The results of this investigation show that it is possible to determine the concentration of hydrofluoric acid in hydrofluoric acid-water solutions by spectrophotometric measurement at 1835 µ.Free hydrofluoric acid can be determined in aqueous hydrofluoric acid solutions, by a spectrophotometric method, in the presence of many metal complexes in equilibrium.Other acids in aqueous solutions can probably be determined in the same manner if only one acid is present and there are no other interfering substances. If several acids are present, then obviously total acid concentration would be determined. This total acid concentration probably represents the concentration of hydronium ion in solution, although further proof of this is required.The ability to measure free hydrofluoric acid in complex aqueous solutions has resulted in the gain of important qualitative information about the ionic species present in tantalum-niobium-hydrofluoric acid solutions. The determination of free acid should be applicable to many other complex systems, making it possible to understand and control the degree of hydrolysis and, hence, types of ionic species in solution.

Layer by layer metal-organic framework (MOF) supported on zirconium phosphate (ZrP) was synthesized at very mild conditions and used for the liquid phase oxidation of cyclohexene in solvent free condition in the presence of molecular oxygen. The MOF-ZrP was characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), thermal gravimetric analyzer (TGA), Fourier-transform infrared spectrometer (FT-IR) and Brunauer-Emmett-Teller (BET) surface area analyzer. The characterization shows a smooth morphology of MOF-ZrP with good stability under 200 °C having surface area 285 m2/g. The catalytic activity of the MOF-ZrP revealed that increase of layers of MOF on ZrP enhances conversion, as well as selectivity of oxidation of cyclohexene. DFT studies were used to explore the structure and electron properties of HKUST-1 (Hong Kong University of Science and Technology), which is a clue for the catalytic behavior of the catalyst.

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Linear amino acids covalently supported on graphene sheet were employed as catalysts for asymmetric aldol reactions between cyclohexanone and aldehydes (aliphatic and/or aromatic) in a batch type reactor in the presence of water. The reactions were found to exhibit high yield as well as excellent ee value. Additionally, the catalysts were found to be truly heterogeneous and eco-friendly.