Gas-phase calorimetry of trimethyl Group Va bases with boron Lewis acids

Mente, Donald C.; Mills, Jerry L.; Mitchell, R. E.

doi:10.1021/ic50143a025

Cited by 45 publications

(14 citation statements)

References 36 publications

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“…An analogous increase in the value of the C-P stretching force constant is then to be expected, and indeed is found, on comparing the free phosphine with the adducts. The value of KpB associated with the stiffness of the P-B stretch, also suggests a successive strengthening of the P-B bond along with the series BCI, < BBr3 < B13 which is in accord with the increased Lewis acidity of the BX3 groups (27). The trend is identical to that observed in the H3PBX3 (5) and Me3PBX3 series (6 For personal use only.…”

Section: Normal Coordinate Analysissupporting

confidence: 57%

Phosphine–borane derivatives. 10. Vibrational spectra of the dimethylphosphine adducts of boron trihalides

Drake¹,

Hencher²,

Khasrou³

1981

Can. J. Chem.

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The infrared (200–4000 cm−1) and Raman (0–3100 cm−1) spectra of (CH3)2PHBX3, (CH3)2PDBX3, and (CD3)2PHBX3, where X = Cl, Br, I, have been recorded in solid state and in solutions at room temperature. The fundamentals have been assigned on the basis of Cs molecular symmetry. A modified Urey–Bradley force field model has been used in calculating the frequencies and potential energy distributions as well as the force constants. The (P—B) force constant was found to be consistent with the structural change upon adduct formation.

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Section: Normal Coordinate Analysissupporting

confidence: 57%

Phosphine–borane derivatives. 10. Vibrational spectra of the dimethylphosphine adducts of boron trihalides

Drake¹,

Hencher²,

Khasrou³

1981

Can. J. Chem.

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“…Apparently, the formation of Lewis acid–base adducts, and hence the attainment of octets in the valence shells of the components, should lead to thermodynamically more stable systems with reduced reactivity. For example, in the complex of trimethylphosphine (Me 3 P) and boron trifluoride (BF 3 ), both the Lewis base and the Lewis acid lose their reactivity . However, there are a plethora of reports in the areas of organocatalysis and transition‐metal catalysis in which stable adducts of this kind offer enhanced reactivity …”

Section: Lewis‐base‐coordinated Halogen(i) Intermediates Generatedmentioning

confidence: 99%

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

et al. 2017

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The widespread use of halogen‐based reagents in organic synthesis is well known. Hypervalent halogens (oxidation states III and V) have been explored to a significant extent. Among them, hypervalent iodine reagents have found major use and applications. In contrast, understanding of the reactivity of halogen(I) species in the presence of Lewis bases, and their reaction mechanisms, are very limited. This microreview sheds light on the importance of halogen(I) species and their applications in organic synthesis. In commercially available halogen(I) precursors such as N‐halosuccinimides, the halogen atom is attached to the nitrogen atom through a covalent bond with low electrophilicity and thus low reactivity. Interestingly, the reactivity increases if the electrophilic halogen(I) atom is attached to a Lewis base through a polarized covalent bond. The halogen‐bonding interaction between the Lewis base and the halonium ion (or halonium ion equivalent) results in highly reactive and thermodynamically stable halogen(I) intermediates that act as versatile reagents. This microreview unravels the evolution of the unstable halogen(I) intermediates to become versatile reagents.

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“…33−35 It was reported that BF 3 did not appear to form an adduct with SbMe 3 . 35 Subsequently, the synthesis and X-ray crystal structures of the thermally and photochemically unstable [BX 3 {Sb(SiMe 3 ) 3 }] were reported; 36 all three complexes have B−Sb bonds of the same length within experimental error. Two early papers mention AlCl 3 /SbR 3 systems and suggest that chlorination of the stibine occurs, but with very little supporting data presented, 37,38 and the only report describing gallium or indium halide-stibine complexes appears to be that of [GaCl 3 (SbMe 3 )].…”

Section: ■ Introductionmentioning

confidence: 99%

Trialkylstibine Complexes of Boron, Aluminum, Gallium, and Indium Trihalides: Synthesis, Properties, and Bonding

2018

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The reaction of BX 3 (X = Cl, Br, I) with SbR 3 (R = Et, i Pr) in anhydrous hexane or toluene produced moisture-sensitive [BX 3 (SbR 3)], whose stability increases with halide: Cl < Br < I. Unstable [BF 3 (SbR 3)] species were also characterized spectroscopically but lose BF 3 very readily. The [MX 3 (SbR 3)] (M = Al, Ga, In) complexes were isolated from hexane solution; the Ga and In complexes can be recrystallized unchanged from CH 2 Cl 2 , but [AlX′ 3 (SbR 3)] (X′ = Br, I) undergoes X′/Cl exchange with the solvent. The new complexes were characterized by IR and multinuclear NMR spectroscopy (1 H, 13 C{ 1 H}, 11 B, 27 Al, 71 Ga, 115 In, as appropriate). X-ray crystal structures are reported for [BX 3 (SbR 3)] (X = Br, I; R = Et, i Pr; X = Cl, R = i Pr), [AlI 3 (Sb i Pr 3)], [GaX 3 (SbR 3)] (X = Cl, I; R = i Pr), [GaBr 3 (SbEt 3)], and [InX 3 (SbR 3)] (X = Cl, I; R = Et, i Pr); all contain pseudotetrahedral geometries at both the group 13 and antimony atoms, and comparisons with phosphine and arsine analogues are discussed. The donor−acceptor bond lengths are unexceptional, but coordination of the stibine is accompanied by a significant widening of the C−Sb−C angles and a small reduction in C−Sb distances. DFT calculations confirm these results from significant changes in the antimony 5s and 5p contributions to the Sb−C bonds, with corresponding increases in the 5p character of the antimony-based "lone pair" on coordination. Intermolecular hypervalent Cl•••Sb interactions are present in the two [InCl 3 (SbR 3)] complexes but absent in the others.

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Gas-phase calorimetry of trimethyl Group Va bases with boron Lewis acids

Cited by 45 publications

References 36 publications

Phosphine–borane derivatives. 10. Vibrational spectra of the dimethylphosphine adducts of boron trihalides

Phosphine–borane derivatives. 10. Vibrational spectra of the dimethylphosphine adducts of boron trihalides

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

Trialkylstibine Complexes of Boron, Aluminum, Gallium, and Indium Trihalides: Synthesis, Properties, and Bonding

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