Trimethyl 3,3',3''-(benzene-1,3,5-triyl)tripropynoate

In the crystal of trimethyl 3,3',3''-(benzene-triyl)tripropynoate, a system of new hydrogen bond ring motifs involving C-H...O interactions give rise to layer formation of molecules while the layers are connected among each other via weak contacts of C---H...O and C---H...pi type to specifically complete the supramolecular packing structure

1-(Hydroxymethyl)pyrene

The asymmetric unit of the title compound, C17H12O, contains two molecules, in which the fused aromatic ring systems are almost planar [maximum deviations = 0.0529 (9) and 0.0256 (9) Å]. In the crystal, aromatic π–π stacking interactions (perpendicular distance of centroids of about 3.4 Å) and strong O—H...O hydrogen bonds result in a helical arrangement of pyrenyl dimers

Different supramolecular interactions mediated by bromine atoms in the crystal structures of three anisole derivatives

Three anisole building blocks featuring bishydroxymethyl or bisbromomethyl pendants have been analyzed with regard to their molecular structure and packing behaviour. A typical supramolecular pattern we found were C—H···π interactions responsible for the generation of molecular stacks. π···π Interactions were only observed in the absence of bromine indicating a striking influence on the distances between adjacent aromatic moieties. When comparing the bishydroxymethyl compound with the respective bisbromomethyl compound we found that the strong O—H···O in the zigzag arrangement in the first is replaced by C—H···Br interactions in the second without changing the general packing

Crystal structure of 25,26,27,28-tetrabenzyloxy-5,11,17,23-tert-butylcalix- [4]arene, C72H80O4

C72H80P4, monoclinic, P121/n1 (no. 14), a = 10.3709(3) Å, b = 23.2467(6) Å, c = 25.1444(7) Å, β= 92.660(1)°, V = 6055.5 Å3, Z = 4, R gt(F) = 0.060, wRref(F2) = 0.190, T = 273 K

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene tetrahydrofuran solvate

The asymmetric unit of the title compound, C44H64O4·C4H8O, comprises two crystallographically independent calixarene mol-ecules, which display a partial cone conformation, and two tetrahydrofuran molecules. The crystal packing is stabilized by C - H⋯π contacts involving the meth-oxy groups, while the solvent mol-ecules are located in voids between the calixarene molecules. Two of the tert-butyl residues of each calixarene mol-ecule are disordered over two positions [0.74/0.26 (ring B), 0.71/0.29 (ring C), 0.77/0.23 (ring C′), 0.67/0.33 (ring D′)], resulting in bond distances that deviate from ideal values

Fine tuning of crystal architecture by intermolecular interactions: synthon engineering

There has been a long time effort to influence or favourably fine tune structural properties by introduction of substituents or guest molecules of different sizes, shapes and chemical composition to consequently alter physico-chemical properties of the respective crystals. These attempts require the recognition, understanding and application of intermolecular interactions, crystallographic and, in case of occurrence, non-crystallographic symmetries. It brings us to the field of crystal engineering, which aims to produce new substances with required properties based on the knowledge of the structural properties of already characterised solids. A series of calixarene crystal structures are presented where the crystal packing is determined by spatial or by electrostatic effects. A series of laterally substituted calixarenes where both steric requirements and electrostatic forces play a role in the crystal architecture shows how the supramolecular synthon can be engineered

An oncocytic adrenal tumour in a patient with Birt‐Hogg‐Dubé syndrome

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106917/1/cen12292.pd