Design, Synthesis And Properties Of The Self-assembled Nano-structure Based On Function-oriented Phthalocyanine/Porphyrinato Metal Complexes

Phthalocyanines、porphyrins and sandwich mixed (phthalocyaninato)(porphyrinato)triple-deckers are most promising microcycle compounds for application due to their highthermal and chemical stabilities. Meanwhile，based on their unique optical，electrical，andmagnetic properties, associated with the intriguing intramolecular π-π interactions, thesecompounds represent an important class of molecular materials for a wide range ofapplication in many fields, such as organic field-effect transistors and chemistry sensors.Our research work has been focused on the following respects:1. Morphology Controlled Nano-structures of an Octa(phenoxy)-substitutedPhthalocyaninato Zinc complex: Solvent Effect on the Self-assembly BehaviourThe2,3,9,10,16,17,24,25-octakis(phenoxy)phthalocyaninato zinc,(Zn[Pc(OPh)8]) wasfabricated into nano-/micro-structures via solution-phase self-assembly. The self-assemblingproperties of Zn[Pc(OPh)8] in coordinating and non-coordinating solvents (methanoland n-hexane) have been comparatively studied by electronic absorption, fluorescence,Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy(SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques.The conducting properties were evaluated by current–voltage (I–V) measurements. Duemainly to the presence of different intermolecular Zn-O coordination interactions betweenthe Zn[Pc(OPh)8] molecules in n-hexane and betweenthe Zn[Pc(OPh)8] and solvent molecules in methanol, the self-assembly of theZn[Pc(OPh)8] results in nano-/micro-structures with distinctly different morphology asfollows: nanobelts in n-hexane, and soft nano-sticks, microscale needle mushroomas well as pine leaves in methanol depending on aggregation time. The size and/ormorphological evolution of the nanostructures have been clearly revealed during theself-assembly process. The present result appears to represent the first effort towardrealization of controlling and tuning the biomorphs of self-assembled nanostructures ofphthalocyanine-related complexes through the solvent coordinating effect. Furthermore, bothnanobelts and micrometer-sized pine leaves were revealed to show goodsemiconductor features. 2. A Sandwich Mixed (Phthalocyaninato)(Porphyrinato) Europium Triple-Decker:Balanced-Mobility, Ambipolar Organic Thin-Film TransistorA new sandwich mixed (phthalocyaninato)(porphyrinato) europium triple-decker(TPP)Eu2[Pc(OPh)8]2(1),[TPP=dianion of5,10,15,20-tetrakisporphyrin; Pc(OPh)8=dianion of2,3,9,10,16,17,23,24-octa(phenoxy)phthalocyanine], has been synthesized andcharacterized by a series of spectroscopic methods including MALDI-TOF mass spectrometry,1H NMR spectroscopy, electronic absorption and infrared spectroscopy. The electrochemicalproperty of1has been studied by cyclic voltammetry. Constructing the target triple-decker bycoordination bonding between an europium ion and isoindole/tetrapyrrole nitrogen atomsfrom n–type double-decker (Eu[Pc(OPh)8]2) and p–type porphyrin (H2TPP) units, not onlyensures the good solubility in conventional organic solvents, but more importantlysuccessfully tunes the HOMO and LUMO levels into the range of ambipolar organicsemiconductors required on the basis of electrochemical studies over1. Using asolution-based quasi–Langmuir–Sh fer (QLS) method, the thin solid films of1werefabricated. The structure and properties of the thin films were investigated by UV-visabsorption spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM).Experimental results indicated the film crystallinity and general molecular order for(TPP)Eu2[Pc(OPh)8]2molecules in the QLS films. Organic thin-film transistor (OTFT)fabricated from the QLS films of1is revealed to show ambipolar properties that have neverbeen revealed for devices fabricated from a single–phthalocyanine/porphyrin mixedcomponent using solution processable technique, with the highly balanced mobilities for holesand electrons of0.04cm2V–1s–1and0.08cm2V–1s–1, respectively.3. A Series of Novel Sandwich Mixed (Phthalocyaninato)(Porphyrinato) EuropiumTriple-Deckers: Design， Synthesis and OFET Properties of the Self-assembledNanostructuresA series of novel sandwich-type mixed (phthalocyaninato)(porphyrinato) europiumtriple-deckers with different number of pyridyl and phenyl groups at the meso-positions ofporphyrin ligand1-4（(MPyPP)Eu2[Pc(OPh)8]2、(Trans-DPyDPP)Eu2[Pc(OPh)8]2、(cis-DPyDPP)Eu2[Pc(OPh)8]2、(TPyMPP)Eu2[Pc(OPh)8]2，）, have been designed, synthesized,and characterized. The self-assembled nanostructures of these triple-decker complexes1-4are obtained using two different methods: quasi-langmuir–sh fer (QLS) and phase transfermethod. The effect of the number and positions of pyridyl groups on the morphology ofself-assembled nanostructures prepared from two different methods of1-4has beencomparatively studied by the electronic absorption spectra, X-ray diffraction (XRD), scanningelectron microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM).J-type aggregates have been formed with an increasing red-shifted degree of the Q-bandsdepending on the increased number of pyridyl groups at the meso-positions of porphyrinligand from1to4, implying the effect of both substituent-and solvet-dependentintermolecular interactions between the triple-decker molecules and between the triple-deckerand solvent molecules on molecular stacking mode. The self-assembly of1-4from a10:1(v/v)mixed solvent of isopropanol/water results in nanostructures with different morphology from1-D nanobelts for1,3-D nano-rectangular parallelepipeds with a decreased length/width ratiofrom2to3, flower-like nanostructures for4, whereas the spherical particles nanostructureswith a decreased diameter gradually from ca.200nm to50nm for1-3, and sheet-likenanostructures for4are found in the QLS film. XRD experimental results revealed thecrystallinity in the nanostructures formed in mixed solvent of isopropanol/water of1-4areimproved effectively in comparison with those of the QLS films of1-4. Furthermore, OFETdevices fabricated from the nanostructures formed in mixed solvent of isopropanol/water of1-4exhibit higher carrier mobilities for both holes and electrons relative to those of the QLSfilms. These imply the influence of the aggregation methods and molecular structures onmorphology and structures of sandwich mixed (phthalocyaninato)(porphyrinato) complexes,and in turn on OFET performance.4. Design，Synthesis and Semiconducting Properties of Self-Assembled NanostructuresBased on a Sandwich-type Mixed (phthalocyaninato)(porphyrinato) Europium ComplexA novel triple-decker complex (TPyP)Eu2[Pc(OPh)8]2has been obtained successfully,which is characterized by a wide range of methods including UV-visible absorption spectra,mass spectrometry,1HNMR spectroscopy, elemental analysis and cyclic voltammetry (CV).The analysis of cyclic voltammetry shows good semiconductor features of(TPyP)Eu2[Pc(OPh)8]2. By controlling a various of volume ratio from10:0,10:1,10:3,10:5,10:10to0:10of mixed solvent, isopropanol and water, self-assembled nanostructures with different morphology are successfully obtained from fiber mesh, cauliflower,nano-rectangular parallelepipeds with two different length/width ratios, nanorods tonano-particles membranous, respectively. Therefore, the cortrolling of the morphylogy of thetriple-decker complex (TPyP)Eu2[Pc(OPh)8]2can be successfully and easily realized just bychanging the ratio of mixed solvent with isopropanol and water. In addition, thenano-rectangular parallelepipeds from the mixed solvent isopropanol/water (v/v,10:5) exhibitthe highest conductivity in the resulting nanostructures.