Preparation and crystal structure of the oxalato-bridged CrIII–AgItwo-dimensional compound {Ag3(H2O)[Cr(dpa)(ox)2]3}n·2nH2O (dpa = 2,2′-dipyridylamine)

The reaction of the mononuclear complex [Cr(dpa)(ox)2]− (dpa = 2,2-dipyridylamine) with Ag+ in aqueous solution affords the two-dimensional compound {Ag3(H2O)[Cr(dpa)(ox)2]3}n·2nH2O (1) whose structure has been determined by single-crystal X-ray diffraction. Six crystallographically independent metal atoms (three chromium and three silver atoms) occur in 1. The three [Cr(dpa)(ox)2]− units in 1 act as ligands towards the silver atoms through the two oxalate groups. Each oxalate group acts as bridging ligand adopting five coordination modes: bis-bidentate, bis-bidentate/monodentate (outer), bis-bidentate/monodentate (inner), bidentate/bis-monodentate (outer) and bidentate/monodentate (outer).…

Cobalt(II)-Copper(II) Bimetallic Chains as a New Class of Single-Chain Magnets

Crystal growth and structural remarks on malonate-based lanthanide coordination polymers

The synthesis, structural characterization and thermal study of new coordination polymers (CPs) of formula [Ln2(mal)3(H2O)5]·2H2O [Ln = Ho (1·2H2O), Tb (1a), Dy (1b), Er (1c) and Yb (1d); mal = malonate], [Ln2(mal)3(H2O)6] [Ln = Sm (2) and Ce (2a)], [Ce2(mal)3(H2O)6]·2H2O (3·2H2O) and [Ce2(mal)3(H2O)3]·2H2O (4·2H2O) are presented. Complexes 1–4 have been also characterized by single crystal X-ray diffraction. The structure of 2 was previously reported (Elsegood, M. R. J., Husain, S., Private Communication, 2014) and it is very close to that of 3. In the light of these results and those previously reported in the literature for malonate-containing lanthanide(III) complexes, a detailed overvi…

High-dimensional malonate-based materials: Synthesis, crystal structures and magnetic properties of [M2(mal)2(L)(H2O)2]n·n(H2O) M = Zn(ii), Co(ii); H2mal = malonic acid, L = pyrimidine, pyrazine

Four novel coordination polymers [M2(mal)2(pym)(H2O)]n·nH2O, M = Zn (1), Co (2) and [M2(mal)2(pyz)(H2O)]n·nH2O, M = Zn (3), Co (4) (H2mal = malonic acid, pym = pyrimidine, pyz = pyrazine), have been synthesized. Compounds 1 and 2 are isomorphous, as are compounds 3 and 4. X-ray diffraction experiments reveal that 1–4 exhibit an interesting 3D-network, containing malonate and either pyrimidine (1 and 2) and pyrazine (3 and 4) as organic ligands. Variable-temperature magnetic susceptibility measurements indicate the occurrence of weak antiferromagnetic interactions between Co(II) ions in 2 and 4.

Novel malonate-containing coordination compounds with ligands having N-And NO-donors: Synthesis, structures, and magnetic properties

In our efforts to tune the structures of mixed-ligands malonate-containing coordination compounds, four copper(II) and two high-spin cobalt(II) complexes of formulas [Cu(mal)(H 2O)(dpo)] n (1), [Cu 2(mal) 2(H 2O) 2(dpp)] n · 7nH 2O (2), [Cu 2(mal) 2(H 2O) 2-(bpe)] n · 2nH 2O (3), {[Cu(mal) 2(H 2O) 2][Cu(dien)]} n · 4nH 2O (4)[Co 2(mal) 2(H 2O) 6(dpo)] ·2H 2O(5) and [Co(mal)(H 2O)(phen)] n · 2nH 2O (6) [H 2mal = malonic acid, dpo =4,4'-bipyridine-N,N'-dioxide, dpp = 2,3-bis(pyridyl)pyrazine, bpe =1,2-bis(4-pyridyl)ethylene, dien = diethylenetriamine and phen = 1,10-phenanthroline] have been synthesized and structurally characterized by X-ray diffraction on single crystals. Complexes 1, 2, 4,…

