Ligand directed synthesis of a unprecedented tetragonalbipyramidal copper (II) complex and its antibacterial activity and catalytic role in oxidative dimerisation of 2‐aminophenol

Abstract

In pursuit of the significant contribution of copper ion in different biological processes, this research work describes the synthesis, X-ray structure, Hirshfeld surface analysis, oxidative dimerization of 2-aminophenol and antibacterial activity of a newly designed copper (II)-Schiff base complex, [Cu(L) 2 ] (1), [Schiff base (HL) = 2-(2-methoxybenzylideneamino)phenol]. X-ray structural analysis of 1 reveals that the Cu (II) complex crystallizes in a cubic crystal system with Ia-3d space group. The Cu (II) centre adopts an unprecedented tetragonal bipyramidal geometry in its crystalline phase. The Schiff base behaves as a tridentate chelator and forms an innermetallic chelate of first order with Cu (II) ion. The copper (II) complex has been tested in the bio-mimics of phenaxozinone synthase activity in acetonitrile and exhibits good catalytic activity as evident from high turnover number, 536.4 h −1. Electrochemical analysis exhibits the appearance of two additional peaks at −0.15 and 0.46 V for Cu (II) complex in presence of 2-AP and suggests the development of AP − /AP •− and AP •− /IQ redox couples in solution, respectively. The presence of iminobenzosemiquinone radical at g = 2.057 in the reaction mixture was confirmed by electron paramagnetic resonance and may be considered the driving force for the oxidative dimerisation of 2-AP. The existence of a peak at m/z 624.81 for Cu (II) complex in presence of 2-AP in electrospray ionization mass spectrum ensures that the catalytic oxidation proceeds through enzyme-substrate adduct formation. The copper (II) complex exhibits potential antibacterial properties against few pathogenic bacterial species like Staphylococcus aureus, Enterococcus and Klebsiella pneumonia and scanning electron microscope studies consolidates that destruction of bacterial cell membrane accounts on the development of antibacterial activity. Shreya Mahato and Nishith Meheta have equal contribution.

Tailor-made isostructural copper(ii) and nickel(ii) complexes with a newly designed (N,N)-donor scaffold as functional mimics of alkaline phosphatase

“…In the design of functional coordination compounds, the role of the polydentate ligand, especially Schiff base as a tailormade chelating ligand is praiseworthy. 21,22 The fine tunability, straightforward synthetic procedure, and simple reaction setup make it a versatile and flexible chelating scaffold in coordination chemistry. 23 The transition metals in coupling with Schiff bases show interesting properties and applications in designing molecular magnets, electrical-transport materials, smart catalysts, efficient chemosensors, etc.…”

“…23 The transition metals in coupling with Schiff bases show interesting properties and applications in designing molecular magnets, electrical-transport materials, smart catalysts, efficient chemosensors, etc. 5,6,[24][25][26][27][28] Therefore, scientists are actively engrossed in the design and synthesis of metal complexes along with their functional activities. Copper and nickel metal ions are considered biologically important metal ions.…”

Biomimics of phenazine oxidase activity of a cobalt (III)‐dipyridylamine complex: Spectroscopic, structural, and computational studies†

“…Therefore, structural and functional adaptation of the metallo-catalysts grabs tremendous attention in bioinspired catalysis. [6][7][8][9] Traditionally, the design of environmentally sustainable and earth-abundant metal catalysts holds a great promise for the effective transformations of small molecules to value-added products. [10][11][12][13][14][15][16][17][18][19][20][21] Among the different d-block metals, cobalt forms highly stable complexes with multidentate ligands under steric and electronic influences and shows great expediency in well-defined molecular forms.…”

Synthesis, X-ray Structure and Evaluation of Bactericidal Activity of an o-vanillin Functionalized Schiff Base

“…Schiff bases are an important class of molecules for their easy preparative accessibility, structural versatility and diverse applications in modern sciences [1][2][3][4][5][6][7]. They exhibit interesting coordinative capability towards metal ions and the metal-Schiff base compounds/chelates have been considered as important compounds for the development of magnetic materials, highly efficient catalysts, bio-inspired oxidation processes, smart photoluminescent materials, therapeutic agents and so on [8][9][10][11][12]. Schiff bases containing different hetero atoms as donor centres like N, O, S, P have emerged as a promising field of research in coordination chemistry since the metal-Schiff base compounds may tune the morphological, physiological, and pharmacological properties to some great extent [13][14][15].…”