Crystallographic Study of Macrocyclic Cyclophane Inclusion Compounds

用X-射线晶体分析方法研究了大环杂环膦(N，N^1，N^&lt；11&gt；，N^&lt；111&gt；-tetramethyl-2，11，20，29-tetraaza-[3.3.3.3]paracyclophane[1]))与苯、吡啶、CHCl_3、CH_3CN、CO_2、CH_2Cl2和CH_2BrCl包合物的晶体结构。这些包合物的晶型分别为：L：苯(P2_L，Z=4)，L：吡啶(Pl，Z=L)，L：CHCl_3(C2，Z=2)，L：CH_3CN和L：CO_2(C2/c，Z=4)，L：CH_2Cl_2和L：CH_2BrCl(C2/c，Z=8)。在这些晶体包合物中，由于L的大环构象是以固体形式冻结的，所以L是以‘R’构象的形式存在的。L沿b轴构筑成容纳客体分子L：L比的分子柱。其中一个分子柱是手性的，因为该柱由L的全部‘R’构象或全部‘S’构象组成。手性晶体由全部‘R’或全部‘S’柱组成，而外消旋晶体由‘R’柱和‘S’柱组成。这五种不同的晶体结构可以从柱子的堆积方式的角度进行解释。在L中，柱的排列与苯环的倾斜角有很大关系，这个倾斜角取决于客体分子的大小和形状。未络合的L的大环构象(C&lt；2v&gt；)与络合的L的(C_4)不同，通过非分子力学计算对L的构象分析表明，L有六种稳定的构象，包括对映体(最大和最小空间能之差为2.3kcal/mol)，这表明L在溶液中这六种构象之间是自由相互转化的。当这些包合物与其他气态客体分子接触时，观察到伴随着相变的客体交换。这一过程的第一步是缓慢的客体交换，直到达到40-50%的交换，第二步是相变和陡峭的气体交换(90%)。

X-Ray crystal analysis of macrocyclic heterocyclophane(N,N^1,N^<11>,N^<111> -tetramethyl-2,11,20,29-tetraaza-[3.3.3.3]paracyclophane[1]) inclusion compounds with benzene, pyridine, CHCl_3, CH_3CN, CO_2, CH_2Cl_2 and CH_2BrCl was undertaken. The crystals of these inclusion compounds show guest dependent polymorphism and are classified as follows: l:benzene(P2_l,Z=4),l:pyridine (Pl,Z=l), l:CHCl_3 (C2, Z=2), l:CH_3CN and l:CO_2 (C2/c, Z=4), and l:CH_2Cl_2 and l:CH_2BrCl (C2/c, Z=8). In these crystalline inclusion compounds,l exists as 'R'-conformer of 'S'-conformer since the macrocyclic conformation of l is frozen in solid state. l is ftacked along the b-axis to form the molecular column which accomodate guest molecules l:l ratio. One molecular column is chiral because the column consistes of all'R'-or all 'S'-conformers of l. The chiral crystals consist of all 'R'-or all 'S'-column, while racemic crystals consist of both 'R'- and 'S'-column. The five different crystal structures can be interpreted from the viewpoint of the packing mode of the columns. The column arrangement is greatly related to the tilt angle of benzene ring in l. This angle depends on the size and shape of the guest molecule. The macrocyclic conformation(C_<2v>) of the uncomplexed l is different from that (C_4 of the complexed l. The conformational analysis of l by nolecular mechanics calculation shows that l has six stable conformation including enantiomer(the difference between maximum and minimum steric energy is 2.3 kcal/mol), suggesting the free interconversion of l among these six conformers in solution. The guest exchange accompanying phase transition was observed when these inclusion compounds were exposed to other gaseous guest molecules. The first step of this process is slow guest exchange until 40-50% exchange is reached and the second step is phase transition with steep gas exchange(90%).