Solution and Solid-State Preparation of 18-Crown-6 and 15-Crown-5 Adducts of Hydrogen Sulfate Salts and an Investigation of the Reversible Dehydration Processes

A new class of organic−inorganic complexes has been prepared by reaction in solution or by mechanical mixing of 15-Crown-5 or 18-Crown-6 ethers with MSO 4 (M = Mn 2+, Cd 2+, Pb 2+ ) and/or H 2 SO 4 in stoichiometric amount. The complexes (15-Crown-5)[Mn(H 2 O) 2 (HSO 4 ) 2 ] ( 1 ), (15-Crown-5)[Cd(H 2 O) 2 (HSO 4 ) 2 ] ( 2 ), (15-Crown-5)[(H 7 O 3 )(HSO 4 ) 2 ]·H 2 O ( 3 ), (18-Crown-6)[Pb(HSO 4 ) 2 ] ( 4 ), and (18-Crown-6)[(H 5 O 2 )(HSO 4 )] ( 5 ) have been characterized by single-crystal X-ray diffraction. Compounds 1 and 2 undergo reversible water release−uptake processes, accompanied by a change in coordination at the metal centers; the dehydration and phase-transition processes have been investigated by DSC, TGA, and variable-temperature X-ray powder diffraction.