Three isotypic polymeric complexes with rare earth cations, but-2-enoate anions and 4,4'-(ethane-1,2-diyl)dipyridine and 4,4'-(ethene-1,2-diyl)dipyridine bridging ligands.

Three isotypic rare earth complexes, catena-poly[[aquabis(but-2-enoato-κ(2)O,O')yttrium(III)]-bis(µ-but-2-enoato)-κ(3)O,O':O;κ(3)O:O,O'-[aquabis(but-2-enoato-κ(2)O,O')yttrium(III)]-µ-4,4'-(ethane-1,2-diyl)dipyridine-κ(2)N:N'], [Y2(C4H5O2)6(C12H12N2)(H2O)2], the gadolinium(III) analogue, [Gd2(C4H5O2)6(C12H12N2)(H2O)2], and the gadolinium(III) analogue with a 4,4'-(ethene-1,2-diyl)dipyridine bridging ligand, [Gd2(C4H5O2)6(C12H10N2)(H2O)2], are one-dimensional coordination polymers made up of centrosymmetric dinuclear [M(but-2-enoato)3(H2O)]2 units (M = rare earth), further bridged by centrosymmetric 4,4'-(ethane-1,2-diyl)dipyridine or 4,4'-(ethene-1,2-diyl)dipyridine spacers into sets of chains parallel to the [201̄] direction. There are intra-chain and inter-chain hydrogen bonds in the structures, the former providing cohesion of the linear arrays and the latter promoting the formation of broad planes parallel to (010).

Crystal structure of zwitterionic 4-(ammonio-methyl)-benzoate: a simple mol-ecule giving rise to a complex supra-molecular structure.

The asymmetric unit of the title compound, C8H9NO2·H2O consists of an isolated 4-(ammonio-meth-yl)benzoate zwitterion derived from 4-amino-methyl-benzoic acid through the migration of the acidic proton, together with a water molecule of crystallization that is disordered over three sites with occupancy ratios (0.50:0.35:0.15). In the crystal structure, N-H⋯O hydrogen bonds together with π-π stacking of the benzene rings [centroid-centroid distance = 3.8602 (18) Å] result in a strongly linked, compact three-dimensional structure.

Crystal structure of 4,4'-(disulfanediyl)dibutanoic acid-4,4'-bipyridine (1/1).

4,4'-(Disulfanediyl)dibutanoic acid (dtba) and 4,4'-bipyridine (4,4'-bpy) crystallize in an 1:1 ratio, leading to the title co-crystal with composition C8H14O4S2·C10H8N2. A distinctive feature of the crystal structure is the geometry of the dtba moiety, which appears to be stretched [with a 9.98 (1) Šspan between outermost carbons] and acts as an hydrogen-bonding connector, forming linear chains along [-211] with the 4,4'-bpy moiety by way of O-H⋯N hydrogen bonds and C-H⋯O interactions. The influence of the mol-ecular shape on the hydrogen-bonding pattern is analysed by comparing the title compound and two other 4,4'-bpy co-crystals with closely related mol-ecules of similar formulation but different geometry, showing the way in which this correlates with the packing arrangement.

On substituted pyrazole derivatives. I. 3-Methyl-4-[(Z)-2-(4-methylphenyl)hydrazin-1-ylidene]-1-(3-nitrophenyl)-1H-pyrazol-5(4H)-one and 3-methyl-4-[(Z)-2-(4-methylphenyl)hydrazin-1-ylidene]-1-[4-(trifluoromethyl)phenyl]-1H-pyrazol-5(4H)-one.

The title substituted pyrazole derivatives, C17H15N5O3 and C18H15F3N4O, share most of their molecular features, in particular the hydrazinylidene (-HN-N=) rather than the diazene (-N=N-) tautomeric form, and differ only in the substituents (NO2 and CF3) on one of the outer phenyl rings. The molecular units are basically planar, with the rotation of the phenyl rings being hindered by the presence of two intramolecular hydrogen bonds having the keto O atom as acceptor. In both structures, the packing is governed by weak C-H...O, C-H...π and π-π interactions. The subtle way in which minor structural differences lead to rather different supramolecular structures is analysed.

Crystal lattice effect on the quenching of the intracluster magnetic interaction in [V12B18O60H6](10-) polyoxometalate.

