Hydrothermal syntheses, characterizations and crystal structures of three new cadmium (II) amino-diphosphonates: effects of substitute groups on the structures of metal phosphonates Academic Article uri icon


  • Hydrothermal reactions of cadmium(II) chloride with three amino-diphosphonic acids, C6H5CH2N(CH 2PO3H2)2 (H4L 1), C6H5CH2CH2N(CH 2PO3H2)2 (H4L 2) and 4-CH3-C6H4CH2N (CH2PO3H2)2) (H4L 3) resulted in three new metal amino-diphosphonates, namely, Cd(H3L1)2, 1 Cd(H3L 2)2·2H2O 2 and Cd(H3L 3)2 3. In all three complexes, the Cd(II) ion is octahedrally coordinated by six phosphonate oxygen atoms from six ligands. Complexes 1 and 3 have a similar structure in which the CdO6 octahedra are cross-linked by bridging ligands into a double chain along the c-axis, such double chains are further interlinked via hydrogen bonds between non-coordinated phosphonate oxygen atoms to form 〈100〉 and 〈200〉 layers with the phenyl groups of the ligands orientated toward the interlayer space. The structure of complex 2 features a 〈100〉 cadmium(II) diphosphonate layer. The effects of the substitute groups attached to the amine groups on the structures of the metal phosphonates are also discussed. © 2003 Elsevier Inc. All rights reserved.

author list (cited authors)

  • Sun, Z., Yang, B., Sun, Y., Mao, J., & Clearfield, A.

citation count

  • 36

publication date

  • November 2003