Malonate Dianion Research Articles

Aquamalonato(1,10-phenanthroline)copper(II) sesquihydrate

In the title compound, [Cu(C3H4O4)(C12H8N2)(H2O)]·1.5H2O, there are two complex mol­ecules and three uncoordinated water mol­ecules in the asymmetric unit. In both complex mol­ecules, the Cu atom is five-coordinated by one bidentate 1,10-phenanthroline mol­ecule, one bidentate malonate dianion and one water mol­ecule, resulting in a distorted square-based pyramidal CuN2O3 chromophore. The structure is stabilized by O—H⋯O hydrogen bonds involving both the coordinated and uncoordinated water mol­ecules.

A novel three-dimensional malonate-bridged complex {[Cu4(4,4′- bpy)8(mal)2(H2O)4](ClO4)2(H2O)4(CH3OH)2}n

A novel malonate-bridged copper (II) compound of formula {[Cu4(4,4′-bpy)8(mal)2(H2O)4](ClO4)2(H2O)4(CH3OH)2}n (4,4′-bpy = 4,4′-bipyridine; mal = malonate dianion) has been prepared and structurally characterized by X-ray crystallography. This compound exhibits a novel three-dimensional network being composed of Cu-4,4′-bipyridine layers which are pillared by malonate bridge ligands. The copper(II) ions has two different coordination environment.

Crowned Tetrameric Spirocyclic Water Chain: An Unusual Building Block of a Supramolecular Metal−Organic Host

A 3D supramolecular metal−organic host could be realized in solid in which the water assembly as a whole acted as a building block of the 3D framework with rectangular channels where guest molecules reside, adding a new dimension to water cluster research where the role of water has been shifted from its usual behavior of guest to that of a host. The crystal structure of the compound, {[Cu(mal)2](picH)2·5H2O}n, 1 [mal = malonate dianion, picH = protonated 2-amino-4-picoline], synthesized from purely aqueous media, shows that the Cu(II)−malonate 2D coordination polymeric sheets are locked together by the water assembly that lines up perpendicular to the Cu(II)−malonate sheets constituting a 3D infinite supramolecular host where within the channels protonated 2-amino-4-picoline auxiliary ligands are accommodated. A spirocyclic tetrameric water chain having a dimeric crown on it describes the composition of the water assembly that runs down the c-axis.

Synthesis, crystal structure and magnetic properties of novel heterobimetallic malonate-bridged MIIReIV complexes (M = Mn, Fe, Co and Ni)

Five novel ReIV-MII bimetallic complexes of formula [ReCl4(mu-mal)M(dmphen)2].MeCN [M = Co (1), Fe (2) and Ni (3)], [ReCl4(mu-mal)Ni(dmphen)(MeCN)2(H2O)].(MeCN)0.5(H2O)0.5 (4), and [ReCl4(mu-mal)Mn(dmphen)(H2O)2].dmphen.MeCN.H2O (5) (mal = malonate dianion, dmphen = 2,9-dimethyl-1,10-phenanthroline) have been synthesized, and the structures of 1, 2, 4, and 5 determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of neutral [ReCl4(mu-mal)M(dmphen)2] dinuclear units where the metal ions are linked through a malonate ligand which adopts simultaneously the bidentate (at ReIV) and monodentate (at MII) coordination modes. The bridging carboxylate-malonate group in them exhibits the anti-syn conformation. The rhenium atom is six-coordinated with four chloro atoms and two carboxylate-oxygens from a bidentate malonate group in a distorted octahedral environment. The M atom is five-coordinated being surrounded by four nitrogen atoms of two bidentate dmphen ligands and one oxygen atom of the malonato ligand. There are also ReIV(mu-mal)NiII dinuclear units in 4 with the same type of bridge, but the nickel atom is six-coordinated with one bidentate dmphen, two molecules of acetonitrile and one water molecule as peripheral ligands. Compound 5 is a neutral chain compound with regular alternating rhenium(IV) and manganese(II) ions. The [ReCl4(mal)]2- units in each chain act as bismonodenate ligands through two carboxylate-oxygen atoms toward [Mn(dmphen)(H2O)2]2+ entities. Variable-temperature magnetic measurements of 1-5 in the temperature range 2.0-300 K show the occurrence of weak antiferromagnetic interactions which are rationalized on the basis of the structural knowledge and simple orbital considerations. Very noticeable is compound 5, a ferrimagnetic chain with regular alternating ReIV and MnII cations.

