The current-voltage characteristics of small aliphatic chains of alkanes, alkenes, alkynes, and oligophenylene-ethylenes, with and without substituents and terminated in sulfur attached nanosized gold electrodes are determined using ab initio procedures for discrete and extended systems in a density functional theory-Green function's approach where most of the chemistry is considered. It is found that the current-voltage characteristics of small molecules can be tailored by the addition of substituents. 2008 Wiley Periodicals, Inc.
