Synthesis and characterization of technetium(<scp>V</scp>) oxo-complexes with quadridentate Schiff-base ligands: X-ray structures of µ-oxo-bis-{oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]technetium(<scp>V</scp>)} and chloro-oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]-technetium(<scp>V</scp>)

Bandoli, Giuliano; Nicolini, Marino; Mazzi, Ulderico; Refosco, Fiorenzo

doi:10.1039/dt9840002505

Cited by 55 publications

(34 citation statements)

References 4 publications

(5 reference statements)

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“…The N202 donor set is found in the equatorial plane relative to the Tc=O group in all three possible types of complexes (vide supra) (7,9 (6,7,24,25). No absorption bands could be assigned to VRew; the two weak absorption bands at 950 and 910 cm-' coincide with two moderate bands of the free ligands.…”

Section: N202 Complexesmentioning

confidence: 99%

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Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

Luo¹,

Liu²,

Rettig

et al. 1995

Can. J. Chem.

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The rhenium(V) and technetium(V) complexes: [ReO(apa)], [{ReO(epa)}2O], and [TcOCl(epa)] have been prepared from a potentially pentadentate N3O2 ligand, N,N′-3-azapentane-1,5-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4(3H)-dione) (H3apa), or a potentially tetradentate N2O2 ligand, N,N′-ethylene-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4(3H)-dione) (H2epa). The N2O2 complexes were synthesized in low yields. There was also evidence indicating that H2ppa, N,N′-propylene-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4(3H)-dione), hydrolyzed in the course of coordination, forms a rhenium complex of the bidentate monoprotic (O,O) dehydroacetate (dha−), [Re(dha)Cl2(OPPh3)(PPh3)]•EtOH. The structure of this complex was determined by X-ray crystallography. Crystals of [Re(dha)Cl2(OPPh3)(PPh3)] EtOH (C44H37Cl2O5P2Re•C2H6O) are monoclinic, a = 11.064(2), b = 24.167(2), c = 16.6687(8) Å, β = 98.779(7)°, Z = 4, space group P21/c. The structure was solved by the Patterson method and refined by full-matrix least-squares procedures to R = 0.030 and Rw = 0.025 for 6942 reflections with I ≥ 3σ(F2). Keywords: dehydroacetic acetate based Schiff base ligands, rhenium, technetium, N3O2 Schiff base, N2O2 Schiff base, oxygen transfer.

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Section: N202 Complexesmentioning

confidence: 99%

“…Some Re/Tc complexes of tetradentate (6)(7)(8)(9) and pentadentate (10, 11) Schiff base ligands have been studied. Most of the ligands are derived from salicylaldehyde; thus they have the disadvantage of producing lipophilic Tc complexes that tend to localize preferentially in the liver (4).…”

mentioning

confidence: 99%

Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

Luo¹,

Liu²,

Rettig

et al. 1995

Can. J. Chem.

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“…There are two different Tc-Cl linkages located cis and trans to the central Tc=O bond that are defined within the structure. [20,21] The trans Tc-Cl(2) linkage in K 2 [TcOCl 5 ] is one of the longest Tc-Cl bonds that has been reported for compounds with a Tc V =O core. Tc-Cl 2.3763(7) Å; av.…”

Section: Crystal Structure Of Dipotassium Oxopentachlorotechnetatementioning

confidence: 99%

X‐ray Crystallographic and First‐Principles Theoretical Studies of K₂[TcOCl₅] and UV/Vis Investigation of the [TcOCl₅]^2– and [TcOCl₄]^– Ions

et al. 2013

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Dipotassium pentachloridooxidotechnetate, K 2 [TcOCl 5 ], has been isolated as green single crystals by the dissolution of (NH 4 )TcO 4 in 12 M HCl at 0°C and careful precipitation with KCl. The structure of this compound was determined by single-crystal X-ray diffraction analysis [a = 13.0815(9), b = 9.8982(6), c = 6.7623(4) Å; V = 875.605 Å 3 , orthorhombic, Pnma, Z = 4] and compared with the corresponding molybd- IntroductionPentachloridooxidometallate(V) [MOCl 5 ] 2complex anions are formed with the transition metals V, Nb, Ta, Cr, Mo, W, Tc, and Re. They can also be precipitated as crystalline salts with the heavier alkali metals (i.e., K, Rb, and Cs) or other small monocationic counter ions, such as NH 4 + . [1][2][3][4] When precipitated as the caesium salt, these compounds crystallize in the cubic lattice with space group Fm3m, whereas with K + , Rb + , or NH 4 + , the orthorhombic Pnma structure is observed. Both the cubic and orthorhombic structures are based on close-packing of the [MOCl 5 ] 2anions with the cations located in the tetrahedral holes. [1] The combination of the strong M=O interactions and readily exchangeable chlorido ligands makes these six-coordinate compounds important precursors to a variety of polyatomic oxido-containing metal complexes. Technetium (Z = 43) is a transition-metal element of particular interest, primarily due to the synergy of its radiolytic properties and [a] 1097 enum and rhenium analogues. The structure of K 2 [TcOCl 5 ] was also investigated by density functional theory, and the results are in agreement with the crystallographic data. The oscillator strengths of the electronic transitions in the C 4v complex anions [TcOCl 5 ] 2and [TcOCl 4 ]were also calculated by using time-dependent density functional theory and compared with the experimental UV/Vis spectra.