Malonate-based copper(II) coordination compounds: Ferromagnetic coupling controlled by dicarboxylates

Studies on structural and magnetic properties of polynuclear transition metal complexes, aimed at understanding the structural and chemical factors governing electronic exchange coupling mediated by multiatom bridging ligands, are of continuing interest to design new molecular materials exhibiting unusual magnetic, optical and electrical properties, bound to their molecular nature. Looking at potentially flexible bridging ligands, the malonate group seems a suitable candidate. The occurrence of two carboxylate groups in the 1,3 positions allows this ligand to adopt simultaneously chelating bidentate and different carboxylato bridging modes (syn–syn, anti–anti and syn–anti trough one or two …

Malonic acid: A multi-modal bridging ligand for new architectures and properties on molecule-based magnets

Abstract In this work, we show how the design of one-, two- and three-dimensional materials can strongly benefit from the use of crystal engineering techniques, which can give rise to structures of different shapes, and how these differences can give rise to different properties. We will focus on the networks constructed by assembling malonate ligands and metal centres. The idea of using malonate (dianion of propanedioic acid, H 2 mal) is that they can give rise to different coordination modes with the metal ions bind. Extended magnetic networks of dimensionalities 1 (1D), 2 (2D) and 3 (3D) can be chemically constructed from malonato-bridged metallic complexes. These coordination polymers b…

Intramolecular ferro- and antiferromagnetic interactions in oxo-carboxylate bridged digadolinium(iii) complexes

Two new digadolinium(III) complexes with monocarboxylate ligands, [Gd2(pac)6(H2O)4] (1) and [Gd2(tpac)6(H2O)4] (2) (Hpac = pentanoic acid and Htpac = 3-thiopheneacetic acid), have been prepared and their structures determined by X-ray diffraction on single crystals. Their structures consist of neutral and isolated digadolinium(III) units, containing six monocarboxylate ligands and four coordinated water molecules, the bridging skeleton being built by a muO(1):kappa2O(1)O(2) framework. This structural pattern has already been observed in the parent acetate-containing compound [Gd2(ac)6(H2O)4] x 4 H2O (3) whose structure and magnetic properties were reported elsewhere (L. Cañadillas-Delgado, …

Protonated malonate: the influence of the hydrogen bonds on the magnetic behaviour

One hydrogen malonato-bridged complex of formula [Cu(Hmal)2] (1) and two polymorphous malonato-bridged complexes of formula [Cu(H2O)(H2mal)(mal)] (2 and 3), in which the three species of the malonate (H2mal, Hmal−, and mal2−) are present, were synthesised and characterized by X-ray diffraction [H2mal = malonic acid]. Their structures consist of corrugated malonate layers of [Cu(Hmal)2] (1) and [Cu(H2O)(H2mal)(mal)] (2 and 3) units bridged by carboxylate–malonate groups. The layers are linked through hydrogen bonds leading to a three-dimensional network. Variable-temperature (1.9–290 K) magnetic susceptibility measurements indicate the occurrence of weak ferromagnetic interactions between th…

Ligand Design for Heterobimetallic Single-Chain Magnets: Synthesis, Crystal Structures, and Magnetic Properties of MIICuII (M=Mn, Co) Chains with Sterically Hindered Methyl-Substituted Phenyloxamate Bridging Ligands

Two new series of neutral ox-amato-bridged heterobimetallic chains of general formula [MCu(L x ) 2 ]- m DMSO (m=0-4) (L 1 =N-2-methyl-phenyloxamate, M=Mn (1a) and Co (1 b); L2 = N-2,6-dimethylphenyloxamate, M=Mn (2a) and Co (2b); L 3 = N-2,4,6-trimethylphenyloxamate, M= Mn (3a) and Co (3b)) have been prepared by reaction between the corresponding anionic oxamatocopper(II) complexes [Cu(L x ) 2 ] 2- with Mn 2+ or Co 2+ cations in DMSO. The crystal structures of [CoCu(L 2 ) 2 (H 2 O) 2 ] (2b') and [CoCu(L 3 ) 2 (H 2 O) 2 ]·4H 2 O (3b') have been solved by single-crystal X-ray diffraction methods. Compounds 2b' and 3b' adopt zigzag and linear chain structures, respectively. The intrachain Cu··…

