A linear trinuclear Ni-Schiff base complex [Ni 3 (salpen) 2(PhCH 2COO) 2(EtOH)] has been synthesized by combining Ni(ClO 4) 2 · 6H 2O, phenyl acetic acid (C 6H 5CH 2COOH), and the Schiff base ligand, N,N′-bis(salicylidene)-1,3- pentanediamine (H 2salpen). This complex is self-assembled through hydrogen bonding and C-H-π interaction in the solid state to generate a sheet-like architecture, while in organic solvent (CH 2Cl 2), it forms vesicles with a mean diameter of 290 nm and fused vesicles, depending upon the concentration of the solution. These vesicles act as an excellent carrier of dye molecules in CH 2Cl 2. The morphology of the complex has been determined by scanning electron microscopy and transmission electron microscopy experiments, and the encapsulation of dye has been examined by confocal microscopic image and electronic absorption spectra. © 2009 American Chemical Society.

ASHUTOSH GHOSH

Chemistry

P MUKHERJEE

M G B DREW

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Inorganic Chemistry

A mononuclear MnIII derivative, [Mn(L)(SCN)(H2O)] (1) [where H2L = N,N′-bis(salicyaldehydene)-1,3-diaminopropan-2-ol] has been synthesized and systematically characterized. In 1, the central MnIII ion is linked to the NNOO donor atoms of the potentially binucleating precursor L2− and additionally coordinates one water molecule and the pseudohalide SCN−, thus yielding a distorted octahedral geometry. The UV–Vis spectra of 1 shows an intense band corresponding to a 5T2g − 5Eg transition at 545 nm; thus presuming the octahedral geometry around the Mn ion. The solid and solution EPR spectra of 1 have been simulated with an HP 53150A microwave frequency counter which has confirmed the +3 oxidation state of the metal ion. We have also conducted a DFT computational study which has confirmed that compound 1 self assembles into a two-dimensional network via O‒H⋯O, π–π, and unconventional C‒H … π(SCN) interactions involving the π-system of the thiocyanate. The room temperature magnetic susceptibility of compound 1 has yielded an effective magnetic moment (μeff) value of 4.96 B.M. © 2019 Elsevier B.V.

Journal of Molecular Structure

Synthesis, structural and DFT interpretation of a Schiff base assisted Mn(III) derivative

Three novel μ2-aqua bridged dinuclear Ni(II) complexes, [Ni2(HL1)4(H2O)] (1), [Ni 2(HL2)4(H2O)] (2) and [Ni 2(HL3)4(H2O)] (3) have been synthesized using Schiff base ligands derived from 5-amino-1-pentanol and salicylaldehyde (H2L1), 5-bromo salicylaldehyde (H 2L2) and 3-methoxy salicylaldehyde (H2L 3), respectively. They are characterized by a variety of physical techniques including elemental analysis, infrared and UV-Vis spectroscopy, NMR, cyclic voltammetry, variable temperature magnetic measurements and single crystal X-ray diffraction. X-ray crystallographic analysis reveals that all the three complexes possess distorted octahedral environment with a bridging aqua ligand. Complexes 1 and 3 exhibit 3D supramolecular architecture whereas 2 demonstrates a 2D netlike arrangement along ab plane. Catecholase activity of the dinuclear Ni(II) systems are investigated using 3,5-di-tert-butylcatechol as the substrate. The complexes are efficient catalysts with turnover numbers 1.87 × 104, 1.79 × 104 and 1.38 × 10 4 h-1 for 1, 2 and 3, respectively. The probable structures of the intermediates formed during the process are proposed on the basis of kinetic and spectral analyses. The magnetic data disclose that weak ferromagnetic couplings are transmitted between the metal centers and the magnetic properties are correlated with the structural features around the Ni(II) centers. © 2014 Elsevier B.V. All rights reserved.

