Construction And Properties Study Of Supramolecular Assemblies Based On Porphyrin

Supramolecular is constructed by the intermolecular noncovalent interactions (hydrogen bonding, coordination bond, electrostatic interactions,π-π interaction, van der Waals, hydrophobic function, etc.) formed from molecular aggregates. Serving porphyrins as building blocks, supramolecular based on porphyrins could construct through intermolecular weak interactions between porphyrins and small molecules (organic or inorganic molecules), macrocyclic molecules (crown, cyclodextrin, calixarene fullerene, etc.) and polymers. The porphyrins are macrocyclic compounds, composed of four conjugated connected pyrrole by methylene, possessing structural stability and diverse functions, and exhibiting optical, electric, and magnetic properties, probably leading to the supramolecular assembly of porphyrins wtih these excellent properties. Therefore, the porphyrin-based supramolecular assemblies maybe have different potential fields in life, information, material science. Herein, a series of porphyrin derivatives as the basic building blocks are designed and synthesized in this paper. A series of supramolecular self-assemblies constructed from porphyrins and cucurbit[n]urils or pillar[n]arenes have been studied in detail, the specific contents as following:(1) A host-guest complex has been formed between cationic tetrakis(4-pyridyl)porphyrin species of (H6TPyP)4+-4Cl-and TMeQ[6] depending on hydrogen bonding interaction. Single crystal X-ray diffraction analysis clearly reveals the supramolecular nature of this novel TMeQ[6]-(H6TPyP)4+·4Cl-host-guest compound, representing the first example of structurally characterized cucurbit[n]uril-porphyrin host-guest complexes. Due to the three dimensional porous framework, the iodine adsorption behavior of this cucurbit[n]uril-porphyrin supramolecular structure has also been studied, the iodine sorption ability of present compound is about29wt%.(2) Host-enhanced hydrogen bonding interaction in combination with the ion-dipole interaction between a four-arm guest molecule, namely5,10,15,20-tetrakis(N-carboxymethyl-4-pyridinium)porphyrin tetrabromide (TCMePyP), and the host molecule of tetramethyl-cucurbit[6]uril (TMeQ[6]) led to the formation of the supramolecular polymer. In addition to NMR, electronic absorption, fluorescence spectroscopic, and DLS characterization, the TMeQ[6]-TCMePyP host-guest supramolecular polymer nature of the present system has been clearly revealed on the basis of sing crystal X-ray diffraction analysis. This, to the best of our knowledge, represents the first structurally characterized cucurbit[n]uril-porphyrin supramolecular polymer.(3) Three novel [5]pseudorotaxanes based on tetramethyl-cucurbit[6]uril (TMeQ[6]) and anchored to a meso-tetra pyridinium porphyrin, namely TBuPyP, THePyP, and TBePyP, have been synthesized and characterized by NMR, electronic absorption, fluorescence spectroscopic. In aqueous solution, TMeQ[6] forms4:1inclusion complexes with these guests specifically TBuPyP, THePyP, and TBePyP.(4) The porphyrin-pillararene hybrid ditopic receptors M(Por-P5)(M=2H, Zn) were designed and prepared for the first time. Stable inclusion complexes of the zinc species with neutral guest1,4-bis(imidazol-1-yl)butane (C4) and1,12-bis(imidazol-1-yl)dodecane (C12) were formed depending on the cooperation interaction between the coordination of zinc ion locating at the center of porphyrin moiety and inclusion complexation of the cavity of pillar[5]arene to the guest molecule on the basis of a wide range of NMR, mass, electronic absorption, and fluorescence spectroscopic investigation results in addition to ITC method with the conformation of the host ditopic receptor in these two supramolecular inclusion complexes changing depending on the alkyl chain length of the guest. Addition of Cdl2into the two supramolecular inclusion systems in chloroform leads to the dissociation of the guest molecule from the zinc site, rendering the Zn(Por-P5)-C4supramolecular system to act just as a molecular acrobatics due to the shorter length of guest C4chain in comparison with the one linking the pillar[5]arene and porphyrin moiety in the host Zn(Por-P5) molecule.(5) Novel supramolecular polymers constructed from Q[8] and1’,1"-(alkylene-1,4-diyl)bis(1-butyl)-4,4’-bipyridine-1,1’-diium)bromide (alkylene=hexylene, octylene)(1,2) have been fabricated and characterized on the basis of a series of NMR, SEM, and DLS techniques. In particular, single crystal X-ray diffraction analysis clearly reveals their ternary host-guest construction nature by mediating the Q[8] host molecule through two terminal butyl chains (that are simultaneously included inside the host cavity) of two guest molecules depending on multiple hydrogen bonding interactions between the host and guest molecules as well as between the host and host molecules with the total energy amounting to as high as161.2kJ/mol. This represents the first example of ternary host-guest supramolecular polymers that are mediated through alkyl chains instead of aromatic moieties included.