Since the first measurements of the thermoelectric response of single molecules bound in conducting junctions[l], there has been considerable interest in tailoring molecules for this purpose.Like many problems in nano-science, our understanding from traditional chemical studies does not provide us with the structure/function relationships we need to predict optimal molecules for this application.We need to understand how molecules respond when they are bound in conducting junctions and how different molecular functionalities give rise to the thermoelectric properties of the junction.