Structural changes in the crystal packing of highly hindered symmetrical vicinal bis-amides

The crystal structures of 1,4-bis(3,5-di-tert-butyl-2-hydroxybenzamido)butane (1) and 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzamido)-2,2-dimethylpropane (2) have being characterized by single crystal X-ray diffraction. Their crystal packing is discussed in terms of the different interactions they exhibit. A brief discussion, based on hydrogen bonds, on the structural features of bis-(3,5-di-tert-butyl-2-hydroxybenzamide) compounds is carried out.

Building-block process for the synthesis of new chromium(iii) malonate complexes

We describe the crystal structures of two bimetallic compounds with the malonate and an exo-polydentate N-donor ligand {[Cu(tren)]4[Cr2(mal)4(OH)2]}(ClO4)4·8H2O (3) and [Ni(Htren)2][Cr2(mal)4(OH)2]·8H2O (4) which are prepared from the dinuclear K4[Cr2(mal)4(OH)2]·6H2O precursor (2) [tren = tris(2-aminoethyl)amine and H2mal = malonic acid]. Their crystal packing and supramolecular structures are analyzed in the context of the influence of the dichromium(III) [Cr2(mal)4(OH)2]4− unit, which acts as a building-block. Different supramolecular motifs built up from hydrogen bonds are discussed, and their self-assembly to yield a 3D arrangement is described. The magnetic properties of the compounds…

Well-resolved unusual alternating cyclic water tetramers embedded in a crystal host

Infinite network involving two hydrogen-bonded tetrameric water rings (S4 and D2h) in a (4,4)-square grid crystal host

Study of the influence of the bridge on the magnetic coupling in cobalt(II) complexes.

Two new cobalt(II) complexes of formula [Co(2)(bta)(H(2)O)(6)](n) x 2nH(2)O (1) and [Co(phda)(H(2)O)](n) x nH(2)O (2) [H(4)bta = 1,2,4,5-benzenetetracarboxylic acid, H(2)phda = 1,4-phenylenediacetic acid] have been characterized by single crystal X-ray diffraction. Compound 1 is a one-dimensional compound where the bta(4-) ligand acts as 2-fold connector between the cobalt(II) ions through two carboxylate groups in para-conformation. Triply bridged dicobalt(II) units occur within each chain, a water molecule, a carboxylate group in the syn-syn conformation, and an oxo-carboxylate with the mu(2)O(1);kappa(2)O(1),O(2) coordination mode acting as bridges. Compound 2 is a three-dimensional comp…

Nuclearity controlled cyanide-bridged bimetallic CrIII-MnII compounds: synthesis, crystal structures, magnetic properties and theoretical calculations.

The preparation, X-ray crystallography and magnetic investigation of the compounds PPh4[Cr(bipy)(CN)4].2 CH3CN.H2O (1) (mononuclear), [[Cr(bipy)(CN)4]2Mn-(H2O)4].4H2O (2) (trinuclear), [[Cr(bipy)(CN)4]2Mn(H2O)2] (3) (chain) and [[Cr(bipy)(CN)4]2Mn(H2O)].H2O.CH3CN (4) (double chain) [bipy=2,2'-bipyridine; PPh4 (+)=tetraphenylphosphonium] are described herein. The [Cr(bipy)(CN)4]- unit act either as a monodentate (2) or bis-monodentate (3) ligand toward the manganese atom through one (2) or two (3) of its four cyanide groups. The manganese atom is six-coordinate with two (2) or four (3) cyanide nitrogens and four (2) or two (3) water molecules building a distorted octahedral environment. In 4…

Synthesis, crystal structures and magnetic properties of single and double cyanide-bridged bimetallic Fe2(III)Cu(II) zigzag chains.

