Hybrid Inorganic‐Organic Frameworks: Synthesis and Crystal Structures of RbFe(SO₄)(C₂O₄)_0.5·H₂O and CsM(SO₄)(C₂O₄)_0.5·H₂O (M = Mn, Fe)

Abstract

Three new alkali metal transition metal sulfate‐oxalates, RbFe(SO4)(C2O4)0.5·H2O and CsM(SO4)(C2O4)0.5·H2O (M = Mn, Fe) were prepared through hydrothermal reactions and characterized by single‐crystal X‐ray diffraction, solid state UV/Vis/NIR diffuse reflectance spectroscopy, infrared spectra, thermogravimetric analysis, and powder X‐ray diffraction. The title compounds all crystallize in the monoclinic space group P21/c (no. 14) with lattice parameters: a = 7.9193(5), b = 9.4907(6), c = 8.8090(6) Å, β = 95.180(2)°, Z = 4 for RbFe(SO4)(C2O4)0.5·H2O; a = 8.0654(11), b = 9.6103(13), c = 9.2189(13) Å, β = 94.564(4)°, Z = 4 for CsMn(SO4)(C2O4)0.5·H2O; and a = 7.9377(3), b = 9.5757(4), c = 9.1474(4) Å, β = 96.1040(10)°, Z = 4 for CsFe(SO4)(C2O4)0.5·H2O. All compounds exhibit three‐dimensional frameworks composed of [MO6] octahedra, [SO4]2– tetrahedra, and [C2O4]2– anions. The alkali cations are located in one‐dimensional tunnels.

Synthesis, Crystal Structures, and Properties of (4,4'‐Hbipy)2[Sn2(C2O4)3] and (4,4'‐Hmbipy)[SnX2] (X = C2O42–, m = 2; X = Cl, m = 0; bipy = bipyridine)

“…The bands at 1686 and 1626 cm –1 (νCO), 1302 and 1265 cm –1 (νCC), 806 cm –1 (νOCO) for 1 , 1642 cm –1 (νCO), 1271 cm –1 (νCC), 789 and 818 cm –1 (νOCO) for 2 are attributed to the coordinated oxalate groups. The bands from 618 cm –1 to 1219 cm –1 can be assigned to the C–H in‐plane or out‐of‐plane bends, ring breathing and ring deformation vibrations of 4,4'‐bipy , , . Thus, the infrared peaks observed at 1201 cm –1 , 1007 cm –1 , 1054 cm –1 , 884 cm –1 in (4,4'‐Hbipy) 2 [Sn 2 (C 2 O 4 ) 3 ], at 893 cm –1 , 994 cm –1 in (4,4'‐H 2 bipy)[Sn(C 2 O 4 ) 2 ] and 1073 cm –1 , 1010 cm –1 , 812 cm –1 in SnCl 2 (4,4'‐bipy) are assigned to the C–H bending vibrations.…”