Tetrakis(4-carboxy­phenyl)­methane-di­methyl sulfoxide-toluene (1/4/1)

The title compound [systematic name: 4,4',4'',4'''-methanetetrayl­tetra­carboxyl­ic acid-di­methyl sulfoxide-toluene (1/4/1)], C₂₉H₂₀O₈, crystallizes from di­methyl sulfoxide (DMSO)/toluene to yield a structure in which the four carboxyl­ic acid groups of each mol­ecule donate a single hydrogen bond to the O atom of four mol­ecules of DMSO. Packing of the resulting aggregates, which have crystallographic twofold symmetry, leaves space for the inclusion of partially disordered mol­ecules of toluene, leading to the formation of crystals of overall composition tetrakis(4-carboxy­phenyl)­methane-di­methyl sulfoxide-toluene (1/4/1).

Penta­erythrit­yl tetra­kis­(4-bromo­benz­yl ether)

The title compound {alternatively called tetra­kis­[(4-bromo­benz­yl­oxy)meth­yl]methane}, C₃₃H₃₂Br₄O₄, was crystallized from eth­yl acetate. The molecule has crystallographic twofold rotation symmetry. Key features of the structure include intra­molecular edge-to-face aromatic inter­actions, inter­molecular Br...π inter­actions and inter­molecular Br...O contacts.

Tetra­kis(3,5-dimethoxy­phen­yl)silane

The title compound, C₃₂H₃₆O₈Si, crystallizes from CH₂Cl₂ by slow evaporation to produce a close-packed structure. In this structure, the mol­ecules have crystallographic symmetry and no guest molecules are included. In contrast, crystallization of the closely related tetra­kis(3,5-dihydroxy­phen­yl)silane from a range of solvents is directed by phenolic hydrogen bonding to yield an open diamondoid network, which is filled by a combination of inter­penetration and inclusion of guests.

Tetra­kis(2-meth­oxy-5-pyrid­yl)silane

The title compound, C₂₄H₂₄N₄O₄Si, crystallizes from propionic acid-hexane to produce a close-packed structure with no included guests. In contrast, crystallization of the closely related tetra­kis(1,2-dihydro-2-oxo-5-pyrid­yl)silane under similar conditions is directed by hydrogen bonding of the pyridinone groups to yield an open diamondoid network, which is filled by a combination of inter­penetration and inclusion of guests.