The bimetallic complexes [[Fe(III)(phen)(CN)4]2Cu(II)(H2O)2].4H2O (1), [[Fe(III)(phen)(CN)4]2Cu(II)].H2O (2) and [[Fe(III)(bipy)(CN)4]2Cu(II)].2H2O (3) and [[Fe(III)(bipy)(CN)4]2Cu(II)(H2O)2].4H2O (4) (phen = 1,10-phenanthroline and bipy = 2,2'-bipyridine) have been prepared and the structures of 1-3 determined by X-ray diffraction. The structure of 1 is made up of neutral cyanide-bridged Fe(III)-Cu(II) zigzag chains of formula [[Fe(III)(phen)(CN)4]2Cu(II)(H2O)2] and uncoordinated water molecules with the [Fe(phen)(CN)4]- entity acting as a bis-monodentate bridging ligand toward two trans-diaquacopper(II) units through two of its four cyanide groups in cis positions. The structure of 2 can …

Single chain magnet behaviour in an enantiopure chiral cobalt(II)–copper(II) one-dimensional compound

The self-assembly of an enantiomerically pure, chiral dianionic oxamatocopper(II) complex with cobalt(II) ions leads to neutral oxamato-bridged heterobimetallic chains that combine chirality and slow magnetic relaxation, providing thus the first example of ‘‘chiral single chain magnets (CSCMs). Ruiz Garcia, Rafael, Rafael.Ruiz@uv.es ; Lloret Pastor, Francisco, Francisco.Lloret@uv.es

Molecular-Programmed Self-Assembly of Homo- and Heterometallic Tetranuclear Coordination Compounds: Synthesis, Crystal Structures, and Magnetic Properties of Rack-Type CuII2MII2 Complexes (M = Cu and Ni) with Tetranucleating Phenylenedioxamato Bridging Ligands

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 (…

Trans-dicyanobis(acetylacetonato)ruthenate(III) as a precursor to build novel cyanide-bridged RuIII–MII bimetallic compounds [M=Co and Ni]

Abstract The use of the mononuclear complex trans-[Ru(acac)2(CN)2]− as a ligand towards the preformed species [Ni2L(H2O)2Cl2], [Co(dmphen)](NO3)2, [Ni(dmphen)](NO3)2 and [Co(H2O)6](NO3)2 afforded the novel cyanide-bridged bimetallic compounds of formula [{Ru(acac)2(CN)2}{Ni2(L)(H2O)2}]{Ru(acac)2(CN)2}·2H2O (1), [{Ru(acac)2(CN)2}{Co(dmphen)(NO3)}]·H2O (2) and [{Ru(acac)2(CN)2}{Ni(dmphen)(NO3)}]·H2O (3) and [{Ru(acac)2(CN)2}2Co] (4) [Hacac = acetylacetone, dmphen = 2,9-dimethylphenanthroline and H2L = 11,23-dimethyl-3,7,15,19-tetrazatricyclo[19.3.1.19,13]hexacosa-2,7,9,11,13(26),14,19,21(25),22,24-decaene-25,26-diol]. Their syntheses, X-ray crystal structures and magnetic properties are repor…

Synthesis, crystal structures and magnetic properties of tricyanomethanide-containing copper(II) complexes

The preparation, crystal structures and magnetic properties of the copper(II) complexes of formula [Cu(pyim)(tcm)(2)](n) (1), [Cu(bpy)(tcm)(2)](n) (2), [Cu(4)(bpz)(4)(tcm)(8)] (3), {[Cu(terpy)(tcm)].tcm}(n) (4) and {[Cu(2)(tppz)(tcm)(4)].3/2H(2)O}(n) (5) [pyim = 2-(2-pyridyl)imidazole, tcm = tricyanomethanide, bpy = 2,2'-bipyridine, bpz = 2,2'-bipyrazine, terpy = 2,2':6',2''-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine] are reported. Complexes, 1, 2 and 4 are uniform copper(II) chains with single- (1 and 4) and double-(2) micro-1,5-tcm bridges with values of the intrachain copper-copper separation of 7.489(1) (1), 7.520(1) and 7.758(1) (2) and 7.469(1) A (4). Each copper atom …

Dinuclear and two- and three-dimensional gadolinium(III) complexes with mono- and dicarboxylate ligands: synthesis, structure and magnetic properties

