Antimony Compounds

Abstract

Antimony is the fourth member of the nitrogen family and has a valence shell configuration of 5 s 2 5 p 3 . A recommended exposure limit for antimony compounds of 0.5 mg/m 3 (as Sb) has been given. Stibine, SbH 3 , is a colorless, poisonous gas having a disagreeable odor. It is the only well‐characterized binary compound of antimony and hydrogen. Stibine is readily oxidized and may be ignited in the presence of air or oxygen to form water and antimony trioxide; at lower temperatures metallic antimony and water are slowly formed. High purity stibine is used as an n ‐type, gas‐phase dopant for Si in semiconductors. The most important binary compounds of antimony with metallic elements are indium antimonide, InSb, gallium antimonide, GaSb, and aluminum antimonide, AlSb, which find extensive use as semiconductors. Antimony trioxide is insoluble in organic solvents and only very slightly soluble in water. Antimony trioxide has numerous practical applications. Its principal use is as a flame retardant in textiles and plastics. Antimony tetroxide finds use as an oxidation catalyst, particularly for the dehydrogenation of olefins. Antimonic acid has been used as an ion‐exchange material for a number of cations in acidic solution. Antimony trifluoride is used as a fluorinating agent to replace nonmetal chloride with fluorine. Antimony trichloride is used as a catalyst or as a component of catalysts to effect polymerization of hydrocarbons and to chlorinate olefins. It is also used in hydrocracking of coal and heavy hydrocarbons. Both antimony tribromide and antimony triiodide readily hydrolyze, form complex halide ions, and form a wide variety of adducts with ethers, aldehydes, mercaptans, etc. Antimony pentafluoride is a strong Lewis acid and a good oxidizing and fluorinating agent. Antimony pentachloride is a strong Lewis acid and a useful chlorine carrier. Antimony trisulfide is used in fireworks, in certain types of matches, as a pigment, and in the manufacture of ruby glass. Antimony pentasulfide, Sb 2 S 5 , commercially known as golden sulfide of antimony, is used in vulcanization to produce a red variety of rubber. The material is also used as a pigment and in fireworks. A large number of compounds have been prepared in which the antimony atom is linked to carbon through an oxygen or sulfur atom. The best known compound of this type is antimony potassium tartrate (tartar emetic), used as an antiparasitic agent in medicine. A wide variety of compounds containing the Sb–C bond is known. Organoantimony compounds can be broadly divided in Sb(III) and Sb(V) compounds. A large number of trialkyl‐ and triarylstibines are known. Tertiary stibines have been widely employed as ligands in a variety of transition‐metal complexes, and they appear to have numerous uses in synthetic organic chemistry, eg, for the olefination of carbonyl compounds. They have also been used for the formation of semiconductors, as catalysts or cocatalysts for a number of polymerization reactions, as ingredients of light‐sensitive substances, and for many other industrial purposes. A considerable number of tetraalkyl‐ and tetraaryldistibines have been investigated. A number of organoantimony compounds containing rings of four, five, or six antimony atoms have been prepared. Antimonin(stibabenzene), C 5 H 5 Sb, the antimony analogue of pyridine, can be prepared by the dehydrohalogenation of a cyclic chlorostibine. The stibonic and stibinic acids are polymeric compounds of unknown structure. Dialkylstibinic acids can be readily prepared. Dichlorotriphenylantimony has been suggested as a flame retardant and as a catalyst for the polymerization of ethylene carbonate. Dibromotriphenylantimony has been used as a catalyst for the reaction between carbon dioxide and epoxides to form cyclic carbonates and for the oxidation of α‐keto alcohols to diketones. In addition to the trialkyldihalo‐ and triaryldihaloantimony compounds, mixed dihalo compounds such as chloroiodotriphenylantimony, (C 6 H 5 ) 3 SbClI, have been reported. Tetraalkyl and tetraaryl compounds, R 4 SbX, are well‐known and are often referred to as stibonium salts. In contrast to phosphorus and arsenic, only a few antimony ylids have been prepared. A new method, utilizing an organic copper compound as a catalyst, has resulted in the synthesis of a number of new antimony ylids. A number of pentaalkyl‐ and pentaalkenylantimony compounds have been prepared from tetraalkyl‐ or tetraalkenylstibonium halides and alkyl or alkenyllithium or Grignard reagents.

Protonated MF3 (M=N–Bi): Structure, stability, and thermochemistry of the H–MF3+ and HF–MF2+ isomers

“…Such variations have been explained [22] in terms of different participation (maximum for the P atom) of surrounding electrons (p, s or p) to bonding with d orbitals of the M atom in the H-MR 3 + cation. The basicities of the F-protonated MF 3 show instead a nearly regular increase down group XV, i.e. PF 3 % NF 3 < AsF 3 < SbF 3 < BiF 3 .…”

“…These processes well accord in fact with a precursor ion-dipole complex HF-AsF 2 + . The PA and GB of SbF 3 and BiF 3 have not yet been experimentally measured. Our calculations suggest that these protonated molecules should be viable species, and indicate the F atoms as the by far favoured protonation sites.…”

“…Most of these compounds are in fact extensively used in the electronic industry to perform etching and cleaning processes [1], to achieve the doping of semiconductors [2], and to deposit amorphous fluorinated materials [3]. All the MF 3 (M = N-Bi) have non-planar structures of C 3v symmetry and their bonding, properties, and reactivity have been extensively investigated, both experimentally and theoretically [4][5][6][7][8].…”

“…According to various ab initio calculations, the two isomers are separated by 2-6 kcal mol À1 [13][14][15][16][17]. Protonated PF 3 was observed so far in the gas phase [18] and the PA of PF 3 , measured by different techniques [18,19], is currently compiled as 166.2 kcal mol À1 [12]. The structure of the gaseous H(PF 3 ) + has never been explored by experimental or theoretical methods, but the observed species has been invariably assigned as the trifluorophosphonium ion H-PF 3 + .…”

Simulating Vapor–Liquid Equilibria of PH3, AsH3, and SbH3 from First Principles

“…Phosphine (PH 3 ), arsine (AsH 3 ), and stibine (SbH 3 ) are group V hydrides that are widely used as dopants in the semiconductor industry and as precursors in chemical vapor deposition processes. , PH 3 is also used as a fumigant . However, all of them are colorless, highly flammable, and highly toxic. − In addition, SbH 3 decomposes slowly at room temperature to give metallic antimony and hydrogen. , Owing to these hazards, experimental data on their vapor–liquid equilibrium (VLE) properties, which are essential for thermodynamic modeling, are relatively sparse and are available mostly at relatively low temperatures.…”