Rhenium

Abram, Ulrich

doi:10.1016/b0-08-043748-6/04177-3

Cited by 62 publications

(75 citation statements)

References 1,078 publications

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“…This phenomenon is also observed in other rhenium complexes with similar coordination spheres and is assigned to delocalization of π-electron density from the oxo bonds to the trans-situated Re-O bonds. [9][10][11] The Re-O and Re-P bond lengths in 2 are similar to the values observed in 1. The distances between the rhenium atoms and the oxo ligands correspond to values normally found for Re=O double bonds in oxorhenium(V) complexes.…”

Section: Crystal Structures Of 1 Andsupporting

confidence: 59%

“…The distances between the rhenium atoms and the oxo ligands correspond to values normally found for Re=O double bonds in oxorhenium(V) complexes. 9 The bond lengths in the Hdhp -ligands in 1 and 2 do not differ significantly from the values found for the uncoordinated H 2 dhp, which is also protonated at the nitrogen atom. 1 The following resonance structures (a, b and c) should best represent the structure of the Hdhpligands in 1 and 2.…”

Section: Crystal Structures Of 1 Andmentioning

confidence: 78%

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Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Souza¹,

Fernandes²,

Deflon³

et al. 2006

J. Braz. Chem. Soc.

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Dois novos complexos zwitteriônicos de oxorrênio(V), [ReOCl 2 (Hdhp)(PPh 3 )] (1) e [ReOBr 2 (Hdhp)(PPh 3 )] (2) (H 2 dhp = 2,3-dihidroxipiridina), foram sintetizados e caracterizados por espectroscopia de absorção no infravermelho, ressonância magnética nuclear de 1 H e 31 P, análise elementar e determinação da estrutura cristalina e molecular por difração de raios X em monocristais. Os complexos apresentam geometria de coordenação octaédrica bastante distorcida, com os dois ligantes haletos arranjados em posições cis equatoriais, o ligante trifenilfosfina em posição trans a um dos haletos e o ligante Hdhp -coordenado de forma bidentada através de seus átomos de oxigênio, sendo um em posição trans ao ligante oxo e o outro em posição trans com relação ao outro haleto. Este ligante tem seu átomo de nitrogênio protonado. Os compostos 1 e 2 apresentam empacotamento cristalino bastante diferente, influenciado em ambos os casos por ligações de hidrogênio intermoleculares dos tipos N-H⋅⋅⋅X (X = Cl, Br) e N-H⋅⋅⋅O.Two novel zwitterionic oxorhenium(V) complexes, [ReOCl 2 (Hdhp)(PPh 3 )] (1) and [ReOBr 2 (Hdhp)(PPh 3 )] (2) (H 2 dhp = 2,3-dihydroxypyridine), were synthesized and characterized by infrared spectroscopy, 1 H and 31 P nuclear magnetic resonance, elemental analysis and crystal and molecular structure determination by X-ray diffraction on single crystals. Both complexes show distorted octahedral coordination geometry, with the halide ligands arranged in equatorial cis positions, the triphenylphosphine ligand in a trans position to one of the halides and the Hdhp -ligand coordinated in a bidentate form through its oxygen atoms, one in trans position to the oxo-ligand and the other in trans position to the second halide. The nitrogen atom of this ligand is protonated. Compounds 1 and 2 show quite different crystal packing, both influenced by hydrogen bonds of the types N-H⋅⋅⋅X (X = Cl, Br) and N-H⋅⋅⋅O.Keywords: oxorhenium(V), zwitterionic complexes, 2,3-dihydroxypyridine IntroductionThe ability of 2,3-dihydroxypyridine (H 2 dhp) to act as a chelating ligand is well known. Previous X-ray diffraction studies showed a bidentate coordination via the oxygen atoms, as Hdhp -, in complexes with the trivalent ions Al 3+ , Cr 3+ and Fe 3+ . The pyridine nitrogen atoms in these examples remain protonated, resulting in zwitterionic structures. 1,2 To the best of our knowledge no rhenium complex was reported so far involving the Hdhp -anion as a ligand. In a recent work we described new zwitterionic rhenium complexes containing 2-hydroxypyridine as ligand. 3 This work describes the synthesis, characterization and the X-ray crystal structure of novel rhenium complexes with Hdhp -ligands. The zwitterionic [ReOX 2 (Hdhp) (PPh 3 )] (X = Cl, Br) complexes contain monoanionic, chelating Hdhp -ligands, which are coordinated via their oxygen atoms. They formally possess a positive charge at the protonated nitrogen atom and a negative charge at the rhenium(V) center. 1579 Souza et al. Vol. 17, No. 8, 2006 Experimental Reagents and...