Three new gadolinium(III) complexes with carboxylate ligands of formula [Gd2(ac)6(H2O)4]·2H2O (1), [Gd2(ac)2(fum)2(H2O)4]n (2) and [Gd2(ox)(fum)2(H2O)4]n·4nH2O (3) (ac = acetate, fum = fumarate and ox = oxalate) have been prepared and their structures determined by X-ray diffraction on single crystals. The structure of 1 is made up of discrete centrosymmetric di-µ-oxo(carboxylate acetate)digadolinium(III) units with an intramolecular Gd⋯Gd separation of 4.1589(3) A. Each gadolinium atom in 1 is nine-coordinated with two water molecules and seven carboxylate-oxygen atoms from four acetate ligands building a monocapped square antiprism environment. Compound 2 exhibits a sheet-like structure, …

Design of single chain magnets through cyanide-bearing six-coordinate complexes

Abstract The design and preparation of stable cyanide-bearing six-coordinate complexes of formula [MIII(L)(CN)x](x + l − m)− (M = trivalent transition metal ion and L = polydentate blocking ligand) are summarized here. Their use as ligands towards either fully hydrated metal ions or coordinatively unsaturated preformed species, to afford a wide variety of low-dimensional metal assemblies whose nuclearity, dimensionality and magnetic properties can be tuned, is also reviewed. Special emphasis is put on the appropriate choice of the end-cap ligand L whose denticity determines the number of coordinated cyanide groups in the mononuclear precursors. Among the different new spin topologies obtain…

Cobalt(II) Sheet-Like Systems Based on Diacetic Ligands: from Subtle Structural Variances to Different Magnetic Behaviors

The preparation, X-ray crystallography, and magnetic investigation of the compounds [Co(H(2)O)(2)(phda)](n) (1), [Co(phda)](n) (2), and [Co(chda)](n) (3) [H(2)phda = 1,4-phenylenediacetic acid and H(2)chda = 1,1-cyclohexanediacetic acid] are described herein. The cobalt atoms in this series are six- (1) and four-coordinated (2 and 3) in distorted octahedral (CoO(6)) and tetrahedral (CoO(4)) environments. The structures of 1-3 consists of rectangular-grids which are built up by sheets of cobalt atoms linked through anti-syn carboxylate bridges, giving rise to either a three-dimensional structure across the phenyl ring (1 and 2) or to regularly stacked layers with the cyclohexyl groups acting…

1,2,4,5‐Benzenetetracarboxylic Acid and 4,4′‐Bipyridine as Ligands in Designing Low‐Dimensional Coordination Polymers

The combined use of 1,2,4,5-benzenetetracarboxylic acid (H4bta) and 4,4′-bipyridine (bpy) as ligands with MnII and CoII ions afforded two polymeric compounds with the formulae [Mn(Hbta)(Hbpy)(H2O)2] (1) and [H2bpy][Co(bta)(bpy)(H2O)2] (2). 1 and 2 were prepared under hydrothermal conditions (145 °C, 3 h) and characterized by elemental analysis, IR spectroscopy, TG-DTA analysis and single-crystal X-ray diffraction methods. 1 exhibits a novel double chain structure growing along the b axis where the manganese atoms are linked by tris-monodentate Hbta3− ligands. The values of the manganese···manganese intrachain separations are 7.627(2) A [Mn(1)···Mn(1c); c = −x + 1/2, y − 1/2, −z] and 9.274(4…

Low-dimensional copper(II) complexes with the trinucleating ligand 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine: synthesis, crystal structures, and magnetic properties.

The preparation and structural characterization of three new copper(II) complexes of formula [Cu(3)(dipyatriz)(2)(H(2)O)(3)](ClO(4))(6) x 2 H(2)O (1), {[Cu(4)(dipyatriz)(2)(H(2)O)(2)(NO(3))(2)(ox)(2)](NO(3))(2) x 2 H(2)O}(n) (2), and [Cu(6)(dipyatriz)(2)(H(2)O)(9)(NO(3))(3)(ox)(3)](NO(3))(3) x 4 H(2)O (3) [dipyatriz = 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine and ox = oxalate] are reported. The structure of 1 consists of trinuclear units [Cu(3)(dipyatriz)(2)(H(2)O)(3)](6+) and uncoordinated perchlorate anions. The two dipyatriz molecules in 1 act as tris-bidentate ligands with the triazine cores being in a quasi eclipsed conformation. Each copper atom in 1 exhibits a distorted square pyr…

