The synthesis and characterization of a new family of ester protected N-substituted [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7-triacetic acid (H3DO3A) derivatives containing a pendant thioctic acid (α lipoic acid, LA) are reported. These compounds (DO3AtBu-NLA, DO3AtBu- NMeNLA, and DO3AtBu-NEtNLA) are suitable for the functionalization of gold surfaces with rare-earth complexes.