Syntheses and crystal structures of copper(II) complexes derived from 2,4,6-tris(2-pyridyl)-1,3,5-triazine

Treatment of freshly precipitated Cu(OH)2 · xH2O and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) with oxalic and malonic acids in methanol-water at room temperature gave [Cu(tptz)(C2O4)(H2O)] · 4H2O (1) and [Cu(pma)(C3H2O4)(H2O)] · H2O (2) (pma = 2-aminocarbonylpyridine), respectively. Reaction in the absence of any acid resulted in [Cu(bpca)(tca)] · 2H2O (3) (bpca = bis(2-pyridylcarbonyl)amide anion; tca = 2-pyridinecarboxylate anion). Complex 1 consists of [Cu(tptz)(C2O4)(H2O)] and lattice H2O molecules; the tridentate tptz ligand, bidentate oxalate dianion and an aqua ligand are bound to Cu with distorted octahedral geometry. Complex 2 is composed of [Cu(pma)(C3H2O4)(H2O)] and lattice H2O molecules; the bidentate 2-aminocarbonylpyridine ligand, a bidentate malonate dianion and an aqua ligand are coordinated to Cu with a slightly distorted square pyramidal geometry. Complex 3 consists of [Cu(bpca)(tca)] and lattice H2O molecules. Square pyramidally coordinated Cu atoms are surrounded by tridentate bpca with nitrogen donor atoms and a bidentate 2-pyridinecarboxylate anion.

Lithium(I) hexaamminecobalt(III) tetrakis(malonato-κ2O,O′′)plutonate(IV) pentahydrate

The title compound, Li[Co(NH3)6][Pu(C3H2O4)4]·5H2O, contains isolated [Pu(C3H2O4)4]4− complex anions. Each malonate dianion binds to the Pu atom in a bidentate fashion, resulting in the formation of six-membered metallocycles. The coordination environment of the Pu atom is a distorted square anti­prism. The average Pu—O distance is 2.318 (10) Å, about 0.08 Å shorter than in analogous ThIV complexes.

Poly[diaqua-di-μ-malonato-cobalt(II)disodium(I)

In the title compound, [CoNa2(C3H2O4)2(H2O)2] n , a heterobimetallic malonate complex, both CoII and NaI ions have distorted octahedral coordination geometries. The CoII ions are located on inversion centres and are surrounded only by carboxylate O atoms, while the NaI ions are coordinated both by water and by carboxylate O atoms. The malonate dianions show an unusual heptadentate bridging mode.

Poly[diaquadi-μ-malonato-manganese(II)disodium(I)

The title compound, [Na2Mn(C3H2O4)2(H2O)2]n, obtained by the hydro­thermal reaction of MnCl2·4H2O, NaOH and malonic acid, is a three-dimensional polymeric complex bridged by malonate dianions. The MnII atom, which occupies an inversion centre, has distorted octa­hedral coordination, with Mn—O bonds in the range 2.1168 (10)–2.2666 (10) Å. The NaI atom has slightly distorted octa­hedral coordination, with Na—O distances ranging from 2.3700 (14) to 2.6117 (12) Å.

