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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 P...O 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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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The polymeric title compounds, namely catena-poly[[[di-μ-but-2-enoato-κ3O:O,O′;κ3O,O′:O′-bis­[diaqua­dibut-2-enoato-κO2O,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.

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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.
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