Study On Synthesis, Separation And Supramolecular Self - Assembly Of Monomethyl

Cucurbit[n]urils(commonly abbreviated as Q[n] or CB[n]) are highly symmetric macrocyclic moleculars known to date besides crown ethers, cryptands, cyclodextrins,and calixarenes. It has been subject of much interest in recent years because of its specific structures and potential applications, and including cucurbit[5]uril(Q[5]),cucurbit[6]uril(Q[6]), cucurbit[7]uril(Q[7]), cucurbit[8]uril(Q[8]), cucurbit[10]uril(Q[10]) and twisted cucurbit[14]uril(tQ[14]) in cucurbit[n]uril family. The improvement of synthesis and separation methods lead to appearance of a series of cucurbit[n]uril derivatives with novel structures and properties, such as the inverted cucurbit-[n]urils(i Q[n]s), the chiral nor-seco-cucurbituril(ns-Q[n]s), and the alkyl-substituted Q[n]s, the hydroxyl-substituted Q[n]s. Recently, great progress has been made in constructing supramolecular assemblies based on s-Q[n]s.Main research works of this thesis based on the former works include: 1)synthesis, separation and characterization of methyl-substituted cucurbiturils derived from 3α-methyl-glycoluril(SMeQ[n]); 2) the interaction investigation and supramolecular self-assemblies of SMeQ[n] with lanthanides show significant differences, which could be used for the isolation of lanthanides; 3) a supramolecular assembly of a methyl-substituted cucurbit[5]uril(SPMeQ[5]) derived from3α-methyl-glycoluril is formed in the presence of the organic structure-directing agent and its potential applications in selective absorption.Using an induced strategy of the outer-surface interaction of Q[n], design and synthesis of a series of SMeQ[n]-based supramolecular assemblies in the presence of third species as the structure directing agents. Based on the chacaterastics of the third species and back-interaction of cucurbit[n]uirls in the costruction of the supramolecular assemblies, the research works include: 1) design and synthesis of SMeQ[n]-based supermolecular assemblies by means of electrodonating effect of the alkyl-substituted groups on the back of cucurbit[n]urils; 2) design and synthesis of SMeQ[n]-based supermolecular assemblies through π???π stacking between portal carbonyl groups of SMeQ[n] as well as C–H???π interaction between methine ormethylene moieties on the back of SMeQ[n] and aromatic moiety of organic structure inducers; 3) design and synthesis of SMeQ[n]-based supermolecular assemblies owe to unusual hydrogen bonding between methine or methylene moieties on the back of SMeQ[n] as well as ion-dipole interactions between positive portal carbonyl carbon of SMeQ[n] and chloride anion from polychlorometallate anions, which may be useful in molecular sieves, sensors, absorption and separation. Thus, outer-surface interaction of Q[n] could result in the development of supramolecular architectures and functional materials in the Q[n] chemistry.The interaction of SMeQ[n] with alkali, alkaline earth metal and lanthanide metal ions gives rise to various coordination complexes and supramolecular assemblies in the presence of [CdCl4]2- anions as a structure-directing agent. In particular, Single crystal X-ray diffraction analysis revealed that SMeQ[n] molecules present high selectivity and recognition ability for lanthanide cations under certain conditions. Meanwhile, a typical SPMeQ[5]-based porous supramolecular assemblies was synthesized in the presence of hydroquinone(Hyq) as an organic structure directing agent. The driving forces of the structure directing effect could be attributed to the C–H···π interaction and hydrogen bonding between Hyq and –CH3 or =CH2groups on the outer-surface of SPMeQ[5] molecules. The structure-directing effect of Hyq is not only useful in the construction of novel Q[n]-based supramolecular assemblies but it could also enable the preparation of Q[n]-based porous materials for in molecular sieves, and sensors, used in absorption and separation.In summary, we have successfully synthesized a series of SMeQ[n]-based supramolecular self-assembly entities in the presence of third species as a structure-directing agent, which may be useful in the isolation of lanthanides,selective absorption and so on.