Syntheses and Nonlinear Optical Studies of Organoruthenium/Gold Nanoparticle Hybrids

Abstract

Synthesis and Nonlinear Optical Studies of Organoruthenium/Gold Nanoparticle Hybrids

Molecular and nano-materials that display nonlinear optical (NLO) processes like nonlinear absorption (NLA) processes have attracted considerable attention due to their potential applications in optical data storage, imaging, optical limiting, telecommunications, medicine, and 3D-patterning. We have extensively studied mono and bis alkynyl ruthenium phosphine complexes with outstanding NLA activity especially two photon (2PA) and multi-photon absorption (3PA and 4PA) in the visible to the near infrared spectrum. On the other hand plasmonic structures like gold nanoparticles are NLA active materials that can be employed to enhance a variety of optical and nonlinear optical processes due to strongly polarizable electrons of the localized surface plasmon resonance absorption band. In our search to develop novel and efficient NLA devices we investigated the properties of hybridized organoruthenium complexes and AuNPs.

In this thesis project is discussed the different synthetic approaches that can be addressed to prepare a broad variety of novel surface functionalized AuNPs with organoruthenium complexes and their characterization, catalytic performance, optical properties and NLA performance. Molecular archetypes like rods, stars, branches and dendrimers were employed in this study to stabilize ultrasmall AuNPs. The hybrids were characterized comprehensively using various molecular and nanomaterial techniques never observed before in similar studies. It was found that the ruthenium complex (trans-Ru(dppe)2) is an essential component in the preparation of this new family of hybrids because it imparts good solubility and stability. More importantly the ruthenium complex/AuNP hybrids exhibit good transparency and exceptional NLA performance is observed for the linear- and star-shaped organoruthenium/AuNP hybrids.