Synthesis and structural characterization of three new manganese(II) diphosphonates with layered and double-chain architectures

Hydrothermal reactions of two substituted aminodiphosphonic acids, C6H5CH2N(CH2PO3H2)2(H4L1) and 4-CH3-C6H4CH2N(CH2PO3H2)2(H4L2), with manganese(II) acetate resulted in three manganese(II) diphosphonates with a layered and double chain structure, namely, Mn(H2L1) (1), Mn(H3L1)2 (2) and Mn2(H2L2)2(H2O) (3). Compounds 1 and 3 are layered with interlayer distances of 12.65 and 16.28 Å, respectively. Compound 2 features 1D double chains along the c-axis that are interlinked by strong hydrogen bonds between non-coordinated phosphonate oxygens.