Synthesis and Crystal Structures of (Phosphine)technetium(V) Complexes with Phenylimido and Phenyldiazenido Ligands Using the Precursor PhNHNHCO3

Rochon, Fernande D.; Melanson, R.; Kong, Pi-Chang

doi:10.1021/ic00113a006

Cited by 19 publications

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“…The chemistry of arylimido complexes of technetium has only scarcely been explored. It is dominated by Tc(VII) and Tc(VI) compounds with multiple, bulky 2,6-disubstituted phenylimido ligands, − and comparatively little is known about technetium(V) compounds with unsubstituted {NPh} 2– ligands. ,,− A key compound of the latter chemistry is [Tc(NPh)Cl 3 (PPh 3 ) 2 ], which is practically the only suitable starting material for the synthesis of other technetium phenylimides via ligand exchange procedures. Further lack of knowledge must be considered for technetium complexes with fluorine-substituted ligands.…”

Section: Results and Discussionmentioning

confidence: 99%

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

et al. 2019

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Reactions of (NBu4)[MOCl4] complexes (M = Tc or Re) with an excess of hexafluoroacetylacetone (Hhfac) give products with a composition of (NBu4)[MOCl3(hfac)] as bright yellow (Tc) or red (Re) solids. The products are stable as solids but rapidly decompose in solution. A number of related phenylimidorhenium(V) complexes were synthesized starting from [Re(NPhF)Cl3(PPh3)2], where (NPhF)2– is a para-fluorinated phenylimido ligand. Products with compositions of [Re(NPhF)Cl2(PPh3)(acac)], [Re(NPhF)Cl2(PPh3)(hfac)], [Re(NPhF)Cl2(PPh3)(tfac)], [Re(NPhF)Cl2(PPh3)(naphtfac)], and [Re(NPhF)Cl2(PPh3)(tbutfac)] (Hacac = acetylacetone, Htfac = trifluoroacetylacetone, Hnaphtfac = naphthoyltrifluoroacetylmethane, and Htbutfac = tert-butyroyltrifluoroacetylmethane) were isolated from reactions of the quite soluble [Re(NPhF)Cl3(PPh3)2] with the corresponding β-diketones and studied spectroscopically and by X-ray diffraction. The β-diketonates are coordinated in a meridional arrangement with the phenylimide. The formation of two isomers was detected for nonsymmetric β-diketones with a preference for the “equatorial” position for the more bulky substituents. Products with more than one chelating ligand were not obtained. The technetium complexes [Tc(NPhX)Cl3(PPh3)2] (X = p-F or p-CF3) were prepared from reactions of pertechnetate, PPh3, HCl, and substituted arylacetylhydrazines and isolated as green solids. They are sufficiently stable as solid but rapidly decompose in moist solvents upon hydrolysis of the Tc–N bonds. From reactions of [Tc(NPh)Cl3(PPh3)2] or [Tc(NPhF)Cl3(PPh3)2] in dry solvents, the complexes [Tc(NPh)Cl2(PPh3)(hfac)] and [Tc(NPhF)Cl2(PPh3)(hfac)] were prepared and isolated in crystalline form. An X-ray diffraction study shows that fluorination of the para position of the phenylimido ligand results in a slight lengthening of all bonds in the coordination sphere of technetium.

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Section: Results and Discussionmentioning

confidence: 99%

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

et al. 2019

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“…In these compounds extended delocalization of the electronic density is warranted by the planar five-membered ring through the π-network system. Also η 1 -hydrazido(3−) groups, frequently referred to as metal−diazenido units, show multiple Tc−N bond distances in the identical 1.76−1.78 Å narrow range − (Table ). The strict analogy in the M−N bond distances along with the diamagnetism shown in solution for both linear and chelated hydrazido(3−) complexes are in agreement with the metal exhibiting a low-spin d 2 configuration typical of Tc(V) and Re(V) species …”

Section: Discussionmentioning

confidence: 99%

Chelated Hydrazido(3−)rhenium(V) Complexes: On the Way to the Nitrido−M(V) Core (M = Tc, Re)

