| Phthalocyanines and their analogues have attracted considerable attention as versatile materials for optical recording media,nonlinear optical application,light absorption,electric conduction,photoconduction,energy conversion,electrode, chemical sensor,and catalyst.Columnar discotic mesophase liquid crystals have shown great potential application in semiconducting and photoconducting devices, light-emitting diodes and sensors due to their anisotropic charge carrier transport properties.(Na)phthalocyanines,as disc-shaped aromatic rings,can be facilely modified upon addition of various kinds of long alkyl,alkoxy and alkyloxymethyl side chains,therefore,to transform the crystalline materials to the liquid crystalline materials.Phthalocyanine derivatives substituted with appropriative side chains generally form a supramolecular organization and demonstrate columnar mesophases, which afford the possibility of combining the opto-electronic properties of phthalocyanines(Pcs) with the orientation control of conventional liquid-crystal systems.Moreover,photochromic materials are attached much importance to owing to their potential application in the areas of optical memory,information storage, dopes,pigments and other correlative industries.In recent years,it has become a popular field to design and synthesize this kind of materials with novel structures or availing in practice.Our research work in these fields has been focused on the following respects:1.Synthesis and Liquid Crystal Behavior of Bis[3,4,12,13,21,22,30,31-oeta(dodecylthio)-2,3-naphthalocyaninato]Rare Earth Complexes A series of novel bis[3,4,12,13,21,22,30,31-octa(dodecylthio)-2,3-naphthalocyaninato]rare earth(Ⅲ) complexes M[Nc(SC12H25)8]2[M=Nd,Eu, Gd,Tb,Y,Ho,Er](1-7) have been prepared by tetramerization of 2,3-bis(dodecylthio)-6,7-dicyanonaphthalene with M(acac)3·nH2O in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) in refluxing n-octanol.These sandwich double-decker complexes were characterized by elemental analysis and various spectroscopic methods including UV-vis,near IR,IR,and mass spectroscopies.Their liquid crystal behavior was studied by polarized optical microscope(POM), differential scanning calorimeter(DSC),and X-ray diffraction.These alkylthio-substituted bis(2,3-naphthalocyaninato) rare earth complexes yield a hexagonal columnar liquid crystal whose wide temperature range is between 42 and 243℃.The stable temperature domain of the mesophase shows a trend to be dependent on the central rare earth ionic size.In contrast,the molecular packing of these complexes as revealed by X-ray diffraction was found to be almost independent of the ionic size of the central rare earth.2.Synthesis and Liquid Crystal Behavior of Tris[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato]Rare Earth ComplexesA series of tris[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato]rare earth(Ⅲ) complexes M2[Pc(OC8H17)8]3[M=Eu,Gd,Y,Lu](1-4) has been prepared by the reaction of corresponding bis[2,3,9,10,16,17,23,24-octakis(octyloxy)-phthalocyaninato] rare earth complexes with M(acac)3·nH2O in refluxing 1,2,4-trichlorobenzene(TCB).These liquid crytalline sandwich triple-decker complexes were characterized by elemental analysis and various spectroscopic methods including 1H NMR,UV-vis,IR and mass spectroscopies.Their liquid crystal phase transition behavior was studied by Polarized Optical Microscope(POM), Differential Scanning Calorimeter(DSC) and X-ray diffraction.The complexes,with octyloxy attached as side chains,showed rectangular columnar liquid crystal phases in liquid crystal temperature range between 83 and 305℃.Along with the rare earth contraction,both the transition temperature and the wide temperature range of the mesophase show slight but obvious decrease trend,respectively,in the same order.In contrast,the molecular packing of these complexes as revealed by X-ray diffraction was found to be almost independent of the ionic size of the central rare earth. 3.Liquid Crystal Behavior of 2,3,9,10,16,17,23,24-Octakis(octyloxy)-phthalocyanine -containing Gadolinium Sandwich ComplexesA series of six liquid crystalline phthalocyaninato gadolinium sandwich complexes including two double-deckers Gd(Pc)[Pc(OC8H17)8](1)[Pc(OC8H17)8= 2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyanine]and Gd[Pc(OC8H17)8]2(2) and four triple-deckers(Pc)Gd(Pc)Gd[Pc(OC8H17)8](3),(Pc)Gd[Pc(OC8H17)8]Gd(Pc)(4), (Pc)Gd[Pc(OC8H17)8]Gd[Pc(OC8H17)8](5),and Gd2(OC8H17)8]3(6) have been designed and their liquid crystal phase transition behavior was systematically studied by differential scanning calorimeter(DSC),X-ray diffraction and polarized optical microscope(POM).The clearing point seems to show a dependence on the molecular structure of sandwich compounds,increasing from double-decker to triple-decker and along with the increase in the number of substituted 2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyanine ligand both in the double- and triple-decker compounds.The liquid crystalline mesophases displayed hexaganol columnar and/or rectangular columnar molecular arrangement depending on the molecular structure of sandwiches,suggesting the cooperation of theπ-πstacking and the influence of octyloxy side chains on the liquid crystalline formation.In addition, textures of this series of double- and triple-decker sandwich compelxes formed in the liquid crystalline mesophase exhibit high stability even after the mesophases of the compounds were treated with heating into the clear isotropic liquid and cooling to the room temperature,which is expected to be an efficient method for constructing molecular electronic devices.4.OFET Properties of the Liquid Crystal Material Bis[2,3,9,10,16,17,23,24-oetakis(octyloxy)phthalocyaninato]Europium(Ⅲ) Complex.The liquid crystal and OFET properties of the free-radical sandwich complex bis(octakis(octyloxy)phthalocyaninato)europium(Ⅲ),Eu[Pc(OC8H17)8]2 have been studied.This compound displays multimesomorphic thermotropic behavior with two columnar liquid crystalline phases,Colr and Colh,between the freshly precipitated crystalline solid at room temperature,K,and the isotropic liquid,I,at 196℃.The ordered mesophases of the compound is demonstrated by the atomic force microscope (AFM).With the help of spin-coating technique,the typical liquid crystal double-decker complex has been fabricated into organic field effect transistors(OFET) with bottom contact configuration on hexamethyldisilazane(HMDS)-treated SiO2/Si substrate.The carrier mobility for hole as high as 0.07 cm2 V-1 s-1 and current modulation of 5.4×102 have been reached for the devices of the mesophase Colr of the double-decker compound.5.A Novel Photochromic and Electrochromic Europium Tetraazaporphyrinato and Phthalocyaninato Heteroleptic Double-Decker for Information Storage. General Synthesis,Spectroscopic,and Electrochemical CharacterizationA novel tetraazaporphyrinato and phthalocyaninato mixed heteroleptic double-decker sandwich rare earth compound with photochromic and electrochromic features has been facilely synthesized by one-pot reaction using Eu(acac)3·nH2O, metal-free phthalocyanine H2Pc'(Pc'=2,3,9,10,16,17,23,24-octakis(decyloxy)-phthalocyanine), and the photochromic precursor 1,2-dicyano-1,2-bis(2,3,5-trimethyl-3-thienyl)ethane as starting materials.The compound was well characterized by elemental analysis,and various spectroscopic methods including UV-vis,IR,1H NMR,and mass spectroscopies.The electrochemical behavior of this compound was studied by cyclic voltammetry(CV) and differential pulse voltammetry(DPV) methods,which showed up to three one-electron oxidation and four one-electron reduction processes,demonstrating an electro-active compound for high density information storage.The photochromic performance of the compound was detected by electronic absorption spectra,suggesting the compound to be good candidate for non-destructive readout by means of UV-vis spectroscopy.
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