Synthesis, molecular and supramolecular structures, electrochemistry and magnetic properties of two diphenoxo-bridged dicopper(II) compounds [CuII2L(H2O)(ClO4)]·ClO4·2H2O (1) and [CuII2L(N3)2]·2H2O (2) derived from a tetraimino diphenolate macrocyclic ligand H2L, obtained on [2+2] condensation of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane, are presented. Supramolecular structure of both 1 and 2 are three-dimensional resulting from hydrogen bonding interactions. Interestingly, the 3-D self-assembly of 2 contains micropores having the dimension of 0.35 nm. Electrochemical analyses reveal that both of these compounds exhibit two-step couples in the reduction window. Variable-temperature (2-300 K) magnetic susceptibilities measurements of the two compounds reveal that the metal centers in both of the complexes are coupled by strong antiferromagnetic interactions with J values (H = -JS1·S2) -776 and -836 cm-1 for 1 and 2, respectively. © 2009 Elsevier Ltd. All rights reserved.

SASANKA MOHANTA

Chemistry

S HAZRA

S MAJUMDER

N ALIAGA-ALCALDE

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

Polyhedron

The syntheses, characterization, crystal and molecular structures, magnetochemistry and electrochemistry of four diphenoxo-bridged dicopper(II) compounds derived from four Robson type tetraiminodiphenolate macrocyclic ligands are presented here. Three of the complexes, [CuII 2L1(ClO4)2] (1), [Cu II 2L2(ClO4)2] (2) and [CuII 2L3(ClO4)2] (3), are derived from three macrocyclic ligands H2L1/H 2L2/H2L3 having 4-ethyl-2,6- diformylphenol as the aldehyde component and ethylenediamine/1,1- dimethylethylenediamine/trans-1,2-diaminocyclohexane as the diamine component. The remaining system, [CuII 2L4(MD-Phenolate) 2]·2H2O (4; MD-Phenolate = 4-methyl-2,6- diformylphenolate), is derived from H2L4, which is the condensation product of 4-methyl-2,6-diformylphenol and 2,2-dimethyl-1,3- diaminopropane. Compounds 1-3 crystallize in monoclinic P21/c system, while the crystal system for 4 is triclinic P1̄. Variable-temperature magnetic susceptibility measurement reveals that the compounds 1-4 are coupled by strong/very strong antiferromagnetic interaction with J values -391, -318, -270 and -412cm 1, respectively. Cyclic voltammetric and square wave voltammetric measurements of the systems have been carried out, revealing two-step redox couples CuIICuII/CuIICuI and CuIICuI/CuICuI. The E 1/2 values (V) of the well resolved peaks are -0.413 for 1, -0.437 and -1.075 for 2, -0.432 for 3 and -0.363 and -0.865 for 4. Sole example of 4-substituted-2,6-diformylphenolate behaving as a monodentate ligand is presented and a new correlation of the E1/2 values on the displacement of copper(II) center from the basal plane is proposed. © 2013 Elsevier B.V. All rights reserved.

Inorganica Chimica Acta

Syntheses, crystal structures, magnetochemistry and electrochemistry of macrocyclic dicopper(II) complexes: Monodentate behavior of a potentially chelating ligand

