Syntheses, structures and magnetic properties of a heterobridged -phenoxido-1,1-NCO dinickel(II) compound [NiII 2(HL)3(-NCO)].2H2O (1) and a heterobridged bis(3-phenoxido)bis(3-alkoxido)tetranickel(II) system, [NiII4(L)2(HL)2(SeCN) 2(H2O)2].C3H7NO.4H 2O (2), containing a cubanetype NiII4O 4 core, derived from the totradontate Schiff base compartmental ligand N-(2-hydroxyolhyl)-3-methoxysalicylaldimine (H2L) were described. Compounds 1 and 2 crystallize in triclinic P1 and monoclinic P2 1/c systems, respectively. Compound 2, in which the Ni 4O4 cubane core is composed of two 3-phenoxido and two 3-alkoxido moieties, represents the sole example of this type. The variable-temperature (2-300 K) magnetic susceptibilities and magnetizations of these two compounds were measured. The interaction between the metal centres in dinuclear compound 1 is weak ferromagnetic, resulting in an ST = 2 ground state at 2 K. The overall interaction observed in 2 is weak ferromagnetic, leading to an unusual ST = 3 ground state. © 2009 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

SASANKA MOHANTA

Chemistry

S HAZRA

R KONER

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

European Journal of Inorganic Chemistry

This investigation deals with the syntheses, crystal structures and experimental and density functional theoretical magnetic properties of two heterobridged and isomorphous µ-phenoxo-µ1,1-azide/isocyanate dinickel(II) compounds of composition [NiII 2(L)2(µ1,1-N3)(CH3CN)(CH3OH)](ClO4)·CH3CN (1) and [NiII 2(L)2(µ1,1-NCO)(CH3CN)(CH3OH)](ClO4)·CH3CN (2), where HL is the 1:1 condensation product of 3-ethoxysalicylaldehyde and 4-(2-aminoethyl)-morpholine. The two compounds are isostructural as well, except that 1 contains end-on azide and 2 contains end-on isocyanate. One metal ion is surrounded by O(µ-phenoxo), N(µ1,1-azide/µ1,1-isocyanate), N(imine), N(amine), O(ethoxy) and O(phenoxide, monodentate) atoms, while the second metal ion is surrounded by O(µ-phenoxo), N(µ1,1-azide/µ1,1-isocyanate), N(imine), N(amine), O(methanol) and N(acetonitrile) atoms. Variable-temperature (2–300 K) magnetic susceptibility and variable-field (up to 5 T) magnetization data reveal ferromagnetic exchange interaction with J = 18.0 cm–1 for 1 and J = 11.4 cm–1 for 2. Broken symmetry density functional calculations of exchange interaction have been performed on both complexes and the DFT-computed J values are nicely matched with the experimental J values [J(exp) = 18.0 cm–1 and J(DFT) = 17.2 cm–1 for 1; J(exp) = 11.4 cm–1 and J(DFT) = 8.9 cm–1 for 2]. The magnetic properties have been nicely rationalized in terms of spin density, magnetic orbitals and breakdown approach. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Synthesis, Crystal Structures and Magnetic Properties of Two Heterobridged Âµ-Phenoxo-Âµ1,1-Azide/Isocyanate Dinickel(II) Compounds: Experimental and Theoretical Exploration

The work in the present investigation reports the syntheses, crystal structures, ESI-MS (positive) and variable-temperature and variable-field magnetic properties of two Ni 4 O 4 cubane compounds of composition [Ni II 4 L 2 (µ 1,3 -HCO 2 ) 2 ](ClO 4 ) 2 ·2H 2 O (1) and [Ni II 4 L 2 (µ 1,3 -o-ClPhCO 2 ) 2 ](ClO 4 ) 2 ·3H 2 O (2) derived from the Robson type tetraiminodiphenol macrocyclic ligand H 2 L (2 + 2 condensation of 4-ethyl-2,6-diformylphenol and 2,2-dimethyl-1,3-diaminopropane). All the four oxygen atoms of the distorted cubane are phenoxido oxygen atoms, coming from two deprotonated macrocycle, [L] 2− , i.e., these compounds are Ni 4 (μ 3 –phenoxido) 4 cubanes. The nickel(II) centers in each of the two pairs in two opposite faces of the cube are additionally bridged by a syn–syn carboxylate, formate in 1 and o-chlorobenzoate in 2. Variable-temperature and variable-field magnetization data reveal an overall antiferromagnetic interaction in both 1 and 2, where two of the six pathways are ferromagnetic (4.06 cm −1 in 1 and 1.58 cm −1 in 2) and the remaining four pathways are antiferromagnetic (−3.03 cm −1 in 1 and −1.55 cm −1 in 2). The possibility of a J versus Ni II –O(phenoxo)–Ni II angle correlation and the roles of carboxylate moiety as well as energy difference between the first excited state and ground state on magnetic properties have been discussed. © 2017 Elsevier Ltd

