Syntheses,Structures And Photoelectric Properties Of Lanthanide-Titanium Oxo Clusters

The lanthanide-titanium oxo clusters have attracted continuous attentions for their promising photoelectric properties,because of low band gap and high stability.Up to now,only few lanthanide-titanium oxo clusters have been reported.In the thesis,we reported synthesis,structures and photoelectric properties of a series of lanthanide-titanium oxo clusters.The findings are following:Ⅰ:A series of lanthanide-titanium oxo clusters Ln2Ti8(1-3)protected by acetic acid and Ln2Ti8(4-6)protected by p-toluic acid ligands have been synthesized.Investigation on the photoelectric properties shows that the p-toluic acid stabilized Ln2Ti8 have better photoelectric activity than that of the acetic acid ligand stabilized Ln2Ti8,which attributed to the ligand effects.The cyclic voltammetry curves showed that the current densities of 4-6 increases about 4-5 times after the illumination of high-pressured mercury lamp,while clusters 1-3 only increase 3 times.Ⅱ:A series of Ln2Ti6(7-10)and Ln1Ti6(11-14)were prepared by the chelate ligand salicylic acid and 3-methoxysalicy acid respectively through solvent-thermal method.Investigation on the photoelectric properties shows that the photoelectric activity of 7-10 was better than that of 11-14.Ⅲ:A novel Ti14 cluster(15)was obtained by using 1,10-phenanthroline as ligand.Single crystal structural analysis show that the Ti14(15)cluster have the same Ti7 arrangement with rutile crystal phase,which maybe regards as the structure unit mode of rutile.Cluster Ti14 had high stability and the band gap was 2.58eV,which is smaller than 3.2eV for P25.The Ti14 shows higher photocurrent density 1.01μA/cm2 than 0.55μA/cm2 for P25.