et al. 2002

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Neutral and asymmetrical hydrazido(3-)rhenium(V) heterocomplexes of the type [Re(eta(2)-L(4))(L(n))(PPh(3))] (eta(2)-L(4) = NNC(SCH(3))S; H(2)L(1) = S-methyl beta-N-((2-hydroxyphenyl)ethylidene)dithiocarbazate, 1, H(2)L(2) = S-methyl beta-N-((2-hydroxyphenyl)methylidene)dithiocarbazate, 2) are prepared via ligand-exchange reactions in ethanolic solutions starting from [Re(V)(O)Cl(4)](-) in the presence of PPh(3) or from [Re(V)(O)Cl(3)(PPh(3))(2)]. The distorted octahedral coordination sphere of these compounds is saturated by a chelated hydrazido group, a facially ligated ONS Schiff base, and PPh(3). Reduction-substitution reactions starting from [NH(4)][Re(VII)O(4)] in acidic ethanolic mixtures containing PPh(3) and H(2)L(n) (or its dithiocarbazic acid precursor H(3)L(4)) produce another example of chelated hydrazido(3-) rhenium(V) derivative, namely [Re(eta(2)-L(4))Cl(2)(PPh(3))(2)], 3. On the contrary, the N-methyl-substituted dithiocarbazic acid H(2)L(3) reacts with perrhenate to give the known nitrido complex [Re(N)Cl(2)(PPh(3))(2)]. Rhenium(V) complexes incorporating the robust eta(2)-hydrazido moiety represent key intermediates helpful for the comprehension of the reaction pathway which generates nitridorhenium(V) species starting from oxo precursors. An essential requirement for the stabilization of such chelated hydrazido-Re(V) units is the triple deprotonation at the hydrazine nitrogens, thereby providing efficient pi-electron circulation in the resulting five-membered ring. The thermal stability of these units is affected by the nature of the anchoring donor, thione sulfur ensuring stronger chelation than nitrogen and oxygen. The eta(2)-hydrazido complexes are characterized by conventional physicochemical techniques, including the X-ray crystal structure determination of 1 and 3.

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“…We decided to synthesize such Tc compounds with phosphines less bulky than PPh 3 . A similar reaction with PMePh 2 produced the expected compound Tc(NPh)(PMePh 2 ) 2 X 3 . When PMe 2 Ph was used, the reaction was quite different.…”

Section: Introductionmentioning

confidence: 94%

Syntheses of New Ionic Technetium(III) Complexes Containing Four Monodentate Phosphine Ligands. Crystal Structures of trans-[Tc(PMe₂Ph)₄Cl₂]PF₆, trans-[Tc(PMe₃)₄Cl₂]BPh₄, and trans-[Tc(PMe₃)₄Cl₂]PF₆

Rochon

Kong

2000

Inorg. Chem.

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New ionic technetium complexes of the type trans-[Tc(PR3)4Cl2]+ are synthesized by various methods. The simplest method is the reaction of [TcO4]- with the phosphine in methanol in the presence of a chloride salt. Compounds containing PMe2Ph and PMe3 are synthesized and characterized by crystallographic methods. The complexes containing the less bulky phosphine can be prepared from complexes containing the bulker phosphine. The compounds are paramagnetic, with two unpaired electrons. The complexes studied by X-ray diffraction methods are the trans isomers. [Tc(PMe2Ph)4Cl2]PF6 crystallizes in the monoclinic space group P2(1)/c, with a = 11.511(2) A, b = 26.713(7) A, c = 12.688(3) A, beta = 92.79(1) degrees, Z = 4, and R1 = 0.0574. [Tc(PMe3)4Cl2]BPh4 (II) crystallizes in the orthorhombic space group Pbcn, with a = 18.213(5) A, b = 22.950(5) A, c = 19.428(6) A, Z = 8, and R1 = 0.0691. [Tc(PMe3)4Cl2]PF6 crystallizes in the monoclinic space group P2(1)/c, with a = 18.152(7) A, b = 16.838(9) A, c = 18.090(6) A, beta = 106.63(1) degrees, Z = 8, and R1 = 0.0670. The compounds all have octahedral coordination, but an important tetrahedral deformation of the plane containing the Tc and the four P atoms is observed in each case. In II, the two independent Tc atoms are both located on 2-fold axes.

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Synthesis and Crystal Structures of (Phosphine)technetium(V) Complexes with Phenylimido and Phenyldiazenido Ligands Using the Precursor PhNHNHCO3

Cited by 19 publications

References 4 publications

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

Chelated Hydrazido(3−)rhenium(V) Complexes: On the Way to the Nitrido−M(V) Core (M = Tc, Re)

Syntheses of New Ionic Technetium(III) Complexes Containing Four Monodentate Phosphine Ligands. Crystal Structures of trans-[Tc(PMe₂Ph)₄Cl₂]PF₆, trans-[Tc(PMe₃)₄Cl₂]BPh₄, and trans-[Tc(PMe₃)₄Cl₂]PF₆

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Synthesis and Crystal Structures of (Phosphine)technetium(V) Complexes with Phenylimido and Phenyldiazenido Ligands Using the Precursor PhNHNHCO3

Cited by 19 publications

References 4 publications

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

Complexes of Technetium(V) and Rhenium(V) with β-Diketonates

Chelated Hydrazido(3−)rhenium(V) Complexes: On the Way to the Nitrido−M(V) Core (M = Tc, Re)

Syntheses of New Ionic Technetium(III) Complexes Containing Four Monodentate Phosphine Ligands. Crystal Structures of trans-[Tc(PMe2Ph)4Cl2]PF6, trans-[Tc(PMe3)4Cl2]BPh4, and trans-[Tc(PMe3)4Cl2]PF6

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Syntheses of New Ionic Technetium(III) Complexes Containing Four Monodentate Phosphine Ligands. Crystal Structures of trans-[Tc(PMe₂Ph)₄Cl₂]PF₆, trans-[Tc(PMe₃)₄Cl₂]BPh₄, and trans-[Tc(PMe₃)₄Cl₂]PF₆