Inorganica Chimica Acta

Syntheses, crystallographic characterization, catecholase activity and magnetic properties of three novel aqua bridged dinuclear nickel(II) complexes

Three new Ni(II) complexes, [NiL(NO2)(H2O)] (1), [Ni2L2(PhCH2COO)2(H2O)] (2) and [Ni2L2(N(CN)2)2(H 2O)] (3), have been synthesized using a tridentate Schiff base ligand, 1-[(3-dimethylamino-propylimino)-methyl]-naphthalen-2-ol (HL) and the polyatomic monoanions NO2-, PhCH2COO - or N(CN)2-. All three complexes (1-3) have been characterized by spectral analysis and X-ray crystallography. Structural analyses reveal that complex 1 is mononuclear, in which the Ni(II) ion is in a distorted octahedral environment, coordinated by the deprotonated tridentate Schiff base (L), a chelating nitrite and one water molecule. The structures of both 2 and 3 consist of dinuclear octahedral Ni(II) units with crystallographic C2 symmetry. In complex 2, two μ2-phenoxido and a water molecule bridge the two Ni(II) centers to make the complex a face sharing bioctahedron, whereas in 3 the Ni(II) atoms are bridged by two μ1,5-dicyanamide ligands. Variable temperature magnetic susceptibility measurements show the presence of ferromagnetic coupling in complex 2 with J = +26.20 cm-1 and antiferromagnetic coupling in complex 3 with J = -1.90 cm-1. © 2013 Elsevier Ltd. All rights reserved.

Polyhedron

Three nickel(II) complexes derived from a tridentate NNO donor Schiff base ligand: Syntheses, crystal structures and magnetic properties

A diphenoxido-bridged dinuclear copper(II) complex, [Cu2L 2(ClO4)2] (1), has been synthesized using a tridentate reduced Schiff base ligand, 2-[[2-(diethylamino)-ethylamino]methyl] phenol (HL). The addition of triethylamine to the methanolic solution of this complex produced a novel triple bridged (double phenoxido and single hydroxido) dinuclear copper(II) complex, [Cu2L2(OH)]ClO4 (2). Both complexes 1 and 2 were characterized by X-ray structural analyses, variable-temperature magnetic susceptibility measurements, and spectroscopic methods. In 1, the two phenoxido bridges are equatorial-equatorial and the species shows strong antiferromagnetic coupling with J = -615.6(6.1) cm -1. The inclusion of the equatorial-equatorial hydroxido bridge in 2 changes the Cu⋯Cu distance from 3.018 Å (avg.) to 2.798 Å (avg.), the positions of the phenoxido bridges to axial-equatorial, and the magnetic coupling to ferromagnetic with J = 50.1(1.4) cm-1. Using 3,5-di-tert-butylcatechol as the substrate, the catecholase activity of the complexes has been studied in a methanol solution; compound 2 shows higher catecholase activity (kcat = 233.4 h-1) than compound 1 (kcat = 93.6 h-1). Both complexes generate identical species in solution, and they are interconvertible simply by changing the pH of their solutions. The higher catecholase activity of 2 seems to be due to the presence of the OH group, which increases the pH of its solution. © 2012 American Chemical Society.

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

Two new nickel(II) complexes, [NiL(H 2O) 2Cl] (1) and [{NiLL′(H 2O)} 2(μ-H)]NO 3·H 2O (2), have been synthesized using a tridentate Schiff base ligand, HL, 2-[(2-dimethylamino-ethylimino)-methyl]-phenol, along with Cl - or NO 3 - as an anionic co-ligand or counter anion (where L′H = salicylaldehyde). Both complexes have been characterized by X-ray crystallography. The structural analyses reveal that complex 1 is mononuclear whereas 2 is a hydrogen-bridged dinuclear complex. The Ni(II) ions possess a distorted octahedral geometry in both structures. Both complexes show negative solvatochromic behaviour with increasing donor number (DN) of the solvent. In more coordinating solvents, like DMSO or methanol, the colour of the solutions is green, whereas in less coordinating solvents, like dichloromethane (DCM) or acetonitrile, it is red. © 2011 Elsevier Ltd. All rights reserved.

Journal	Inorganic Chemistry
Publisher	-
ISSN	0020-1669
Open Access	No