14406-71-4Relevant articles and documents
Electropolymerization and electrochemical behavior of nickel Schiff base complexes with different groups between imine linkages
Chen, Cheng,Li, Xinping,Deng, Fuhai,Li, Jianling
, p. 79894 - 79899 (2016)
Nickel Schiff base complexes Ni(salen), Ni(salphen) and Ni(saldmp) are synthesized and electropolymerized on multiwalled carbon nanotube electrodes. The structures of the three monomers are similar except for the groups between the imine linkages, so the difference in electrochemical behavior can be related to the influence of the groups. Polymerization parameters such as the consumed charge, the apparent surface coverage and the doping level are investigated to elucidate the effects of groups between imine linkages. The results show that poly[Ni(salen)] has higher consumed charge and apparent surface coverage than others, which means that poly[Ni(salen)] can be deposited more easily on the electrodes. While poly[Ni(salphen)] has the highest doping level, there are more electrons transferred per monomer unit, indicating a better capacitance for energy storage. The electrochemical characteristics are also evaluated and the peak potential in cyclic voltammetry plots is about 0.9 V for Ni(salen) and Ni(salphen), and about 0.7 V for Ni(saldmp). The different peak potentials indicate the redox potential will be related to the various groups. Meanwhile the galvanostatic charge/discharge curves display a specific capacitance of about 200 F g-1 for poly[Ni(salphen)], and about 150 F g-1 for poly[Ni(salen)] and poly[Ni(saldmp)]. The variation in electrochemical behavior is mainly caused by the different molecular structure and the groups between imine linkages are the unique differences in structure. So we propose a new electronic transmission mechanism that the electrons will transmit via the Ph-CN-Y-NC-Ph path (Y represents groups between imine linkages), and these groups can provide an electronic transmission path as imine bridges and then influence the electrochemical behavior.
Synthesis, characterization, antimicrobial, BSA binding, DFT calculation, molecular docking and cytotoxicity of Ni(II) complexes with Schiff base ligands
Rani, J. Jeevitha,Jayaseeli, A. Mary Imelda,Rajagopal,Seenithurai,Chai, Jeng-Da,Raja, J. Dhaveethu,Rajasekaran
, (2021)
A series of a tetradentate N2O2 Schiff base ligands (1a-e), [N,N′-(X)bis(salicylidene)1,2-phenylenediamine], salphens {where X = H (1a), Cl (1b), Br (1c), CH3 (1d), OCH3(1e)} were synthesized from condensation of substituted salicylaldehydes with 1,2-phenylenediamine and nickel(II) complexes(2a-e) from corresponding Schiff base ligands(1a-e). The stoichiometric ratios of the prepared ligands (1a-e) and their Ni(II)-salphen complexes (2a-e) were structurally characterized by various analytical and spectroscopic techniques such as 1H NMR, FT-IR, mass, UV‐–visible, PXRD, magnetic moments and molar conductivity measurements. These results suggest that Ni(II)-salphen complexes (2a-e) have square planar geometry. The molar conductivity measurements indicate that all complexes (2a-e) are non-electrolytes. Density Functional Theory (DFT) calculations have been used to investigate the optimized structure and chemical reactivity of these Ni(II) complexes(2a-e) from their Frontier Molecular Orbitals (FMO). The binding capabilities of the Ni(II) Schiff base complexes (2a-e) with Bovine Serum Albumin (BSA) have been studied through electronic absorption, fluorescence and cyclic voltammetric methods. Further the nature of interaction of Ni(II) complexes (2a-e) towards BSA were confirmed using molecular docking analyses. All these results demonstrated that the Ni(II) complexes 2d and 2e have better binding affinity towards BSA among all the Ni(II) complexes. The antimicrobial studies reveal that the Ni(II)-salphen complexes (2a-e) have higher inhibitory effect than ligands (1a-e) against the selected pathogenic microorganisms. Furthermore, in vitro cytotoxicity of ligands (1a-e) and Ni(II) complexes(2a-e) were evaluated by MTT assay against MCF-7. The observed IC50 values against MCF-7 cell lines suggest that Ni(II) complexes(2a-e) show more significant anticancer activity than their corresponding ligands(1a-e). It is explored that complexes 2d and 2e bearing electron donating groups have greater anticancer potency. Comparison of our results with cisplatin, Zn(II)-salphen and V(IV)-salphen complexes indicated that Ni(II)-salphen complexes can be considered as the potential candidates for use as effective anticancer agent in future.
