In this work the result of the synthesis of the 4- hexil-dithiocarboxilate-1-phenil-3-methyl-2-pirazolin-5-ona(PirC6), and 4-dithiocarboxilate of dodecil-1-phenil-3-methyl-2-pirazolin-5-ona(PirC12), is presented and the products are characterized, using the microanalysis ,the infrared spectroscopy, the spectroscopy of NMR of H1 and C13 and the NMR in twodimensions (HSQC and HMBC), in order to determine their structures. In addition, theligand potential capacity of these products are studied in order to produce coordinationcompounds with the uranil (UO22+).

There has been structural analysis of 1-phenyl-3-methyl-2-pirazolin-5-one-4-etoxicarbonil (PirC2) by means of two techniques of two-dimensional NMR, the HSQC and HMBC, which helped to elucidate the interaction between the atoms of carbon and hydrogen present in the organic molecule. It was interacted this compound with a salt of uranyl in order to test the possible formation of the respective complex compound. Using the vibrational spectrum was possible to determine the force constant and the bond length of the uranium and oxygen atoms at the UO2 2+ present in the complex, using the model of Badger modified by Jones.

There has been the structural analysis of six derivatives of the 4- aminoantipyrine(4AAP) by means of two techniques of two-dimensional NMR, the HSQC and HMBC, which helped to elucidate the structure of four derivatives using the data provided by the interaction between the atoms of carbon and hydrogen present in the different molecules.