Poly[tetraaquadi-μ4-malonato-barium(II)zinc(II)

The title complex, [BaZn(C3H2O4)2(H2O)4]n, is polymeric, due to the connectivity brought about by each malonate dianion bonding to two different Zn(II) cations and two different Ba(II) cations. The Ba(II) cations, on crystallographic twofold axes, have slightly distorted square-antiprismic coordination, with Ba-O distances ranging from 2.795 (2) to 2.848 (2) A. The Zn(II) cations, which lie on crystallographic centres of symmetry, have distorted octahedral coordination, with Zn-O bonds in the range 2.0364 (19)-2.3248 (18) A. The water molecules participate in extensive O-H...O hydrogen bonding. The structure comprises alternating layers along [100], with one type containing Zn(II) cations and malonate dianions, while the other is primarily composed of Ba(II) cations and water molecules.

Diaquamalonato(1,10-phenanthroline)zinc(II)

In the crystal structure of the title complex, [Zn(C3H2O4)(C12H8N2)(H2O)2], the Zn(II) atom displays a distorted octahedral geometry, being coordinated by two N atoms from the 1,10-phenanthroline ligand, two O atoms from different carboxylate groups of the chelating malonate dianion and two O atoms of cis water molecules. The complex molecules are linked to form a three-dimensional supramolecular array by both hydrogen-bonding interactions between coordinated water molecules and the uncoordinated carboxylate O atoms of neighboring molecules, and aromatic pi-pi stacking interactions between neighboring phenanthroline rings.

Trans-Diaqua(malonato)(1,10-phenanthroline)nickel(II) trihydrate

The title complex, [Ni(C3H2O4)(C12H8N2)(H2O)2]·3H2O, displays a distorted octa­hedral NiN2O4 coordination geometry, formed by a malonate dianion, a 1,10-phenanthroline ligand and two trans water mol­ecules. The Ni atom and one O atom, the latter from a solvent water mol­ecule, are located on twofold axes of symmetry. The crystal structure is stabilized by extensive O—H⋯O hydrogen-bonding inter­actions.

Synthesis and Crystal Structures of Two Metal Complexes Incorporating Malonate and Organodiamine Ligands

Investigation on novel organic-inorganic hybrid framework assemblies represents one of the most active areas of material science and chemical research. Major advances have been made in these materials due to their interesting properties and potential in various applications, e.g., electrical conductivity, magnetism, host-guest chemistry, ion exchange, catalysis, nonlinear optics, etc. Moreover, discovery and design of such new materials with specific networks remain of a particularly important and active subject in the field of supramolecuar chemistry and crystal engineering. A variety of complexes with interesting compositions and topologies have been prepared through taking certain factors into account, such as the coordination nature of the metal ion and the shape, functionality, flexibility, and symmetry of organic ligand. Recently, some dicarboxylate ligands, such as oxalate, malonate, and terephthalate, have been widely used in the construction of these interesting structures. Among them, the malonate dianion can function as a versatile bridging ligand, and the complexity of its structure is associated with the simultaneous adoption of chelating bidentate and different carboxylate bridging coordination modes like syn-syn, syn-anti and anti-anti. On the other hand, an example of the advance in the field of supramolecular chemistry and crystal engineering is the generation of polymeric structures by applying carboxylate bridging ligands together with organodiamine ligands (such as 4,4'-, 2,2'-bypyridine and 1,10-phenanthroline). A larger number of this type of complexes have been synthesized and characterized recently, whereas the structural chemistry of metal complexes incorporating mixed malonate and organodiamine ligands has been less studied. In the present work we report the synthesis and X-ray crystal structures of two new malonato complexes incorporating organodiamine ligands: [Ni(phen)(mal)(H2O)2]·3H2O (H2mal = malonic acid, phen = 1,10-phenanthroline) (1) and [Zn(bpy)(H2O)]2[Zn(bpy)(mal)(H2O)2]2(NO3)4·4H2O (bpy = 2,2'-bipyridine) (2).

Zwitterion−Dianion Complexes and Anion−Anion Clusters with Negative Dissociation Energies

Clusters of oxalate and malonate dianions with glycine in its zwitterionic form were found by ab initio and density functional theory calculations. Proton transfer is impeded by an electrostatic barrier, but the resulting anion-anion pairs form complexes despite having negative dissociation energies. A variety of X-/Y- species with exothermic dissociation energies ranging from 10 to 141 kcal mol-1, but large enough barriers to be experimentally produced, are reported. These dianions may represent an unrecognized control element in nature and provide a unique opportunity to probe electrostatic effects and a wealth of novel clusters.

