Metallkomplexe von Farbstoffen. VIII Übergangsmetallkomplexe des Curcumins und seiner Derivate

Metal Complexes of Dyes. IX. Transition Metal Complexes of Curcumin and Derivatives The bidentate monoanions of curcuminCU, (1, 7-bis(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione)], diacetylcurcuminDACU, (1,7-bis(4-acetyl-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione)], dihydroxycurcuminDHCU, (1,7-bis(4-hydroxiphenyl)-hepta-1,6-diene-3,5-dione)], dimethylcurcumin DMCU, (1,7-bis(3,4-dimethoxyphenyl)-hepta-1, 6-diene-3,5-dione)] and trimethylcurcuminTMCU, (1,7-bis(3,4-dimethoxyphenyl)-4-methylhepta-1,6-diene-3,5-dione)] form with chloro bridged complexes (R₃P)MCl₂]₂ (M?Pd, Pt; R?phenyl, n-butyl, ethyl, tolyl), η⁵-C₅Me₅)MCl₂]₂ (M?Rh, Ir), (η⁶-p-cymene)RuCl₂]₂, (η³-C₃H₅)PdCl]₂, di-μ-chlorobisN-(diphenylmethylene)-glycinethylester-(C,N)]-dipalladium(II) and with (η⁵-C₅Me₅)Co(CO)I₂] monochelate dye complexes. The structure of (η⁶-p-cymene)(Cl)Ru(DMCU)] was determined by X-ray diffraction. The dichelates (DMCU)₂M with M?Cu, Ni, (CU)₂Pd and the trichelate (CU)₃Fe were obtained. Cationic bipyridine copper(II) complexes with CU, DHCU, and DMCU were sythesized by treating the dye ligands with copper(II) acetate, 2,2′-bipyridine and ammoniumtetrafluoroborate. In comparison to the free 1.3-diketones the dye complexes show a bathochromic shift in the UV/VIS spectra.