Uranyl and transition metal chelates of tenoxicam.: Crystal structures of trans,trans-[Co(II)(Hten)2(dmso)2], trans,trans-[Zn(II)(Hten)2(dmso)2] and cis,cis-[UO2(VI)(Hten)2(H2O)] • 2C2H5OH

The synthesis and characterization of ternary Fe(III)- (1), Co(II)- (2), Ni(II)- (3), Cu(II)- (4), Zn(II)- (5) and UO2(VI)- (6) chelates with the potent anti-inflammatory drug tenoxicam (H(2)ten) and (dl-alanine, Hala) are reported. All complexes are octahedral except Cu(II) and Zn(II) chelates, which are tetrahedral, and U-atoms in the uranyl chelates have a pentagonal-bipyramidal coordination sphere. The ternary Co(II) and Zn(II) complexes dissociate in dmso where orange and yellow crystals of trans, trans-[Co(II)(Hten)(2)(dmso)(2)] (8) and trans, trans[Zn(II)(Hten)(2)(dmso)(2)] (9), respectively, were obtained. Crystallization of the binary uranyl chelate (7) from ethanol afforded the ethanol solvate cis, cis-[UO2(VI)(Hten)(2)(H2O)] center dot 2C(2)H(5)OH (7a). trans, trans-[Co(II)(Hten)(2)(dmso)(2)] (8) and trans, trans-[Zn(II)(Hten)(2)(dmso)(2)] (9) crystallize in the monoclinic space group P2(1)/n while 7a crystallizes in the triclinic space group P (1) over bar. The kinetics of the thermal decompositions for 1, 3, 4, 6 and 7 were studied and the thermodynamic parameters E*, Delta H*, Delta S* and Delta G* evaluated.