Cognizurecreating knowledge for future

     Two isomorphous silver-deficient oxalatometalate salts, viz. [(Ag_0.25/Co_0.25)(H₂O)] @[Ag₂Co(C₂O₄)₃].4H₂O (1) and [(Ag_0.25/Cr_0.25)(H₂O)]@[Ag₂Cr(C₂O₄)₃].4H₂O (2), have been synthesized in water and fully characterized by elemental analysis, single crystal X-ray structure determination, vibrational and electronic spectra, and by thermogravimetry. Compounds 1 and 2 crystallize as interesting three-dimensional coordination polymer networks that surround isolated nanochannels parallel to the c axis, encapsulating guest water clusters. In both crystal structures, the respective Co1 and Cr1 centers are each pseudo-octahedrally chelated by three oxalato ligands with usual propeller orientation. The Ag1 centers (on two-fold axes) are in strongly distorted octahedral coordination of two trans-chelating oxalato ligands lying within the equatorial plane and two axial monodentate oxalato ligands. The Ag2 centers, in general positions, are pentacoodinated by one chelating and three singly linked oxalato ligands. The Ag3/Co2 or Ag3/Cr2 sites, also in general positions, are occupied  by 0.75Ag^I/0.25Co^III or 0.75Ag^I/0.25Cr^III atom pairs, and are pentacoordinated to one chelating, two monodentate oxalato and one aqua ligands. The bulk structure is consolidated by O-H…O bridgings within the nanochannels, and by coulombic interactions. The shortest intermetallic distances are Ag3/Co2–Ag3/Co2^V = 3.241(2) Å and Ag3/Cr2–Ag3/Cr2^V = 3.226(2) Å.