In situ X-ray structural studies of a flexible host responding to incremental gas loading.

Crystallographic pressure-lapse snapshots of a porous material responding to gas loading were used to investigate the stepwise uptake of carbon dioxide and acetylene molecules into discrete confined spaces. Based on the data, a qualitative statistical mechanical model was devised that reproduces even subtle features in the experimental gas sorption isotherms.

Bromido-1κBr-tricarbonyl-2κC-(2η-cyclo-penta-dien-yl)molybdenum(I)tungsten(I)(W-Mo).

The title compound, [WMoBr(C(5)H(5))(CO)(3)], is built up from a pseudo-square-pyramidal piano-stool coordination around the Mo atom, the important geometry being Mo-W = 2.6872 (7) Å, W-Br = 2.5591 (9) Šand Mo-W-Br = 158.35 (3)°.

Dibenzyl penta-thio-dicarbonate.

In the title compound, C(16)H(14)S(5), the non-bonded intra-molecular distances between the non-terminal S atoms are 2.808 (16) and 2.784 (16) Å, shorter than the typical distance of 2.9 Å. One phenyl ring participates in an offset π-π inter-action with another phenyl ring related by a centre of inversion; the inter-planar distance is 3.41 (2) Å. The crystal structure also exhibits edge-to-face C-H⋯π stacking of the phenyl rings, thus forming a herring-bone packing motif.

Tripodal imidazole frameworks: Reversible vapour sorption both with and without significant structural changes.

A series of tripodal imidazole frameworks (TIFs) are reported based on a tripodal, cavity-containing tris(imidazole) derivative. In the case of [Co(3)Cl(6)(1)(2)]·n(solvent) (TIF-1) which possesses a doubly interpenetrated framework structure, the material exhibits rigid, permanent porosity and selectively absorbs CO(2). The non-interpenetrated [Co(1)(2)(H(2)O)(2)]Cl(2)·4H(2)O (TIF-2) also absorbs gases and vapours fully reversibly exhibiting a reversible phase change in the process and considerable conditioning and hysteresis. The very highly hydrated [Co(1)(2)]Cl(2)·22H(2)O (TIF-3) irreversibly dehydrates to the layered structure [Co(1)(2)]Cl(2)·H(2)O (TIF-4). A nickel analogue [Ni(1)(2)]Cl(2)·22H(2)O (TIF-5) closely related to TIF-3 is also reported along with two isostructural, non-porous materials [MCl(2)(1)] (M = Mn, TIF-6; M = Cd, TIF-7) based on d(5) and d(10) Mn(II) and Cd(II). Some of the materials may be prepared by mechanochemical as well as solution based methods. We liken TIF-1 to a gas cylinder, TIF-2 to a sponge and TIF-3 to a fragile soda can that is crushed on emptying to give TIF-4.

A catenated imidazole-based coordination polymer exhibiting significant CO2 sorption at low pressure.

A robust, porous, catenated coordination polymer based on a neutral, flexible imidazole-derived tripodal ligand (a 'tripodal imidazole framework', TIF) reversibly absorbs vapours and gases, particularly CO2.