Synthesis, characterization and crystal structures of two discrete Cu(II) complexes with mixed-ligands: [Cu(mal)( L)(H 2O)]·H 2O and [Cu(Phmal)( L) 2] (mal=malonate dianion, phmal=phenylmalonate dianion and L=5,5′-dimethyl-2,2′-bipyridine)

Two new Cu(II) complexes with mixed ligands, [Cu(mal)( L)(H 2O)]·H 2O ( 1) and [Cu(phmal)( L)] 2 ( 2) (mal=malonate dianion, phmal=phenylmalonate dianion, L=5,5′-dimethyl-2,2′-bipyridine) have been synthesized and characterized by elemental analyses, IR, UV–vis and X-ray single crystal diffraction. In both complexes the Cu(II) ions take five-coordinated square pyramidal geometry. 1 has a mononuclear structure, and assembles into a 2D supramolecular network by hydrogen bonding. 2 is a dinuclear complex, and also forms 2D framework via π–π interactions. The structural differences of the two complexes may be attributed to the variation of the substituted group of malonate dianion.

Synthesis of a metal–dicarboxylate hybrid with three dimensional Na–O–Cu connectivity: structure, magnetic property and controlled solid state thermolysis leading to CuO nanorod

A one-pot reaction of CuCl 2 · 2H 2O and malonic acid leads to a novel three dimensional inorganic–organic hybrid framework, [Na 2Cu(mal) 2(H 2O) 2] n , ( 1) (mal = malonate dianion). Single crystal X-ray structure of 1 reveals that it is a novel heterometallic three dimensional coordination-polymeric network which consists of interlocked anionic Cu–malonate and cationic Na–water–malonate sheets, where malonate dianion functions as an unprecedented heptadentate ligand. Low temperature magnetic study reveals that the compound is weak ferromagnetically coupled and this is supported by magneto-structural correlation. Thermogravimetric analyses are performed and it is observed that complex 1 upon heating finally transforms to CuO, which is evident by X-ray powder diffraction technique. Controlled solid state thermolysis of complex 1 at ∼850 °C for 24 h leads to the formation of CuO nanorods, which is confirmed by scanning electron microscopy and X-ray powder diffraction technique. The nanorods formed here have average diameters of ca. 40–200 nm and lengths up to 13 μm.

Syntheses and crystal structures of two 2D coordination polymers of cobalt(II) and nickel(II) with the Malonate Dianion Ligand

Two 2D complexes, [Co(mal)(phen)(H2O)2] (1) and [Ni(mal)(phen)(H2O)2] (2) (mal = malonate dianion; phen = 1,10-phenanthroline), have been synthesized by the reaction of Co(ClO4)2·6H2O and Ni(ClO4)2·6H2O with disodium malonate and 1,10-phenanthroline in MeOH/H2O solution. Their crystal structures have been determined by X-ray diffraction. The structures of Complexes 1 and 2 show that each metal ion is coordinated by one 1,10-phenanthroline, two water molecules and a malonate ligand forming a distorted octahedral environment and each mononuclear fragment forms a 2D supramolecular network through H-bonding interactions.

Cis-Diaquamalonato(1,10-phenanthroline)manganese(II)

In the title complex, [Mn(C3H2O4)(C12H8N2)(H2O)2], the MnII atom displays a distorted octahedral geometry, being coordinated by two N atoms of a 1,10-phenanthroline ligand, two O atoms from the carboxyl­ate groups of the chelating malonate dianion and two O atoms of cis water mol­ecules. The complex mol­ecules are linked to form a three-dimensional supramolecular array via O—H⋯O hydrogen bonds and π–π interactions.

