Synthesis and Characterisation of Molecular Bismuth Phosphorus Compounds Containing Bi<sub>2</sub> Units with Bi–Bi Single and Double Bonds

Hänisch, Carsten von; Nikolova, Donna

doi:10.1002/ejic.200600474

Cited by 37 publications

(29 citation statements)

References 19 publications

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“…The solid-state structure of 2 ( Figure 2, Table 1) resembles the only two other structurally characterized uncomplexed dibismuthenes in that it has a trans-bent core structure. [10,11,26] The molecule resides on a crystallographic centre of symmetry and displays a strictly anti-periplanar, trans-bent geometry of the C-Bi-Bi-C core. The Bi-Bi bond length of 2.8560(3) Å is significantly (5.5 %) shorter than the Bi-Bi distance in ArЈ(Cl)Bi-Bi(Cl)ArЈ (1) [11] This small difference may be a consequence of the higher steric repulsion between the much larger ArЈ ligands in 2.…”

Section: Resultsmentioning

confidence: 99%

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

Wolf

Fischer

et al. 2008

Eur J Inorg Chem

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The reactions of terphenylbismuth dihalides with various reducing agents were investigated. Attempted metathesis of Ar′BiCl2 [Ar′ = 2,6‐(2,6‐iPr2‐C6H3)2‐C6H3] with one equivalent of KSi(SiMe3)3 gave the 1,2‐dichlorodibismuthane Ar′(Cl)Bi–Bi(Cl)Ar′ (1) in 40 % yield. The reaction of Ar′BiCl2 (1) with the dianionic salt K2Si2(SiMe3)4 yielded the dibismuthene Ar′Bi=BiAr′ (2) in 72 %. The terphenylbismuth dihalides ArBiCl2 [Ar = 2,6‐(2,6‐iPr2‐C6H3)2‐C6H3 (Ar′), 2,6‐(2,4,6‐Me3‐C6H2)2‐C6H3 (Ar#)] were treated with Na2[Fe(CO)4] in THF to afford the iron dibismuthene complexes [Fe(CO)4(Bi2Ar′2)] (3) and [Fe(CO)4(Bi2Ar#2)] (4) in modest yields (25 and 15 % respectively). The compounds 1–4 were characterized by X‐ray crystallography and by spectroscopic methods (1H and 13C NMR, IR, and UV/Vis spectroscopy). The results show that reduction of the bismuth center is strongly preferred over salt metathesis chemistry due to the reducing power of the silanide and ferrate salts and the strength of the Bi=Bi bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

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Section: Resultsmentioning

confidence: 99%

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

Wolf

Fischer

et al. 2008

Eur J Inorg Chem

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“…Introduction of bulky groups, such as terphenyl [9] and delocalization have been found to be the key to stabilize heavy-element double bonds in low-coordinated reactive species. [4,20,21] A straight forward route to the desired 1,3diarsa-2,4-diaza-cyclo-butane-1,3-diyl [As(m-NTer)] 2 (2As) would appear to be to treat three equivalents of activated Mg (twofold excess) with 1As (Scheme 1) at ambient temperatures in thf (all manipulations were performed under argon). [22] A clean reaction occurred within 12 h as indicated by a color change of the initial yellow to a deep purple solution.…”

