1-(2,6-Dihydroxy­phenyl)butanone

The title compound, C₁₀H₁₂O₃, has several intra- and intermolecular hydrogen bonds in the crystal structure. The molecules are linked into infinite chains along [011] via intermolecular O—H...O hydrogen bonds. There are two molecules in the asymmetric unit.

3,4-Di­hydro-8-hydroxy-3,5-di­methyl-7-methoxy­isocoumarin (avicennin B)

The title compound, C₁₂H₁₄O₄, contains two mol­ecules in the asymmetric unit, each with an intramolecular O—H...O hydrogen bond.

(2-Methyl­propane-1,2-diamine-κ²N,N′)[tris­(2-amino­ethyl)amine-κ⁴N,N′,N′′,N′′′]nickel(II) diperchlorate

In the title compound, [N(C₄H₁₂N₂)(C₆H₁₈N₄)](ClO₄)₂, the Ni^II atom is coordinated in a distorted octa­hedron by four N atoms of the tris­(2-aminoethyl)amine (tren) ligand and by two N atoms of the 2-methyl­propane-1,2-diamine (2-Mepn) ligand. The primary amino group of 2-Mepn at the C-2 position occupies the position trans to the tertiary amino group of tren. The complex cations and perchlorate anions are linked via N—H...O hydrogen bonds, forming one-dimensional zigzag chains along the [101] direction.

5-(But-3-enyl)­pyridinium-2-carboxyl­ate–5-butyl­pyridine-2-carboxyl­ic acid (1/1), a co-crystal from Fusarium moniliforme

In the title co-crystal, C₁₀H₁₁NO₂·C₁₀H₁₃NO₂, the carboxyl­ic acid moiety uses its acid H atom as the donor atom to bind strongly to the negatively charged O atom of the zwitterionic moiety [O...O = 2.557 (2) Å]. Meanwhile, the protonated N atom of the zwitterionic moiety forms a hydrogen bond with the double-bonded O atom of an adjacent zwitterionic moiety [N...O = 2.703 (2) Å] to give rise to a linear chain motif. The butenyl substituent (on the zwitterion) is disordered with respect to a butyl group and the butyl substituent (on the neutral mol­ecule) is disordered with respect to a butenyl group, the site occupancy for both being in an approximate 0.6:0.4 ratio.

(1,3-Diamino­propane-κ²N,N′)[tris­(2-amino­ethyl)amine-κ⁴N,N′,N′′,N′′′]nickel(II) bis­(perchlorate)

In the title compound, [Ni(C₃H₁₀N₂)(C₆H₁₈N₄)](ClO₄)₂, the Ni^II atom has a distorted octa­hedral coordination, formed by four N atoms of the tris­(2-amino­ethyl)amine (tren) ligand and two N atoms of the 1,3-diamino­propane (pn) ligand. The tren ligand consists of three five-membered chelate rings in gauche conformations and the pn ligand consists of a six-membered chelate ring in a chair conformation. In the crystal structure, a two-dimensional network of hydrogen bonds extends parallel to the (100) plane.