title: Aroylhydrazone Cu(II) Complexes in keto Form: Structural Characterization and Catalytic Activity towards Cyclohexane Oxidation.
abstract: The reaction of the Schiff base (3,5-di-tert-butyl-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H3L) with a copper(II) salt of a base of a strong acid, i.e., nitrate, chloride or sulphate, yielded the mononuclear complexes [Cu(H2L)(NO3)(H2O)] (1), [Cu(H2L)Cl]·2MeOH (2) and the binuclear complex [{Cu(H2L)}2(µ-SO4)]·2MeOH (3), respectively, with H2L(-) in the keto form. Compounds 1-3 were characterized by elemental analysis, Infrared (IR) spectroscopy, Electrospray Ionisation Mass Spectrometry (ESI-MS) and single crystal X-ray crystallography. All compounds act as efficient catalysts towards the peroxidative oxidation of cyclohexane to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone, under mild conditions. In the presence of an acid promoter, overall yields (based on the alkane) up to 25% and a turnover number (TON) of 250 (TOF of 42 h(-1)) after 6 h, were achieved.
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. manaschem@yahoo.co.in.
authors.forename: Manas
authors.initials: M
authors.lastname: Sutradhar
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. ebastos@deq.isel.ipl.pt.|Chemical Engineering Department, Instituto Superior de Engenharia da Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal. ebastos@deq.isel.ipl.pt.
authors.forename: Elisabete C B A
authors.initials: EC
authors.lastname: Alegria
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. fatima.guedes@tecnico.ulisboa.pt.
authors.forename: M Fátima C
authors.initials: MF
authors.lastname: Guedes da Silva
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. lmartins@deq.isel.ipl.pt.|Chemical Engineering Department, Instituto Superior de Engenharia da Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal. lmartins@deq.isel.ipl.pt.
authors.forename: Luísa M D R S
authors.initials: LM
authors.lastname: Martins
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. pombeiro@tecnico.ulisboa.pt.
authors.forename: Armando J L
authors.initials: AJ
authors.lastname: Pombeiro
mesh_terms: D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D003510:Cyclohexanes / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*; D015394:Molecular Structure; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D003510:Cyclohexanes; D006835:Hydrazones; D012545:Schiff Bases; C506365:Cyclohexane; D003300:Copper
keywords: Cu(II) complex; O,N,O ligands; X-ray structure; cyclohexane oxidation