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Section: Crystal Structures Of 1 Andsupporting

confidence: 59%

Section: Crystal Structures Of 1 Andmentioning

confidence: 78%

Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Souza¹,

Fernandes²,

Deflon³

et al. 2006

J. Braz. Chem. Soc.

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“…The Re=O distances of 1.662(4) and 1.681(2) Å are in the expected range of rhenium-oxygen double bonds. [17] Figure 2. Ellipsoid representation of the molecular structure of 4a.…”

Section: Resultsmentioning

confidence: 98%

“…Such side reactions, which finally yield rhenium(III) complexes, are common when phosphanes are present. [17] The mixed complexes can be also prepared in good yield in one-pot reactions starting from (NBu 4 ] (path D). The yields of such reactions are not significantly lower than those following path A.…”

Section: Resultsmentioning

confidence: 98%

Mixed‐Ligand Complexes of Technetium and Rhenium with Tridentate Benzamidines and Bidentate Benzoylthioureas

2009

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Mixed‐ligand complexes of technetium(V) or rhenium(V) containing tridentate N‐[(dialkylamino)(thiocarbonyl)]benzamidine (H2L1) and bidentate N,N‐dialkyl‐N′‐benzoylthiourea (HL2) ligands were formed in high yields when (NBu4)[MOCl4] (M = Tc or Re) or [ReOCl3(PPh3)2] was treated with mixtures of the proligands. Other approaches for the synthesis of the products are reactions of [MOCl(L1)] complexes with HL2 or compounds of the composition [ReOCl2(PPh3)(L2)] with H2L1. The resulting air‐stable [MO(L1)(L2)] complexes possess potential for the development of metal‐based radiopharmaceuticals. [TcO(L1)(L2)] complexes are readily reduced by PPh3 with formation of [Tc(L1)(L2)(PPh3)]. The resulting TcIII complexes undergo two almost‐reversible oxidation steps corresponding to one‐electron transfer processes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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“…Rhenium(IV) is a 5d 3 ion that usually forms inert, relatively stable, octahedral complexes. [8] The high value of the spin-orbit coupling constant of around 1000 cm -1 for the free ion [9] is the main factor responsible for its large magnetic anisotropy. In fact, the combination of spin-orbit coupling and low molecular symmetry explains the SMM behaviour of even mononuclear Re IV compounds, as in the case of the recently reported (NBu 4 ) 2 [ReBr 4 (ox)].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear Re^IVM^II Complexes Based on the Robust [ReCl₅(pyzCOO)]^2– Unit (pyzCOO = 2‐pyrazinecarboxylate)

et al. 2016

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Rhenium

Cited by 62 publications

References 1,078 publications

Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Mixed‐Ligand Complexes of Technetium and Rhenium with Tridentate Benzamidines and Bidentate Benzoylthioureas

Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear Re^IVM^II Complexes Based on the Robust [ReCl₅(pyzCOO)]^2– Unit (pyzCOO = 2‐pyrazinecarboxylate)

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Rhenium

Cited by 62 publications

References 1,078 publications

Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Novel zwitterionic oxorhenium(V) complexes: synthesis, characterization and crystal structure of [ReOX2(Hdhp)(PPh3)] (X = Cl, Br; H2dhp = 2,3-dihydroxypyridine)

Mixed‐Ligand Complexes of Technetium and Rhenium with Tridentate Benzamidines and Bidentate Benzoylthioureas

Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear ReIVMII Complexes Based on the Robust [ReCl5(pyzCOO)]2– Unit (pyzCOO = 2‐pyrazinecarboxylate)

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Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear Re^IVM^II Complexes Based on the Robust [ReCl₅(pyzCOO)]^2– Unit (pyzCOO = 2‐pyrazinecarboxylate)