In the present work, the synthesis and structural characterization of four new polyoxovanadoborate (BVO) frameworks based on the [V12B18O60H6](10-) polyanion are reported: (NH4)8(1,3-diapH2)[V12B18O60H6]·5H2O (1), K8(NH4)2[V12B18O60H6]·18H2O (2), K10[V12B18O60H6]·10H2O (3) and K8Cs2[V12B18O60H6]·10H2O (4). A global antiferromagnetic behaviour is observed for these 10V(IV)/2V(V) mixed valence clusters. The magnetic data of 1, 2 and 3, which present different countercation environments, show that 1 is more coupled than 2 and 3. DFT calculations show that the positive charges strongly influence the polarization mechanism of the spin density of the vanadyl groups and the extent of the magnetic orbitals, therefore corroborating the experimental observation of the quenching effect of the magnetic coupling between vanadium centres of 2 and 3.

Two nickel(II) bis[(pyridin-2-yl)methyl]amine complexes with homophthalic and benzene-1,2,4,5-tetracarboxylic acids.

Two new Ni(II) complexes involving the ancillary ligand bis[(pyridin-2-yl)methyl]amine (bpma) and two different carboxylate ligands, i.e. homophthalate [hph; systematic name: 2-(2-carboxylatophenyl)acetate] and benzene-1,2,4,5-tetracarboxylate (btc), namely catena-poly[[aqua{bis[(pyridin-2-yl)methyl]amine-κ(3)N,N',N''}nickel(II)]-µ-2-(2-carboxylatophenyl)aceteto-κ(2)O:O'], [Ni(C9H6O4)(C12H13N3)(H2O)]n, and (µ-benzene-1,2,4,5-tetracarboxylato-κ(4)O(1),O(2):O(4),O(5))bis(aqua{bis[(pyridin-2-yl)methyl]amine-κ(3)N,N',N''}nickel(II)) bis(triaqua{bis[(pyridin-2-yl)methyl]amine-κ(3)N,N',N''}nickel(II)) benzene-1,2,4,5-tetracarboxylate hexahydrate, [Ni2(C10H2O8)(C12H13N3)2(H2O)2]·[Ni(C12H13N3)(H2O)3]2(C10H2O8)·6H2O, (II), are presented. Compound (I) is a one-dimensional polymer with hph acting as a bridging ligand and with the chains linked by weak C-H···O interactions. The structure of compound (II) is much more complex, with two independent Ni(II) centres having different environments, one of them as part of centrosymmetric [Ni(bpma)(H2O)]2(btc) dinuclear complexes and the other in mononuclear [Ni(bpma)(H2O)3](2+) cations which (in a 2:1 ratio) provide charge balance for btc(4-) anions. A profuse hydrogen-bonding scheme, where both coordinated and crystal water molecules play a crucial role, provides the supramolecular linkage of the different groups.

A dense hydrogen-bonding network and an unusually large packing index in triaquatris(2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylato)neodymium(III) trihydrate.

The title mononuclear complex, [Nd(C5H3N2O3)3(H2O)3]·3H2O, consists of an Nd(III) cation, three 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate ligands and three aqua ligands forming the neutral complex molecule, and three solvent water molecules. The pyrimidinecarboxylate ligands act in a chelating manner, via carboxylate and keto O atoms. The NdO9 coordination polyhedron is in the form of a distorted monocapped square antiprism. The availability of numerous hydrogen-bonding donors and acceptors results in a very dense hydrogen-bonding network, the immediate effect of which is an unusually large packing index.

Dimers linked by type-I C-F···F-C contacts in (Z)-3-methyl-4-[2-(4-methylphenyl)hydrazinylidene]-1-(pentafluorophenyl)-1H-pyrazol-5(4H)-one.

The title compound, C17H11F5N4O, is described and compared with two closely related analogues in the literature. There are two independent molecules in the asymmetric unit, linked by N-H···O hydrogen bonds and π-π interactions into dimeric entities, presenting a noticeable noncrystallographic C2 symmetry. These dimers are in turn linked by a medium-strength type-I C-F···F-C interaction into elongated tetramers. Much weaker C-H···F contacts link the tetramers into broad two-dimensional substructures parallel to (101).

Two complexes derived from the reaction of M3(CO)12 clusters (M = Ru, Os) with the 9-(triphenylphosphonio)fluorenide ylide: tricarbonyl[9-(triphenylphosphonio)fluorenylidene]ruthenium and nonacarbonyl-µ3-fluorenylidene-µ2-hydrido-triangulo-triosmium(III).

