Bismuth Compounds

Abstract

Bismuth is the fifth member of the nitrogen family of elements and like its congeners possesses five electrons in its outermost shell, (6 s 2 )(6 p 3 ). In many compounds, the bismuth atom utilizes only the three 6 p electrons in bond formation and retains the two 6 s electrons as an inert pair. Compounds are also known where bismuth is bonded to four, five, or six other atoms. Many bismuth compounds do not have simple molecular structures and exist in the solid state as polymeric chains or sheets. Inorganic compounds of bismuth include bismuthine, bismuthides, bismuth halides, bismuth oxide halides, bismuth oxides and bismuthates, higher oxides of bismuth and related compounds, sulfides and related compounds, and bismuth salts. In a manner similar to phosphorus, arsenic, and antimony, the bismuth atom can be either tri‐ or pentacovalent. Methylbismuthine, CH 3 BiH 2 , and dimethylbismuthine, (CH 3 ) 2 BiH, are prepared by the lithium aluminum hydride reduction of methyldichlorobismuthine, CH 3 BiCl 2 , and dimethylchlorobismuthine, respectively. Tertiary bismuthines appear to have a number of uses in synthetic organic chemistry and for a number of other industrial purposes. Chloro‐, dichloro‐, bromo‐, and dibromobismuthines are best prepared by the reaction of a tertiary bismuthine and bismuth trichloride or tribromide. Tetraalkyl‐ and tetraaryldibismuthines can be obtained by the reaction of a sodium dialkyl‐ or diarylbismuthide and a 1,2‐dihaloethane. Dibismuthines tend to be thermally unstable. They also are very sensitive to oxidation. Organobismuth(V) compounds have found considerable use as oxidizing agents. After the tertiary bismuthines, the triarylbismuth dihalides constitute the most important class of organobismuth compounds and are by far the largest class of compounds containing pentacovalent bismuth. Very few trialkylbismuth dihalides have been prepared. In addition to use in organic synthesis and limited industrial use, triarylbismuth dihalides have been used as catalysts for the carbonation of epoxides to form cyclic carbonates. A number of bismuthonium ylides, have been prepared and their reactions studied. A number of pentaarylbismuth compounds are known. Pentaphenylbismuth, C 30 H 25 Bi, is a violet‐colored, crystalline compound that decomposes spontaneously after standing for several days in a dry nitrogen atmosphere. It has been studied as a reagent in organic synthesis where it can act either as an oxidizing or an arylating agent. Commercially available preparations of Bismuth subsalicylate (Pepto‐Bismol), a basic salt of varying composition, corresponding approximately to o ‐HOC 6 H 4 CO 2 (BiO), and De‐Nol, tripotassium dicitratobismuthate (bismuth subcitrate) are applied in the treatment of duodenal ulcers, gastritis and diarrhea.

Application of Solid-State 209Bi NMR to the Structural Characterization of Bismuth-Containing Materials

“…Bismuth is an element rarely found naturally in its pure form; however, it is acquired as a byproduct of lead ore mining and is commonly encountered in bismuth oxides , and man-made coordination complexes. , Recently, bismuth-containing compounds have become important in a number of research areas, including synthesis of pharmaceuticals, − design of superconductors, and catalytic processes . With the increased occurrence in the literature of bismuth-containing systems and associated chemistry and materials science implications, methods of characterizing the structure and bonding at the Bi sites are becoming increasingly important.…”