Polyhedron

Syntheses, crystal structures and magnetic properties of two Ni 4 (Î¼ 3 â€“phenoxido) 4 cubanes: Role of additional bridging carboxylates

Reaction of benzene-1,2,4,5-tetracarboxylic acid (H<inf>4</inf>L) with Zn(II) salt in DMF/MeOH leads to the formation of the new (μ2-benzene-1,2,4,5-tetracarboxylato-O,O')- hexaaqua-dizinc(II)-dihydrate complex [Zn<inf>2</inf>L(H<inf>2</inf>O)<inf>6</inf>]·2H<inf>2</inf>O (1) (L = benzene-1,2,4,5-tetracarboxylate). Crystal structure analysis reveals that each tetracoordinated zinc(II) center adopts a distorted tetrahedral geometry occupied by one Ocarboxylate and three Owater atoms. A 3D supramolecular associate in the crystal lattice of 1 has been stabilized by a number of non-covalent interactions (O-H···O). Topology of the H-bonded 3D network has been also analyzed.

Fulltext

Zeitschrift fur Kristallographie

Synthesis, supramolecular structure and thermal study of a new dinuclear zinc(II) complex derived from benzene-1,2,4,5-tetracarboxylic acid

The work in this report describes the syntheses, characterization, crystal structures and magnetic properties of eight linear trinickel(ii) compounds of the composition [NiII3(Lsal-pyr) 2(propionate)4] (1), [NiII3(L sal-pyr)2(benzoate)4]·CH3CN (2), [NiII3(Lsal-pip)2(acetate) 4]·2CH3CN (3), [NiII3(L sal-pip)2(propionate)4] (4), [Ni II3(Lsal-pip)2(benzoate) 4]·CH2Cl2 (5), [NiII 3(Lsal-mor)2(propionate)4] (6), [NiII3(Lsal-mor)2(benzoate) 4]·3CH2Cl2 (7) and [NiII 3(Lsal-mor)2(o-Cl-benzoate)4] ·2CH3CN·2H2O (8), where HL sal-pyr, HLsal-pip and HLsal-mor are the 1:1 condensation products of salicylaldehyde and 1-(2-aminoethyl)-pyrrolidine, 1-(2-aminoethyl)-piperidine and 4-(2-aminoethyl)-morpholine, respectively. One-half of the trinuclear core in each complex is symmetry related to the second part due to the presence of an inversion centre on the central metal ion and so the terminal nickel⋯central nickel⋯terminal nickel angle is 180°. The terminal and central nickel(ii) ions are triply bridged by a phenoxo, a μ1,1-carboxylato and a μ1,3-carboxylato moiety. The μ1,1-carboxylato also acts as a chelating ligand for the terminal metal ion. Both the variable-temperature (2-300 K) susceptibilities at a fixed field strength of 0.1 T and variable-field (up to 7 T) magnetization at different fixed temperatures (2-10 K) were recorded. The magnetic data indicate the ferromagnetic interaction in all the cases with J (Ĥ = -2Jij∑SiSj) values ranging between 2.37 and 3.89 cm-1 and the single-ion zero-field parameter (D) ranging between 7.21 and 8.94 cm-1. Satisfactorily simulation of both the χMT vs. T and M vs. H data has been obtained. Comparison of the structures and magnetic properties of compounds 1-8 with those of the previously published related systems reveals some interesting aspects. This journal is © the Partner Organisations 2014.

Dalton Transactions

Syntheses, crystal structures and magnetic properties of a series of Î¼-phenoxo-Î¼1,1-carboxylato-Î¼1,3-carboxylato trinickel(ii) compounds

The work in this paper presents the syntheses, characterization, crystal structures and magnetic properties of bis(end-on azide) bridged dicopper(II) complexes [CuIIL1(μ1,1-N3)] (1), [CuIIL2(μ1,1-N3)] (2) and [CuIIL3(u1,1-N3)]·MeOH (3), where HL1, HL2 and HL3 are half-condensed ligands produced from, respectively, 3-ethoxysalicylaldehyde and ethylenediamine, salicylaldehyde and trans-1,2-diaminocyclohexane, and 3-methoxysalicylaldehyde and trans-1,2-diaminocyclohexane. While compound 1 crystallizes in the monoclinic crystal system and P21/c space group, the crystal system and space group for 2 and 3 are triclinic and P1. There are two independent units, Unit-I and Unit-II, in 3. Each metal center in 1-3 is pentacoordinated and adopts a distorted square pyramidal coordination geometry. Each of the two bridging azide nitrogen atoms occupies an equatorial position of one copper(II) center, but the axial position of the second metal center. The Cu-N3-Cu bridge angle in 1, 2 and Unit-II of 3 lie in the range 87.8-90.8°, while Unit-I in 3 displays a Cu-N3-Cu angle of 84.3°, which is the smallest bridge angle observed so far in end-on azide bridged dicopper(II) systems. Variable-temperature (2-300 K) magnetic studies reveal weak antiferromagnetic interactions in 1-3 withJ values (H= -JS 1S2) of -10.16, -4.18 and -1.43cm-1, respectively. © 2013 Elsevier Ltd. All rights reserved.

