Charge-transfer complex formation between N-butyl guanine and FTCNQ yielded an ionic product composed of neutral and protonated N-butyl guanines and fully ionized FTCNQ molecules in a 1:1:1 ratio. Neutral and protonated N-butyl guanines were alternately connected by complementary hydrogen-bonds to form a one-dimensional ribbon, which stacked to establish a two-dimensional cation layer. FTCNQ formed a face-to-face dimer, which was separated from adjacent dimers because of the butyl group of N-butyl guanine. This salt was an insulator, and exhibited a strong antiferromagnetic interaction within the FTCNQ dimer.