Waste-free synthesis and production all across chemistry with the benefit of self-assembled crystal packings

摘要

A systematic mechanistic discussion of solid-state reactions (intracrystalline, intercrystalline, gas-solid thermal, or photochemical) at local molecular resolution is the basis for industrial sustainable production with waste-free solid-gas and stoichiometric solid-solid reactions at low energy requirement. These profit from the bargain of the self-assembled crystal packing. They rapidly complete to give 100% yield and require no solvent for workup. The basic requirements are thermodynamic feasibility and anisotropic molecular migrations at local pressure or suction in opposition to claims of 'minimal atomic and molecular movements' that do not know gas-solid and solid-solid reactions. Topochernical failures are settled on that experimental basis by atomic force microscopy (AFM), correlation with the crystal packing, scanning near field optical microscopy (SNOM), and nanoscratching. A general three-step phase rebuilding mechanism is derived that provides directions for all experimental situations including stereoregular polymerizations. Heat control in gas-solid equipment and solid-solid small-scale vibration or large-scale rotation ball-mills is essential. If AFM identifies (nano)liquids cooling is required. Also rare cases of surface passivation are detected by AFM. Molecular solid-state chemistry and mechanochemistry are differentiated. Solid-state techniques easily exclude moisture and are able to synthesize hitherto inaccessible compounds. Some of the latter are selected for discussion out of more than 1000 waste-free solid-state reactions in addition to already executed kg-scale productions using reasonably inexpensive starting materials with promise for industrial applications and extensions. They cover salt formations, complexations, additions, eliminations, substitutions, esterifications, carboxylations, rearrangements, linear dimerizations, cycloreversions, cyclizations, ring openings, cascade reactions, and C - C-couplings (Knoevenagel, Michael, aminomethylation).