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confidence: 99%

An Arsenic–Nitrogen Biradicaloid: Synthesis, Properties, and Reactivity

et al. 2013

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Biradicals are molecules which contain two unpaired electrons in two nearly degenerate non-bonding molecular orbitals. [1] Both electrons can either be antiparallel forming an open-shell singlet state or parallel describing a triplet state. [2] As a result of the two unpaired electrons such biradicals are usually transient species during the process of bond breaking and making. Introduction of steric strain by bulky substituents to prevent bond formation or dimerization, delocalization, and substitution of carbon atoms by suitable main-group elements can lead to a considerable stabilization of such biradicals, however, at the expense of the biradical character, which decreases. Thus the designation of such stabilized species as biradicaloids seems to be more appropriate. [3, 4] Singlet biradicals commonly show a relatively small energy gap between their lowest energy singlet and triplet state. The stability of biradicals is increased by increasing the HOMO-LUMO gap leading to a larger singlet-triplet splitting, and lower occupation of the LUMO. [1] However, when the LUMO occupation reaches zero, a closed-shell singlet is finally obtained, and such species cannot be referred to as biradical or biradicaloid, respectively, anymore.Following our interest in the heterocyclic chemistry of Group 15 elements, [5] we studied the reaction of four-membered rings of the type [XE(m-NR)] 2 E = Group 15 element, X = halogen) containing alternating pnictogen(III) and nitrogen centers, with reducing agents such as [Cp 2 Ti(btmsa)] (Cp = h-C 5 H 5 , btmsa = bis(trimethylsilyl)acetylene, Me 3 Si-C C-SiMe 3 ), [6] [{Cp 2 TiCl} 2 ] or Mg. [7] Upon chloride abstraction and reduction (Scheme 1), such cyclo-1,3-dipnicta(III)-2,4diazanes [ClE(m-NR)] 2[8] with bulky substituents R (R = terphenyl = Ter = 2,6-Mes 2 C 6 H 3 , Mes = 2,4,6-Me 3 C 6 H 2 ) [9] should form remarkably tight ring structures of the type [E(m-NR)] 2 featuring two localized radical sites. The only known example, the [P(m-NR)] 2 biradicaloid, exhibits two radical centers in the

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“…A similar effect was described recently for noncyclic diphosphane [(tBuPh 2 Si) 2 P] 2 . [7] The Si 3 The 31 P NMR spectrum shows a singlet at δ = -188.3 ppm with two kinds of Si satellites. In the 29 Si NMR spectrum, two signals in the form of a triplet can be seen ( Figure 3).…”

Section: Resultsmentioning

confidence: 98%

Metalation and Oxidative Coupling of the Unique Cyclic Silylphosphanes (iPr₂Si)₃PH and (iPr₂Si)₄PH

2009

Self Cite

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The cyclic tetrasilaphosphane (iPr2Si)4PH (6) can be synthesised in five steps starting from diisopropylchlorsilane and [Li(DME)PH2]. Subsequent lithiation and oxidative coupling with dibromethane yields the diphosphane [(iPr2Si)4P]2(7). In an analogous manner the bicyclic diphosphane [(iPr2Si)3P]2 (3) can be obtained from the cyclic trisilaphosphane (iPr2Si)3PH (1). Moreover, the reaction of 1 with [W(CO)5THF] yields the Lewis acid–base complex [(iPr2Si)3P(H)W(CO)5] (2), and the trimeric lithiumphoshpanide [(iPr2Si)4PLi]3 (8) occurs from the reaction of 6 with nBuLi in heptane. All intermediate and final products are characterised by multinuclear NMR spectroscopy, IR spectroscopy and mass spectrometry. Furthermore, the crystal structures determined by X‐ray diffraction are described for compounds 2, 3, 6, 7 and 8.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Synthesis and Characterisation of Molecular Bismuth Phosphorus Compounds Containing Bi₂ Units with Bi–Bi Single and Double Bonds

Cited by 37 publications

References 19 publications

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

An Arsenic–Nitrogen Biradicaloid: Synthesis, Properties, and Reactivity

Metalation and Oxidative Coupling of the Unique Cyclic Silylphosphanes (iPr₂Si)₃PH and (iPr₂Si)₄PH

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Synthesis and Characterisation of Molecular Bismuth Phosphorus Compounds Containing Bi2 Units with Bi–Bi Single and Double Bonds

Cited by 37 publications

References 19 publications

Reactions of Terphenylbismuth Dihalides with KSi(SiMe3)3, K2Si2(SiMe3)4 and Na2[Fe(CO)]4: Reduction vs. Metathesis

Reactions of Terphenylbismuth Dihalides with KSi(SiMe3)3, K2Si2(SiMe3)4 and Na2[Fe(CO)]4: Reduction vs. Metathesis

An Arsenic–Nitrogen Biradicaloid: Synthesis, Properties, and Reactivity

Metalation and Oxidative Coupling of the Unique Cyclic Silylphosphanes (iPr2Si)3PH and (iPr2Si)4PH

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Synthesis and Characterisation of Molecular Bismuth Phosphorus Compounds Containing Bi₂ Units with Bi–Bi Single and Double Bonds

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

Reactions of Terphenylbismuth Dihalides with KSi(SiMe₃)₃, K₂Si₂(SiMe₃)₄ and Na₂[Fe(CO)]₄: Reduction vs. Metathesis

Metalation and Oxidative Coupling of the Unique Cyclic Silylphosphanes (iPr₂Si)₃PH and (iPr₂Si)₄PH