Tricarbonyl[9-(triphenylphosphonio)fluorenylidene]ruthenium, [Ru(C31H21P)(CO)3], (I), is mononuclear, consisting of a single Ru centre, to which three carbonyl units and a chelating µ3-9-(triphenylphosphonio)fluorenide ylide bind to generate a distorted octahedral RuC6 core. Nonacarbonyl-µ3-fluorenylidene-µ2-hydrido-triangulo-triosmium(III), [Os3H(C13H7)(CO)9], (II), is trinuclear and presents a triangular triosmium core, nine carbonyl ligands and one fluorenylidene ligand. Two of the Os(III) centres present a highly distorted hexacoordinated Os(Os2C4) core and are in turn bridged by a hydride ligand. The remaining Os(III) cation is octacoordinated, with an Os(Os2C6) nucleus. The crystal structures of both compounds are the result of nondirectional forces, much resembling the packing of weakly interacting quasi-spherical units, viz. the molecules themselves in (I) and centrosymmetric π-π-bonded dimers in (II).

A polymeric cobalt(II) complex derived from citric acid (H4cit) and 2,6-diaminopurine (dap): {[Co4(cit)2(dap)4(H2O)4]·6.35H2O}n.

Poly[[tetraaquadi-µ4-citrato-tetrakis(2,6-diaminopurine)tetracobalt(II)] 6.35-hydrate], {[Co4(C6H4O7)2(C5H6N6)4(H2O)4]·6.35H2O}n, presents three different types of Co(II) cations in the asymmetric unit, two of them lying on symmetry elements (one on an inversion centre and the other on a twofold axis). The main fragment is further composed of one fully deprotonated citrate (cit) tetraanion, two 2,6-diaminopurine (dap) molecules and two aqua ligands. The structure is completed by a mixture of fully occupied and disordered solvent water molecules. The two independent dap ligands are neutral and the cit tetraanion provides for charge balance, compensating the 4+ cationic charge. There are two well defined coordination geometries in the structure. The simplest is mononuclear, with the Co(II) cation arranged in a regular centrosymmetric octahedral array, coordinated by two aqua ligands, two dap ligands and two O atoms from the ß-carboxylate groups of the bridging cit tetraanions. The second, more complex, group is trinuclear, bisected by a twofold axis, with the metal centres coordinated by two cit tetraanions through their α- and ß-carboxylate and α-hydroxy groups, and by two dap ligands bridging through one of their pyridine and one of their imidazole N atoms. The resulting coordination geometry around each metal centre is distorted octahedral. Both groups are linked alternately to each other, defining parallel chains along [201], laterally interleaved and well connected via hydrogen bonding to form a strongly coupled three-dimensional network. The compound presents a novel µ4-κ(5)O:O,O':O',O'',O''':O'''' mode of coordination of the cit tetraanion.

3,5-Dimethyl-4-[(E)-(2-nitrophenyl)diazenyl]-1-(2,3,4,5,6-pentafluorophenyl)-1H-pyrazole.

The title compound, C(17)H(10)F(5)N(5)O(2), is described and compared with its 4-nitrophenyl isomer [Bustos, Sánchez, Schott, Alvarez-Thon & Fuentealba (2007). Acta Cryst. E63, o1138-o1139]. The title molecule presents its nitro group split into two rotationally disordered components, which in conjunction with the rotation of the `unclamped' rings constitute the main molecular differences. Packing is directed by a head-to-tail type `I' C-F...F-C interaction, generating double-chain strips running along [100]. These substructures are interlinked by a variety of weak F...F, O...F, F...π and O...π interactions.

Isoquinolin-5-amine.

The title compound, C(9)H(8)N(2), presents two almost identical independent molecules in the asymmetric unit, both of them exhibiting an extremely planar isoquinoline core (maximum r.m.s. deviation = 0.014 Å). The most significant deviation is found in the -NH(2) groups, which present a noticeable pyramidalization around the N atom, a feature also present in related structures containing the molecule as a ligand. The supramolecular structure is based on pairs of parallel hydrogen-bonded chains formed by just one molecular type each, defined by the strongest hydrogen bonds in the structure, which are of the N-H···N type. These parallel chains are linked into pairs (or strips) via weaker C-H···N hydrogen bonds. Related strips generated by the c-glide plane define two families running along [110] and [110], giving rise to an interesting system of interwoven chains stabilized by a number of weaker contacts of the C-H···π type.

Bis(2-amino-1H-benzimidazol-3-ium) tetrakis(µ-but-2-enoato)-κ4O:O';κ3O,O':O;κ3O:O,O'-bis[bis(but-2-enoato-κ2O,O')holmium(III)].