Surface-enhanced resonance-Raman scattering: An informative probe of surfaces
Rodger, Caroline,Smith, W. Ewan,Dent, Geoffrey,Edmondson, Michael
, p. 791 - 799 (1996)
Surface-enhanced resonance-Raman scattering (SERRS) experiments using a citrate-coated silver colloid have been performed. Transmission electron microscopy showed that the colloid consists of nearly mondisperse hexagonal particles with a maximum dimension of 36 nm. For maximum sensitivity, SERRS requires the controlled aggregation of the colloid. The nature of the aggregate formed is dependent on the method of aggregation. The effect of poly-L-lysine on the aggregation procedure was characterised using transmission and scanning electron microscopy. With SERRS, sensitivities down to 6.87 × 10-18 mol dm-3 were obtained using rhodamine dye. This corresponds to less than 200 molecules in the beam at any one time and suggests a sensitivity equal to or greater than that of fluorescence. A comparison of the use of SERRS with surface-enhanced Raman scattering (SERS) to follow adsorbate reactivity on a surface at less than monolayer coverage was obtained by studying metal complex formation using a preresonant Schiff base (SERRS) and 2-hydroxy-1-naphthaldehyde excited off resonance (SERS). In the former case, complex formation on the surface at well below monolayer coverage was observed and differences between the surface and the bulk complex characterised. In the latter complex formation was again observed but the bands were broad and problems of contamination, photodecomposition and selectivity evident. Copyright 1996 by the Royal Society of Chemistry.
Elastic Crystalline Fibers Composed of a Nickel(II) Complex
Kusumoto, Sotaro,Sugimoto, Akira,Zhang, Yingjie,Kim, Yang,Nakamura, Masaaki,Hayami, Shinya
, p. 1294 - 1298 (2021)
The generation of elastic crystalline fibers from a nonfibrous crystal of metal complex is demonstrated. Applying mechanical stimuli to a platelike crystal of NiII(salophen) [1; H2salophen = N,N′-bis(salicylidene)-o-phenylenediamine] resulted in this complex being transformed into crystal fibers, which could be bent into a loop and demonstrated its high elasticity. Single-crystal X-ray diffraction analyses revealed that the transformation reflects the presence of molecular strands that are composed of a one-dimensional assembly of the slip-stacked arrangement by nearly planar Ni(salophen) molecules. The fiber flexibility was demonstrated to be lost upon the introduction of chloroform solvent molecules into the crystal lattice by recrystallization.
Air-Stable Cobalt(II) and Nickel(II) Complexes with Schiff Base Ligand for Catalyzing Suzuki–Miyaura Cross-Coupling Reaction
Ansari,Kumar,Bhat
, p. 1 - 8 (2018)
The Co(II) complex [Co{C6H4–1,2-(N=CH–C6H4O)2}] (I) and Ni(II) complex [Ni{C6H4–1,2-(N=CH–C6H4O)2}] (II) with Schiff base of o-phenylenediamine and salicylaldehyde have been synthesized. The structure of the ligand and its complexes were derived on the basis of various techniques such as elemental analysis, mass, FT-IR, electronic spectra and magnetic susceptibility. From the Singal crystal X-ray diffraction (SCXRD) analysis techniques (CIF file CCDC no. 1498772 (II)), it has been confirmed that the Schiff base ligand (L), coordinates to the metal ion in a tetradentate fashion through the nitrogen and oxygen atom. In addition, the square planar geometry of Ni(II) complex also has been confirmed from SCXRD. Electronic spectra, mass spectra, and magnetic susceptibility measurements reveal square planar geometry for the Co(II) complex. Synthesized complexes were used in cross-coupling of arylhalides with phenylboronic acid. The transformation offers products in good yields using 0.02 mmol catalysts loading, thereby proving the efficiency of the complexes as catalysts for Suzuki–Miyaura reaction.
Function of 7,7,8,8-tetracyanoquinodimethane (TCNQ) on electrocatalytic hydrogen generation catalyzed by N,N′-benzene bis(salicylideniminato)nickel(II)
Xue, Dan,Lv, Qi-Ying,Lin, Chen-Neng,Zhan, Shu-Zhong
, p. 300 - 308 (2016)
In the presence of trimethylamine, the reaction of N,N′-benzene bis(salicylidenimine) (H2L) with NiCl2·6H2O affords a nickel(II) complex, [NiL] (1), and the reaction of H2L with NiCl2·6H2O
Zeolite encapsulated Ni(ii) Schiff-base complexes: improved catalysis and site isolation
Kumari, Susheela,Ray, Saumi
supporting information, p. 14953 - 14963 (2020/09/23)
Two series of zeolite encapsulated Ni(ii) Schiff-base complexes,i.e., the Ni(ii) sal-1,2-phen and Ni(ii) sal-1,3-phen series, have been synthesized in neat and encapsulated states and characterized by using different characterization techniques such as XRD, SEM-EDS, BET, thermal analysis, XPS, IR spectroscopy, UV-vis spectroscopy and magnetic studies. UV-vis spectroscopy, XPS and magnetic studies all together reveal the structural modification of the guest complex and, thereby, the adaptation of electron density around the metal center upon encapsulation. However, encapsulation causes structural alterations for these two series differently and, hence, introduces a certain level of proficiency to these Ni(ii) complexes as catalysts for phenol oxidation reaction. However, analysis of catalytic data emphasizes site isolation as a major governing factor for the improved reactivity over the modified electron density around the metal center for phenol oxidation reaction where the heterogeneous mode of catalysis is concerned.
