| This doctoral thesis focuses firstly on the step-wise synthesis of a library of rigidrod-type conjugated difunctional oligo(p-phenylene vinylene)s (OPVs) with varying chain lengths of the main chain and side chain substitution, i.e., monomer, dimer, and trimer units with chain end - terminal alcohol, aldehyde, vinyl, and alkyne functionality. All oligomers are soluble and show trans configuration at the internal vinylene bonds. The solublizing side-chains are of the alkyloxy type, i.e. heptyloxy (-OC7H 15), butyloxy (-OC4H9), and methyloxy (-OCH 3). All OPVs were characterized by means of ATR-FTIR, 1H-NMR (200 or 600 MHz) and 13C-NMR (50 or 150 MHz), 2D-NMR (HMBC, HSQC experiments), and optical spectroscopy.;In subsequent steps, the OPVs were used as "building blocks". One application involved using a Cu(1)-catalyzed [3+2] Huisgen "click" cycloaddition to connect biotin ligands to both ends of the OPV, using spacer chains of varying length, consisting of oligo(ethylene glycol). Combining the valuable electro-optical properties of conjugated organic molecules with the biological recognition capability of biotin, the latter can be placed at variable distances via choosing an appropriate length of the hydrophilic spacer, which also serves to regulate the binding capabilities of the two terminal biotin units. To demonstrate this binding potential, networks were formed with streptavidin-coated quantum dots. The synthetic conditions are presented, together with representative optimizations of the key reactions. The organic compounds were analyzed by means of ATR-FTIR, 1H-NMR (200 or 600 MHz), 13C-NMR (50 or 150 MHz), 2D-NMR (HMBC, HMQC experiments), MS (ESI or MALDI-TOF), and optical spectroscopy. Networks were imaged with TEM.;Another application involved templated grafting of the rigid-rod-type OPVs to flat surfaces of Si(100) and Si(111) via covalent Si(100)/Si(111)-O-C or Si(100)/Si(111)-C bonds. OPVs with terminal hydroxide (-OH), aldehyde (-CHO), alkyne (-C=CH), and vinyl (-CH=CH2) functionalities were used. One approach involved the reaction of --OH, --CHO, and --CH=CH 2 functional OPVs with Si(100)/Si(111)-H and/or Si(100)/Si(111)-Cl functionalized surfaces. Subsequent reaction of resulting the Si(100)/Si(111)-OPV-OH surfaces with ptolyl isocyanate produced urethane containing monolayers in a "click like" approach. The monolayers were characterized by means of XPS, ATR-FTIR, AFM, and confocal fluorescence laser scanning microscopy (CFLSM).;A second approach involved synthesizing Si(100)/Si(111)-OCH2CH 2N3 functional surfaces from the Si(100)/Si(111)-H and/or Si(100)/Si(111)-Cl with HOCH2CH2N3, then using a "click reaction" to attach -C=CH functional OPV to the surface-bound N3. The resulting monolayers were characterized by means of XPS, ATR-FTIR, AFM, and CFLSM.;A third approach involved the synthesis of Si(111)-OCH2CH 2OH functional surfaces from Si(111)-H and/or Si(111)-Cl with HOCH 2CH2OH, and then using a "click like" reaction between the Si(111)-OCH2CH2OH functionalized surfaces and 1,4-phenylene diisocyanate (OCN-Ph-NCO) to afford Si(111)-U-Ph-NCO surfaces. Subsequent reaction of these with the --OH functional OPVs produced urethane containing OPV monolayers. The latter were characterized by means of XPS, ATR-FTIR, AFM, and CFLSM.;The combined results presented in this thesis represent a further major advance in the controlled functionalization of Si-surfaces and herald a variety of potential applications that use such a combination of inorganic and organic semiconductors. |
