Superoxidedismutase-mimetic Copper(II) complexes containing saccharinate and 4-aminopyridine/4-cyanopyridine,

E. G. FERRER; NATALIA BAEZA; L. NASO; E.E.CASTELLANO; O.E.PIRO; P. A. M. W ILLIAMS

JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY

ELSEVIER GMBH

Año: 2009 vol. 24 p. 20 - 26

0946-672X

Two copper(II)complexes,[Cu(sac)2(4-cypy)2(H2O)], 1 and [Cu(sac)2(4-Ampy)2(H2O)], 2 (4-cypy: 4-cyanopyridine;4-Ampy:4-aminopyridine)wereprepared.Physicochemicalpropertiesofthe complexeswerestudiedbyspectroscopic(solutionUV–vis,diffusereflectanceandIR)techniques. StructuralX-raydiffractiondatacouldbeobtainedonlyfor[Cu(sac)2(4-cypy)2(H2O)] thatitcrystallized in thetetragonalspacegroupP4ccwith a=b=15.313(1), c=13.240(1) ˚ A, and Z=4moleculesperunitcell. The complexwascitedonacrystallographic C2-axis withtheCu(II)ioninasquare–pyramidal environment, coordinatedatthepyramidbasistothenitrogenatomoftwosaccharineanions [d(Cu–N)=2.011(3) ˚ A] andthepyridineN-atomoftwo4-cyanopyridineligands[d(Cu–N)=2.038(4) ˚ A]. The coordinationwascompletedbyawatermoleculeatthepyramidapex[d(Cu–Ow)=2.189(5) ˚ A]. ElementalandspectroscopicanalysesrevealedanO-saccharinatecoordinationmodeforcomplex 2 and a square–pyramidalstructure.Onlycomplex 2 retained itsstructureinmethanolicsolution.However, both complexeswereabletocatalyzethedismutationofsuperoxideanion(O2_) (pH7.5)atmicromolar concentrations.Therefore,thesecomplexesbehavedasusefulSOD-mimeticcompounds.