Hydrothermal synthesis of two layered indium oxalates with 12-membered apertures

Two layered indium oxalates, In(C 2 O 4 ) 2.5 (C 3 N 2 H 12 )(H 2 O) 3 , I, and In(C 2 O 4 ) 1.5 (H 2 O) 3 , II, have been hydrothermally synthesized. In I, the linkage between indium and oxalate units gives rise to a sheet with a rectangular 12-membered aperture (six indium atoms and six oxalate units). Indium atom of II has an unusual pentagonal bipyramidal coordination arrangement. The connectivity between indium and oxalate units forms a neutral puckered layer with 12- (along a -axis) and eight-membered (along b -axis) apertures. Crystal data for these two indium oxalates are as follows: I, triclinic, space group: P -1 (No. 2), a =8.725(3) A, b =9.170(3) A, c =9.901(3) A, α =98.101(4)°, β =97.068(4)°, γ =102.403(4)°, V =756.3(4) A 3 , Z =2, M =463.0(5), ρ calc =2.042 g/cm 3 , R 1 =0.0377, w R 2 =0.0834. II, monoclinic, space group: P 2 1 / c (No. 14), a =10.203(5) A, b =6.638(1) A, c =11.152(7) A, β =95.649(4)°, V =751.7(4)A 3 , Z =4, M =300.9(0), ρ calc =2.659 g/cm 3 , R 1 =0.0229, w R 2 =0.0488. TG analyses indicate the water molecules of I can be removed at 150°C. The dehydrated product retains structural integrity.