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.

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.

Dendocarbin A: a sesquiterpene lactone from Drimys winteri

Natural dendocarbin A is a sesquiterpene lactone isolated from Drimys winteri. X-ray crystal structure analysis confirmed the S/R character of the chiral centres at C-5/C-10 and C-9/C-11, respectively. The α-OH group at C-11 was found to be involved in inter­molecular hydrogen bonding, defining chains along the <100> 2₁ screw axis.

Hobartine: a tetra­cyclic indole alkaloid extracted from Aristotelia chilensis (maqui)

In the crystal structure of the natural compound hobartine, a tetra­cyclic alkaloid isolated from Aristotelia chilensis, the supra­molecular structure in strongly related to the twofold screw axis, around which isolated chains build up, inter­nally linked by an N—H...N hydrogen bond which is the only significant inter­molecular inter­action present in the structure.