title: Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.
abstract: The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to β-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, β-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as β-diketone provides a solid example of the pharmacological potential of this system.
authors.affiliation: Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, ‡Institute of Biosciences & Applications, and §Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, Department of Materials Science, National Centre for Scientific Research "Demokritos" , 15310 Athens, Greece.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Triantis
authors.forename: Theodoros
authors.initials: T
authors.lastname: Tsotakos
authors.forename: Charalampos
authors.initials: C
authors.lastname: Tsoukalas
authors.forename: Marina
authors.initials: M
authors.lastname: Sagnou
authors.forename: Catherine
authors.initials: C
authors.lastname: Raptopoulou
authors.forename: Aris
authors.initials: A
authors.lastname: Terzis
authors.forename: Vassilis
authors.initials: V
authors.lastname: Psycharis
authors.forename: Maria
authors.initials: M
authors.lastname: Pelecanou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Pirmettis
authors.forename: Minas
authors.initials: M
authors.lastname: Papadopoulos
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis; D001665:Binding Sites; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D003474:Curcumin / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D010422:Pentanones / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D010720:Phosphines / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D058225:Plaque, Amyloid / Q000473:pathology; D011522:Protons
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D010422:Pentanones; D010720:Phosphines; D011522:Protons; C008790:acetylacetone; C044646:phosphine; D003474:Curcumin