| Abstract: The complexes of rare earth and salicylhydroxamic acid (SHA) benzohydroxamic acid (BHA) and o-phthalichydroxamic acid (OPHA)were first prepared from aqueous alcohol solution at pH 3.5-5.0.Elemental and thermogravimetric analysis demonstrated that the formula are RE(SHA)3·nH2O (where n=2 for La,Ce,Pr,Nd and Tm,n=3 for Sm,Eu,Gd and Tb,n=4 for Y),RE(BHA)3·mH2O (where m=3 for La,Ce and Y,m=4 for Pr,Nd,Sm and Eu,m= 5 for Gd,Tb and Tm)and RE2(OPHA)3·xH2O)(whcre x=4 for Ce and Y,x=5 for La,Pr,Nd,Eu,Gd,Tb and Tm).The structure of some of the complexes crystals were confirmed by X-ray powder diffraction.These new complexes were insoluble in water,slightly soluble in mcthanol,chloroform,acetone,dimethyl sulfoxide and ethyl nitrite etc.but soluble in mineral acids.It was shown in data of thermogravimetric analysis that these complexes are stable thermally (most of them decomposed at a temperature higher than 300℃ ).The molecular conductance and stability constants of complexes have also been studied.The complexes were investigated by infrared,ultraviolet.HNMR and fluorescence spectra.Experimental results proved that these complexes of Tb with BHA,SHA and OPHA have a brilliant green emission in 485 and 490nm respectively,and complex of Eu with BHA,SHA and OPHA have two distinct red emission in 595-675nm. |
