Most devices using NLO processes on the market today use glasses or crystals of inorganic salts to provide the necessary NLO responses. A need to meet the growing technological requirements of devices and processes has caused the field to branch into organic and organometallic materials. The combination of metals and organics has the potential to combine the advantages of organic molecules (design flexibility, fast response) and inorganic salts (ease of fabrication, durability), making organometallic materials increasingly popular in the field of nonlinear optics.

In order to design new compounds with optimal characteristics for applications, it is imperative to understand the structural properties of molecules that lead to enhanced NLO processes. For many years, the NLO responses of different materials were measured at only a handful of different wavelengths (energies of light). By examining NLO processes across a broad spectrum of wavelengths, considerably more information about their optical behaviour can be obtained. Using a measurement technique known as Z-scan, the second chapter of this thesis looks at the nonlinear optical responses of a variety of compounds made by several different researchers. Comparison of these results allows for an expansion of the known NLO structure-property relationships of organometallic materials.

The remaining chapters cover the design, synthesis and measurement of two different series of compounds, with the intention of furthering this knowledge. The third chapter looks at the incorporation of electron withdrawing and donating groups at the termini of molecules known to have good NLO properties. Their role is to alter the polarity of the molecules, which, in turn, should alter their NLO responses. The final chapter contains compounds with varying levels of substitution about a central core. A higher level of substitution has a beneficial effect for organic molecules and the compounds were designed to see if these benefits translate to organometallic molecules.