Two lanthanide–organic frameworks [Ln(HPIDC)(m-bdc)·1.5H₂O]_n (Ln = Eu 1 or Tb 2; H₃PIDC = 2-(4-pyridyl)-1H-imidazole-4,5-dicarboxylic acid; m-H₂bdc = 1,3-benzenedicarboxylic acid) were synthesized under hydrothermal conditions.

A novel 1D chain organic–inorganic hybrid polyoxovanadium borate Na[V₁₂B₁₆O₅₀(OH)₇(en)]₂(enH₂)₆(enH)₂(OH)(H₂O)₁₉ (1, en = ethylenediamine), based on a [V₁₂B₁₆O₅₀(OH)₇(en)]⁷⁻ cluster unit, has been hydrothermally synthesized and characterized. Interestingly, organic amine is incorporating into the V₁₂B₁₆ clusters.

Three α-Keggin heteropolymolybdates with the formula [(C₅H₄NH)COOH]₃[PMo₁₂O₄₀] 1, {[Sm(H₂O)₄(pdc)]₃}{[Sm(H₂O)₃(pdc)]}[SiMo₁₂O₄₀]·3H₂O 2 and {[La(H₂O)₄(pdc)]₄}[PMo₁₂O₄₀]F 3 (H₂pdc = pyridine-2,6-dicarboxylate), have been synthesized under hydrothermal condition and characterized by single crystal X-ray diffraction analyses, elemental analyses, inductively coupled plasma atomic emission spectroscopy (ICP-AES), IR, thermal gravimetric analyses, thermal infrared spectrum analyses and powder X-ray diffraction (PXRD) analyses. Single crystal X-ray diffraction indicates all three compounds comprise ball-shaped Keggin type [XMo₁₂O₄₀]ⁿ⁻ polyoxometalates (POMs) (n = 3, X = P; n = 4, X = Si, respectively) with different types of carboxylic ligands derived from H₂pdc, and these cluster anions are isostructural. In order to explore structural characteristics, Rhodamine B photocatalytic (RhB) degradation and two-dimensional infrared correlation spectroscopy (2D-IR COS) tests, are investigated for 1, 2 and 3. In RhB degradation, all compounds show good photocatalytic activity. For 1, the activity mainly comes from POMs. While in 2 and 3, POMs’ photocatalytic activity is enhanced by the Ln(III)–pdc metal–organic frameworks. Structural properties like POM's stability and magnetic sensitivity are discussed by 2D-IR COS under thermal/magnetic perturbations.

A novel 3D bismuth–organic framework with helical channels, {[Bi(mna)₂]⁻·(HDMA)⁺}_n (1, H₂mna = 2-mercaptonicotinic acid, DMA = dimethylamine) based on homo-chiral Bi–mna helices was hydrothermally synthesized and characterized. The optical diffuse reflectance spectrum and the theoretical calculations indicate that compound 1 is a potentially semiconductive material.