Rhenium(IV)−Copper(II) Heterobimetallic Complexes with a Bridge Malonato Ligand. Synthesis, Crystal Structure, and Magnetic Properties

The Re(IV) complex [ReCl4(mal)]2-, in the form of two slightly different salts, (AsPh4)1.5(HNEt3)0.5[ReCl4(mal)] (1a) and (AsPh4)(HNEt3)[ReCl4(mal)] (1b), and the Re(IV)-Cu(II) bimetallic complexes [ReCl4(mu-mal)Cu(phen)2].CH3CN (2), [ReCl4(mu-mal)Cu(bpy)2] (3), and [ReCl4(mu-mal)Cu(terpy)] (4) (mal=malonate dianion, AsPh4=tetraphenylarsonium cation, HNEt3=triethylammonium cation, phen=1,10-phenanthroline, bpy=2,2'-bipyridine and terpy=2,2':6',2' '-terpyridine) have been synthesized and the structures of 1a, 1b, 2, and 3 determined by single-crystal X-ray diffraction. The structures of 1a and 1b are made up of discrete [ReCl4(mal)]2- anions and AsPh4+ and HNEt3+ cations, held together by electrostatic forces and hydrogen bonds. The Re(IV) atom is surrounded by four chloride anions and a bidentate malonate group, in a distorted octahedral environment. The structure of 2 consist of neutral dinuclear units [ReCl4(mu-mal)Cu(phen)2], with the metal ions united through a bridge carboxilato. The environment of Re(IV) is nearly identical to that in the mononuclear complex, and Cu(II) is five coordinate, being surrounded by four nitrogen atoms of two bidentate phen ligands and one oxygen atom of the malonato ligand. In 3, there are also dinuclear units, [ReCl4(mu-mal)Cu(bpy)2], but the Cu(II) ions complete a distorted octahedral coordination by binding with the free malonato oxygen atom of a neighbor unit, resulting in an infinite chain. The magnetic properties of 1-4 were also investigated in the temperature range 2.0-300 K. The magnetic behavior of 1a and 1b is as expected for a Re(IV) complex with a large value of the zero-field splitting (2D ca. 110 cm(-1)). For the bimetallic complexes, the magnetic coupling between Re(IV) and Cu(II) is antiferromagnetic in 2 (J=-0.39 cm(-1)), ferromagnetic in 4 (J=+1.51 cm(-1)), and nearly negligible in 3 (J=-0.09 cm(-1)).

A novel 3D malonato-bridged compound Cu(mal)(pz) 2: synthesis, spectroscopy, crystal structure and magnetism

A novel 3D malonato-bridged copper(II) complex of formula Cu(mal)(pz) 2 ( 1) (mal = malonate dianion; pz = pyrazole) has been prepared and characterized by elemental analyses, IR, electronic and EPR spectroscopies, TG analysis, single crystal X-ray diffraction and magnetic susceptibility. 1 crystallizes in the tetragonal space group I4(1), a = 9.4951(16) Å, b = 9.4951(16) Å, c = 12.620(4) Å, V = 1137.8(5) Å 3, Z = 4. The 3D framework of the title compound is formed by the connection of malonate bridges. Magnetic characterization of 1 suggests that the complex exhibits overall a weak ferromagnetic coupling with an antiferromagnetic interaction in the very low temperature range.

The tris(malonato)chromate(III) anion with an organic cation

The structure of 1,2-bis(4-pyridyl)­ethyl­enium tris­(malonato-κ2O,O′)­chromate(III) octahydrate, (Hbpe)3[Cr(mal)3]·8H2O, where mal is the malonate dianion (C3HO42−) and bpe is 1,2-bis(4-pyridyl)­ethyl­ene (C12H12N2), is presented. The crystal structure is made up of [Cr(mal)3]3− anions, Hbpe+ cations and water mol­ecules of crystallization. The anions are connected through hydrogen bonding involving malonate O atoms and uncoordinated water mol­ecules in distinct layers, with the cations stacked in separate layers. One of the Hbpe cations is located on a center of inversion, another one on a twofold rotation axis.