In pursuit of environmental sustainability and energy efficiency, assorted macrocyclic compounds have recently emerged as crystalline adsorbents for the efficient molecular sieving of various chemical commodities. Herein, we delve into the conformational characteristics and solid-state packing modes of tiara[5]arenes (<b>T[5]</b>), a rim-differentiated pillar[5]arene derivative. By meticulously exploring the conformational space, we have successfully identified a multitude of distinct <b>T[5]</b> conformers within a relatively narrow energy range of 22 kJ/mol. This finding underscores the inherent conformational flexibility of this macrocyclic scaffold, enabling <b>T[5]</b> to adapt diverse packing arrangements in the solid state. While solvent-free <b>T[5]</b> crystals do not exhibit permanent porosity, they undergo solvomorphic interconversions when exposed to various guest compounds. Our study demonstrates that <b>T[5]</b>-based crystalline materials exhibit a notable preference for selectively capturing aromatic and olefinic solvents, such as benzene, toluene, chlorobenzene, and cyclohexene, over their aliphatic hydrocarbon counterparts from equivalent volume liquid mixtures, achieving up to 10:1 selectivity between benzene and cyclohexane. Herein, we delve into the conformational characteristics and solid-state packing modes of tiara[5]arenes ( T[5] ), a rim-differentiated pillar[5]arene derivative. By meticulously exploring the conformational space, we have successfully identified a multitude of distinct T[5] 41 − 45 Understanding the structure–property interplay is essential to advance further research into novel macrocycle-based functional materials. In the context of NACs, the structural flexibility inherent to the macrocyclic scaffold is poised to exert a substantial impact. This innate adaptability empowers these macrocycles to assume diverse conformations or configurations during interactions with various guest molecules and to conform to distinct packing arrangements within the crystalline lattice. As a result, these NACs can undergo energetically favorable solid-state structural transformations while achieving highly selective guest inclusions. The R g values for the T[5] conformers exhibit a wider spread compared to those of the P[5] conformers, suggesting that T[5] possesses greater structural flexibility. The conformer with the highest relative energy exhibits five unfolded rims, resulting in a relatively extended and open conformation ( T[5] -1 and P[5] -1; see Figure 3 ). Conversely, the conformer with the lowest relative energy or the minimum radius of gyration, characterized by the presence of five folded rims, respectively, adopts compact shapes ( T[5] -2, T[5] -3, P[5] -2, and P[5] -3; see Figure 3 ). The results of P[5] demonstrated a greater energy gap, indicative of a more restricted range of possible conformations. The P[5] conformer with the smallest radius or least relative energy display exhibits increased distortion and compactness compared to the conformer with the highest energy. These observations align with the experimental findings indicating that T[5] can readily switch between different conformers with low energy barriers when the crystallization conditions are altered. This implies that molecules undergoing crystallization may not always be limited to adopting their lowest energy shape, and the conformations observed in experimental crystals may potentially influenced by kinetic factors. Furthermore, we conducted geometric matching on single-crystal structures that underwent DFT optimization ( Figure S7 ). Remarkably, it was observed that the single crystal structures exhibited a high level of concordance with the estimated structures following the optimization process, with a small RMSD value for each ( Figure S7 ). The bicomponent atmospheres comprised four distinct combinations: benzene/cyclohexane (BZ/CH), 40 , 50 , 61 − 64 cyclohexene/cyclohexane (CHE/CH), 62 toluene/methylcyclohexane (TOL/MCH), 65 and chlorobenzene/chlorocyclohexane (CBZ/CCH). 66 In the BZ/CH atmosphere, 1 H NMR analysis indicated a gradual increase in BZ uptake by T[5] , reaching approximately 0.8 mol of BZ per T[5] after saturation ( Figures 4 c and S17 ). Conversely, only a minute amount of CH was adsorbed. Similarly, across the other bicomponent atmospheres, T[5] exhibited more effective adsorption of CHE, TOL, and CBZ compared to MCH, CCH, and CH, respectively. 67 Molecular docking serves as a predictive tool, providing insights into how two molecules might orient themselves to form a stable complex with optimal binding. 68 This approach allowed us to pinpoint the most favorable low-energy structures for both the aromatic/olefinic@ T[5] and aliphatic@ T[5] host–guest pairs. Building on this, we performed DFT-D geometry optimization of these complexes, utilizing the results from the docking study as our starting point. 69 The geometry optimized conformations of aromatic/olefinic@ T[5] and aliphatic@ T[5] complexes are shown in Figure 5 b–e. Figure 5 (a) Simplified docking process overview. X-ray crystallography analysis has revealed the presence of multifaceted conformations of T[5] in the solid state, shedding light on its structural adaptability. Our theoretical exploration of conformational energy landscapes has allowed us to pinpoint stable T[5] conformers and emphasize the minor energy differential (22 kJ/mol) between the highest and lowest energy states, underscoring its flexible nature. The precision method is standard precision, and ligand sampling is set to flexible, incorporating both nitrogen inversions and ring conformation sampling. All DFT calculations were performed in Gaussian09, 79 aiming to identify the absolute minimum conformation. The DFT-D geometry optimization employs the B3LYP functional with a 6-311G* basis set. 69 , 76 Additionally, dispersion energy corrections are Grimme’s D3 scheme with Becke and Johnson (BJ) damping. 77 , 78