2-MERCAPTOPYRIDINE DERIVATIVES AS NEUTRAL OR IONIC DONORS TOWARDS TINTETRAHALIDES

The esters of 2-mercaptopyridine-5-carboxylic acid NH(CS)CHCHC(COOR)CH (HL; R = Me, HTNME; R = Et, HTNEE; and R = iso-Pr, HTNIPE) can act to ward tin(IV) halides as either neutral or anionic donors, yielding com pounds with the general formulae SnX2(L)(2), SnX4(HL)(2), and SnX4(HL) (4). The SnX2(L)(2) (X = Cl or Br) species can be also obtained by rea cting tin(ll) halides with the ligands in ethanol. The complexes have been characterized by IR, NMR, and Mossbauer spectroscopies. The struc ture of SnCl2(TNIPE)(2) was determined by X-ray diffraction. Crystals are monoclinic (space group P2(1)/n), a=14.973(2), b=6.965(1), c=22.92 3(2) alpha, beta=98.3(1)degrees, Z=4,and V=2365.5(8) Angstrom(3). Some of them have been tested for their cytostatic activity on a KB cell l ine.