Nanochanneled silver-deficient tris(oxalato)chromate(III) coordination polymers: Synthesis, crystal structure, spectroscopy, thermal analysis and magnetism

Two silver-deficient tris(oxalato)chromate(III) coordination polymers, SrK0.5Ag0.5[Cr(C2O4)(3)] (1) and SrAg[Cr(C2O4)(3)]center dot 6H(2)O (2) have been synthesized and fully characterized by elemental and TGA-DSC analyses, IR and UV-Vis spectroscopies, single-crystal X-ray diffraction and magnetic measurements. Salt 1 crystallizes in the orthorhombic polar space group Fdd2, whereas 2 crystallizes in the monoclinic space group P2(1/c). Compared to the well-known salt Ag-3[Cr(C2O4)(3)]center dot 3H(2)O with no silver deficiency, 1 and 2 can be seen as nanochanneled silver-deficient oxalatochromate(III) coordination polymers featuring silver deficiency values of 2.5 and 2.0, respectively. In 1, nanochannels host K+ and Ag+ cations, whereas in 2, they solely host hydrogen-bonded water molecules. The magnetic properties of 1 and 2 have been investigated in the temperature range 2-300 K. The decrease of chi T-M observed at low temperatures for 1 and 2 revealed weak antiferromagnetic interactions in the two compounds. (C) 2020 Elsevier B.V. All rights reserved.