This book deals with the electrochemical studies on the adsorption behaviour of some sulphur containing organic compounds mainly self-assembled monolayers (SAMs) of alkanethiol and alkanethiol derivatives on gold surfaces. More specifically, this book focuses on the effect of different solvents on the structure, integrity and interfacial properties of different organic thiol monolayers like alkanethiol, aliphatic and aromatic dithiol, hydroxy and carboxylic acid thiol and thiocholesterol.This book also introduces the concept of "hydrophobic gap" at the alkanethiol SAM-water interface due to drying transition. The experimental observation based on double-layer capacitance measurement and Scanning tunneling microscope (STM) study supports the Lum-Chandler-Weeks (LCW) theory on hydrophobicity.