A new self-assembling tricyclic module (x K1) featuring the Watson Crick H-bonding arrays of guanine and cytosine fused to an internal pyridine ring was synthesized. When dissolved in water at room temperature, this module rapidly self-assembles into hexameric rosettes, which then stack to form J-type rosette nanotubes (RNTs) with increased inner/outer diameters and the largest molar ellipticity ever reported (4 x 10(6) deg.M-1.m(-1)). Using a combination of imaging and spectroscopic techniques we established the structure of x K1-RNT and have shown that the extended pi system of the self-assembling module resulted in a new family of J-type RNTs with enhanced inter-modular electronic communication.