Molecular recognition, crystalline

Crystalline 1 1 complex formation can be regarded as molecular recognition in the process of crystallization. Since the formation of a new type of the crystalline 1 1 complex depends on the shapes of R7 and R8 35), the influence of the spatial relationship between R7 and R8 on the complex formation was investigated. 

All of the experiments in pure and mixed SSME systems, as well as in the Af-stearoyltyrosine systems, have one common feature, which seems characteristic of chiral molecular recognition in enantiomeric systems and their mixtures enantiomeric discrimination as reflected by monolayer dynamic and equilibrium properties has only been detected when either the racemic or enantiomeric systems have reverted to a tightly packed, presumably quasi-crystalline surface state. Thus far it has not been possible to detect clear enantiomeric discrimination in any fluid or gaseous monolayer state. 

Crystalline fructose, 23 485-486 Crystalline glycolic acid, 14 127 Crystalline hybrid compounds, 13 546-548 Crystalline inclusion compounds, 14 184 molecular recognition behavior of, 16 796 preparation of, 14 182 Crystalline melting point, of polymers, 20 399... 

Fouquey, C. Lehn, J.-M. Levelut, A.-M. Molecular recognition directed self-assembly of supramolecular liquid crystalline polymers from complementary chiral components. Adv. Mater. 1990, 2, 254-257. 

Gulikkrzywicki T, Fouquey C, Lehn JM. Electron-microscopic study of supramolecular liquid-crystalline polymers formed by molecular-recognition-directed self-assembly from complementary chiral components. Proc Natl Acad Sci USA 1993 90 163-167. 

Self-Organization of Supramolecular Liquid Crystalline Polymers from Complementary Components. If two (or more) complementary units e or 3 are grafted on a template T, mixing Te m with the complementary T3m may lead to the hetero-self-assembly of a linear or cross-linked, main-chain supramolecular copolymer species (Te m, Tsw), whose existence is conditioned by the molecular recognition-directed association between the e and a groups. 

It is reasonable to assume that the complementary units form the expected triply hydrogen bonded pairs, so that the entirely different behaviour of the pure compounds and of the 1 1 mixtures may be attributed to the spontaneous association of the complementary components into a polymolecular entity based on hydrogen bonding. The overall process may then be described as the self-assembly of a supramolecular liquid-crystalline polymer based on molecular recognition (Figure 40). The resulting species (TP2, TU2) is represented schematically by structure 174. 

Molecular recognition directed self-assembling of organized phases has been described recently in the formation 1) of mesophases by association of complementary molecular component, as in 13 (23) 2) of supramolecular liquid crystalline polymers of type 14 (24) and 3) of ordered solid state structures, such as that represented by 15 (25). In all these cases, the incorporation of NLO active groups may be expected to produce materials whose SHG properties would depend on molecular recognition induced self-organization. 

Molecular Recognition of Crystalline Dipeptides and Its Application to Separation... 

THE DIVERSE TYPES OF SHEET STRUCTURE USED IN THE MOLECULAR RECOGNITION OF CRYSTALLINE (R)-ARYLGLY C YL-(R)-PHENYLGLY CINE... 

As Tonelli et al. [44,45] have pointed out, the study of crystalline inclusion complexes provides an approach to investigate the behaviors of single polymer chains in isolated and well - defined environments. Then, it is helpful in understanding the mechanism of molecular recognition between hosts and polymeric guests. 

The molecular recognition between mismatched (R,R)-29 and (S,S)-43 is less efficient compared with the matched pair complex. Even if the complex (R,R)-29 (S,S)-42 could be obtained in a crystalline form (Scheme 19), the X-ray analysis shows that one H-bond between the hydroxy and carboxylate moieties is lost and coordination has been achieved with two water molecules included in the crystal (Figure 52). The loss of such water molecules, for example after drying of the sample, determines the erosion of crystallinity. 

---