organic compounds
Crystalline cyano-stabilized triphenylphosphonium ylids with keto or ester groups give rise to an extended electronic delocalization. In methyl 2-cyano-2-(trimethylphosphonio)ethenoate, Ph3P=C(CN)CO2CH3 or C22H18NO2P, (I), and 1-cyano-1-(trimethylphosphonio)prop-1-en-2-olate, Ph3P=C(CN)CO-CH3 or C22H18NOP, (II), the carbonyl groups are oriented toward the cationoid P atom. Bond lengths and angles, torsion angles and PO contact distances are consistent with a dominant coplanar conformation where the molecular structures are the result of a balance between intra- and intermolecular interactions. The main interactions presented by cyano-ester (I) and cyano-keto (II) are intramolecular interactions between the carbonyl O and the P atoms. In addition, both compounds show other less important intramolecular interactions between the carbonyl O and phenyl H atoms, which could contribute to form a preferred conformation in the crystal structure.
metal-organic compounds
catena-Poly[[[tetraaquazinc(II)]-μ-4,4′-bipyridine-κ2N:N′] [[μ-thiosulfato-κ2O:S-bis[(thiosulfato-κS)zinc(II)]]-di-μ-4,4′-pyridine-κ4N:N′] dihydrate], {[Zn(C10H8N2)(H2O)4][Zn2(S2O3)3(C10H8N2)2]·2H2O}n, is a polymeric zinc complex built up from thiosulfate-containing anionic chains, where the Zn atom is tetrahedrally coordinated, and aqua-containing cationic chains incorporating octahedrally coordinated Zn. In each type of chain, the 4,4′-bipyridine units act as spacers, and the chains run along three non-intersecting almost orthogonal directions in space. The profusion of hydrogen-bond donors (all the H atoms of the water molecules) and acceptors (the thiosulfate O and S atoms) generates a very complex hydrogen-bonding scheme.
metal-organic compounds
catena-Poly[[[tetraaquanickel(II)]-μ-4,4′-bipyridine-κ2N:N′] thiosulfate dihydrate], {[Ni(C10H8N2)(H2O)4]S2O3·2H2O}n, (I), and catena-poly[[[tetraaquanickel(II)]-μ-4,4′-bipyridine-κ2N:N′] sulfate methanol solvate monohydrate], {[Ni(C10H8N2)(H2O)4]SO4·CH4O·H2O}n, (II), are built up of {[Ni(4,4′-bipy)(H2O)4]2+}n chains (4,4′-bipy is 4,4′-bipyridine) interwoven in an unusual P31 fashion. Voids are filled by the corresponding counter-anions and solvate molecules, defining a complex three-dimensional network surrounding them. In both structures, the cationic chains evolve around a set of twofold axes passing through the NiII ions and bisecting the aromatic amines through their N (and their opposite C) atoms.
metal-organic compounds
The title compound, {[Zn2(SO3)2(C10H8N2)]·H2O}n, is a two-dimensional polymer built up of a [ZnSO3]n chain evolving around a 21 axis and interconnected by a 4,4′-bipyridine spacer. The resulting two-dimensional structures are linked, in turn, by hydrogen bonding mediated by the solvent water molecule. The organic ligand lies on a centre of symmetry located on the mid-point of the bond between the rings, while the solvent water molecule is halved by a twofold axis passing through the O atom.
metal-organic compounds
Two polymorphic forms of a mixed zinc/copper biquinoline dihydrogenphosphate are presented, showing almost identical monomeric units, viz. (2,2′-biquinoline-κ2N,N′)bis(dihydrogenphosphato-κO)copper(II)/zinc(II), formulated as [ZnxCu1−x(H2PO4)2(C18H12N2)], with x = 0.88 (1) and 0.90 (2). The cation is tetrahedrally coordinated to a chelating biquinoline system and two diprotonated phosphate anions. The structures differ mainly in their intermolecular hydrogen-bonding interactions, leading to different packing schemes. No significant evidence of stress due to the Zn/Cu solid solution formation was detected.
organic compounds
Hydrogen bonding and crystal packing play major roles in determining the conformations of ethyl methyl 2-(triphenylphosphoranylidene)malonate, Ph3P=C(CO2CH3)CO2CH2CH3 or C24H23O4P, (I), and dimethyl 2-(triphenylphosphoranylidene)malonate, Ph3P=C(CO2CH3)2 or C23H21O4P, (II). In (I), the acyl O atom of the ethyl ester group is anti to the P atom, while the O atom of the methyl ester group is syn. In (II), the dimethyl diester is a 1:1 mixture of anti-anti and syn-anti conformers.
metal-organic compounds
The title compound, {[Cd(C6H4NO2)2(H2O)]·0.5C12H10N4}n, presents an intricate three-dimensional network with cavities traversing it in three orthogonal directions, where the (disordered) guest molecules lodge. The compound is a member of a series of coordination polymers presenting the same main host framework but with guests of variable size and geometry, to which the flexible skeleton seems to adapt. The disorder in the structure is explained in terms of an apparently well defined specificity in the position/orientation of the guest molecules, as determined by the main framework.
metal-organic compounds
In the title lanthanum complex, {[La(C4H4O5)(H2O)3]NO3}n, the lanthanum cation is immersed in a nine-coordinate environment provided by a tridentate oxydiacetate (oda) ligand (through two carboxylate and one ether O atoms), three carboxylate O atoms from neighbouring oda ligands and three aqua ligands. The LaO9 polyhedra are interlinked into a tight three-dimensional framework, which leaves holes where the nitrate anions lodge. The links to the polymeric framework are by an extensive hydrogen-bonding scheme utilizing all the water H atoms. Thermogravimetric analysis shows that the three coordinated water molecules leave the structure in two well differentiated steps.
metal-organic compounds
In the title monomer, [Cu(NO3)2(C18H12N2)], the six-coordinated CuII atom lies on a twofold axis which bisects one of the ligands (a chelating biquinoline) and duplicates the remaining ligand, a chelating nitrate. The latter binds in a very asymmetric way, consistent with a Jahn–Teller distortion in the coordination polyhedron which, due to the triple chelation, is extremely distorted and difficult to describe in terms of any regular model.
metal-organic compounds
The polymeric title compounds, namely catena-poly[[[di-μ-but-2-enoato-κ3O:O,O′;κ3O,O′:O′-bis[diaquadibut-2-enoato-κO;κ2O,O′-neodymium(III)]]-μ-4,4′-bipyridyl N,N′-dioxide-κ2O:O′] 4,4′-bipyridyl N,N′-dioxide solvate] and the erbium(III) and yttrium(III) analogues, {[Ln2(C4H5O2)6(C10H8N2O2)(H2O)4]·C10H8N2O2}n (Ln = Nd, Er and Y), form from [Ln2(bt)6(H2O)4] dimers (bt is but-2-enoate) bridged by 4,4′-bipyridyl dioxide (bno) spacers into sets of parallel chains; these linear arrays are interconnected by aqua-mediated hydrogen bonds into broad two-dimensional structures, which in turn interact with each other though the hydrogen-bonded bridged bno solvent units. Both independent bno units in the structures are bisected by symmetry centres.
metal-organic compounds
This new hydrate of barium acetate presents six independent barium centres, 12 independent acetate ligands and three complete and one disordered aqua molecule to generate a tight three-dimensional structure in which extensive hydrogen bonding is present.