Seven dinuclear and one dinuclear based dicyanamide bridged polymeric NiII complexes of phenol based compartmental ligands (HL1–HL4) have been synthesized with the aim to investigate their catecholaselike activity and to evaluate the most probable mechanistic pathway involved in this process. The complexes have been characterized by routine physicochemical studies as well as by X-ray single crystal structure analyses namely [Ni2(L2)(SCN)3(H2O)(CH3OH)] (1), [Ni2(L4)(SCN)3(CH3OH)2] (2), [Ni2(L2)(SCN)2(AcO)- (H2O)] (3), [Ni2(L4)(SCN)(AcO)2] (4), [Ni2(L2)(N3)3(H2O)2] (5), [Ni2(L4)(N3)3(H2O)2] (6), [Ni2(L1)(AcO)2- (N(CN)2)]n (7) and [Ni2(L3)(AcO)2(N(CN)2)] (8), [SCN = isothiocyanate, AcO = acetate, N3 = azide, and N(CN)2 = dicyanamide anion; L1–4 = 2,6-bis(R2-iminomethyl)-4-R1-phenolato, where R1 = methyl and tert-butyl, R2 = N,N-dimethyl ethylene for L1–2 and R1 = methyl and tert-butyl, R2 = 2-(N-ethyl) pyridine for L3–4]. A UV-vis spectrophotometric study using 3,5-di-tert butylcatechol (3,5-DTBC) reveals that all the complexes are highly active in catalyzing the aerobic oxidation of (3,5-DTBC) to 3,5-di-tert-butylbenzoquinone (3,5-DTBQ) in methanol medium with the formation of hydrogen peroxide.

A radical pathway in catecholase activity with nickel(ii) complexes of phenol based “end-off” compartmental ligands

ZANGRANDO, ENNIO;
2014-01-01

Abstract

Seven dinuclear and one dinuclear based dicyanamide bridged polymeric NiII complexes of phenol based compartmental ligands (HL1–HL4) have been synthesized with the aim to investigate their catecholaselike activity and to evaluate the most probable mechanistic pathway involved in this process. The complexes have been characterized by routine physicochemical studies as well as by X-ray single crystal structure analyses namely [Ni2(L2)(SCN)3(H2O)(CH3OH)] (1), [Ni2(L4)(SCN)3(CH3OH)2] (2), [Ni2(L2)(SCN)2(AcO)- (H2O)] (3), [Ni2(L4)(SCN)(AcO)2] (4), [Ni2(L2)(N3)3(H2O)2] (5), [Ni2(L4)(N3)3(H2O)2] (6), [Ni2(L1)(AcO)2- (N(CN)2)]n (7) and [Ni2(L3)(AcO)2(N(CN)2)] (8), [SCN = isothiocyanate, AcO = acetate, N3 = azide, and N(CN)2 = dicyanamide anion; L1–4 = 2,6-bis(R2-iminomethyl)-4-R1-phenolato, where R1 = methyl and tert-butyl, R2 = N,N-dimethyl ethylene for L1–2 and R1 = methyl and tert-butyl, R2 = 2-(N-ethyl) pyridine for L3–4]. A UV-vis spectrophotometric study using 3,5-di-tert butylcatechol (3,5-DTBC) reveals that all the complexes are highly active in catalyzing the aerobic oxidation of (3,5-DTBC) to 3,5-di-tert-butylbenzoquinone (3,5-DTBQ) in methanol medium with the formation of hydrogen peroxide.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/2836967
 Avviso

Registrazione in corso di verifica.
La registrazione di questo prodotto non è ancora stata validata in ArTS.

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 61
  • ???jsp.display-item.citation.isi??? 59
social impact