Mc. Rodriguezarguelles et al., 2,6-DIACETYLPYRIDINE BIS(THIOSEMICARBAZONES) ZINC-COMPLEXES - SYNTHESIS, STRUCTURE, AND BIOLOGICAL-ACTIVITY, Journal of inorganic biochemistry, 58(3), 1995, pp. 157-175
The reaction of zinc chloride, acetate, or perchlorate with two bis(th
iosemicarbazones) of 2,6-diacetylpyridine [H(2)daptsc = 2,6-diacetylpy
ridine bis(thiosemicarbazone) and H(2)dapipt = 2,6-diacetylpyridine bi
s(hydrazinopyruvoylthiosemicarbazone)] leads to the formation of four
novel complexes that have been characterized by spectroscopic studies
(NMR, IR) and biological properties. The crystal structures of the two
compounds-[Zn(daptsc)](2) . 2DMF (1) and [Zn(H(2)dapipt)(OH2)(2)](ClO
4)(2) . 3H(2)O (2)-also have been determined by x-ray methods from dif
fractometer data. Compound (1) is dimeric and the two zinc atoms have
a distorted octahedral coordination. The ligand is deprotonated. In co
mpound (2), the coordination geometry about zinc is pentagonal-bipyram
idal and the ligand is in the neutral form. The molecular structure of
(2) consists of cations [Zn(H(2)dapipt)(OH2)(2)](2+), ClO4- disordere
d anions, and three water molecules of solvation. Biological studies h
ave shown that the ligands and the complexes Zn(daptsc). 1/2EtOH and Z
n(H(2)daptsc)Cl-2 have an effect in vitro on cell proliferation and di
fferentiation (inhibition); both are concentration dependent. [Zn(dapt
sc)](2) . 2DMF (1) shows the effects at lower concentration values wit
h respect to other compounds.