MECHANISMS FOR MOLECULAR COMPLEX FORMATION AND FACTORS WHICH DOMINATE MOLECULAR ORIENTATION IN MOLECULAR COMPLEXES

本文比较了四[4-（N-甲基）吡啶]卟啉（TMPyP）在D_2O中的~ 1H NMR谱，并与邻位上有三个吡啶基和一个苯基的卟啉（TriMPyP）和两个吡啶基和两个苯基的卟啉（DiMPyP）的~ 1H NMR谱进行了比较。光谱表明，尽管卟啉正电荷间存在静电排斥，但TriMPyP和DiMPyP均通过货车deb Waals相互作用形成二聚体.由此可以得出结论，卟啉环在水中的π-π相互作用是如此之强，以至于形成二聚体的吸引力克服了静电排斥力。另一方面，TMPyP即使在高浓度下和/或在无机盐存在下也以单体形式存在于水中。在这种情况下，静电排斥力克服了货车吸引力。以四芳基卟啉为探针，研究了离子型客体分子包结到疏水环糊精中的机理 关于我们 (CDx)蛀牙在卟啉的邻位上具有阴离子或非离子取代基的苯基基团被天然-β-环糊精（β-CDx）松散地包含，而阳离子外围基团几乎不包含在β-CDx空腔中。阴离子和非离子卟啉与七（三-O-甲基）-β-CDx（TMe-beta-CDx）形成非常稳定的包合物。同时，阳离子卟啉与TMe-beta-CDx完全不形成配合物。这些现象可以用微观极化的CDx空腔来解释，阴离子客体优先停留在此，而阳离子客体由于主客体间的静电排斥作用而形成非常不稳定的络合物，CDx是很难识别中心手性的主体。事实上，天然和烷基化的CDx识别氨基酸及其衍生物的手性的能力非常弱。然后，我们尝试使用库仑相互作用，通过使用质子化胺化的CDx。质子化的氨基-β-CDx可以区分N-乙酰基氨基酸和扁桃酸及其相关酸的（R）-和（S）-对映异构体。主客体之间的库仑相互作用以及客体分子进入CDx空腔的过程需要实现手性识别。少

^1H NMR spectra of tetrakis [4- (N-methyl) pyridinium] porphyrin (TMPyP) in D_2O was compared with those of prophyrins having three pyridinium groups and one phenyl group (TriMPyP) and two pyridinium groups and two phenyl groups (DiMPyP) at the peri positions. The spectra indicate that both TriMPyP and DiMPyP form their dimers through van deb Waals interaction in spite of the electrostatic repulsion between the positive charges of the porphyrins. It might be concluded that the pi-piinteraction between the porphyrin rings in wateris so strong that the attractive force to form the dimers overcomes the electrostatic repulsive force. On the other hand, TMPyP exists as the monomer form in water even at high concentrations and/or in the presence of inorganic salt. In such a case, the electrostatic repulsive force overcomes the van der Waals attractive force.Tetraarylporphyrins were used as probes to study the mechanism for inclusion of ionic guest molecules into the hydrophobic cyclodextrin … More (CDx) cavities. The phenyl groups having anionic or nonionic substituents at the peripositions of the porphyrins are loosely included by native-beta-cyclodextrin (beta-CDx) while the cationic peripheries are hardly included into the beta-CDx cavity. Anionic and nonionic porphyrins form very stable inclusion complexes with heptakis (tri-O-methyl) -beta-CDx (TMe-beta-CDx). Meanwhile, cationic porphyrins do not form the complexes with TMe-beta-CDx at all. These phenomena can be intepreted in terms of the microscopically polarized CDx cavity where anionic guest is preferable to stay but cationic guest forms very unstable complex because of electrostatic repulsion between the host and the guest.It has been known that CDx are poor hosts to recognize central chirality. Indeed, native and alkylated CDxs have very weak ability to recognize the chirality of amino acids and their derivatives. Then we tried to use coulomb interaction by using protonated aminated CDxs. Protonated amino-beta-CDxs can discriminate between the (R) -and (S) -enantiomers of N-acetyl amino acids and mandelic acid and its related acids in their dissociated forms. The coulomb interaction between the host and the guest as well as inclusion of the guest into the CDx cavity needs to achieve the chiral recognition. Less