Porous molecular crystals are an emerging class of porous materials that is unique in being built from discrete molecules rather than being polymeric in nature. In this study, we examined the effects of molecular structure of the precursors on the formation of porous solid-state structures with a series of 16 rigid aromatics. The majority of these precursors possess pyrazole groups capable of hydrogen bonding, as well as electron-rich aromatics and electron-poor tetrafluorobenzene rings. These precursors were prepared using a combination of Pd- and Cu-catalyzed cross-couplings, careful manipulations of protecting groups on the nitrogen atoms, and solvothermal syntheses. Our study varied the geometry and dimensions of precursors, as well as the presence of groups capable of hydrogen bonding and [π···π] stacking. Thirteen derivatives were crystallographically characterized, and four of them were found to be porous with surface areas between 283 and 1821 m g. Common to these four porous structures were (a) rigid trigonal geometry, (b) [π···π] stacking of electron-poor tetrafluorobenzenes with electron-rich pyrazoles or tetrazoles, and

Cyanide-catalyzed benzoin condensation of terephthaldehyde produces a cyclic tetramer, which we propose to name cyclotetrabenzoin. Cyclotetrabenzoin is a square-shaped macrocycle ornamented with four α-hydroxyketone functionalities pointing away from the central cavity, the dimensions of which are 6.9×6.9 Å. In the solid state, these functional groups extensively hydrogen bond, resulting in a microporous three-dimensional organic framework with one-dimensional nanotube channels. This material exhibits permanent-albeit low-porosity, with a Langmuir surface area of 52 m(2)  g(-1) . Cyclotetrabenzoin's easy and inexpensive synthesis and purification may inspire the creation of other shape-persistent macrocycles and porous molecular crystals by benzoin condensation.

A series of alkali-metal tin benzenedicarboxylates A 2 Sn 2 (bdc) 3 (H 2 O) x , A = Li, Na, K, Rb, Cs, in single crystal forms have been synthesized by using a hydrothermal technique. The compounds all have cubic crystal structures based on a very open anionic [Sn 2 (bdc) 3 ] 2framework which is 8-fold interpenetrated noncentrosymmetrically (space group I23) in Li 2 Sn 2 (bdc) 3 (H 2 O) 2 , 1, K 2 Sn 2 (bdc) 3 , 3, Rb 2 Sn 2 (bdc) 3 , 4, and Cs 2 Sn 2 (bdc) 3 , 5, but centrosymmetrically (space group Pn3) in Na 2 Sn 2 (bdc) 3 (H 2 O), 2. The ion size and coordination requirements of the alkali ions play an important role in the interpenetration of the anionic framework and the symmetry of the structures.

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A large spin, magnetically anisotropic, ferromagnetically coupled octanuclear vanadium(iii) wheel-like cluster has been synthesized.