Crystal structure of 3-[4-(1-methyl-eth-yl)phen-yl]-1-(naphthalen-2-yl)prop-2-en-1-one.

The title compound, C22H20O, was synthesized by reacting 4-iso-propyl-benzaldehyde with 2-acetonaphtone by aldolic condensation under Claisen-Schmidt conditions. The mol-ecule consists of a naphthalene group and a benzene ring with a pendant isopropyl moiety, both rings bound by a propenone linker. The naphthalene ring system is almost planar [maximum deviation from the least-squares plane = 0.

Hydrogen bonding in 1-carb-oxy-propanaminium nitrate.

There are two crystallographically independent cations and two anions in the asymmetric unit of the title compound, C(4)H(5)NO(2) (+)·NO(3) (-). In the crystal, the 1-carb-oxy-propanaminium cations and nitrate anions are linked to each other through strong N-H⋯O and O-H⋯O hydrogen bonds, forming a three-dimensional complex network. C-H⋯O inter-actions also occur.

trans-Diaqua-bis-(dl-valinato-κN,O)nickel(II).

In the title complex, [Ni(C(5)H(9)NO(2))(2)(H(2)O)(2)], the Ni(II) atom, located on a centre of inversion, is trans-coordinated by two O atoms and two N atoms from d-bidentate valine and l-bidentate valine ligands and two water O atoms in an octa-hedral geometry. In the crystal, the discrete mononuclear units are linked into a three-dimensional network via O-H⋯O and N-H⋯O hydrogen bonds. C-H⋯O inter-actions are also observed.

Hydrogen bonding in cytosinium dihydrogen phosphite.

In the title compound, C(4)H(8)N(3)O(4)P(+)·H(2)PO(3) (-), the cytosine mol-ecule is monoprotonated and the phospho-ric acid is in the monoionized state. Strong hydrogen bonds, dominated by N-H⋯O inter-actions, are responsible for cohesion between the organic and inorganic layers and maintain the stability of this structure.

Creatinium perchlorate.

The title compound, C(4)H(8)N(3)O(+)·ClO(4) (-), is built up from creatininium cations and perchlorate anions. Crystal cohesion and perchlorate stability are ensured by N-H⋯O hydrogen bonds that together with weak C-H⋯O inter-actions build up a three-dimensional network.