Characterization of Tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) Cations

Edwards, David S.; Liu, Shuang; Poirier, Michael J.; Zhang, Zaihui; Webb, Gordon A.; Orvig, Chris

doi:10.1021/ic00102a042

Cited by 17 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bis(ligand) Complexes. Attempts to prepare tris(ligand) technetium complexes by the addition of 2−5 equiv of a reducing agent (sodium dithionite or sodium bisulfite) , to a basic aqueous methanol solution containing NH 4 TcO 4 and from 3 to 10 equiv of Hthoz were not successful. Over the trials performed, the primary product was invariably the black, insoluble TcO 2 · x H 2 O and no reduced metal−ligand complex was ever isolated.…”

Section: Resultsmentioning

confidence: 99%

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

et al. 1996

Self Cite

View full text Add to dashboard Cite

Attempts to prepare tris(ligand) metal complexes of technetium in intermediate oxidation states with potentially bidentate oxazoline- and thiazoline-containing ligands were unsuccessful; when pertechnetate was reduced in the presence of excess ligand, TcO(2).xH(2)O was produced. Instead, by reaction with preformed M.O cores, a series of oxotechnetium(V) and oxorhenium(V) complexes of the formula MOXL(2) (M = Re, X = Br; M = Tc, X = Cl) and HL = 2-(2'-hydroxyphenyl)-2-oxazoline (Hoz), 2-(2'-hydroxy-3'-methylphenyl)-2-oxazoline (Hmoz), 2-(2'-hydroxyphenyl)-2-thiazoline (Hthoz), and 2-(2'-hydroxyphenyl)-2-benzoxazoline (Hhbo) have been prepared. These compounds have been characterized by a variety of techniques including single-crystal X-ray diffraction. Crystals of Hthoz (C(9)H(9)NOS) are monoclinic, with space group P2(1)/n, a = 7.5342(6) Å, b = 12.2187(6) Å, c = 9.3942(8) Å, beta = 94.233(7) degrees, and Z = 4; those of TcOCl(thoz)(2) (C(18)H(16)ClN(2)O(3)S(2)Tc) are monoclinic, with space group P2(1)/n, a = 16.506(1) Å, b = 7.664(1) Å, c = 16.3216(6) Å, beta = 111.154(4) degrees, and Z = 4; those of ReOBr(oz)(2) (C(18)H(16)BrN(2)O(5)Re) are orthorhombic, with space group Pbca, a = 12.864(2) Å, b = 25.369(2) Å, c = 11.025(2) Å, and Z = 8. The structures were solved by direct (Hthoz) or Patterson (metal complexes) methods and were refined by full-matrix least-squares procedures to R = 0.033, 0.032, and 0.028 for 1600, 3152, and 2651 reflections with I >/= 3sigma(I), respectively. In the two complexes, the geometry around the metals is distorted octahedral with the halide ligands in each bound cis, and one phenolate oxygen from one ligand in each bound trans to the metal-oxo linkage. In ReOBr(oz)(2), the two oxazoline nitrogens are coordinated trans to one another; in TcOCl(thoz)(2), the two thiazoline nitrogens are found cis to one another.

show abstract

Section: Resultsmentioning

confidence: 99%

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

et al. 1996

Self Cite

View full text Add to dashboard Cite

show abstract

“…Metal complexes of 3,4-HPs have been studied as metallopharmaceuticals. For example, neutral vanadyl(IV) complexes of hydroxypyrones and HPs have shown promising results as orally active insulin-enhancing agents. − Zn(II) and Tin(II) complexes of HPs are useful in dental care formulations, while their 67 Ga, 111 In, and 99m Tc complexes have been proposed as radiopharmaceuticals for scintigraphic imaging. − However, there is very little information available about their Mn(II) and Mn(III) complexes. We are interested in DMHP and related 3,4-HPs for their potential as Mn chelators for the treatment of chronic Mn toxicity.…”

Section: Discussionmentioning

confidence: 99%

Synthesis, Characterization, and Structures of Mn(DMHP)₃·12H₂O and Mn(DMHP)₂Cl·0.5H₂O

