Reactivity and Properties of [−O−Bi^III...OMo−]_nChains

Abstract

A coordination polymer [Cp(O)2Mo-O-Bi(o-tolyl)2]n, II, containing Mo-O-Bi and Mo=O...Bi moieties was investigated with respect to its behavior in contact with OH- and Cp2MoH2 and as potential single source precursor in the polyol method. It turned out that hydroxide as a base breaks up the polymer to yield CpMoO3- and (o-tolyl)2BiOH. The latter polymerizes to give the coordination polymer [(o-tolyl)2BiOH]n, 1. Alternatively, 1 can be prepared by reacting [(o-tolyl)2Bi(hmpa)2]SO3CF3 with NBu4OH/H2O in thf/water. If, however, NBu4OH/MeOH is used in dichloromethane as the solvent, the (o-tolyl)2BiOH formed intermediately undergoes methanolysis, and finally, [(o-tolyl)2BiOMe]n, 3, is isolated. Although 1 and 3 are very similar compounds, their crystal structures differ significantly: while the structure of 1 is dominated by secondary bonding leading to seesaw-type coordination geometries around the Bi centers, the Bi atoms in 3 are coordinated in a distorted tetrahedral fashion, and secondary bonding plays only a minor role. If 1 is dissolved in a nonpolar, nonprotic solvent, condensation reactions occur immediately leading to [(o-tolyl)2BiOBi(o-tolyl)2], 2, which can be obtained on a preparative scale this way. Compound 3 which can be prepared in good yields may prove to be a useful starting material in bismuth chemistry. Here, it was shown to react with molybdocene dihydrides to provide stable Bi-substituted molybdocene monohydrides [(R)Cp2Mo(H)(Bi(o-tolyl)2)] (R = Me 4, R = H 5); compounds of that type were identified in solution before but had so far eluded isolation. Compound 4, whose crystal structure is discussed, also forms when II is treated with methylated molybdocene dihydride. This obviously leads to the formation of Mo-Bi bonds (--> 4), as well as Mo-OH units, which undergo condensation reactions leading to Mo-O-Mo moieties (i.e., [Cp2Mo2O5] is formed as a byproduct). The use of II as precursor in the polyol method successfully led to bismuthmolybdate nanoparticles (accompanied by crystallites); however, no single phase is obtained, but biphasic materials consisting of Bi(2)Mo2O9 and Bi2MoO6, whose ratio can be determined by the choice of the hydrolyzing reagent, are formed instead. One of these materials proved to be capable of sensing EtOH selectively at elevated temperatures.

Efficient Fixation of Carbon Dioxide by Hypervalent Organobismuth Oxide, Hydroxide, and Alkoxide

“…8 The 5,6,7,12‐tetrahydrodibenz[c,f][1,5]azabismocine framework is highly stable as a diorganobismuth fragment and, therefore, is suitable for the study of diorganobismuth compounds bearing various heteroatom groups on the bismuth atom. Since structural and reactivity studies of diorganobismuth(III) hydroxides,5, 9 oxides,5, 9, 10 and alkoxides9, 11 are limited, we examined the synthesis of such compounds with the 5,6,7,12‐tetrahydrodibenz[c,f][1,5]azabismocine framework. In analogy to the synthesis of {(2,4,6‐Me 3 C 6 H 2 ) 2 Bi} 2 O 2 ,10d bismuth chloride 3 was treated with aqueous sodium hydroxide solution, and subsequent recrystallization of the crude product from toluene under nitrogen exclusively afforded bismuth oxide 6 .…”

Efficient Fixation of Carbon Dioxide by Hypervalent Organobismuth Oxide, Hydroxide, and Alkoxide

“…[7,8] The 5,6,7,12-tetrahydrodibenz[c,f]-[1,5]azabismocine framework is highly stable as a diorganobismuth fragment and, therefore, is suitable for the study of diorganobismuth compounds bearing various heteroatom groups on the bismuth atom. Since structural and reactivity studies of diorganobismuth(III) hydroxides, [5,9] oxides, [5,9,10] and alkoxides [9,11] are limited, we examined the synthesis of such compounds with the 5,6,7,12-tetrahydrodibenz[c,f]-[1,5]azabismocine framework. In analogy to the synthesis of {(2,4,6-Me 3 C 6 H 2 ) 2 Bi} 2 O 2, [10d] bismuth chloride 3 was treated with aqueous sodium hydroxide solution, and subsequent recrystallization of the crude product from toluene under nitrogen exclusively afforded bismuth oxide 6.…”

Creating Iron– and Rhenium–Bismuth Bonds by Reactions with Organometallic Hydrides

“…The molecular structure is shown in Figure . Besides {(mes) 2 Bi} 2 O, (mes = 1,3,5‐trimethylbenzyl) and {( o ‐tolyl) 2 Bi} 2 O, 1 is only the third bismuth containing compound with a [Bi–O–Bi] motif, the molecular structure of which was determined. Two [(Cp 2 Re) 2 Bi] units are connected by an oxygen atom to form a bent [Bi–O–Bi] entity.…”

“…Furthermore the oxidation of primary and secondary alcohols with [( o ‐ans) 3 BiO] 2 ( o ‐ans = 2‐anisole) led to the formation of the side product {( o ‐ans) 2 Bi} 2 O and the oxidation of tetraorganodibismuthanes R 2 Bi‐Bi R 2 with dioxygen was found to lead to {(mes) 2 Bi} 2 O as a side product, which could be analyzed by means of X‐ray diffraction , . In previous work we have shown that the oxide [( o ‐tolyl) 2 BiOBi( o ‐tolyl) 2 ] ( V ) and the polymeric hydroxide [( o ‐tolyl) 2 BiOH] n ( VI ) form via the hydroxide IV in thf / water solutions (Scheme ) . Hence, the formation of 1 in mixtures of [Cp 2 ReH] ( I ), [Bi(O t Bu) 3 ] and [{Cp 2 Re} 2 Bi(O t Bu)] ( II ) / [CpRe( μ ‐ η 5 , η 1 ‐C 5 H 4 )Bi–ReCp 2 ] ( III ) was conceivable to have taken place due to the presence of H 2 O (in commercially available C 6 D 6 ).…”

“…Synthesis of [( o ‐tolyl) 2 BiOBi( o ‐tolyl) 2 ] V and [( o ‐tolyl) 2 BiOH] n VI (hmpa = hexamethylphosphoric acid triamide) …”