Gas-Solid Chemisorption/Adsorption and Mechanochemical Selectivity in Dynamic Nonporous Hybrid Metal Organic...

Gas-solid chemisorption of HCl and adsorption of MeOH/EtOH by nonporous chiral copper(II) coordination complexes 1·MeOH and 1″·MeOH occur in a cooperative and dynamic manner to give solvated second sphere adducts 1'·MeOH/EtOH. The chemisorption process involves dramatic atomic rearrangements in the crystalline state upon cleavage and formation of H-Cl, N-H, Cu-N, and Cu-Cl coordination and covalent bonds from the gas and solid state, respectively. Using mechanochemistry, the chloride-bridged coordination complex 1″·MeOH is selectively produced by means of a dehydrochlorination reaction, but not in solution in which a mixture of 1·MeOH and 1″·MeOH is obtained. 1″·MeOH also via chemisorption and adsorption can trap HCl and MeOH to give the second sphere adduct 1'·MeOH. The adsorption process is confirmed by forming the second sphere adduct 1'·EtOH by exposing both 1·MeOH and 1″·MeOH to HCl and ethanol. Quantum-mechanical (QM) calculations specific for solid phases give insights into the relative stabilities of the hybrid metal organic materials involved in the mechanochemical reaction producing selectively 1″·MeOH, giving a good agreement with the experimental results.