The Formation of Rhenium(V) Complexes with Dihydroxyphosphoranes and Diarylphosphinic Acid Derivatives Generated from Tris(1,2,3-triazolyl)phosphine Oxides

Tris­(1-phenyl-1H-1,2,3-triazol-4-yl)­phosphine oxide (OP­(1,2,3Tz1‑Ph)3) and tris­(1-benzyl-1H-1,2,3-triazol-4-yl)­phosphine oxide (OP­(1,2,3Tz1‑benz)3) react with (NBu4)­[ReOCl4] under partial hydrolysis and formation of rhenium­(V) complexes with unprecedented dihydroxyphosphoranato or diarylphosphinato ligands. Anionic, binuclear complexes of the compositions [Cl3(O)­Re­{O2P­(1,2,3Tz1‑Ph)3}­Re­(O)­Cl2]− and [Cl3(O)­Re­{O2P­(1,2,3Tz1‑benz)3}­Re­(O)­Cl2]− are formed as the result of a first hydrolysis step of the phosphine oxides, which has been proven by an experiment with H218O. Two more metal-containing products of these reactions, [ReOCl3{O2P­(1,2,3Tz1‑Ph)2}]− and [Cl3(O)­Re­{O2P­(1,2,3Tz1‑benz)2}­Re­(O)­Cl3]−, could also be isolated and studied by X-ray diffraction. Their structures confirm a metal-mediated P–C bond cleavage and the formation of arylphosphinic acids, which finally act as ligands in the products

Technetium Tetrachloride as A Precursor for Small Technetium(IV) Complexes

Polymeric technetium tetrachloride reacts with monodentate donor ligands such as THF, acetonitrile, DMSO, thioxane (1-oxa-4-thiacyclohexane), PMe2Ph, PPh3, OPPh3, or OH2 via cleavage of the polymeric network and the formation of [TcCl4(L)2] complexes. The configuration of the products is dependent on the donor atoms such that trans coordination is established with ‘soft' donor atoms such as sulfur or phosphorus, while cis-[TcCl4(L)2] complexes are formed with the ‘harder' donors oxygen or nitrogen. The ambivalent thioxane binds to technetium via the sulfur atom. The trans products are air stable and resistant to hydrolysis. The cis complexes, however, undergo stepwise hydrolysis, during which complexes of the composition [Cl3(L)2TcOTc(L)2Cl3] (L = CH3CN, DMSO, or OH2) are formed. They are the first representatives of a new class of technetium(IV) complexes with a bridging oxo ligand. The Tc−O bond lengths in these bridges are between 1.803(1) and 1.823(2) Å

Organometallic [Re(CO)₃]⁺ and [Re(CO)₂(NO)]²⁺ Labeled Substrates for Human Thymidine Kinase 1

Thymidine was functionalized at position N3 with a tridentate iminodiacetic acid chelating system and a potentially tetradentate mercaptoethyliminodiacetic acid chelating system. Spacers of different lengths (ethyl and butyl) were introduced between the chelators and thymidine. The derivatives were labeled with the [Re(CO)2(NO)]2+ and [Re(CO)3]+ cores to give isostructural complexes with different overall charges. All complexes were analyzed by NMR, MS, and IR, and in addition, the X-ray structure of a [Re(CO)2(NO)]2+ labeled thymidine derivative functionalized at the N3 position was solved. The ligands incorporating the potentially tetradentate mercaptoethyliminodiacetic acid chelating system coordinated tridentately through iminodiacetic acid to both the [Re(CO)2(NO)]2+ core and the [Re(CO)3]+ core. This was surprising given that the reaction of [NEt4][Re(CO)2(NO)Br3] with the model ligand ethylmercaptoethyliminodiacetic acid led to dissociation of a carbonyl ligand and formation of a monocarbonyl−mononitrosyl complex, as confirmed by X-ray structure analysis. All of the organometallic thymidine derivatives were substrates for human thymidine kinase 1, a key enzyme in (cancer) cell proliferation. Neutral [Re(CO)2(NO)]2+ labeled thymidine derivatives revealed substrate activity ranging from 24 to 40%, and the structurally analogous anionic [Re(CO)3]+ labeled thymidine derivatives from 20 to 38% compared with the natural substrate thymidine

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-

Organometallic [Re(CO)₃]⁺ and [Re(CO)₂(NO)]²⁺ Labeled Substrates for Human Thymidine Kinase 1

Thymidine was functionalized at position N3 with a tridentate iminodiacetic acid chelating system and a potentially tetradentate mercaptoethyliminodiacetic acid chelating system. Spacers of different lengths (ethyl and butyl) were introduced between the chelators and thymidine. The derivatives were labeled with the [Re(CO)2(NO)]2+ and [Re(CO)3]+ cores to give isostructural complexes with different overall charges. All complexes were analyzed by NMR, MS, and IR, and in addition, the X-ray structure of a [Re(CO)2(NO)]2+ labeled thymidine derivative functionalized at the N3 position was solved. The ligands incorporating the potentially tetradentate mercaptoethyliminodiacetic acid chelating system coordinated tridentately through iminodiacetic acid to both the [Re(CO)2(NO)]2+ core and the [Re(CO)3]+ core. This was surprising given that the reaction of [NEt4][Re(CO)2(NO)Br3] with the model ligand ethylmercaptoethyliminodiacetic acid led to dissociation of a carbonyl ligand and formation of a monocarbonyl−mononitrosyl complex, as confirmed by X-ray structure analysis. All of the organometallic thymidine derivatives were substrates for human thymidine kinase 1, a key enzyme in (cancer) cell proliferation. Neutral [Re(CO)2(NO)]2+ labeled thymidine derivatives revealed substrate activity ranging from 24 to 40%, and the structurally analogous anionic [Re(CO)3]+ labeled thymidine derivatives from 20 to 38% compared with the natural substrate thymidine

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-

Technetium Fluoride Trioxide, TcO₃F, Preparation and Properties^†

TcO4- in HF solution reacts to form Tc3O9F4- along with some TcO3F. Pure TcO3F is obtained if a mixture of HF/BiF5 is applied. TcO3F dimerizes in the solid state via fluoride bridges, similar to the structures of CrO2F2 and VOF3. TcO3F reacts in HF with AsF5 or SbF5 under formation of TcO2F2+As(Sb)F6-