COMPARATIVE STRUCTURAL AND SPECTRUM ANALYSES OF 6-MERCAPTOPURINE MONOHYDRATE AND 6-MERCAPTOPURINE HYDROCHLORIDE

The molecular structure of 6-mercaptopurine hydrochloride C5H5N4SCl (6 -MPH+Cl-) has been determined by X-ray diffraction method. The crystal s are monoclinic, space group P2(1)/c with a=7,875(4), b=11,742(7), c= 9,077(5) Angstrom, beta=116,25(4)degrees, V=752(1) Angstrom(3) and Z=4 . The structure teas refined to R=0.044. The compound was found to be in the thione form with hydrogen atoms bonded to the N-1, N-7 and N-9 nitrogen atoms. A comparison with 6-mercaptopurine monohydrate (6-MP.H 2O) was made. The Raman and the infrared spectra of the cristalline po wders of the 6-mercaptopurine monohydrate, anhydrous (6-MP) deuterated (6-MP.D2O) and hydrochloride forms were investigated from 4600 to 200 cm(-1) and the results were compared with those of the Raman spectrum of the hydrochloride form in aqueous solution. The assignments of the fundamental vibrations involved in the intermolecular H-bonds N-H(D). .. X (X=O,N) and N+-H(D)... Cl- are discussed.