In the title hydro-bromide salt, C(8)H(10)NO(3) (+)·Br(-), the positive charge resides on the N atom and the carboxyl -CO(2) end of the cation carries an H atom. In the crystal, N-H⋯Br, O-H⋯Br and N-H⋯O hydrogen bonds link the cations and anions, forming a ladder propagating along the a axis.

In the title compound, C(19)H(34)N(+)·Br(-)·H(2)O, the dihedral angle between the trans-planar alkyl side chain and the pyridinium ring is 52.73 (7)°. In the crystal structure, O-H⋯Br, C-H⋯Br and C-H⋯O hydrogen bonds form a network, while the hydro-phobic alkyl chains inter-digitate, forming bilayers.

INTRODUCTION The cardiac bioprostheses are related to thromboembolic events, infectious and degenerative diseases. Wear is mainly attributed to the denaturation of collagen. Glutaraldehyde, the predominant method of preservation of bioprostheses, favors the calcification process and limits their durability. Several techniques try to contain the degenerative process of bioprostheses. OBJECTIVE...

In the title compound, C16H22N2O, the azepan-2-one ring adopts a chair conformation, while the 1,2,3,4-tetra-hydro-pyridine ring adopts a half-chair conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming supra-molecular chains propagated along [10-1], with weak C-H⋯O inter-actions occurring between the chains.

In the crystal structure of the title salt, C4H6N3O(+)·HSeO3 (-), systematic name 6-amino-2-methyl-idene-2,3-di-hydro-pyrim-idin-1-ium hydrogen selenite, the hydrogenselenite anions and the cytosinium cations are linked via N-H⋯O, N-H⋯Se, O-H⋯O, O-H··Se and C-H⋯O hydrogen bonds, forming a three-dimensional framework.

The title compound, C(13)H(8)FNO(2), was synthesized from 3,4-difluoro-benzonitrile and hydro-quinone. The dihedral angle between the two aromatic rings is 70.9 (2)°. In the crystal structure, mol-ecules are linked by O-H⋯N hydrogen bonds, forming zigzag chains.

In the crystal of the title compound, C26H31N3O2, pairs of N-H⋯O hydrogen bonds link molecules, forming inversion dimers, which enclose an R 2 (2)(20) ring motif. One N atom does not form hydrogen bonds and lies in a hydro-phobic pocket with closest inter-molecular contacts of 4.196 (2) and 4.262 (2) Å.

The title compound, C(12)H(22)NSi(+)·Cl(-), contains two formula units in the asymmetric unit and is a hydro-chloride salt in which the amine N atom is protonated and the NH(3) (+) group forms hydrogen bonds with the Cl(-) anion, forming a ribbon in the c-axis direction.

The title compound [systematic name: (4bS)-4-hy-droxy-2-isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a-hexa-hydro-phenanthrene-3,9-dione], C20H26O3, is an abietane-type diterpene, which was isolated from Taxodium ascendens (B.). In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming supra-molecular chains propagating along the [001] direction.

The title compound, C12H15NO3S, was prepared by 1,3-dipolar cyclo-addition of 3,4-di-hydro-2H-pyrrole 1-oxide and phenyl vinyl sulfone. In the mol-ecule, both fused five-membered rings display a twisted conformation. In the crystal, C-H⋯O hydrogen bonds link neighbouring mol-ecules, forming chains running parallel to the b axis.