The relative stabilities of four aggregates composed of 1 equiv of a tris-melamine and 3 equiv of neohexyl isocyanurate were investigated using molecular mechanics and dynamics; the results from the simulations were compared with experiments. The relative deviation from planarity (DP) of the cyanuric acid-melamine (CA(3)(.)M(3)) rosette correlated with stability in this series of aggregates. The amount of distortion in the aggregate was computed using a Langevin dynamics simulation (using a structure inferred from H-1 NMR experiments) of a system comprising the aggregate and four molecules of chloroform. These four molecules of chloroform made particularly important contributions to the conformational behavior and stability of the aggregate, as judged by the results of a simulation of fully-solvated HubM(3)(.)(RCA)(3) (that is, one explicitly including solvent molecules). One molecule of chloroform seemed to occupy a unique position in the center of the aggregate and to contribute strongly to the stability of these aggregates. The order of stabilities suggested by the relative values of DP is HubM(3).(RCA)(3) > AdM(3) II.(RCA)(3) > FlexM(3).(RCA)(3) > AdM(3) I-.(RCA)(3) (Schame 1). This order was confirmed by H-1 NMR competition experiments (AdM(3) I-.(RCA)(3) was not observed as a stable complex). The rationale for the relationship between the DP and the stabilities of the aggregates, and the influence of solvation by chloroform on these stabilities, is discussed.