Phenol Ligand
作者:Manindranath Bera、Wing Tak Wong、Guillem Aromi、Joan Ribas、Debashis Ray
DOI:10.1021/ic049817+
日期:2004.8.1
In methanol, the reaction of Cu(ClO4)(2).6H(2)O and the hexadentate amine phenol ligand (H(2)bahped) in the presence of triethylamine affords a tetranuclear copper(II) complex having, the formula [Cu-4(mu(4)-O)(bahped)(2)](ClO4)(2). The X-ray structure of this complex shows a tetrahedral central Cu-4(II)(mu(4)-O)} unit coordinated to two hexadentate bridging (via the central ethylenediamine part) ligands. The compound is the first example of a mu(4)-OXO tetranuclear copper(II) complex without any bridging ligand along the six tetrahedral edges. Variable-temperature magnetic data clearly show an S-t = 0 spin ground state for antiferromagnetic interactions between four B-2(2) copper(II) ions in a dimer of dimers.