Synthesis and Properties of a Series of Phenylene-Bridged Bi_n-Bismuthanes

Abstract

A series of meta- and para-phenylene-bridged Bi(III) n and Bi(V) n compounds (n ≥ 2) have been synthesized. Reaction of Ph2BiX (X = Cl, OSO2CF3) with p-Li2C6H4, p-(BrMg)2C6H4, or p- and m-(Me2S·Cu)2C6H4 generated in situ from dibromobenzenes gave the corresponding para- and meta-phenylene-bridged Bi n −bismuthanes, Ph2BiC6H4BiPh2 (2), Ph2BiC6H4Bi(Ph)C6H4BiPh2 (3), and Ph2BiC6H4Bi(Ph)C6H4Bi(Ph)C6H4BiPh2 (4), in 2−30% yields. Bi n -bismuthanes 2−4 were oxidatively chlorinated by SO2Cl2 to yield the Bi n -bismuth polychlorides 5−7, in which all pentavalent bismuth atoms bore three aryl groups and two chlorine atoms. Compounds 2−7 showed λmax at around 244−249 and 285−290 nm in the UV−vis spectra, suggesting that the phenylene bridges did not perturb significantly the σ- and π-transitions of the aromatic systems in these bismuth oligomers. Ortho-lithiation directed by the sulfonyl group was employed for the one-pot preparation of highly branched Bi n -bismuthanes; successive treatment of Ar3Bi 9a with 3 equiv of t-BuLi and Ar2BiI (10b) (Ar = 2-Et2NSO2C6H4) afforded m-phenylene-bridged Bi n -bismuthanes, Ar2Ar‘Bi (11a), ArAr‘2Bi (12a), and Ar‘3Bi (13a) in 2−49% yields (Ar‘ = 3-Ar2Bi-2-Et2NSO2C6H3). Treatment of ortho-lithiated (2-t-BuSO2C6H4)(p-Tol)2Bi (14) with p-Tol2BiCl gave sulfone-substituted Bi2-bismuthane 15, which was converted to the corresponding Bi2-chlorodiarylbismuthane (16) by the Bi−C cleavage reaction. An X-ray diffraction analysis of 16 showed that both bismuth centers have a distorted trigonal pyramidal geometry weakly coordinated by the neighboring sulfonyl-oxygen atoms. The symmetrically branched Bi4-bismuthane 13a was successfully converted to a dendritic Bi10-bismuthane 17 in 20% isolated yield by successive treatment with t-BuLi and 10b. The reaction between ortho-lithiated 9a and ArBiI2 (10c) followed by GPC separation afforded two fractions of oligomeric Bi n -bismuthanes, the vapor depression measurement of which revealed that the average numbers of the bismuth atoms present therein were 7 and 16, respectively. UV−vis spectra of 9a, 11a, 12a, 13a, and 17 exhibited no bathochromic shift; the inefficient π-electron delocalization would probably be due to the twisted geometry between aromatic rings, as inferred from the X-ray structure of the related Bi2-bismuthane 16. The extinction coefficients of these phenylene-bridged Bi n -bismuthanes were found to increase with increasing number of bismuth atoms.

Mixed triorganobismuthines RAr2Bi [Ar = C6F5, 2,4,6-(C6F5)3C6H2] and hypervalent racemic Bi-chiral diorganobismuth(iii) bromides RArBiBr (Ar = C6F5, Mes, Ph) with the ligand R = 2-(Me2NCH2)C6H4. Influences of the organic substituent

“…30 Bismuth-chiral diorganobismuth(III) halides are better represented in the literature. Examples of compounds structurally characterized in the solid state include, but may not be limited to, R(4-MeC 6 H 4 )BiCl [R = 2-(Me 2 NCH 2 )C 6 H 4 ], 27 R Fc (4-ClC 6 H 4 )BiI (R = (R)-(+)-N,N-dimethyl-1-ferrocenylethylamine), 31 2,6-[(4-MeC 6 H 4 )(Cl)Bi] 2 C 6 H 3 SO 2 (t-Bu) 32 R C,N Bi(Ph)Cl (R C,N = [2-(CHvN-2,6-iPr 2 C 6 H 3 )C 6 H 4 ]), 33 R C,O (4-MeC 6 H 4 )BiBr (R C,O = 2-MeC(O)C 6 H 4 ), 29 and others. 26,34 A significant number of organobismuth(III) compounds with intramolecular coordination-induced chirality at the Bi centre and planar chirality have been reported to date.…”

Development and Scale-Up of a New Sulfone-Based Bismacycle as a Universal Precursor for Bi(V)-Mediated Electrophilic Arylation

“…While lithiation of diphenyl sulfone with n -butyllithium is facile, addition of the resulting dilithiodiphenyl sulfone 4 to BiBr 3 afforded less than 20% of the desired bismacycle 1-Br as part of a complex mixture containing side-products 5 and 6 (Scheme , entry 1). The former is presumably formed via addition of highly nucleophilic dilithiodiphenyl sulfone 4 to the initially formed 1-Br , followed by protonation of a pendant aryllithium or an intermediate 10-Bi-4 “ate” complex − during reaction quench. As determined by comparison to authentic samples, the likely products of reductive coupling ( 7 and 8 ) were not formed in observable quantities.…”

Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds

“…Matano et al synthesized a series of meta - and para -phenylene-bridged Bi(III) n and Bi(V) n compounds ( n ≥ 2) [ 64 ]. The compounds Ph 2 BiC 6 H 4 BiPh 2 ( 55a ), Ph 2 BiC 6 H 4 Bi(Ph)C 6 H 4 BiPh 2 ( 56a ) and Ph 2 BiC 6 H 4 Bi(Ph)C 6 H 4 Bi(Ph)C 6 H 4 BiPh 2 ( 57a ), which bore two or more bismuth atoms, were obtained in 2%–30% yields ( Scheme 22 ).…”