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“…(benzoylacetoneimine) [46], N,N'-1,3-propylene-bis(salicylideneimine) [47], N,N'-1,2-phenylene-bis(salicylideneimine) [48] [49], N,N'-ethylene-bis(2-hydroxy-acetophenoneimine) [50], N,N'-ethylene-bis(2-hydroxy-benzophenoneimine) [51], N,N'-ethylene-bis(2-hydroxy-1-naphthylideneimine) [52], N,N'-ethylene-bis(5,5'-dinitro-salicylideneimine) [53]. Since a number of further ligands with incomplete analytical data are described, in the following we report here these data.…”

Section: Nn'-ethylene-bis(acetylacetoneimine) Nn'-ethylene-bismentioning

confidence: 99%

Salicylidene-imine-zirconium(IV) complexes in combination with methylalumoxane as catalysts for the conversion of hexa-1,5-diene: adjusting of the catalytic activity

Schweder¹,

Walther²,

Döhler³

et al. 1999

J. prakt. Chem.

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Over the last decade enormous efforts and progress have been made in the investigation of metallocene-type catalysts of group IV: The discovery that methylalumoxanes (MAO) promote the formation of highly active cationic species, the design of "single site" catalysts for the polymerization of 1-olefines, the isolation of cationic species involving [Cp 2 M-R] + cations, which are responsible for the catalytic reactivity, the tuning of the catalytic reactivity by adjusting the ligands, and the development of industrial processes are some examples for this rapidly growing field [1 -5].Most recently group IV metal complexes that contain inorganic donor sets have been to focus attention as potential catalysts [2, 6 -34]. However, the coordination chemistry and organometallic chemistry of these compounds is more complicated and much less developed than the metallocene chemistry. Especially, the understanding of the controlling effects of ligands containing an inorganic donor set in group IV metal catalysts is not well understood. This might be the most important problem in the development of new highly active and selective group IV catalysts containing anionic ancillary ligands having for example N or O donor atoms. Salicylidene-imine-Zirconium(IV) Complexes in Combination with Dedicated to Professor Egon Uhlig on the Occasion of his 70th BirthdayKeywords: Cyclizations, Schiff bases, Zirconium, Catalysis Abstract. A variety of substituted Schiff base complexes of the composition ("salen")ZrCl 2 (thf) (1 -21) were synthesized, with methylalumoxane ("MAO") activated and used for a systematic study of their catalytic activity towards hexa-1,5-diene ("salen": substituted salicylidene-ethylene-iminato ligands). Main product of the catalytic cycle is methylenecyclopentane. Dimers are only formed in minor amounts. The catalytic activity and selectivity of the Ziegler-Natta systems strongly depend on the nature and the position of the peripheric substituents in the Schiff base ligands. Electron-withdrawing substituents in para-position to the phenolato oxygen (5-position) decrease the catalytic activity. Improved activity andIn this paper we report on the catalytic conversion of hexa-1,5-diene by a number of MAO-activated (salicylidene-ethylene-imine)Zr(IV)(thf) complexes in which a N 2 -O 2 donor set is coordinated as four-dentate chelate ligand opening the possibility to study the electronic and steric influence of peripheric groups on the catalytic reactivity.Our aim was to get a deeper insight into the possibility to control the catalytic reactivity of the metal center depending on the coordinative environment. Since the catalytic conversion of hexa-1,5-diene was a slow reaction it was also possible to indicate the starting steps of the catalysis. Catalytic Reactions of (Salen)ZrCl 2 (thf)/MAO with Hexa-1,5-dieneFor the preparation of the Zr(IV) complexes 1 -21 the quadridentate Schiff base N,N'-ethylene-bis(salicylideneimine) ("salen") ligands were treated with two equivalents n-butyl-lithium to form the lithium salts. Re...

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Synthesis and characterization of technetium(V) oxo-complexes with quadridentate Schiff-base ligands: X-ray structures of µ-oxo-bis-{oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]technetium(V)} and chloro-oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]-technetium(V)

Cited by 55 publications

References 4 publications

Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

X‐ray Crystallographic and First‐Principles Theoretical Studies of K₂[TcOCl₅] and UV/Vis Investigation of the [TcOCl₅]^2– and [TcOCl₄]^– Ions

Salicylidene-imine-zirconium(IV) complexes in combination with methylalumoxane as catalysts for the conversion of hexa-1,5-diene: adjusting of the catalytic activity

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Synthesis and characterization of technetium(V) oxo-complexes with quadridentate Schiff-base ligands: X-ray structures of µ-oxo-bis-{oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]technetium(V)} and chloro-oxo[N,N′-propane-1,3-diylbis(salicylideneiminato)]-technetium(V)

Cited by 55 publications

References 4 publications

Rhenium and technetium complexes from pentadentate (N3O2) and tetradentate (N2O2) Schiff base ligands

Rhenium and technetium complexes from pentadentate (N3O2) and tetradentate (N2O2) Schiff base ligands

X‐ray Crystallographic and First‐Principles Theoretical Studies of K2[TcOCl5] and UV/Vis Investigation of the [TcOCl5]2– and [TcOCl4]– Ions

Salicylidene-imine-zirconium(IV) complexes in combination with methylalumoxane as catalysts for the conversion of hexa-1,5-diene: adjusting of the catalytic activity

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Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

Rhenium and technetium complexes from pentadentate (N₃O₂) and tetradentate (N₂O₂) Schiff base ligands

X‐ray Crystallographic and First‐Principles Theoretical Studies of K₂[TcOCl₅] and UV/Vis Investigation of the [TcOCl₅]^2– and [TcOCl₄]^– Ions