(E)-2-({2-[(E)-(Hy­droxy­imino)­meth­yl]phen­oxy}meth­yl)-3-o-tolyl­acrylonitrile

In the title compound, C18H16N2O2, the dihedral angle between the mean planes through the two benzene rings is 56.8 (6)°. The enoate group assumes an extended conformation. The hy­droxy­ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane being 0.047 (1) Å for the hy­droxy­imino O atom. In the crystal, the mol­ecules are linked into cyclic centrosymmetric dimers with R 2 2(6) motifs via O—H⋯N hydrogen bonds

High-pressure phase and transition phenomena in ammonia borane NH3BH3 from X-ray diffraction, Landau theory, and ab initio calculations

Structural evolution of a prospective hydrogen storage material, ammonia borane NH3BH3, has been studied at high pressures up to 12 GPa and at low temperatures by synchrotron powder diffraction. At 293 K and above 1.1 GPa a disordered I4mm structure reversibly transforms into a new ordered phase. Its Cmc21 structure was solved from the diffraction data, the positions of N and B atoms and the orientation of NH3 and BH3 groups were finally assigned with the help of density functional theory calculations. Group-theoretical analysis identifies a single two-component order parameter, combining ordering and atomic displacement mechanisms, which link an orientationally disordered parent phase I4mm with ordered distorted Cmc21, Pmn21 and P21 structures. We propose a generic phase diagram for NH3BH3, mapping three experimentally found and one predicted (P21) phases as a function of temperature and pressure, along with the evolution of the corresponding structural distortions. Ammonia borane belongs to the class of improper ferroelastics and we show that both temperature- and pressure-induced phase transitions can be driven to be of the second order. The role of N-H...H-B dihydrogen bonds and other intermolecular interactions in the stability of NH3BH3 polymorphs is examined.Comment: 23 pages, 7 figure

9-Ethyl-N-(3-nitro­benzyl­idene)-9H-carbazol-3-amine

The title compound, C21H17N3O2, crystallizes with two mol­ecules in the asymmetric unit. The carbazole groups show relatively small deviations from planarity [maximum displacements from the mean carbazole plane are 0.077 (7) and 0.101 (7) Å]. The dihedral angles between the 3-nitro­benzyl­idene­amine and carbazole groups are 37.9 (1) and 37.0 (1)° in the two mol­ecules

5-Methyl-7,8,9,10-tetra­hydro­cyclo­hepta­[b]indol-6(5H)-one

In the title mol­ecule, C14H15NO, the dihedral angle between the benzene and pyrrole rings is 1.99 (12)°. The cyclo­heptene ring adopts a slightly distorted boat conformation

Propyl­amine–borane

The title compound, C3H12BN, was solved using data collected from a multiple crystal (note incomplete data shell). The cell packing is dominated by bifurcated attractive N—Hδ+⋯δ−H—B inter­actions

(E)-6-Chloro-2-(furan-2-yl­methyl­idene)-2,3,4,9-tetra­hydro-1H-carbazol-1-one

In the title compound, C17H12ClNO2, the carbazole unit is nearly planar [maximum deviation = 0.052 (1) Å]. The pyrrole ring makes dihedral angles of 1.92 (8) and 4.71 (11)° with the benzene and furan rings, respectively. Inter­molecular N—H⋯O hydrogen bonds form R 2 2(10) rings in the crystal structure

Aqua­(μ-cone-26,28-dibut­oxy-25,27-bis­{N-[5-(dimethyl­amino)­naphthalene-1-sulfon­yl]carbamoylmeth­oxy}-5,11,17,23-tetra­kis­(1,1-dimethyl­eth­yl)calix[4]arene(2−))disodium acetonitrile tetra­solvate

The structure of the title complex, [Na2(C80H98N4O10S2)(H2O)]·4CH3CN, obtained after crystallization from aceto­nitrile, contains two formula units in the asymmetric unit (Z′ = 2) and an estimated four mol­ecules of acetonitrile per calixarene moiety. It is unusual for two Na+ ions to occupy the lower rims of the cone calix[4]arene, as in this case, with one Na+ ion forming two O→ Na+ coordinate bonds with the two but­oxy groups and four such bonds with the two N-dansyl carboxamide groups, forming six dative bonds between Na+ and O. On the other hand, the other Na+ ion forms only five O→Na+ coordinate bonds on the far end of the calix[4]arene lower rim, bringing the two dansyl groups in close proximity with each other. There also appears to be an O→Na+ coordination coming from a dangling water mol­ecule. The structure contained both resolved and poorly resolved solvent mol­ecules. The latter were treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]

Investigations into the assembly behaviour of a 'rigidified': P-carboxylatocalix[4]arene

The p-carboxylatocalix[4]arenes have been shown to be versatile supramolecular building blocks capable of forming a range of bi-layers, capsules and nanoscale tubules in the solid state. Here we report the synthesis of a new 'rigidified' analogue, as well as investigations into its self-assembly and related coordination chemistry. These behaviours are reminiscent of other p-carboxylatocalix[4]arenes despite the presence of rigidifying groups at the lower-rim, suggesting that this building block may be further exploited in the assembly of a range of new metal-organic cages and coordination polymers

[N,N'-bis(2-thiobenzylidene)-1,2-phenylenediaminato]nickel(II)

Metals in Catalysis, Biomimetics & Inorganic Material