Reagents with a Crystalline Coat

Abstract

Tetrakis(dimethoxyphenyl)adamantane (TDA) readily forms crystalline inclusion complexes with reactive, toxic, or malodorous reagents, such as benzoyl chloride, acetyl chloride, cyclohexyl isocyanide, phosphorus trichloride, and trimethylsilyl chloride. The crystals are stable and largely free of the problematic properties of the free reagents. When exposed to solvents such as DMSO or MeOH, the reagents react, and a large portion of the TDA precipitates. The TDA-coated reagents may lead to a safer way of storing, handling, and delivering reagents, and ultimately to synthetic protocols that do not require fume hoods.

High‐Loading Crystals of Tetraaryladamantanes and the Uptake and Release of Aromatic Hydrocarbons from the Gas Phase

“…When the guests are dangerous, labile, and/or malodorous compounds, their problematic properties can be masked. The TDA crystals can thus act as a formulation or “crystalline coating” for reactive compounds …”

“… Overlays of the conformations of tetraaryladamantanes found in X‐ray crystal structures, with each conformer displayed in a different color. a) Overlay of 25 different TDA conformers found in triclinic crystal systems; b) overlay of the (near‐identical) conformations of TEO in eight triclinic crystal systems; c) overlay of the conformations of TEO in the three monoclinic crystal systems (see Table for details).…”

“…The TDA crystalsc an thus act as af ormulation or "crystalline coating" for reactive compounds. [10] The guestst hat were found in crystals of TDA include aromatics, but only one molar equivalent of benzene or trifluorobenzenew as found in X-ray crystal structures, and just 0.5 equivalents of nitrobenzene weret hus encapsulated. [9] Furthermore, uptake andr eleaseo fg uest molecules occurred through the solution phase and the release of capturedb enzene required immersing the crystalsi nc hloroform to liberate the molecularc argo.…”

“…Overlaysoft he conformations of tetraaryladamantanes found in Xray crystal structures,w ith each conformer displayed in ad ifferent color. a) Overlay of 25 different TDA conformersf ound in triclinic crystal systems; [9,10] mation. Because TEO takes up more guest molecules, it is am ore efficient crystal coating material than TDAf or most of the guest compounds studied thus far.T he maskinga bility of TEO can help to store, handle, and dispenser eagents.…”

Determining the Relative Configuration of Propargyl Cyclopropanes by Co-Crystallization

“…Tetraaryladamantanes are known to form crystalline inclusion complexes for a wide range of small molecules, 6,7,8,9 and the resulting solids have been referred to as 'encapsulating organic crystals' (EnOCs). 10 Thermal cocrystallization is rapid, does not require screening for suitable solvents, and produced well diffracting co-crystals for the majority of over 50 liquid compounds tested.…”