Synthesis, Characterization and X-Ray Structure of a Ba(II)/Ag(I)/Cr(III)-Oxalate Salt with Water-Filled Nanochannels

A novel mixed barium(II)/silver(I)/chromium(III) oxalate salt, Ba0.5Ag2[Cr(C2O4)3]·5H2O (1), with open architecture has been synthesized in water and characterized by elemental analysis, vibrational and electronic spectra, and single crystal X-ray structure determination. Compound 1 crystallizes in a monoclinic space group C2/c, with unit cell parameters a = 18.179(3), b = 14.743(2), c = 12.278(2)A, β = 113.821(3), V = 3010.34(90) A3, Z = 8. The structure is characterized by a network of anionic [Cr(C2O4)3]3- units connected through the O atoms of the oxalates to Ba2+ and Ag+ sites, forming a three-dimensional coordination polymer with one-dimensional isolated nanochannels parallel to the c axis, and encapsulating hydrogen-bonded guest water molecules. The bulk structure is consolidated by O–H···O bridgings within the nanochannels and by coulombic interactions.