The title ionic compound, (C(7)H(8)N(3))(2)[Ho(2)(C(4)H(5)O(2))(8)], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2-amino-1H-benzimidazol-3-ium (Habim(+)) cations. The asymmetric part of each dimer is made up of one Ho(III) cation and four crotonate (crot or but-2-enoate) anions, two of them acting in a simple η(2)-chelating mode and the remaining two acting in two different µ(2):η(2) fashions, viz. purely bridging and bridging-chelating. Symmetry-related Ho(III) cations are linked by two Ho-O-Ho and two Ho-O-C-O-Ho bridges which lead to rather short intracationic Ho···Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho(2)(crot)(8)](2-) and Habim(+) ions are linked by a number of N-H···O hydrogen bonds, in which all N-H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two-dimensional structures parallel to (110), which are linked to each other by weaker π-π contacts between Habim(+) benzene groups.

Poly[[diaquabis(µ2-crotonato-κ3O:O,O')(crotonato-κ2O,O')lanthanum(III)] adenine monosolvate monohydrate].

The asymmetric unit of the title compound, {[La(C(4)H(5)O(2))(3)(H(2)O)(2)]·C(5)H(5)N(5)·H(2)O}(n), consists of an La(III) cation, three crotonate (but-2-enoate) anions and two coordinated water molecules forming the neutral complex, completed by an external adenine molecule and one hydration water molecule. The LaO(10) coordination polyhedra, connected through the sharing of a single edge, form isolated chains running along the [100] direction. These one-dimensional structures are characterized by two different centrosymmetric La(2)O(2) loops, with La...La distances of 4.5394 (6) and 4.5036 (6) Å. The unbound adenine and water solvent molecules form a highly planar hydrogen-bonded array parallel to (110) (r.m.s. deviation from the mean plane < 0.10 Å) which intersects the isolated La-crotonate chains in a slanted fashion to form an extremely connected hydrogen-bonded three-dimensional structure.

Two isomorphous lanthanide crotonate complexes: di-µ-but-2-enoato-bis[diaquabis(but-2-enoato)dysprosium(III)] adenine monosolvate heptahydrate and the samarium(II) analogue.

The asymmetric unit of the title dimeric compounds, [Ln(2)(C(4)H(5)O(2))(6)(H(2)O)(4)]·C(5)H(5)N(5)·7H(2)O, with Ln = Dy, (I), and Sm, (II), consists of an Ln(III) cation, three crotonate (but-2-enoate) anions and two coordinated water molecules forming the neutral complex, cocrystallized with half of an external adenine molecule and 3.5 water molecules. The metal complex has crystallographic inversion symmetry. The LnO(9) coordination polyhedra are connected through the sharing of a single edge to form isolated dimeric units, with Ln...Ln separations of 4.1766 (12) Å for (I) and 4.2340 (12) Å for (II). The unbound adenine molecule and one of the solvent water molecules are disordered around an inversion centre into two overlapping, equally populated, units. The structure is sustained by a complex hydrogen-bonding scheme involving all possible O-H and N-H groups as donors, and crotonate and water O and adenine N atoms as acceptors. The system is compared with recently published related compounds.

Poly[[µ3-2-(carboxylatomethyl)benzoato-κ3O1:O2:O2]bis(1H-imidazole-κN3)copper(II)].

In the title polymeric compound, [Cu(C(9)H(6)O(4))(C(3)H(4)N(2))(2)](n), the copper(II) cation occupies an N(2)O(3) coordination sphere defined by two 1H-imidazole (imid) ligands in trans positions and three carboxylate O atoms from three different 2-(carboxylatomethyl)benzoate (hpt(2-)) dianions. The geometry is that of a square pyramid with one of the O atoms at the apex, bridging neighbouring metal centres into an [-ON(2)CuO(2)CuN(2)O-] dinuclear unit. These units are in turn connected by hpt anions into a reticular mesh topologically characterized by two types of loops, viz. a four-membered Cu(2)O(2) diamond motif and a 32-membered Cu(4)O(8)C(20) ring. The imid groups do not take part in the formation of the two-dimensional structure, but take part in the N-H···O interactions. These arise only within individual planes, interplanar interactions being only of the van der Waals type.

Poly[4,4'-(propane-1,3-diyl)dipyridinium bis{tetraaquabis(µ2-5-carboxybenzene-1,2,4-tricarboxylato)bis[µ2-1,3-bis(4-pyridyl)propane]dicobalt(II)} pentahydrate].

