In this study, two perimidinium derivatives (1 and 2) were designed, synthesized, and developed as efficient fluorescent and colorimetric chemodosisensors for F⁻ in DMSO or more competitive media (DMSO containing 10 % water). In the presence of F⁻, the yellow and non-fluorescent solution of 1/2 became colourless and exhibited strong blue fluorescence. This unique spectroscopic behaviour of 1/2 towards F⁻ was attributed to the formation of N-heterocyclic carbene deprotonated by F⁻, which immediately reacted with water to give a colourless and fluorescent carbinol. Interestingly, it was found that this carbinol intermediate was unstable and further underwent a redox disproportionation to generate two other optically changed compounds. All the proposed mechanisms for the sensing process have been carefully confirmed by experiments.

An effective one-pot method for the conversion of carbon dioxide, ethylene oxide, and amines to 3-aryl-2-oxazolidinones has been developed. This one-pot method consists of two parallel reactions and a subsequent cascade reaction between the two products of the corresponding parallel reactions. Notably, the binary ionic liquids of 1-butyl-3-methyl-imidazolium bromide and 1-butyl-3-methyl-imidazolium acetate demonstrate a synergistic catalytic effect on this new strategy. 1-Butyl-3-methyl-imidazolium bromide is essential in two parallel reactions owing to the good nucleophilicity and leaving ability of bromide, and 1-butyl-3-methyl-imidazolium acetate plays a dominant role in the subsequent cascade reaction owing to the strong basicity of acetate. In addition, the binary ionic liquids can be used thrice without significant loss of catalytic activity.

A series of cyclic receptors 1–5 based on bis-benzimidazolium group were designed and synthesized. Their anion recognition properties were investigated by UV-vis, fluorescent spectroscopy, ¹H NMR and MALDI-TOF mass spectrometry. The UV-vis and fluorescent spectroscopic studies showed that the receptors 1–5 had different binding abilities for various anions such as fluoride, chloride, bromide, iodide and acetate. The high selectivity of the receptors for fluoride and acetate anions is attributed to their basicity. Job plot and MALDI-TOF mass spectrometry demonstrated that the receptors form 1:1 complex with fluoride. DFT calculation and ¹H NMR studies indicated that the receptors bind anions through (CH)⁺···X⁻ hydrogen bond.

The cooperative effects of cation–anion are elucidated in ionic liquid-catalyzed reactions of aniline with ethylene carbonate and the reaction of phenylacetonitrile with dimethyl carbonate. Cations of ionic liquids activate electrophiles by the proton in the 2-position of the imidazolium ring through the hydrogen-bond interaction with the carbonyl group. The catalytic activity follows the order of 1-butyl-3-methyl-imidazolium ([Bmim])>1,2-dimethyl-3-butyl imidazolium ([Bmmim])>1-butyl-pyridinium ([Bpy]), which is consistent with the order of the hydrogen bond donor ability. Simultaneously, anions of ionic liquids activate nucleophiles by accepting the hydrogen bond. The catalytic activity of imidazolium-based ionic liquids follows the order Cl>Br>BF₄>PF₆>C(CN)₂COOEt≈NTf₂>BPh₄, which is consistent with the order of the hydrogen bond acceptor ability. The dual activation of nucleophiles and electrophiles by the cations and anions of ionic liquids is crucial to promote the reaction in high yields.

The application of several titanosilicates to the oxidation of aromatic sulfur compounds such as thiophene, benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene with H₂O₂ under mild conditions is reported. Superior to other titanosilicates, Ti-MWW demonstrates a higher activity for the oxidation of 4,6-dimethyldibenzothiophene owing to the unique pore structure of the MWW topology. The effects of solvent, temperature, catalyst amount, and H₂O₂/S ratio on the oxidation of 4,6-dimethyldibenzothiophene over this catalyst are studied in detail. The catalyst is also applied to the oxidative desulfurization of commercial diesel. The sulfur compounds in the commercial diesel were oxidized to the corresponding sulfones, which could be readily extracted by acetonitrile, resulting in a maximum sulfur removal of 88 % .

A series of novel amide anion based ionic liquids containing nitrile groups have been synthesized using the method of ion-exchange between potassium amide and various quaternary halide salts such as trimethylamine, triethylamine, tributylamine, N-methylpyrrolidine, and N-methylimidazole. All of the functionalised ionic liquids were characterized by IR, ¹H and ¹³C NMR, and MS. The synthesized ionic liquids exhibited advantageously high thermal stability. The decomposition temperature of ionic liquids measured via TGA ranged from 224 to 289°C. The functionalised ionic liquid, 1-ethyl-3-methylimidazolium propionyl cyanamide ([EMIm][N(CN)COC₂H₅]), was used as a ligand in the palladium catalyzed Suzuki coupling reaction. The yields of the coupling reaction increased by 10%–20% by the addition of [EMIm][N(CN)COC₂H₅].

A series of asymmetric methide anion based ionic liquids containing nitrile groups have been synthesized for the first time using the method of ion-exchange between sodium/potassium methide and various quaternary bromide/chloride salts of trimethylamine, triethylamine, tributylamine, N-methylpyrrolidine, and N-methylimidazole. All of the functionalised ionic liquids were characterized by IR, ¹H, ¹³C NMR, MS and elemental analysis. The decomposition temperature of the ionic liquids measured via TGA ranged from 219 to 339 °C. The functionalised ionic liquid, [Bmim][C(CN)₂COCH₃], was used as a ligand for Suzuki coupling reaction. The yields of the coupling reaction increased 10% –15% by the addition of the functionalised ionic liquid, [Bmim][C(CN)₂COCH₃].