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
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.