Search results for "Bridging"

A Family of Dinuclear Iron(II) SCO Compounds Based on a 1,3,4‐Thiadiazole Bridging Ligand

2015

A new family of dinuclear iron(II) spin-crossover (SCO) compounds with the formula [Fe2(μ-L)2]X4, with three different counteranions [X = BF4– (1), ClO4– (2) and F3CSO3– (3)], was prepared and characterized by single-crystal X-ray diffraction, variable-temperature magnetic susceptibility and Mossbauer measurements. These are the first dinuclear iron(II) SCO complexes with a 1,3,4-thiadiazole bridging ligand L {with L = 2,5-bis[(2-pyridylmethyl)amino]methyl-1,3,4-thiadiazole}. The magnetic measurements reveal a gradual and incomplete SCO of the three compounds around room temperature, starting from a diamagnetic [LS–LS] state. The diamagnetic ground state is in agreement with the single-crys…

A Family of Dinuclear Iron(II) SCO Compounds Based on a 1,3,4‐Thiadiazole Bridging Ligand (Eur. J. Inorg. Chem. 22/2015)

2015

Molecular-Programmed Self-Assembly of Homo- and Heterometallic Tetranuclear Coordination Compounds: Synthesis, Crystal Structures, and Magnetic Prope…

2009

New homo- and heterobimetallic tetranuclear complexes of formula [Cu4(mpba)(Me4en)4(H2O)4](ClO4)4·3H2O (1), [Cu4(mpba)(Me4en)4(H2O)4](PF6)4·2H2O (2), [Cu4(ppba)(Me4en)4(H2O)4](ClO4)4·2H2O (3), [Cu4(mpba)(dipn)4](ClO4)4·3H2O (4), [Cu4(ppba)(dipn)4](ClO4)4·2H2O (5), and [Cu2Ni2(ppba)(dipn)4(H2O)2](PF6)4 (6) [mpba = N,N′-1,3-phenylenebis(oxamate), ppba = N,N′-1,4-phenylenebis(oxamate), Me4en = N,N,N′,N′-tetramethylethylenediamine, and dipn = dipropylenetriamine] have been synthesized and structurally and magnetically characterized. Complexes 1−6 have been prepared following a molecular-programmed self-assembly method, where a heteropolytopic tetranucleating phenylenedioxamato bridging ligand (…

Three different types of bridging ligands in a 3d-3d'-3d'' heterotrimetallic chain.

2017

A one-pot synthesis of a 3d–3d′–3d′′ heterotrimetallic coordination polymer with double diphenoxido, single cyanido and bis-bidentate oxalate as alternating bridges which exhibits an overall antiferromagnetic behaviour has been developed.

Homo- and heterobinuclear Cu2+ and Zn2+ complexes of abiotic cyclic hexaazapyridinocyclophanes as SOD mimics

2013

The new receptor 3,7,11,15,19,23-hexaaza-1(2,6)-pyridinacyclotetracosaphane (L1) containing a complete sequence of propylenic chains has been synthesised. The acid–base behaviour and Cu2+ and Zn2+ coordination have been analysed by potentiometric measurements in 0.15 M NaClO4 for L1 and for the related compounds 3,7,11,14,18,22-hexaaza-1(2,6)-pyridinacyclotricosaphane (L2), 3,7,10,13,16,20-hexaaza-1(2,6)-pyridinacycloheneicosaphane (L3) and 3,7,10,12,15,19-hexaaza-1(2,6)-pyridinacycloicosaphane (L4). The crystal structure of [(CuH4L2)(H2O)(ClO4)](ClO4)5·3H2O shows an interesting combination of a metal ion coordinated by the pyridine nitrogen atom and the adjacent amine groups of the chain, …

Bridging the Gap between Advanced Distributed Teaching and the Use of Learning Management Systems in the University Context

2007

The selection of appropriate learning management system (LMS) is critical for supporting advanced distributed teaching. A survey was targeted for understanding the features that the LMS offer for university teachers and to find if the advanced features of the LMS were utilized, The findings imply that there is a gap between the LMS tools for advanced distributed teaching and their use in the university context. The teachers using LMS were also found to be heterogeneous by their computer skills and LMS uses.

Solvent-modulated structures in anilato-based 2D coordination polymers

2017

Abstract This work highlights the key role of the solvents in the structures of the series of 2D compounds [Ln2(C6O4Br2)3·(Solvent)n]·G (G = Guest). This study is based on the affinity and ability of these solvents to coordinate to lanthanides and on their possibility to act as solvation molecules. For this purpose here we focus on the Er(III) ion and on the bromanilato bridging ligand ([C6O4Br2]2− = dianion of 3,6-dibromo-2,5-dihydroxy-1,4-benzoquinone) and we play with three solvents: H2O, DMSO (dimethylsulfoxide) and DMF (dimethylformamide). Here we report the synthesis, crystal structure and magnetic characterization of compounds [Er2(C6O4Br2)3(H2O)6]·12H2O (1), [Er2(C6O4Br2)3(DMSO)4]·2…

Asymmetric Ring Opening in a Tetrazine-Based Ligand Affords a Tetranuclear Opto-Magnetic Ytterbium Complex.

2020

We report the formation of a tetranuclear lanthanide cluster, [Yb4 (bpzch)2 (fod)10 ] (1), which occurs from a serendipitous ring opening of the functionalised tetrazine bridging ligand, bpztz (3,6-dipyrazin-2-yl-1,2,4,5-tetrazine) upon reacting with Yb(fod)3 (fod- =6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octandionate). Compound 1 was structurally elucidated via single-crystal X-ray crystallography and subsequently magnetically and spectroscopically characterised to analyse its magnetisation dynamics and its luminescence behaviour. Computational studies validate the observed MJ energy levels attained by spectroscopy and provides a clearer picture of the slow relaxation of the magnetisati…

A thermal- and light-induced switchable one-dimensional rare loop-like spin crossover coordination polymer

2019

Rare loop-like isostructural one-dimensional coordination polymer (1D-CP) systems formulated as {Fe(DPIP)2(NCSe)2}n·4DMF (1) and {Fe(DPIP)2(NCSe)2}n·4DMF (2) were obtained by self-assembling FeII and pseudohalide NCX−(X = S, Se) ions in presence of the V-shaped bidentate bridging ligand, namely, N,N′-dipyridin-4-ylisophthalamide (DPIP), and were characterized by elemental analysis, IR spectroscopy, TGA, single crystal X-ray diffraction and powder X-ray diffraction. The magnetic studies show that complex 2 undergoes a complete thermally induced spin crossover (SCO) behavior centered at T1/2 = 120 K with ca. 5 K thermal hysteresis loop and light-induced excited spin state trapping effect (LIE…

New coordination polymers with a 2,2-dicyano-1-ethoxyethenolate (dcne–) bridging ligand: syntheses, structural characterisation and magnetic properti…

2002

New polymeric materials [M(dcne)2(H2O)2] with M = MnII (1), FeII (2), CoII (3), NiII (4) and ZnII (5) and [Cu(dcne)2(H2O)] (6) (dcne− = [(CN)2CC(O)OEt)]− = 2,2-dicyano-1-ethoxyethenolate anion) have been synthesised and characterised by infrared spectroscopy, X-ray crystallography and magnetic measurements. In these compounds, each organic ligand acts in a bridging mode with its two nitrogen atoms bound to two different metal cations. In compounds 1–5, each metal cation has a pseudo-octahedral cis-MN4O2 environment with four nitrogen atoms from four different organic ligands and two oxygen atoms from two water molecules. In compound 6, only one water molecule is coordinated and each copper(…