Syntheses, crystal structures and magnetic properties of three bis(end-on azide) bridged dicopper(II) complexes derived from half-condensed ligands: Observation of the smallest Cu-azide-Cu bridge angle in dinuclear systems

The synthesis, molecular and supramolecular structure, spectroscopy and electrochemistry of a dialkoxo-bridged diuranyl(VI) compound [(UO2)2(L)2(dimethylformamide)2] (1) derived from the Schiff base ligand H2L, obtained on condensation of 3-methoxysalicylaldehyde with 2-aminoethanol, have been described. The compound has been characterized by IR, UV-Vis, NMR and mass spectra, as well as by single crystal X-ray structure determination. The title compound crystallizes in the monoclinic P21/n space group with the following unit cell parameters a = 10.5713(2) Å, b = 11.9895(2) Å, c = 12.9372(2) Å, β = 102.773(3)° and Z = 2. The structure of 1 reveals that it is a dialkoxo-bridged dinuclear compound of uranium(VI) containing two deprotonated ligands, [L]2-, two dimethylformamide (dmf) molecules and two UO22+ centers. The coordination geometry around the uranium(VI) center is distorted pentagonal bipyramidal; two uranyl oxygens occupy the axial positions, while the basal pentagonal plane is defined by a phenoxo oxygen, two bridging alkoxo oxygens, one imine nitrogen, and one dmf oxygen. Three C-H⋯O type hydrogen bonds involving one uranyl oxygen, two dmf hydrogens and the imine hydrogen link the dinuclear units into a two-dimensional network. The ESI-MS spectrum of 1 in dimethylsulfoxide exhibits two peaks at m/z = 464.17 and 927.26, which are assignable to [(UO2)2L2H]+ (60%) and [(UO2)2LH]+ (100%) cations, respectively. Cyclic voltammetric measurements of 1 reveal that the uranium(VI) center is reduced quasireversibly at E1/2 = -1112 mV with ΔEP = 97 mV. © 2008 Elsevier Ltd. All rights reserved.

Synthesis, molecular and supramolecular structure, spectroscopy and electrochemistry of a dialkoxo-bridged diuranyl(VI) compound

Syntheses, structures, and magnetic properties of two heterobridged μ-alkoxo-μ-7-azaindolate dicopper(II) complexes, [CuII 2(L-F)(μ-C7H5N2)] (1) and [CuII2(L-H)(μ-C7H5N 2)]·CH3OH (2) (H3L-F = 1,3-bis(3-fluorosalicylideneamino)-2-propanol; H3L-H = 1,3-bis-(salicylideneamino)-2-propanol) have been reported. Aside from being a new type of heterobridged complex, 1 and 2 exhibit ferromagnetic interaction (2J = 52 cm-1 for 1 and 33.4 cm-1 for 2) despite orbital complementarity (7-azaindolate HOMO is antisymmetric).

Inorganic Chemistry

Ferromagnetic Exchange in Two Dicopper(II) Complexes Using a Î¼-Alkoxo-Î¼-7-azaindolate Bridge

Journal of the American Chemical Society

“Switching On” the Properties of Single-Molecule Magnetism in Triangular Manganese(III) Complexes

Crystal Structure and Magnetic Interactions in Nickel(II) Dibridged Complexes Formed by Two Azide Groups or by Both Phenolate Oxygen−Azide, −Thiocyanate, −Carboxylate, or −Cyanate Groups

Polynuclear Nickel(II) Complexes: Preparation and Magnetic Properties of NiII4, NiII5, and NiII6 Species with Ligands containing O∩X∩O (X = S, Se or N) Donor Atoms

Syntheses, structures and magnetic properties of heterobridged dinuclear and cubane-type tetranuclear complexes of nickel(II) derived from a schiff base ligand

Journal	Data powered by TypesetEuropean Journal of Inorganic Chemistry
Publisher	Data powered by TypesetWILEY-V C H VERLAG GMBH
ISSN	1434-1948
Open Access	No