Hydro­gen-bonded adducts of ferrocene-1,1′-diyl­bis­(di­phenyl­methanol): monomeric and dimeric 1:1 adducts with 1,2-bis(4-pyridyl)­ethane and 1,2-­diamino­ethane

In ferrocene-1,1′-diyl­bis­(di­phenyl­methanol)–4,4′-ethyl­enedi­pyridine (1/1), [Fe(C₁₈H₁₅O)₂]·C₁₂H₁₂N₂, there is an intra­molecular O—H...O hydrogen bond in the ferrocenediol component and a single O—H...N hydrogen bond linking the two components into a finite monomeric adduct. Ferrocene-1,1′-diyl­bis­(di­phenyl­methanol)–ethyl­enedi­amine (1/1), [Fe(C₁₈H₁₅O)₂]·C₂H₈N₂, crystallizes with Z′ = 2 in space group P, and there are two independent four-component aggregates in the structure, both of which are centrosymmetric. In the first type of aggregate, the molecular components are linked by O—H...N and N—H...O hydrogen bonds, in which both di­amine N atoms participate; in the second type of aggregate, the di­amine component is disordered over two sets of sites, but only one N atom is involved in the hydrogen bonding.

Sodium 2-nitro­ethanaloximate forms a layered-framework structure

In the title compound, [Na(C₂H₃N₂O₃)], the Na⁺ cation lies on a centre of inversion in space group P2₁/m and all the atoms of the anion lie on a mirror plane. Na is octahedrally coordinated by four O and two N atoms from six different anions and each anion is coordinated to six different Na⁺ cations, forming chains of confacial octahedra which link the anion layers. Within these layers, the individual anions are linked by both O-H...O and C-H...O hydrogen bonds.

N,N'-Di­methyl­piperazinium(2+) phos­phonoacetate: hydrogen-bonded anion sheets containing cation-templated R₆⁶(28) rings

In the title compound, C₆H₁₆N₂²⁺·2C₂H₄O₅P^-, the cations lie across centres of inversion; in the anions, two of the H-atom sites have 0.50 occupancy. The anions are linked by short O-H...O hydrogen bonds [O...O 2.465 (3)-2.612 (3) Å and O-H...O 165-171°] into sheets of alternating R(12) and R(28) rings, both of which are centrosymmetric; the cations lie at the centres of the larger rings linked to the anion sheet by N-H...O hydrogen bonds [N...O 2.642 (2) Å and N-H...O 176°].

Hydrogen-bonded bilayers in ­piperazinium(2+) bis(mandelate) bis(methanol) solvate

In the title compound, C₄H₁₂N₂²⁺·2C₈H₇O₃^-·2CH₄O, the cations lie across centres of inversion and are disordered over two orientations with equal occupancy; there are equal numbers of (R)- and (S)-mandelate anions present (mandelate is [alpha]-hydroxy­benzene­acetate). The anions and the neutral water mol­ecules are linked by O-H...O hydrogen bonds [O...O 2.658 (3) and 2.682 (3) Å, and O-H...O 176 and 166°] into deeply folded zigzag chains. Each orientation of the cation forms two symmetry-related two-centre N-H...O hydrogen bonds [N...O 2.588 (4) and 2.678 (4) Å, and N-H...O 177 and 171°] and two asymmetric, but planar, three-centre N-H...(O)₂ hydrogen bonds [N...O 2.686 (4)-3.137 (4) Å and N-H...O 137-147°], and by means of these the cations link the anion/water chains into bilayers.