Impact of Thiocyanate on the Catecholase Activity of Cu(II) and Fe(III) Complexes of 2-((4-(2-Hydroxy-4-Methylbenzyl)Piperazin-1-YL)Methyl)-5-Methylphenol (A Mannich Base)

Abstract Four metal complexes viz Cu(II) and Fe(III) with or without thiocyanate have been synthesized from a Mannich base prepared by a simple synthetic route. These complexes were characterized by elemental and spectroscopic techniques. Bonding modes of the thiocyanate group with the metal complexes as studied by infrared spectroscopy revealed the presence of bridging N- and S- bonding modes. Detailed kinetic studies of these complexes were carried in the evaluation of their catecholase activity. The Fe(III) complex demonstrated the highest catalytic activity using 3,5-di-tert-butyl catechol (3,5-DTBC) as substrate with a turnover rate (kcat) of 112.32 h−1.

[1]  D. Das,et al.  Catecholase activity of Mannich-based dinuclear CuII complexes with theoretical modeling: new insight into the solvent role in the catalytic cycle , 2016 .

[2]  A. Salifoglou,et al.  Schiff base coordination flexibility toward binary cobalt and ternary zinc complex assemblies. The case of the hexadentate ligand N,N′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine , 2015 .

[3]  G. Roman.  Mannich bases in medicinal chemistry and drug design , 2014, European Journal of Medicinal Chemistry.

[4]  A. Ayeni,et al.  Studies of some morpholino- and methylpiperazin-1-yl mannich ligands and their Cu(II) and Ni(II) complexes , 2015 .

[5]  A. Panja.  Syntheses and structural characterizations of cobalt(II) complexes with N4-donor Schiff base ligands: Influence of methyl substitution on structural parameters and on phenoxazinone synthase activity , 2014 .

[6]  N. Dalal,et al.  Di-, tri-, and tetranuclear nickel(II) complexes with oximato bridges: magnetism and catecholase-like activity of two tetranuclear complexes possessing rhombic topology. , 2013, Inorganic chemistry.

[7]  I. Ali,et al.  Empirical Formulae to Molecular Structures of Metal Complexes by Molar Conductance , 2013 .

[8]  M. Drew,et al.  Insertion of a hydroxido bridge into a diphenoxido dinuclear copper(II) complex: drastic change of the magnetic property from strong antiferromagnetic to ferromagnetic and enhancement in the catecholase activity. , 2012, Inorganic chemistry.

[9]  N. Raman,et al.  DNA interaction studies of d9 and d10 metal complexes having Schiff base and polypyridyl ligands , 2012 .

[10]  M. Ibrahim,et al.  Synthesis, characterization, and ascorbic acid oxidase biomimetic catalytic activity of cobalt(III) oxime complexes , 2011 .

[11]  S. Anbu,et al.  Electrochemical, magnetic, catalytic, DNA binding and cleavage studies of new mono and binuclear copper(II) complexes , 2011 .

[12]  M. Drew,et al.  Synthesis, structure and magnetic properties of mono- and di-nuclear nickel(II) thiocyanate complexes with tridentate N3 donor Schiff bases , 2010 .

[13]  N. Aliaga-Alcalde,et al.  Synthesis, crystal structure, spectral and magnetic studies and catecholase activity of copper(II) complexes with di- and tri-podal ligands , 2010 .

[14]  R. Peralta,et al.  Catalytic Promiscuity: Catecholase-like Activity and Hydrolytic DNA Cleavage Promoted by a Mixed-Valence Fe III Fe II Complex , 2010 .

[15]  S. Tabassum,et al.  Synthesis of new piperazine derived Cu(II)/Zn(II) metal complexes, their DNA binding studies, electrochemistry and anti-microbial activity: validation for specific recognition of Zn(II) complex to DNA helix by interaction with thymine base. , 2009, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[16]  L. Jagadish,et al.  Synthesis of new unsymmetrical “end-off” phenoxo bridged copper(II), nickel(II) and zinc(II) complexes: spectral, magnetic, electrochemical, catalytic, and antimicrobial studies , 2009 .

[17]  M. J. Al-jeboori,et al.  Synthesis and structural studies of new Mannich base ligands and their metal complexes , 2008 .

[18]  C. Philouze,et al.  Catecholase activity of a μ-hydroxodicopper(II) macrocyclic complex: structures, intermediates and reaction mechanism , 2005, JBIC Journal of Biological Inorganic Chemistry.

[19]  J. Cary,et al.  Cloning and characterization of cDNAs coding for Vicia faba polyphenol oxidase , 1992, Plant Molecular Biology.

[20]  R. Mukherjee,et al.  Catecholase activity of dinuclear copper(II) complexes with variable endogenous and exogenous bridge , 2002 .

[21]  L. Rossi,et al.  Catecholase activity of a series of dicopper(II) complexes with variable Cu-OH(phenol) moieties. , 2002, Inorganic chemistry.

[22]  C. Philouze,et al.  Dicopper(II) complexes of H-BPMP-type ligands: pH-induced changes of redox, spectroscopic ((19)F NMR studies of fluorinated complexes), structural properties, and catecholase activities. , 2002, Inorganic chemistry.

[23]  M. Ray,et al.  Highly Stabilized Low-Spin Iron(III) and Cobalt(III) Complexes of a Tridentate Bis-Amide Ligand 2,6-Bis(N-phenylcarbamoyl)pyridine. Novel Nonmacrocyclic Tetraamido-N Coordination and Two Unusually Short Metal-Pyridine Bonds. , 1997, Inorganic chemistry.

[24]  B. Brycki,et al.  Preparation and NMR characterisation of hydrogen bonding in 2- and 2,6-bis- (N,N-diethylaminomethyl) - 4R-phenols , 1991 .

[25]  J. Gaz̆o,et al.  Influence of methyl- and dimethylsubstituted pyridines as ligands on the structure and the electron transfer in thiocyanato-copper(II) complexes , 1976 .

[26]  B. J. Deverall.  Phenolase and Pectic Enzyme Activity in the Chocolate Spot Disease of Beans , 1961, Nature.