The synthesis of new resorcinarene derivatives featuring extended sides and self-complementary hydrogen-bonding sites is described. Dimerization occurs in solvents such as toluene-d(8), and large cavities result. The dimerization constant K-D = 1700 +/- 250 M-1 was determined, and the cavity of the dimer was found to encapsulate two heptyl or octyl chains of the subunits. It is proposed that hydrogen bonding and self-inclusion are responsible for the large and compensating thermodynamic parameters for dimerization : Delta H = -20.9 +/- 1.3 kcal mol(-1) and Delta S = -58 +/- 5 cal mol(-1) K-1.