Y Trinuclear Cu-II structural isomers coordination, magnetism, electrochemistry and catalytic activity towards the oxidation of alkanes


Autoria(s): Sutradhar, Manas; Martins, Luísa Margarida D. R. S.; Silva, Maria de Fátima C. Guedes da; Mahmudov, Kamran T.; Liu, Cai-Ming; Pombeiro, Armando J. L.
Data(s)

14/03/2016

14/03/2016

01/08/2015

Resumo

The reaction of the Schiff base (3,5-di-tert-butyl-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H3L) with copper(II) nitrate, acetate or metaborate has led to the isomeric complexes [Cu-3(L)(2)(MeOH)(4)] (1), [Cu-3(L)(2)(MeOH)(2)]2MeOH (2) and [Cu-3(L)(2)(MeOH)(4)] (3), respectively, in which the ligand L exhibits dianionic (HL2-, in 1) or trianionic (L3-, in 2 and 3) pentadentate 1O,O,N:2N,O chelation modes. Complexes 1-3 were characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography, electrochemical methods and variable-temperature magnetic susceptibility measurements, which indicated that the intratrimer antiferromagnetic coupling is strong in the three complexes and that there exists very weak ferromagnetic intermolecular interactions in 1 but weak antiferromagnetic intermolecular interactions in both 2 and 3. Electrochemical experiments showed that in complexes 1-3 the Cu-II ions can be reduced, in distinct steps, to Cu-I and Cu-0. All the complexes act as efficient catalyst precursors under mild conditions for the peroxidative oxidation of cyclohexane to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone, leading to overall yields (based on the alkane) of up to 31% (TON = 1.55x10(3)) after 6 h in the presence of pyrazinecarboxylic acid.

Identificador

SUTRADHAR, Manas; [et al.] - Y Trinuclear Cu-II structural isomers coordination, magnetism, electrochemistry and catalytic activity towards the oxidation of alkanes. European journal of inorganic chemistry. ISSN. 1434-1948. Vol. 2015, Nr. 23, (2015), 3959-3969

1434-1948

1099-0682

http://hdl.handle.net/10400.21/5857

10.1002/ejic.201500440

Idioma(s)

eng

Publicador

Wiley-V C H Verlag GMBH

Relação

http://onlinelibrary.wiley.com/doi/10.1002/ejic.201500440/abstract

Direitos

closedAccess

Palavras-Chave #N,O ligands #Copper #Magnetic properties #Electrochemistry #Oxidation
Tipo

article