Two novel 3-D bismuth oxalates with organic amines protruding in channels

Abstract

Two novel 3-D oxalate-containing bismuth compounds of formula (C 3N 2H 5) 2 [Bi 2(C 2O 4) 4(H 2O) 2]·2H 2O 1 and [NH(C 2H 5) 3][Bi 3(C 2O 4) 5] 2 were obtained by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic P2/ n space group with a = 9.7541 ( 13 ) Å , b = 17.7404 ( 15 ) Å , c = 14.6321 ( 6 ) Å , β = 97.280 ( 3 ) ° , Z = 4 , R 1 = 0.0340 and w R 2 = 0.0766 for unique 4734 reflections I > 2 σ ( I ) . Compound 2 belongs to the orthorhombic Pbcn space group with a = 14.803 ( 4 ) Å , b = 19.783 ( 7 ) Å , c = 8.202 ( 2 ) Å , Z = 4 , R 1 = 0.0222 and w R 2 = 0.0568 for unique 2472 reflections I > 2 σ ( I ) . The Bi III centers have nine-fold coordination for 1 and eight-fold for 2 with the Bi atoms in distorted monocapped square antiprism and distorted dodecahedron, respectively. And oxalate ligands adopt different coordination modes: bidentate for 1, bidentate and tricoordinate for 2. Compounds 1 and 2 are both 3-D open-framework structures containing channels with guest molecules. These two compounds exhibit intense blue luminescence with the emission peaks at 419 nm for 1 and 442 nm for 2, respectively, in the solid state at room temperature. These compounds with novel structural frameworks could be useful in the field of photoactive materials.