Hydrothermal Synthesis and Characterization of Two Novel Lead(II) Frameworks: From 1D Infinite Helical Pb–(O–C–O)–Pb Linkage to 3D Infinite Pb– X –Pb Network ( X = O and Br)

Abstract . Two aliphatic dicarboxy1ic acid ligands, iminodiacetic acid (H 2 L 1 ) and 3,3‐thiodipropionic acid (H 2 L 2 ), were used to construct two novel lead(II) frameworks, namely, [Pb(μ 4 ‐L 1 )Br] n ( 1 ) and [Pb 3 (μ 9 ‐L 2 )(μ 2 ‐Br) 2 Br 2 ] n ( 2 ), under hydrothermal conditions. It has to be noted that for 1 the central Pb II ions are bridged by L 2– ligands resulting in infinite right‐ and left‐handed helical Pb–(O–C–O)–Pb linkage. Compound 2 represents a novel 3D hybrid luminescent lead(II) framework with I 3 O 0 type connectivity. For 2 infinite 2D Pb–O–Pb inorganic layers and trinuclear Pb 3 Br 4 clusters are inter‐linked forming a 3D inorganic connectivity. In 1 the five‐coordinate central Pb II ions adopt a hemi‐directed coordination arrangement, whereas in 2 six‐coordinate Pb1, six‐coordinate Pb2, and four‐coordinate Pb3 atoms adopt hemi‐directed coordination arrangements. The variable lead(II) coordination environment and flexible coordination modes of carboxy1ic acid ligands such as H 2 L 1 and H 2 L 2 also reveal great potential for constructing novel inorganic‐organic hybrid materials. Furthermore TGA, FT‐IR, PXRD, elemental analysis, and photo‐luminescent properties of 1 and 2 were investigated.