The precursor [Re(CO)3(PPh3)2Cl] reacts with natural bile acids to give new carboxylato-carbonyl(phosphine) rhenium(I) complexes [Re(CO)2(PPh3)2(L)] (HL=natural bile acids). Coupling reactions between the carboxylic group of bile acids with the NH2 moiety of 2-aminothiazole, 2-(2-aminoethyl)pyridine and hydrazine form derivatives which coordinate the metal ion through the deprotonated amidic group. For a comparison, the carboxylato-rhenium(I) complex [NEt4][Re(CO)3Cl(L1)] (HL1=3α,7α,12α-trihydroxy-5β-cholic acid) was synthesized starting from the [Re(CO)3Cl3]2- precursor. The complex [Tc(CO)3(PPh3)2Cl] reacts with HL1 to form the corresponding carboxylato-carbonyl compound [Tc(CO)2(PPh3)2(L1)]. No difference in reactivity is observed with respect to the reactions carried out with the Re(I) starting materials. The complexes were characterized by elemental analyses, IR and NMR spectra, and a few also by mass spectrometry. An octahedral geometry may be assigned to these complexes. The two phosphine ligands are located in the axial position, and the two cis-CO groups having in trans the chelating ligand define the equatorial plane. © 1999 Elsevier Science S.A.
Organometallic radiopharmaceuticals: rhenium(I) carbonyl complexes of natural bile acids and derivatives
CATTABRIGA, Michela;MARVELLI, Lorenza;MARCHI, Andrea;ROSSI, Roberto;FOGAGNOLO, Marco
1999
Abstract
The precursor [Re(CO)3(PPh3)2Cl] reacts with natural bile acids to give new carboxylato-carbonyl(phosphine) rhenium(I) complexes [Re(CO)2(PPh3)2(L)] (HL=natural bile acids). Coupling reactions between the carboxylic group of bile acids with the NH2 moiety of 2-aminothiazole, 2-(2-aminoethyl)pyridine and hydrazine form derivatives which coordinate the metal ion through the deprotonated amidic group. For a comparison, the carboxylato-rhenium(I) complex [NEt4][Re(CO)3Cl(L1)] (HL1=3α,7α,12α-trihydroxy-5β-cholic acid) was synthesized starting from the [Re(CO)3Cl3]2- precursor. The complex [Tc(CO)3(PPh3)2Cl] reacts with HL1 to form the corresponding carboxylato-carbonyl compound [Tc(CO)2(PPh3)2(L1)]. No difference in reactivity is observed with respect to the reactions carried out with the Re(I) starting materials. The complexes were characterized by elemental analyses, IR and NMR spectra, and a few also by mass spectrometry. An octahedral geometry may be assigned to these complexes. The two phosphine ligands are located in the axial position, and the two cis-CO groups having in trans the chelating ligand define the equatorial plane. © 1999 Elsevier Science S.A.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
