Microwave-assisted synthesis, spectroscopy, and crystal structures of [(H_2-(4,4'-bipy)]^{2+} [Cr_2O_7]^{2-} and one-dimensional polymeric {[Mn(4,4'-bipy)(Cr_2O_7)(H_2O)_2]}_n compounds

摘要

A compound (1), [H_2-(4,4'-bipy)]^{2+}[(Cr_2O_7)]^{2-} and ametal organic-inorganic coordination framework (2),[Mn(4,4'-bipy)(Cr_2O_77)(H_2O)_2] (4,4'-bipy=4,4' -bipyridine) weresuccessfully synthesized by microwave method. Their characterizationwas performed by single crystal X-ray crystallography and FT-IRspectroscopy. The crystal structure of 1 revealed a diprotonated4,4'-bipyridium dichromate compound while compound 2 is anonedimensional (1D) polymer in which (Cr_2O_7)^{2-} acts as a bridgingligand supporting the formation of infinite {[Mn(4,4'-bipy)(Cr_2O_7)(H_2O)_2]}_npolymeric chains. The geometry of the 4,4'-bipy ring in 1 is typicalcoplanar, but twists in 2. In the free molecule 1, dichromate ligandadopts an eclipsed conformation, but adopts a staggered conformationin complex. The principal features of the crystal supramolecularityof 1 and 2 are non-covalent weak interactions which occurred viaN-H...O and C-H...O hydrogen bonding.