New Organometallic Technetium Complexes for Radiopharmaceutical Imaging

Tricarbonylrhenium(I) and ‐technetium(I) Complexes with Tris(1,2,3‐triazolyl)phosphine Oxides

“…Reactions of [Re(CO) 5 Br] with OP( 1,2,3 Tz 1À Ph ) 3 or OP-( 1,2,3 Tz 1À benz ) 3 in boiling CHCl 3 result in the replacement of two carbonyl ligands and the formation of [Re(CO) 3 Br{OP( 1,2,3 Tz 1À R ) 3 }] complexes (Scheme 1). Remarkably, these reactions are not straightforward and accompanied by a number of sidereactions, which lower the yields and result in the formation of a number of decomposition products.…”

“…Stable and kinetically inert tricarbonyl complexes of rhenium and technetium are of ongoing interest for the development of novel radiopharmaceuticals for diagnostics and therapy. [1][2][3][4][5][6][7][8][9] The metastable nuclear isomer 99m Tc is still the 'workhorse' in diagnostic nuclear medicine with some 40 million annual administrations worldwide, [10] and rhenium possesses two β Àemitting isotopes suitable for therapy: 186 Re and 188 Re. For both elements, normal pressure syntheses have been developed for corresponding [M(CO) 3 (H 2 O) 3 ] + (M = 99m Tc, 188 Re) cations, which are perfect precursors for nuclear medical preparations.…”

Ligand exchange and complex formation kinetics studied by NMR exemplified on fac-[(CO)3M(H2O)]+ (M=Mn, Tc, Re)

“…Tricarbonyl complexes of Tc I and Re I are interesting precursors for radiopharmaceuticals because the three water ligands can readily be replaced by incoming ligands and a large number of compounds have been synthesized and characterized [18,20,21,23,24,29]. Both M I centres bind a variety of ligand atoms like nitrogen, phosphorous, oxygen and sulfur.…”

“…An important isotope for radioactive imaging agents is 99m Tc and there is a strong interest in the development of new labelling techniques using this short-lived isotope. The use of the water-soluble tricarbonyl trihydrate technetium(I) cation, fac-[(CO) 3 Tc(H 2 O) 3 ] + , as building block has allowed to synthesize a series of new, promising compounds [20][21][22][23][24]. Because the majority of compounds that have been labelled with 99m Tc can also be labelled with 186 Re or 188 Re these complexes form couples that can be used for diagnosis (Tc) and therapy (Re) [20].…”

Technetium Complexes and Radiopharmaceuticals with Scorpionate Ligands

“…Relevant examples of the first type of technetium functional moieties are the Tc-trioxo ([ mer -TcO 3 ] + ) [ 14 , 15 ] Tc-oxo ([Tc≡O] 3+ ) [ 10 , 11 ], Tc-sulfido ([Tc≡S] 3+ ) [ 16 ], Tc-nitrido [Tc≡N] 2+ [ 17 , 18 ] and Tc-dioxo ( trans -[O=Tc=O] + ] [ 10 , 11 ] cores. The most important examples of the second type of technetium moieties are the Tc- tris -carbonyl ( fac -[Tc(CO) 3 ] + ) [ 19 , 20 ] and Tc-HYNIC ([Tc=N–NH–C 5 H 5 N] [ 21 ] metallic fragments. A unique example of functional group where the two types of cores are intimately entangled into the same moiety is provided by the mixed Tc-nitrido-diphosphane ([(PNP)Tc≡N] 2+ ) metallic fragment [ 22 ].…”