Versatile supramolecular self-assembly : Part II. Network formation and magnetic behaviour of copper(ii) malonate anions in ammonium derivatives

Five new metal–organic compounds of formula An[Cu(mal)2(H2O)m] (A being an amine cation and H2mal = malonic acid) have been structurally and magnetically characterized. The crystal structure of these compounds consists of an alternation of malonate-containing copper(II) anionic and amine cationic layers. Depending on the amine cation, the bis(malonate)cuprate(II) units can be connected to other units through carboxylate bridges resulting in anionic networks which exhibit different topologies: monomers (2 and 5), layers (3 and 4) and three-dimensional structures (1). Hydrogen bonding plays an important role in the self-assembling of metal–organic compounds and how the size of the amine catio…

The flexibility of molecular components as a suitable tool in designing extended magnetic systems

In this work we show how the design of n-dimensional magnetic compounds (nD with n = 1–3) can strongly benefit from the use crystal engineering techniques, which can give rive to structures of different shapes with different properties. We focus on the networks built by assembling the malonato-bridged tetranuclear copper(II) units Cu4(mal)4 (mal2− is the dianion of propanedioic acid, H2mal) through the potentially bridging 2,4′-bipyridine (2,4′-bpy), 4,4′-bipyridine (4,4′-bpy) and pyrazine (pyz). The magneto-structural study of the complexes of formula [Cu4(mal)4(2,4′-bpy)4(H2O)4]·8H2O (1), [Cu4(mal)4(H2O)4(4,4′-bpy)2] (2) (this compound was the subject of a previous report but it is includ…

Versatile supramolecular self-assembly. Part I. Network formation and magnetic behaviour of the alkaline salts of the bis(malonate)cuprate(ii) anion

Five malonate-containing copper(II) compounds of formula {[A(H2O)n]2 [Cu(mal)2(H2O)m]} [A = Li (1), Na (2), K (3), Rb (4) and Cs (5); H2mal = malonic acid] have been synthetized and characterized by X-ray diffraction. The structure of these compounds consists of bis(malonate)cuprate(II) anions and alkaline cations that are held together by means of carboxylate bridges and water molecules leading to 3D networks. A study of the self-assembling of the bis(malonate)cuprate(II) and the alkaline cations is carried out, the size of the alkaline metal ion playing an important role in the control of the resulting malonate-bridged copper(II) structure. A regular alternation of layers of anionic malon…

Novel cobalt(II) coordination polymers based on 1,2,4,5-benzenetetracarboxylic acid and extended bis-monodentate ligands

Four new high-spin cobalt(II) complexes of formulae [Co2(bta)(4,4′-bpy)2(H2O)2]n (1), {Hbpe[Co(Hbta)(bpe)(H2O)2]}n (2), {[Co(H2bta)(azpy)(H2O)2]·azpy}n (3) and {[Co2(bta)(bpa)2(H2O)4]·8H2O}n (4) with H4bta = 1,2,4,5-benzenetetracarboxylic acid, 4,4′-bpy = 4,4′-bipyridine, bpe = trans-1,2-bis(4-pyridyl)ethene, azpy = 4,4′-azobispyridine and bpa = trans-1,2-bis(4-pyridyl)ethane, have been prepared and characterized by single crystal X-ray diffraction. Compounds 1–4 exhibit two-dimensional networks where the fully (1 and 4) or partially (2 and 3) deprotonated tetracarboxylic ligand connects two (2 and 3) or four (1 and 4) cobalt(II) ions through two trans-carboxylate (1–3) or all the carboxyla…

Structural versatility of the malonate ligand as a tool for crystal engineering in the design of molecular magnets

The synthesis of ferro- and ferri-magnetic systems with a tunable Tc and three-dimensional (3-D) ordering from molecular precursors implying transition metal ions is one of the active branches of molecular inorganic chemistry. The nature of the interactions between the transition metal ions (or transition metal ions and radicals) is not so easy to grasp by synthetic chemists working in this field since it may be either electrostatic (orbital) or magnetic (mainly dipolar). Therefore, the systems fulfilling the necessary requirements to present the expected magnetic properties are not so easy to design on paper and realize in the beaker. In this work we show how the design of one-, two- and t…

New anionic cobalt complexes using highly hindered bis-amides with varying donor abilities as ligands.

