Theranostics is a field of nuclear medicine which uses the same targeting vector and chelating system for both a diagnostic and therapeutic radionuclide, allowing for uniformity in imaging and treatment. This growing field requires the development of more flexible chelate systems that permit novel targeting strategies. Toward this end, a multimodal architecture has been realized, making use of a phosphazene-based core and click chemistry to achieve a flexible and customizable scaffold.
View Article and Find Full Text PDFCarbon capture has been an important topic of the twenty-first century because of the elevating carbon dioxide (CO) levels in the atmosphere. CO in the atmosphere is above 420 parts per million (ppm) as of 2022, 70 ppm higher than 50 years ago. Carbon capture research and development has mostly been centered around higher concentration flue gas streams.
View Article and Find Full Text PDFRationale: The selective separation of the minor actinides (Am, Cm) from the lanthanides is a topic of ongoing nuclear fuel cycle research, and dithiophosphinic acids are candidate ligands in these processes. Ligand instability has been noted under radiolytic and harsh acid conditions but explicit degradation pathways for ligands such as bis(2,4,4-trimethylpentyl)-dithiophosphinic acid (CyxH), the major compound in the commercial product Cyanex 301, have been elusive.
Methods: Organic solutions of CyxH were contacted with aqueous solutions of HNO(3), and their degradation was studied by analyzing samples from these experiments by direct infusion electrospray ionization mass spectrometry.
Synthetic routes to alkyl and aryl substituted dithiophosphinate salts that contain non-coordinating PPh(4)(+) counter cations are reported. In general, these compounds can be prepared via a multi-step procedure that starts with reacting secondary phosphines, i.e.
View Article and Find Full Text PDFA synthetic route for the formation of 2-[bis(2-trifluoromethylphenyl)phosphinoylmethyl]pyridine N-oxide (1c) and 2-[bis(3,5-trifluoromethylphenyl)phosphinoylmethyl]pyridine N-oxide (1d) was developed and the new ligands characterized by spectroscopic methods and single-crystal X-ray diffraction analyses. The coordination chemistry of 1c was examined with Yb(NO3)3 and the molecular structure of one complex, [Yb(1c)(NO3)3(DMF)].DMF.
View Article and Find Full Text PDFPhosphinoyl Grignard-based substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation of the intermediate 2,6-bis(phosphinoyl)methylpyridine compounds with mCPBA give the target trifunctional ligands 2,6-bis[bis(2-trifluoromethylphenyl)phosphinoylmethyl]pyridine 1-oxide (2a) and 2,6-bis[bis(3,5-bis(trifluoromethyl)phenyl)phosphinoylmethyl]pyridine 1-oxide (2b) in high yields. The ligands have been spectroscopically characterized, the molecular structures confirmed by single crystal X-ray diffraction methods, and the coordination chemistry surveyed with lanthanide nitrates. Single crystal X-ray diffraction analyses are described for the coordination complexes Nd(2a)(NO(3))(3), Nd(2a)(NO(3))(3) x (CH(3)CN)(0.
View Article and Find Full Text PDFDiphenyldithiophosphinate (DTP) ligands modified with electron-withdrawing trifluoromethyl (TFM) substitutents are of high interest because they have demonstrated potential for exceptional separation of Am (3+) from lanthanide (3+) cations. Specifically, the bis( ortho-TFM) (L 1 (-)) and ( ortho-TFM)( meta-TFM) (L 2 (-)) derivatives have shown excellent separation selectivity, while the bis( meta-TFM) (L 3 (-)) and unmodified DTP (L u (-)) did not. Factors responsible for selective coordination have been investigated using density functional theory (DFT) calculations in concert with competitive dissociation reactions in the gas phase.
View Article and Find Full Text PDFThe preparation of a large series of new N-silyl-P-alkylphosphoranimines and their (silylamino)phosphine precursors is reported. Oxidative bromination of the P-functional (silylamino)phosphines, (Me(3)Si)(2)NP(R)X [R = n-Pr, n-Bu, i-Pr, t-Bu; X = Br, OR' (R' = CH(2)CF(3), Ph)], occurred smoothly at 0 degrees C and afforded the desired P-bromophosphoranimines, Me(3)SiN=P(R)(X)Br. Nucleophilic substitution reactions of the P-dibromo members of this series with LiOR' gave the corresponding P-trifluoroethoxy- and P-phenoxyphosphoranimines, Me(3)SiN=P(R)(OR')(2) (R' = CH(2)CF(3), Ph).
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