This paper deals with the diprotonated salt, [H4L](ClO 4)2 (1), of the tetraiminodiphenolate macrocyclic ligand, H2L which is the [2 + 2] condensation product of 4-ethyl-2,6- diformylphenol and 2,2′-dimethyl-1,3-diaminopropane, and two diphenoxo-bridged dicopper(II) complexes [Cu2L(ClO4) 2] (2) and [Cu2L(ClO4)](ClO4) (3). The syntheses, characterization and crystal structures of 1-3 and the magnetic and electrochemical properties of the metal complexes 2 and 3 are presented. The cationic macrocycle [H4L]2+ is stabilized by four intramolecular and symmetric NH...O...HN hydrogen bonds involving phenoxo oxygen and imino nitrogen atoms. One metal center in 3 is tetracoordinated and in a square planar geometry. The second metal ion of 3 and both the metal ions in 2 are pentacoordinated and in a square pyramidal geometry; one perchlorate oxygen atom occupies the apical position in each case. Both 2 and 3 exhibit quasireversible two-step one-electron couples in the reduction window. The E (ΔEp) values (in mV) for the Cu IICuII/CuIICuI couple is -0.466 V (0.067 V) for 2 and -0.490 V (0.076 V) for 3, while the E (ΔEp) values (in mV) for the CuIICuI/CuICu I couple is -0.953 V (0.060 V) for 2 and -0.985 V (0.069 V) for 3. Variable-temperature (2-300 K) magnetic susceptibility measurements of the two compounds reveal that the metal centers in both of the complexes are coupled by strong antiferromagnetic interactions with 2J values (H = -JS 1·S2) of -780 and -820 cm-1 for 2 and 3, respectively. © 2012 Elsevier B.V. All rights reserved.

Journal of Molecular Structure

A new tetraiminodiphenol macrocyclic ligand and its two dicopper(II) complexes: Syntheses, crystal structures, electrochemistry and magnetochemistry

The synthesis, characterization, and crystal engineering of an enolic 4-terpyridone (L1) based three-dimensional supramolecule, [Ni II(L1)2](dicyanamide)2· 2H2O, have been described. One aim of this study has been to demonstrate that the H-O-pyridine-M-pyridine-O-H moiety in [M(L 1)2]n+ can participate in extended hydrogen-bonding interactions and, thus, can act as a building block to generate supramolecular frameworks. A second objective has been to stabilize a coordination compound containing dicyanamide in only noncoordinating form, which in turn would get involved in extended hydrogen bondings. The title compound crystallizes in the triclinic space group P1 with the following unit cell parameters: a = 8.7482(9) Å, b = 9.0810(7) Å, c = 20.5411(18) Å, α = 92.143(7)°, β = 93.011(8)°, γ = 94.315(7)°, and Z = 2. In this compound, the metal center is hexacoordinated by the three pyridine nitrogens of each of the two enolic 4-terpyridones. A number of hydrogen bonds, involving the H-O-pyridine-M-pyridine-O-H moiety and a few C-H hydrogens of the dication as well as the two noncoordinating dicyanamide anions and two waters of crystallization, results in the generation of three-dimensional assembly in this molecule. The fragment analyses reveal the existence of helical dimers and a pair of one-dimensional chains. The overall three-dimensional structure of the title compound can be considered as the stitching of the two-dimensional sheets, which consist of the interlinked pairs of one-dimensional chains, by the second type of one-dimensional chains created due to the attachment of the helical dimers, which in turn consist of the hydrogen-bonded monomers. © 2005 American Chemical Society.

Crystal Growth and Design

Hydrogen-bonded one-dimensional zigzag pairs and helical dimers in an enolic 4-terpyridone based nickel(II) dicyanamide supramolecule

Nonius Marcellus

II.—NONIUS MARCELLUS

Inorganic Chemistry

Microporous Lanthanide Metal-Organic Frameworks Containing Coordinatively Linked Interpenetration: Syntheses, Gas Adsorption Studies, Thermal Stability Analysis, and Photoluminescence Investigation

Journal of the American Chemical Society

Complete Mechanism of σ* Intramolecular Aromatic Hydroxylation through O2Activation by a Macrocyclic Dicopper(I) Complex

A Nanoporous Ag−Fe Mixed-Metal−Organic Framework Exhibiting Single-Crystal-to-Single-Crystal Transformations upon Guest Exchange

Synthesis, molecular and supramolecular structures, electrochemistry and magnetic properties of two macrocyclic dicopper(II) complexes: Microporous supramolecular assembly

Journal	Data powered by TypesetPolyhedron
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ISSN	0277-5387
Open Access	No