Improvements in the Preparation of Cyclopentadienyl Thallium and Methylcyclopentadienylthallium and in Their Use in Organometallic Chemistry

Neto, Alberto Federman; Borges, Áurea Donizete Lanchote; Miller, Joseph; Darin, Vitor André

doi:10.1080/00945719708000159

Cited by 11 publications

(6 citation statements)

References 23 publications

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“…For crossover experiments (see below), selectively deuterated analogues of 1 b 2 and 2 a 2 were synthesized. As shown in Scheme , base‐catalyzed perdeuteration of [{RhCp*Cl 2 } 2 ]16 according to the literature17 was followed by treatment with freshly sublimed TlCp;18 subsequent addition of aqueous NH 4 + PF 6 − gave the Cp*‐deuterated salt 1 b′ + PF 6 − . An analogue with cyclopentadienyl deuteration, 1 b′′ + , was obtained in an analogous fashion using [{RhCp*Cl 2 } 2 ]16 and Tl(C 5 D 5 ), which was prepared from deuterated cyclopentadiene19 using a modification of literature procedures 20.…”

Section: Resultsmentioning

confidence: 99%

“…[D 6 ]Benzene and [D 8 ]toluene were dried over Na–K alloy and [D 5 ]chlorobenzene was purified using CaH 2 . 1 b + PF 6 − ,15a [{RhCp*Cl 2 } 2 ],16 TlCp,18 [RuCp*(NCMe) 3 ] + PF 6 − ,22 2 a + PF 6 − ,15b 2 a 2 ,8a, 9a 2 b 2 ,9a and 2 c 2 8b were synthesized according to literature methods. 6,13‐Bis[tri(isopropyl)silylethynyl]pentacene ( 3 ) was purchased from Aldrich and used without further purification.…”

Section: Methodsmentioning

confidence: 99%

“…[D 6 ]Benzene and [D 8 ]toluene were dried over Na-K alloy and [D 5 ]chlorobenzene was purified using CaH 2 . 1 b + PF 6 À , [15a] [{RhCp*Cl 2 } 2 ], [16] TlCp, [18] [RuCp*-A C H T U N G T R E N N U N G (NCMe) 3 ] + PF 6 À , [22] 2 a + PF 6 À , [15b] 2 a 2 , [8a, 9a] 2 b 2 , [9a] and 2 c 2 [8b] were synthesized according to literature methods. 6,13-…”

Section: Methodsmentioning

confidence: 99%

“…For crossover experiments (see below), selectively deuterated analogues of 1 b 2 and 2 a 2 were synthesized. As shown in Scheme 1, base-catalyzed perdeuteration of [{RhCp*Cl 2 } 2 ] [16] according to the literature [17] was followed by treatment with freshly sublimed TlCp; [18] subsequent addition of aqueous NH 4 + PF 6 À gave the Cp*deuterated salt 1 b' + PF 6…”

Section: Synthesis: the Dimers 1 Bmentioning

confidence: 99%

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n‐Doping of Organic Electronic Materials Using Air‐Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds

Guo

Mohapatra

Romanov

et al. 2012

Chemistry A European J

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Several 19-electron sandwich compounds are known to exist as "2×18-electron" dimers. Recently it has been shown that, despite their air stability in the solid state, some of these dimers act as powerful reductants when co-deposited from either the gas phase or from solution and that this behavior can be useful in n-doping materials for organic electronics, including compounds with moderate electron affinities, such as 6,13-bis[tri(isopropyl)silylethynyl]pentacene (3). This paper addresses the mechanisms by which the dimers of 1,2,3,4,5-pentamethylrhodocene (1 b(2)), (pentamethylcyclopentadienyl)(1,3,5-trialkylbenzene)ruthenium (alkyl=Me, 2 a(2); alkyl=Et, 2 b(2)), and (pentamethylcyclopentadienyl)(benzene)iron (2 c(2)) react with 3 in solution. Vis/NIR and NMR spectroscopy, and X-ray crystallography indicate that the products of these solution reactions are 3(·-) salts of the monomeric sandwich cations. Vis/NIR kinetic studies for the Group 8 dimers are consistent with a mechanism whereby an endergonic electron transfer from the dimer to 3 is followed by rapid cleavage of the dimer cation. NMR crossover experiments with partially deuterated derivatives suggest that the C-C bond in the 1 b(2) dimer is much more readily broken than that in 2 a(2); consistent with this observation, Vis/NIR kinetic measurements suggest that the solution reduction of 3 by 1 b(2) can occur by both the mechanism established for the Group 8 species and by a mechanism in which an endergonic dissociation of the dimer is followed by rapid electron transfer from monomeric 1 b to 3.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Synthesis: the Dimers 1 Bmentioning

confidence: 99%

See 2 more Smart Citations

n‐Doping of Organic Electronic Materials Using Air‐Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds

Guo

Mohapatra

Romanov

et al. 2012

Chemistry A European J

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“…Hexafluorophosphate salts of the 18-electron monomeric cations – 1 + PF 6 – , 2 + PF 6 – , 3a + PF 6 – , 3b + PF 6 – , and 4 + PF 6 –12 – were synthesized as previously described. Cyclic voltammetry was performed using a Pine Research Instruments (Durham, NC) WaveNow potentiostat.…”

Section: Methodsmentioning

confidence: 99%

Dimers of Nineteen-Electron Sandwich Compounds: An Electrochemical Study of the Kinetics of Their Formation

et al. 2015

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Rate constants for the dimerization of FeCp*C 6 H 6 , RuCp*mes, RhCp 2 , RhCp*Cp, and IrCp*Cp (Cp* = pentamethylcyclopentadienyl; mes = 1,3,5-trimethylbenzene; Cp = cyclopentadienyl) have been investigated by cyclic voltammetry. Rates increased in the order FeCp*C 6 H 6 ≪ RhCp*Cp ∼ RhCp 2 < RuCp*mes and IrCp*Cp. The difference in rates between the Rh compounds and the Ru and Ir species is consistent with the thermodynamic driving forces for dimerization estimated from DFT calculations. However, the sluggish dimerization of FeCp*C 6 H 6 cannot be rationalized with purely thermodynamic considerations and may be attributable to the very different spin-density distribution in this species. On the basis of the activation parameters for dimerization, determined by variable temperature cyclic voltammetry, and those previously determined for dissociation of the corresponding dimer, the free energy of dimerization for the RhCp*Cp monomer was estimated to be −43 kJ mol −1 , and the effective redox potential for the RhCp*Cp + / 0.5(RhCp*Cp) 2 couple was estimated as −1.84 V vs FeCp 2 + /FeCp 2 .

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Thallium: Organometallic ChemistryBased in part on the article Thallium: Organometallic Chemistry by William S. Rees, Jr. & Gertrud Kräuter which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.

Pike¹

2005

Encyclopedia of Inorganic Chemistry

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The organometallic chemistry of thallium(I) is dominated by cyclopentadienyl complexes. These may be polymeric through bridging Cp arrangements or oligomeric as a result of Tl⋯Tl contacts. ThCp complexes are easily prepared and are highly useful Cp‐transfer agents. There are two known Tl(I) organometallics with direct TlC σ‐bonds; one is monomeric and the other is tetrameric due to Tl⋯Tl contact. A variety of Tl(I) π‐complexes are recognized. Bonding in the latter tends to be fairly weak. Two R 2 TlTlR 2 dimers (R = silyl group) are known, but no such Tl(II) complexes are known for carbon ligands. The chemistry of organothallium(III) compounds is more extensive, encompassing such species as R 3 Tl, R 2 TlX, RTlX 2 (X = anionic ligand), and complexes of these species with additional ligands. A wide array of X‐ray crystal structures for Tl(III) complexes reveals monomeric, oligomeric, and polymeric arrangements, with bridging ligands being very common. Thallium compounds are highly toxic and should be handled with great care. Volatile Tl species are of use in the chemical‐vapor deposition of superconducting phases. Finally, Tl(III) salts are fairly important reagents in organic syntheses, especially in oxidations and in ring expansion and contraction reactions.

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Improvements in the Preparation of Cyclopentadienyl Thallium and Methylcyclopentadienylthallium and in Their Use in Organometallic Chemistry

Abstract: Improved preparation methods of cyclopentadienylthallium and methylcyclopentadienylthallium, giving quantitative yields and incorporating ultrasound techniques, are described. Their use as starting materials for a wide range of organometallic syntheses is discussed and demonstrated.

Cited by 11 publications

References 23 publications

n‐Doping of Organic Electronic Materials Using Air‐Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds

n‐Doping of Organic Electronic Materials Using Air‐Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds

Dimers of Nineteen-Electron Sandwich Compounds: An Electrochemical Study of the Kinetics of Their Formation

Thallium: Organometallic ChemistryBased in part on the article Thallium: Organometallic Chemistry by William S. Rees, Jr. & Gertrud Kräuter which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.

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