Design, Synthesis, Properties And Morphology Controlled Self-assembled Nanostructures Of Phthalocyaninato/Porphyrinato Complexes

Owing to the unique optical,electrical,and properties,associated with the intriguing intramolecularÏ€-Ï€interactions,porphyrins,phthalocyanines,as well as sandwich type rare complexes,as a novel functional materials,have been expected to be widely potential application in materials science,such as in molecular electronics,molecular information storage,and nonlinear optics,etc.Recently,it is significantly interested in ordered supramolecular aggregate and nanoscale assembly fields.However,it must be pointed out that self-assembly of functional molecules into a prerequisite nanostructure with desirable dimension and morphology via controlling and optimizing inter-molecular interaction still remains a great challenge for chemists and material scientists.In order to extensively investigate supramolecular aggregation behaviors and supramolecular assembly methodology of porphyrinato and/or phthalocyninato complexes,in this thesis a series of porphyrin and/or phthalocyanine derivatives are selected,and some modern measuring techniques were performed to examine their aggregate structures,morphologies and nanostructures.Our research work has been focused on the following respects:1.Tuning the Morphology of Self-Assembled Nanostructures of Amphiphilic Tetra(p-hydroxyphenyl)Porphyrins with Hydrogen Bonding and Metal-Ligand Coordination BondingTypical amphiphilic metal free tetrakis(4-hydroxyphenyl)porphyrin H₂THPP(1) and tetrakis(4-hydroxyphenyl)porphyrinato copper complex CuTHPP(2) were fabricated into organic nanostructures by a phase-transfer method.Their self-assembly properties in aqueous solution have been comparatively studied with those of tetra(phenyl)porphyrin H₂TPP(3) by electronic absorption and Fourier transform infrared(FT-IR) spectroscopy, transmission electronic microscopy(TEM),scanning electronic microscopy(SEM),and X-ray diffraction(XRD) techniques.Experimental results reveal different molecular packing models in these aggregates,which in turn result in the self-assembled nanostructures with different morphology from nano-scale hollow spheres for 1,nanoribbons for 2,and to nanobelts for 3.The present study,representing part of our continuous efforts towards understanding the relationship between synergistic interplay among noncovalent interactions such as the n-n interaction,metal-ligand coordination bonding,and hydrogen bonding on controlling and tuning the morphology of self-assembled nanostructures of tetrapyrrole derivatives,will provide information helpful on preparing self-assembled nanostructures with controlled molecular packing conformation and morphology through molecular modification.2.Morphology Controlled Self-assembled Nanostructures of Sandwich Mixed (Phthalocyaninato)(porphyrinato) Europium Triple-deckers.Effect of Hydrogen Bonding on Tuning the Inter-molecular InteractionA series of five novel sandwich-type mixed(phthalocyaninato)(porphyrinato) europium triple-decker complexes with different number of hydroxyl groups at the meso-substituted phenyl groups of porphyrin ligand 1-5 have been designed,synthesized,and characterized. Their self-assembly properties,in particular the effects of the number and positions of hydroxyl groups on the morphology of self-assembled nanostructures of these triple-decker complexes,have been comparatively and systematically studied.Competition and cooperation between the inter-molecularÏ€-Ï€interaction and hydrogen bonding in the direction perpendicular to theÏ€-Ï€interaction direction for different compounds were revealed to result in nanostructures with different morphology from nano-leafs for 1, nano-fibbons for 2,nano-sheets for 3,curved nano-sheets for 4,and to spherical shapes for 5. The IR and X-ray diffraction(XRD) results reveal that in the nanostructures of triple-decker 2 as well as 3-5,a dimeric supramolecular structure was formed through an intermolecular hydrogen bond between two triple-decker molecules,which as the building block self-assembles into the target nanostructures.Electronic absorption spectroscopic results on the self-assembled nanostructures reveal the H-aggregate nature in the nano-leafs and nano-ribbons formed from triple-deckers 1 and 2 due to the dominantÏ€-Ï€inter-molecular interaction between triple-decker molecules,but J-aggregate nature in the curved nano-sheets and spherical shapes of 4 and 5 depending on the dominant hydrogen bonding interaction in cooperation withÏ€-Ï€interaction among the triple-decker molecules.Electronic absorption and XRD investigation dearly reveal the decrease in theÏ€-Ï€interaction and increase in the hydrogen bonding interaction among triple-decker molecules in the nanostructures along with the increase of hydroxyl number in the order of 1-5.The present result appears to represent the first effort towards realization of controlling and tuning the morphology of self-assembled nanostructures of sandwich tetrapyrrole rare earth complexes through molecular design and synthesis.3.Lanthanide(â…¢) Double-Decker Complexes with Octaphenoxy- or Octathiophenoxyphthalocyaninato Ligands.Revealing the Electron-Withdrawing Nature of the Phenoxy and Thiophenoxy Groups in the Double-Decker ComplexesA series of heteroleptic and homoleptic bis(phthalocyaninato) lanthanide(â…¢) complexes, namely M(Pc)[Pc(OPh)₈],M[Pc(OPh)₈]₂,Eu(Pc)[Pc(SPh)₈],and Eu[Pc(SPh)₈]₂[M = Eu,Ho, Lu;Pc = unsubstituted phthalocyaninate;Pc(OPh)₈ = 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninate;Pc(SPh)₈ = 2,3,9,10,16,17,23,24-octathiophenoxyphthalocyaninate](1-8) have been prepared.The molecular structure of Eu[Pc(OPh)₈]₂(4) has been determined by single-crystal X-ray diffraction analysis.All the new sandwich compounds have been characterized with various spectroscopic methods.Their electrochemical characteristics show that the introduction of phenoxy or thiophenoxy groups onto the peripheral positions of the phthalocyaninato ligand makes the double-decker harder to oxidize and easier to reduce.Theoretical calculations, using semi-empirical PM3 method,indicate that the change in the energy level of the frontier orbitals of these ligands induced by the electron-withdrawing substituents is responsible for these unusual electrochemical properties.