Asymmetric Sandwich-type Phthalocyanine Rare Earth With The Material Preparation Of Lb Films, Structural Characterization And Properties Of Study

Sandwich-type phthalocyaninato and / or porphyrinato rare earth complexes, possessing highly delocalized macrocycles, have attracted increasing interest in areas of semi-conductors, molecular metals, and molecular electronics due to their special optical and electronic properties. Because of the extensive planar conjugated molecular structure and narrow HOMO-LUMO energy gap, phthalocyanine derivatives have been used as building blocks for ordered molecular systems. With the help of Langmuir-Blodgett technique, this kind of building block can be fabricated into well-ordered thin films. Preparing the monolayer and multilayers of different bis(phthalocyaninato) rare earth complexes by Langmuir-Blodgett method to meet the need of different applications attract many chemists.In this thesis, the ordered molecular assemblies of novel alkylthio-substituted bis(phthalocyaninato) rare earth complexes M[PcPc(OC8H17)8] (M = Eu, Tb, Er, Lu), M[PcPc(OC8H17)8] ( M = Er, Lu) and its mixture with stearic acid (SA) have been fabricated by Langmuir-Blodgett technique and characterized by using surface pressure-area isotherms, electronic absorption spectra, polarized absorption spectra, low-angle X-ray diffraction patterns, Transmission Electron Microscope experiments and the supramolecular structures were discussed. The results are briefly illustrated as follows:1. The fabrication and characterization of the ordered supramolecular assemblies of unsymmetrical sandwich-type bis(phthalocyaninato) rare earth complexesThe π-A isotherms of M[PcPc(OC8H17)8] (M = Eu, Tb, Er, Lu) were obtained and the molecular areas in the air/water interface of this series of compounds were then estimated. The isotherms for this type of the rare earth analogues show satisfying stability of Langmuir films and similar character of figure. We find that the central rare earth ionic radius makes slight influence to the molecular area.Langmuir-Blodgett (LB) films of the complexes M[PcPc(OC8H17)8] (M = Eu, Tb, Er, Lu) were deposited onto glass plate by vertical dipping method. Experimental results indicated that the molecules of the substituted unsymmetrical bis(phthalocyaninato) rare earth complexes form well-ordered stable monolayers with a face-to-face orientation and edge-on configuration to the water surface at the air / water interface and lamellar multilayers on solid substrates. The conclusion was hold out by results of electronic absorption spectra, polarized absorption spectra and low-angle X-ray diffraction. The UV-vis absorption peaks of LB films are red shifted compared with those in solution, indicating the formation of J-aggregates. The monolayer morphology was investigated by transmission electron microscopy (TEM). Columnar domains appearing in the TEM micrograph of the monolayer have highly ordered orientation. The columnar supramolecular assemblies are proved to be monomolecular lines in which the molecules stack face-to-face.2. Study on mixed LB films of sandwich unsymmetrical bis(phthalocyaninato) rare earth complexes with stearic acidMonolayers and Langmuir-Blodgett (LB) films of the sandwich-type complex M[PcPc(OC8H17)8] ( M =Er, Lu) and its mixture with stearic acid (SA) have been studied. Surface pressure-area isotherm indicates that stable monolayer was formed. The UV-vis absorption peaks of LB films are red shifted compared with those in solution, indicating the formation of J-aggregates. The orientation angles, of the phthalocyanine rings with respect to the substrate in the LB films were evaluated to be ca. 36 ° and 40° for Er[PcPc(OC8H17)8] and Lu[PcPc(OC8H17)g] according to the Polarized UV-vis spectra. The low-angle X-ray diffraction pattern suggested that the mixed LB films were regular multiplayer with periodic structure, and the thickness of the monolayer is 2.15nm and 2.26nm, respectively. Based on all these considerations, a schematic arrangement of the complex molecules in LB films was suggested. The monolayermorphology was investigated by transmission electron microscopy (TEM). The monolayer of the complex mixed with SA w...