Microwave-assisted synthesis, spectroscopy, and crystal structures of [(H2 -(4,4´-bipy)]^2+ [Cr2O7] ² ̵ and one-dimensional polymeric {[Mn(4,4´ -bipy)(Cr2O7)(H2O)2 ]}n compounds

A compound (1), [H2 -(4,4´ -bipy)]^2+ [(Cr2O7)] ² ̵ and a metal organic-inorganic coordination framework (2), [Mn(4,4 ´ -bipy)(Cr 2O7)(H2 O)2] (4,4 ´ -bipy=4,4 ´ -bipyridine) were successfully synthesized by microwave method. Their characterization was performed by single crystal X-ray crystallography and FTIR spectroscopy. The crystal structure of 1 revealed a diprotonated 4,4 ´-bipyridium dichromate compound while compound 2 is an onedimensional (1D) polymer in which (Cr 2O7) ² ̵ acts as a bridging ligand supporting the formation of infinite {[Mn(4,4´ -bipy)(Cr 2O7)(H2 O)2 ]}n polymeric chains. The geometry of the 4,4 ´ -bipy ring in 1 is typical coplanar, but twists in 2. In the free molecule 1, dichromate ligand adopts an eclipsed conformation, but adopts a staggered conformation in complex. The principal features of the crystal supramolecularity of 1 and 2 are non-covalent weak interactions which occurred via N-H· · ·O and C-H· · ·O hydrogen bonding.