Zhi-Min Jin

Diethyl 3,8-dimethyl-4,7-diazadeca-2,8-dienedioate.

The title compound, C14H24N2O4, consists of two symmetric moieties related through a twofold axis. The whole molecule has a cis conformation. Both the ionic enol form and the non-ionic keto form make comparable contributions to the structure. In the crystal structure, infinite supramolecular chains are formed through N-H...O hydrogen bonds.

Bis(2-amino-6-methylpyridinium) tetrachlorozincate(II).

The title compound, (C6H9N2)2[Zn(II)Cl4], consists of two 2-amino-6-methylpyridinium (AMP) cations and one [ZnCl4]2- anion, which are held together by N-H...Cl hydrogen bonds. Bond lengths within the AMP cation indicate that the imine tautomer makes a significant contribution to the structure. The molecules are associated by two different pi-pi interactions between identical antiparallel AMP cations, with face-to-face distances of 3.627 (4) and 3.342 (3) A, to form a one-dimensional chain.

Isolation and absolute configurations of diastereomers of 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol from Chimonanthus salicifolius.

Phytochemical investigation of the aerial parts of Chimonanthus salicifolius resulted in the isolation of two sesquiterpenoids, 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol, together with 13 known compounds. The 15 structures were established by means of 1D and 2D NMR spectroscopy. The relative and absolute configurations of 8α-hydroxy-T-muurolol and 8α,11-elemodiol were achieved by NOESY experiments and X-ray crystallography using CuKα radiation. 8α-hydroxy-T-muurolol and (1α,6β,7β)-cadinane-4-en-8α,10α-diol showed immunosuppressive activities in a dose-dependent manner.

2-Amino-5-methyl­pyridinium (2-amino-5-methyl­pyridine)trichloro­zincate(II)

The title compound, (C6H9N2)[ZnCl3(C6H8N2)], consists of one 2-amino-5-methylpyridinium cation and one (2-amino-5-methylpyridine)trichlorozincate(II) anion, which are held together by N-H...Cl hydrogen bonds and pi-pi interactions. The cation and the pyridine ligand show similar geometric features, except for the N-C bond lengths. Molecules of the title compound are connected by N-H...Cl hydrogen bonds to form chiral chains; these chains are associated further by C-H...Cl hydrogen bonds to form layers, which are in turn linked by pi-pi interactions.

Redetermination of l-valinium chloride monohydrate

The crystal structure of the title compound, C5H12NO2+·Cl−·H2O, has been reported previously by Rao [Z. Kristallogr. (1969), 128, 339–341], with an R value of 0.11, without locating the H atoms. The present redetermination shows better agreement of bond lengths with expected values.

The 1:1 adduct of 5-methylbenzene-1,3-diol (orcin) and 1,4-diazabicyclo[2.2.2]octane

In the title adduct, C 6 H 12 N 2 .C 7 H 5 O 2 , the orcin and 1,4-diazabicyclo[2.2.2]octane moieties are held together by O-H...N hydrogen bonds. One-dimensional chiral hydrogen-bonded chains are formed along the b axis. Neighbouring chains are held together principally by van der Waals interactions and are interrelated by translation, resulting in a chiral layer.

The directional polymeric chain of [(BiCl5)2−]n in 2,2′-Bi(2-1H-imidazolium) pentachlorobismuthate dihydrate

The title compound, (C6H6N4)(BiCl5) · 2H2O, is built up by 2,2′-bi(2-1H-imidazolium) dications and (BiCl5)2− anions. Distorted BiCl6 octahedra are joined with each other alternatively to form [(BiCl5)2−]n polymeric chains, where the bridging chlorine atoms are shared by two octahedra. The lone pair at the Bi atom shows obviously stereochemical activity, leading to distortion of the BiCl6 octahedra and formation of the chain directionality. In solid state, the chains are stabilized by O-H···Cl and C-H···Cl hydrogen bonds.

Doxofyllinium tetra­chloridoanti­monate(III) monohydrate

The title compound, (C11H14N4O4)[SbCl4]·H2O, comprises a protonated doxofyllinium cation [7-(1,3-dioxolan-2-ylmethyl)-1,3-dimethyl-2,6-dioxo-3,7-dihydro-1H-purin-9-ium], an [SbCl4]− anion and a water molecule linked by N—H⋯O and O—H⋯Cl hydrogen bonds: the [SbCl4]− anions form centrosymmetric dimers via weak Sb⋯Cl interactions [Sb⋯Cl = 3.1159 (9) Å]. The geometrical arrangement in the crystal structure is characterized by slipped π–π stacking of the parallel purine ring systems, with an interplanar separation of 3.32 Å.

Redetermination of ethyl­ene­diammonium bis­(p-methyl­benzene­sulfonate) monohydrate

In the asymmetric unit of the title compound, C2H10N2 2+·2C7H7O3S−·H2O, there are two independent 4-methylbenzenesulfonate anions, one ethylenediammonium cation and a water molecule. The present redetermination was carried out to improve the treatment of disorder, which was not refined in the previous study [Ahn & Kim (1985 ▶). J. Korean Chem. Soc. 29, 335–340]. One of the sulfonate groups is disordered over two positions, with site-occupancy factors of 0.588 (14) and 0.412 (14). Intermolecular N—H⋯O and O—H⋯O hydrogen bonds hold the three components together, affording a layer structure extending parallel to the (001) plane.

Bis(dimethyl­oxonium) penta­chlorido­antimonate(III)

The title compound, (C2H7O)2[SbCl5], contains one-half of an [SbCl5]2− anion lying on a mirror plane and one C2H7O+ cation in the asymmetric unit. The ion pairs are linked togather by strong O—H⋯Cl hydrogen bonds. The [SbCl5]2− anions are also linked through coordinated Sb—Cl bonds to form parallel chains.