Application of supramolecular chemistry in the catalytic transition metal/polycarbodiimide nanocomposite and the photoactive surface patterning

This study was devoted to nanotechnology and supramolecular chemistry. In the nanotechnology part, this research work was focused on the synthesis of transition metal nanoparticles using synthetic polymer as stabilizer and their catalytic property in Suzuki cross coupling reactions. Poly( N,N′-di-n-alkylcarbodiimide), a chiral, highly basic polymer with a rigid backbone, was synthesized and found to be an effective polymeric ligand for preparing narrowly dispersed gold, palladium, platinum and CdS nanoparticles. It served as a stabilization matrix for long-term storage of the resulting colloidal nanoparticles. The stability of the colloids was studied under different pH conditions and with ligand exchange experiments. Furthermore, Palladium nanoparticles stabilized by polycarbodiimide were found to be an efficient catalyst for the Suzuki cross coupling reaction under microwave or regular heating process.; In the supramolecular chemistry part, 7-substituted-2,4,9-trithiaadamantane derivatives were found to be effective free-standing surface anchors. The supramolecular structure of 7-hydroxycarbonyl-2,4,9-trithiaadamantane with β-cyclodextrin was studied using NMR titration, mass spectrometry, and 2D ROSEY experiments. The 7-hydroxycarbonyl-2,4,9-trithiaadamantane was found to form a very stable inclusion complex with β-cyclodextrin with 1:1 mole ratio with a stability constant of 1550.5 M−1. 2D ROSEY experiments reveal the supramolecular structure of the inclusion complex. A polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) instrument was built and used for the characterization of a number of self-assembled monolayers (SAMs) based on the 7-substituted-2,4,9-trithiaadamantane derivatives. A new type of photoactive surface anchor 7-diazoacetyl-2,4,9-trithiaadamantane was synthesized and was used to form a photoactive self-assembled monolayer (SAM) on the gold surface. The photoactivity of this SAM on the gold surface was characterized by real time Fourier transform infrared (FTIR) spectrometry and PM-FTIRRAS. When the SAM was treated with UV light, photoreaction could be trigged and the resulting Wolff rearrangement ketene intermediate could be trapped with alkyl amine or pyrene methyl alcohol. The surface patterning was demonstrated by the moisture condensing on the cold film and surface fluorescence measurements.