Four potential tetradentate ligands of formulae 1,2-bis-(3,5-di-tert-butyl-2-hydroxybenzamido)ethane (H(4)L(1), 1), 1,2-bis-(3,5-di-tert-butyl-2-hydroxybenzamido)propane (H(4)L(2), 2), 1,2-bis-(3,5-di-tert-butyl-2-hydroxybenzamido)benzene (H(4)L(3), 3) and 1,8-bis-(3,5-di-tert-butyl-2-hydroxybenzamido)naphthalene (H(4)L(4), 4) have been prepared and the crystal structures of three of them (1, 3 and 4) determined by single crystal X-ray diffraction. The investigation of their complexing ability toward Co(II) afforded the compounds of formulae [Co(III)(L(3))Na(I)(H(2)O)(2)] (5), [Co(III)(L(n))Li(I)(H(2)O)2] with n = 1 (6), 2 (7) and 3 (8) and [Co(II)(L(4))Li(I)(2)] (9). Complexes 5-8 are squa…

Synthesis, crystal structure and magnetic properties of two-dimensional malonato-bridged cobalt(ii) and nickel(ii) compounds

Two isostructural malonato-bridged complexes of formula {[M(H2O)2][M(mal)2(H2O)2]}n [M = Co(II) (1), Ni(II) (2); H2mal = malonic acid] have been synthesised and characterized by X-ray diffraction. Their structure consists of corrugated layers of trans-diaquabismalonatemetalate(II) and trans-diaquametal(II) units bridged by carboxylate–malonate groups in the anti–syn conformation. Two crystallographycally independent metal atoms occur in 1 and 2. The malonate anion acts simultaneously as a bidentate and bis-monodentate ligand. Variable-temperature (1.9–295 K) magnetic susceptibility measurements indicate the occurrence of weak antiferro- (1) and ferromagnetic (2) interactions between the cob…

The construction of open GdIII metal–organic frameworks based on methanetriacetic acid: New objects with an old ligand

11 páginas, 11 figuras, 2 esquemas.-- et al.

CCDC 294297: Experimental Crystal Structure Determination

Related Article: Fernando S. Delgado, Pablo Lorenzo-Luís, Jorge Pasán, Laura Cañadillas-Delgado, Oscar Fabelo, María Hernández-Molina, Antonio D. Lozano-Gorrín, Francesc Lloret, Miguel Julve, Catalina Ruiz-Pérez|2016|CrystEngComm|18|7831|doi:10.1039/C6CE01360K

CCDC 294298: Experimental Crystal Structure Determination

Related Article: Fernando S. Delgado, Pablo Lorenzo-Luís, Jorge Pasán, Laura Cañadillas-Delgado, Oscar Fabelo, María Hernández-Molina, Antonio D. Lozano-Gorrín, Francesc Lloret, Miguel Julve, Catalina Ruiz-Pérez|2016|CrystEngComm|18|7831|doi:10.1039/C6CE01360K

CCDC 1475076: Experimental Crystal Structure Determination

Related Article: Fernando S. Delgado, Pablo Lorenzo-Luís, Jorge Pasán, Laura Cañadillas-Delgado, Oscar Fabelo, María Hernández-Molina, Antonio D. Lozano-Gorrín, Francesc Lloret, Miguel Julve, Catalina Ruiz-Pérez|2016|CrystEngComm|18|7831|doi:10.1039/C6CE01360K

CCDC 294299: Experimental Crystal Structure Determination

Related Article: Fernando S. Delgado, Pablo Lorenzo-Luís, Jorge Pasán, Laura Cañadillas-Delgado, Oscar Fabelo, María Hernández-Molina, Antonio D. Lozano-Gorrín, Francesc Lloret, Miguel Julve, Catalina Ruiz-Pérez|2016|CrystEngComm|18|7831|doi:10.1039/C6CE01360K