The title polymeric compound, {(C(13)H(16)N(2))[Co(C(10)H(3)O(8))(C(13)H(14)N(2))(H(2)O)(2)](2)·5H(2)O}(n), is an ionic structure comprising an anionic two-dimensional mesh characterized by a {[Co(Hbtc)(bpp)(H(2)O)(2)](-)}(2) motif [Hbtc is 5-carboxybenzene-1,2,4-tricarboxylate and bpp is 1,3-bis(4-pyridyl)propane], with interspersed 4,4'-(propane-1,3-diyl)dipyridinium cations, denoted (H(2)bpp)(2+), and water molecules providing the charge balance and structure stabilization. The reticular mesh consists of two independent types of [Co(H(2)O)(2)](2+) cationic nodes (lying on inversion centres), interconnected in the [101] direction by two independent sets of neutral bridging bpp ligands, both types of ligands being split by non-equivalent twofold axes. One set is formed by genuinely symmetric moieties, while those in the second set are only symmetric by disorder in the central propane bridge. These chains contain only one type of Co(II) centre and one type of bpp ligand; the metal cations therein are laterally bridged by Hbtc anions, thus forming transverse chains of alternating types of Co(II) cations. The elemental motif of the resulting grid is a highly distorted parallelogram, with metal-metal distances of 13.5242 (14) Å in the bpp direction and 9.105 (2) Å in the Hbtc direction, and a large internal angle of 138.42 (18)°. These two-dimensional structures have a profusion of hydrogen-bonding interactions with each other, either directly (with the aqua molecules as donors and the Hbtc anions as acceptors) or mediated by the unbound (H(2)bpp)(2+) cations and water molecules of hydration. These interactions generate a very complex hydrogen-bonding scheme involving all of the available N-H and O-H groups and which links these two-dimensional grids into a three-dimensional network.

Tetraaquabis(2,6-diamine-7H-purine-κN9)cobalt(II) benzene-1,2,4,5-tetracarboxylate tetrahydrate.

The title compound, [Co(C(5)H(7)N(6))(2)(H(2)O)(4)](C(10)H(2)O(8))·4H(2)O, is an ionic structure comprising a [Co(Hdap)(2)(H(2)O)(4)](4+) cation (dap is 2,6-diaminopurine) in a general position, two benzene-1,2,4,5-tetracarboxylate (btc(4-)) anions straddling two different inversion centres and four solvent water molecules. The structure presents a remarkable degree of pseudosymmetry, with the Co(II) cation lying almost exactly on a noncrystallographic pseudo-inversion centre. The overall spatial arrangement can be described in terms of cationic and anionic chains running along the [111] direction and linked into a three-dimensional network by a very complex hydrogen-bonding scheme in which all the available N-H and O-H groups take part.

Conformations of diester triphenylphosphonium ylides with an ylidic ester or keto and ester ylidic groups.

The structures of three related keto diester and diester ylides, namely diethyl 3-oxo-2-(triphenylphosphoranylidene)glutarate, C(27)H(27)O(5)P, (I), diethyl 3-oxo-2-(triphenylphosphoranylidene)glutarate acetic acid monosolvate, C(27)H(27)O(5)P·C(2)H(4)O(2), (II), and diethyl 2-(triphenylphosphoranylidene)succinate, C(26)H(27)O(4)P, (III), are presented. The syn-keto anti-ester conformations in the crystalline keto diesters are governed by electronic delocalization between the P-C and ylidic bonds and an acyl group, and by intra- and intermolecular interactions. There are also intramolecular attractive and repulsive interactions of different types (C-H...O and C-H...π) controlling the molecular conformations. The mono-ylidic diester (III) has an anti-ester conformation, while those for (I) and (II) are related to pyrolytic formation of acetylene derivatives. The terminal nonylidic ester group in (I) was disordered over two sets of almost equally populated positions.

Two isomorphous transition metal complexes containing a protonated diaminopurine ligand: diaquabis(2,6-diamino-7H-purin-1-ium-κN9)bis(homophthalato-κO)nickel(II) tetrahydrate and the cobalt(II) analogue.

The two isomorphous title compounds, [M(C(5)H(7)N(6))(2)(C(9)H(6)O(4))(2)(H(2)O)(2)]·4H(2)O or M(2+)(Hdap(+))(2)(hpt(2-))(2)(H(2)O)(2)·4H(2)O {where dap is 2,6-diaminopurine, H(2)hpt is homophthalic acid [2-(2-carboxyphenyl)acetic acid] and M is Ni(II) or Co(II)}, consist of neutral M(2+)(Hdap(+))(2)(hpt(2-))(2)(H(2)O)(2) monomers, where the M(II) cation lies on an inversion centre and its MN(2)O(4) octahedral environment is defined by one N atom (from Hdap(+)), two O atoms (from one hpt(2-) dianion and one water molecule) and their inversion images. The structures are unusual in that the Hdap(+) cation occurs in an uncommon protonated state (as 2,6-diamino-7H-purin-1-ium) and both ligands bind in an unprecedented monodentate fashion. The existence of a large number of donors and acceptors for hydrogen bonding, together with π-π interactions, leads to a rather complex three-dimensional structure.