[en] A number of trisalicylimino-uranylates with metallic, organic and complex cations have been prepared. Their general compositions are M¹ (UO₂(C₇H₆NO)₃) where M¹=K⁺, Cs⁺, Tl⁺, NH₄⁺Ph₄As⁺, pyridinium (C₅H₆N⁺), quinolinium (C₉H₈N⁺), oxinium (C₉H₈N⁺O), cis-(Co(en)₂Cl₂)⁺, trans-(Co(-en)₂Cl₂)⁺ cations and Msup(II)(UOsub(2)(Csub(7)Hsub(6)NO)sub(3))sub(2) where Msup(II)=Casup(2+), Sr²⁺, Ba²⁺, Zn²⁺ etc. From IR spectra of these complexes, the asymmetric stretching frequency (v₃ in cm^-1) values of the UO₂²⁺ entity indicate the following decreasing order of stability of the complexes and the increasing order of νsub(3) values: Cs⁺>cis-(Co(en)₂Cl₂)⁺>Ba²⁺>Tl⁺=trans-(Co(en)₂Cl₂)⁺>Ph₄As⁺=Nh₄⁺>Zn²⁺>OXH⁺>PyH⁺. Thermogravimetric analyses of these compounds also indicate the same decreasing order of stability with the exception of the complex cationic compounds for which an explanation has been provided. So there is a direct parallelism between thermal stability and stability indicated by νsub(3) values from IR spectra. From the observed asymmetric stretching frequency (νsub(3) in cmsup(-1)) of the UO₂²⁺ entity, the force constant, Fsub(UO) in mdynes/A and the bond length Rsub(UO) in A of 'U-O' bond have been calculated. Plot of decomposition temperature (T₀) vs νsub(3) is a straight line and these two parameters are inversely related. Electronic spectra of some of these compounds have also been measured. All these data indicate linearity of the UO₂²⁺-entity and a chain structure for the trisalicylimino-uranylates. (author)