Synthesis and structure of manganese(ii) coordination polymers with 1,4-diazabicyclo[2.2.2]octane N, N′-dioxide: solvent and template effects

Abstract

New metal-organic frameworks [Mn(DMF)2(odabco)2](ClO4)2 · H2O (1), [Mn(H2O)2− (HCOO)2] · odabco (2), and [Mn(Hodabco)2(odabco)3](NO3)4 (3) were synthesized by the reaction of manganese Perchlorate with 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide (odabco) in N, N-dimethylformamide (DMF) under varying reaction conditions. The reaction in N-methylpyrrolidone afforded the metal-organic framework [Mn(odabco)3](NO3)2 (4). The structures of compounds [Mn(DMF)2(odabco)2](ClO4)2 · DMF · H2O (1 · DMF · H2O), [Mn(DMF)2(odabco)2](ClO4)2 · THF (1 · THF), 2, 3, and 4 were determined by single-crystal X-ray diffraction analysis. In compounds 1 · DMF · H2O, 1 · THF, 3, and 4, odabco acts as a bridging ligand; in 2, as a guest template. Compound 1 · DMF · H2O has a layered structure and contains a system of intersecting channels occupied by perchlorate anions and disordered solvent molecules. The framework of 1 proved to be stable during the post-synthetic exchange of DMF by THF. The coordination framework of the adduct 1 · THF containing localized THF molecules has a similar structure. The layered (2) and chain-like (3) compounds are stabilized by extensive hydrogen-bonding systems, giving rise to pseudo-three-dimensional close-packed structures. The replacement of DMF by N-methylpyrrolidone under conditions similar to the synthesis of 3 affects the coordination ability of odabco and affords compound 4 having a three-dimensional framework with pcu topology.