Hsieh

Liu

2005

Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

This report describes the synthesis, characterization, and X-ray crystal structures of two Mn(III) complexes, Mn(DMHP)3 x 12H2O and Mn(DMHP)2Cl x 0.5H2O (DMHP = 1,2-dimethyl-3-hydroxy-4-pyridinone). Mn(DMHP)2Cl was prepared from the reaction of Mn(II) chloride with 2 equiv of DMHP under reflux in the presence of triethylamine. Mn(DMHP)3 was obtained by reacting Mn(II) acetate with 3 equiv of DMHP in the presence of sodium acetate. Mn(DMHP)3 could also be prepared by reacting Mn(OAc)3 x 2H2O with 3 equiv of DMHP in the presence of triethylamine. Both Mn(III) complexes have been characterized by elemental analysis, infrared spectroscopy, electronic paramagnetic resonance, electrospray ionization spectroscopy, electrochemical method, and X-ray crystallography. The X-ray crystal structure of Mn(DMHP)2Cl x 0.5H2O revealed a rare example of five-coordinated Mn(III) complexes with two bidentate ligands and a square pyramidal coordination geometry. Surprisingly, the average Mn-O (hydroxy) bond distance in Mn(DMHP)2Cl x 0.5H2O is approximately 0.025 A longer than that of the average Mn-O (carbonyl) bond, suggesting an extensive delocalization of electrons in the two pyridinone rings. The structure of Mn(DMHP)3 x 12H2O, a rare example of six-coordinate high-spin Mn(III) complexes without Jahn-Teller distortion, is isostructural to M(DMHP)3 x 12H2O (M = Al, Ga, Fe, and In). The electrochemical data for Mn(DMHP)3 suggests that the Mn(III) oxidation state is highly stabilized by three DMHP ligands. DMHP has the potential as a chelator for the removal of excess intracellular Mn and the treatment of chronic Mn toxicity.

show abstract

“…111 A series of these water soluble, hydrolytically stable monocations with moderate lipophilicity was tested in rabbits and mice as potential radiopharmaceuticals. 112 The 1-p-methoxyphenyl and 1-cyclohexyl N-substituents showed evidence of particularly high kidney uptake and retention of the 99m Tc radionuclide.…”

Section: Hydroxypyrones and Hydroxypyridinones As Binders Of Gallium ...mentioning

confidence: 97%

Metal complexes of maltol and close analogues in medicinal inorganic chemistry

2006

Self Cite

View full text Add to dashboard Cite

The family of hydroxypyrones and close congeners, the hydroxypyridinones, is a particularly versatile class of ligands. The most widely investigated for medicinal applications are the 3-hydroxy-4-pyrones and the 1,2- 3,2- and 3,4-hydroxypyridinones. Key features of these ligands are: a six-membered ring, with a ring N or O atom either ortho or para to a ketone group, and two ortho exocyclic oxygen atoms. Readily functionalizable, the hydroxypyrones and hydroxypyridinones allow one to achieve a range of di- and trivalent metallocomplex stabilities and can include tissue or molecular targeting features by design. Research over the past several decades has greatly expanded the array of ligands that are the subject of this critical review. Ligand applications as diverse as iron removal or supplementation, contrast agents in imaging applications, and mobilization of undesirable excess metal ions will be surveyed herein.

show abstract

Characterization of Tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) Cations

Cited by 17 publications

References 0 publications

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

Synthesis, Characterization, and Structures of Mn(DMHP)₃·12H₂O and Mn(DMHP)₂Cl·0.5H₂O

Metal complexes of maltol and close analogues in medicinal inorganic chemistry

Contact Info

Product

Resources

About

Characterization of Tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) Cations

Cited by 17 publications

References 0 publications

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

Bis(ligand) Rhenium(V) and Technetium(V) Complexes of Two Naturally Occurring Binding Moieties (Oxazoline and Thiazoline)

Synthesis, Characterization, and Structures of Mn(DMHP)3·12H2O and Mn(DMHP)2Cl·0.5H2O

Metal complexes of maltol and close analogues in medicinal inorganic chemistry

Contact Info

Product

Resources

About

Synthesis, Characterization, and Structures of Mn(DMHP)₃·12H₂O and Mn(DMHP)₂Cl·0.5H₂O