Synthesis and Structure of Pentavalent Bismuth(V) Alkoxides and Ligand Redistribution Equilibria in Solution

Abstract

The six new pentavalent Bi(V) alkoxide complexes Ph3Bi(OR)2, 1, Ph3BiBr(OR), 2, and Ph4Bi(OR), 3 (a, R = C6F5; b R = C6Cl5) have been prepared. Ph4Bi(OR) was synthesized by alcoholysis of BiPh5 with ROH. Ph3Bi(OR)2 and Ph3BiBr(OR) were products of the salt elimination reaction between Ph3BiBr2 and NaOR. These compounds were characterized spectroscopically and by single-crystal X-ray diffraction. In the solid state, they possess distorted trigonal bipyramidal coordination geometries. Although the mixed species Ph3BiBr(OR) may be isolated in pure form as crystalline solids, they do not exist as pure compounds in solution owing to the very rapid redistribution equilibrium Ph3Bi(OR)2 + Ph3BiBr2 ⇌ 2Ph3BiBr(OR). The equilibrium constants were measured using VT NMR spectroscopy. For comparison, the equilibrium constants for the previously unreported cross-exchange reactions between the dihalides Ph3BiX2 (X = F, Cl, Br) were also measured at 226 K. Trends observed in the values of K eq correlate with the difference in the electronegativity of the mixed X species. The thermal stabilities of Ph3Bi(OR)2 were examined in toluene solution and in the solid state. Pyrolysis results in elimination of ROPh for both R = C6F5 and C6Cl5.

Formation of Bismuth(V) Thiolates: Protolysis and Oxidation of Triphenylbismuth(III) with Heterocyclic Thiols

“…Thus, bismuth(III) thiolates are common stable species and have a special relevance in biology and medicine 17. While both Hoppe and Whitmire8d and Sharutin et al 8a–c. have had some success in synthesizing triarylbismuth(V) phenoxides, there is no corresponding thiolate chemistry.…”

Synthesis and structure of 2,4,6-tribromophenoxytetraphenylbismuth

“…The Bi atom shifts from the equatorial plane toward the C atom of the axially arranged phenyl ligand, which induces a distortion of the bond angles between the axial and equatorial substituents: OBiC eq is smaller (79.5(2)°-83.1(2)°) and C ax BiC eq is larger (97.9 (2) ). In the other two structurally characterized tetraphenylbismuth aroxides (pentafluorophenoxytetraphenylbismuth (V) and pentachlorophenoxytetraphenylbismuth (VI)), the Bi-O bonds are longer (2.544(7) and 2.543(9) Å, respectively) [4]. However, it can be noted that the geometric parameters of a molecule of compound I are close, as a whole, to similar characteristics of compounds V and VI.…”

“…It was found that different organic compounds are formed depending on the phenol nature: phenols phenylated at the orthoposition and nonsymmetric diaryl ethers or phenylated unsaturated cyclic ketones. However, the reactions of pentaphenylbismuth with triphenylsilanol [1] or pentafluoro-and pentachlorophenols [4] afford alkoxide and triphenylbismuth aroxides, respectively. This work is aimed at studying the possibilities of synthesizing stable tetraphenylbismuth aroxides and establishing specific features of their structures by Xray diffraction analysis.…”

A Multiply Bonded Trigonal‐Planar Bismuth(III) Complex: Prodigious Lewis Acidity, Solvatochromism, Etherification, and Semiconducting Characteristics

“…[12] In contrast, the formation of ethersi nt his study occurred through 1-OR (R = Me, Et, t Bu) with C-O-activated alcohols, promoted by the ionic Bi III -OR bonds, providing ana lternative route to the etherification in bismuth chemistry. To rationalize this unexpected result, we replaced OMe À with OEt À in EtOH.…”