The topotactic dehydration of monoclinic {[Co(pht)(bpy)(H₂O)₂]·2H₂O}_n into ortho­rhom­bic [Co(pht)(bpy)(H₂O)₂]_n (pht is phthalate and bpy is 4,4'-bi­pyridine)

{[Co(pht)(bpy)(H₂O)₂]·2H₂O}_n (P2/n) single crystals (where pht is phthalate and bpy is 4,4'-bi­pyridine) dehydrate in a topotactic fashion into an anhydrate formulated as [Co(pht)(bpy)(H₂O)₂]_n, which organizes in the ortho­rhom­bic system (Pmn2₁) in a disordered fashion, where two mirror-related 0.50:0.50 occupancy two-dimensional planar substructures are mirrored in a plane perpendicular to [100]. These two-dimensional substructures are also present in the parent hydrate, and have been found in topologically related structures with different anions and cations.

The structure of {[Co(pht)(bpy)(H₂O)]·3H₂O}_n (pht is phthalate and bpy is 4,4′-bi­pyridine) and the role of solvent water clusters in structure stability

In a two-dimensional cobalt(II) coordination polymer of benzene-1,2-di­carboxyl­ate and 4,4′-bi­pyridine, inter­planar cohesion is achieved via oligomeric solvent water clusters.

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 are presented, i.e. a one-dimensional polymeric complex incorporating homophthalate, where the anion acts as the bridging ligand, and a complex incorporating benzene-1,2,4,5-tetra­carboxyl­ate, with two independent Ni centres in different environments, one of them a centrosymmetric 4- dinuclear complex and the other a 2+ mononuclear unit, appearing in a 1:2 ratio. The supra­molecular structure is supported by a profuse hydrogen-bonding network.

An ethanol-solvated centrosymmetric dimer of bismuth(III) and thiosaccharinate resulting from `semicoordination' contacts

In an ethanol-solvated centrosymmetric dimer of bismuth(III) and thiosaccharinate, the Bi³⁺ cation is coordinated by three thio­saccharinate ligands, all of them acting as bidentate chelates through the N and exocyclic S atoms (in a [kappa]²N,S mode). Centrosymmetric dimers result from the association of molecules via [pi]-[pi] interactions.

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 pyrazolone compounds, one of them presenting two mol­ecules in the asymmetric unit, differ in the substituents on two terminal benzene rings. The three-dimensional supra­molecular structure is achieved in both cases via a number of C-H...O, C-H...[pi] and [pi]-[pi] weak inter­actions, linking the mol­ecules into more or less compact supra­molecular structures.