Technetium cyclopentadienyls

Keywords Technetium Carbonyl complexes Technetium cyclopentadienyl Vitamin B12 Molecular imaging... 

Masi S, Top S, Boubeker L, Jaouen G, Mundwiler S, Spingler B, Alberto R (2004) Direct synthesis of tricarbonyl(cyclopentadienyl)rhenium and tricarbonyl(cyclopentadienyl)-technetium units from ferrocenyl moieties. Preparation of 17alpha-ethynylestradiol derivatives bearing a tricarbonyl(cyclopentadienyl)technetium group. Eur J Inorg Chem 10 2013-2017... 

Cyclopentadienyl (Cp) complexes (see Cyclopentadienyl) are known for almost all the metals of the periodic chart, including technetium. The compounds with transition metals usually possess covalent jt Cp M bonding. The nature of the metal Cp bond is multiple. The <7-bond is formed from the overlap of an empty d orbital of Tc with one of the frUed jt bonding molecular orbital on Cp with good symmetry. Back-donation is usually also present from the filled d orbitals of Tc to one of the empty n molecular orbitals on Cp. These molecules are usually called sandwich compounds (see Sandwich Compound), when there are two Cp ligands bonded to the metal, or half-sandwich complexes (see Half-sandwich Complexes) when only one Cp ligand is present. 

Attempts were made to use cyclopentadienyl technetium tricarbonyl derivatives for labeling estrogen receptor binding ligands as well as proteins and peptides. ... 

The formation of the hydrides may proceed via bis(jr-cyclopentadienyl)-metal halide complexes, since compounds such as (ir-CeH ReCU+CI-and (t-CjHOjWCU are known and are readily reduced to the neutral hydrides on treatment with lithium aluminum hydride 64) (Eq. 5). Treatment of technetium tetrachloride with sodium cyclopentadiene does not give a hydride analogous to that of rhenium. Molecular weight determina-... 

Bernard J, Ortner K, Spingler B, Pietzsch HJ, Alberto R (2003) Aqueous synthesis of derivatized cyclopentadienyl complexes of technetium and rhenium directed toward radiopharmaceutical application. Inorg Chem 42 1014-1022... 

Bigott HM, Parent E, Luyt LG, Katzenellenbogen JA, Welch MJ (2005) Design and synthesis of functionalized cyclopentadienyl tricarbonylmetal complexes for technetium-94m PET imaging of estrogen receptors. Bioconjugate Chem 16 255-264... 

Saidi M, Kothari K, Pillai MRA et al (2001) Cyclopentadienyl 99m-technetium tricarbonyl piperi-din conjugate biodistribution and imaging studies. J Labelled Cpd Radiopharm 44 603-618 Saidi M, Seifert S, Kretzschmar M et al (2004) Cyclopentadienyl tricarbonyl complexes of 99m-Tc for the in vivo imaging of the serotonin 5-HTia receptor in the brain. J Organomet Chem 689 4739-4744... 

Cyclopentadienyl-tricarbonyl-technelium(I) was prepared by reacting TeCU in the presence of copper powder with CO under a pressure of 325 atm to yield technetium carbonylchloride which was then heated in ethyleneglycoldimethylether with sodium cyclopcntadienyl. The sublimable, colorless, and diamagnetic [(C5H5)Tc(CO)3]° melts at 87.5 °C [662]. Irradiation of the dimeric compound [(C5Hs)Mo(CO)3]2° with Iher-mal neutrons produced [(C5H5) " Tc(CO)3]° by nuclear transformation of molybdenum to technetium [663] ... 

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