Antimony monoxide

The role of antimony halides as flame-retardant species in the gaseous phase is well established when SbX3 (X = chlorine or bromine) is introduced into premixed methane-oxygen flames, atomic antimony and antimony monoxide are found in the flame.43 Sb203 was shown by mass spectrometry to be present only in the preflame zone and no antimony-halogen species could be detected in the flame itself. 

Other important uses of stannic oxide are as a putty powder for polishing marble, granite, glass, and plastic lenses and as a catalyst. The most widely used heterogeneous tin catalysts are those based on binary oxide systems with stannic oxide for use in organic oxidation reactions. The tin—antimony oxide system is particularly selective in the oxidation and ammoxidation of propylene to acrolein, acryHc acid, and acrylonitrile. Research has been conducted for many years on the catalytic properties of stannic oxide and its effectiveness in catalyzing the oxidation of carbon monoxide at below 150°C has been described (25). 

Kizhakevariam N, Weaver MJ. 1994. Structure and reactivity of bimetaUic electrochemical interfaces Infrared spectroscopy studies of carbon monoxide adsorption and formic acid electrooxidation on antimony-modified Pt(lOO) and Pt(lll). Surf Sci 310 183-197. 

Hence, the zinc stannates have been shown to impart"5beneficial properties to this polymer system, in terms of flammability and smoke/carbon monoxide evolution, and the improvements in performance are clearly superior to those exhibited by the commercially available antimony trioxide. 

Acrolein is immediately passed through a second oxidation reactor to form acrylic acid. The reaction talces place at 475-575 E, over a tin-antimony oxide catalyst. A few by-products form, namely, formic acid (HCOOH), acetic acid (CH3COOH), low molecular weight polymers, carbon monoxide, and dioxide. But overall yields of propylene to acrylic acid are high—85 to 90%. 

The monoxide SgO forms the 0-bonded adduct SgO SbCl5 upon treatment with antimony pentachloride in CSy adduct formation results in pyramidal inversion at the three-coordinate sulfur atom. In contrast, the treatment of 850 with antimony pentachloride induces dimerisation to give the 2 1 adduct of SbCls with the cyclic dioxide SiyOy. The chair form of the two S O constituents of this dimerisation process are evident in the conformation of the 12-membered S12 ring in the adduct. 

Carbonyl fluoride can be prepared by any of several methods, including the conversion of carbonyl chloride to the fluoride by such reagents as hydrogen fluoride1 and antimony (III) fluoride.2 The direct combination of carbon monoxide and fluorine is another route to this fluoride, but carbon tetrafluoride is a by-product of the reaction.8 A particularly suitable laboratory preparation of carbonyl fluoride is the fluorination of carbon monoxide by silver (II) fluoride.4 This method, described below, gives directly carbonyl fluoride of rather high purity without recourse to a low-temperature distillation. 

Polyvinyl Chloride (PVC) In flexible PVC, the partial replacement of antimony oxide with the zinc borate cannot only display synergy in flammability test performance but also results in dramatic smoke reduction.56 This synergy can be more dramatic when used in conjunction with ATH or magnesium hydroxide (MDH) (Figures 9.4 through 9.6). A recent Cone Calorimeter study49 showed that, in flexible PVC, the partial replacement of antimony with the zinc borate could reduce both the HRR and carbon monoxide production drastically at a... 

The trihalides of phosphorus and antimony have been shown to be slightly and quite selectively basic, being rather similar in coordinating action to carbon monoxide (p. 156). Compounds analogous to nickel carbonyl, Ni(CO)4, may be prepared by treating the carbonyl with an excess of the appropriate trihalide ... 

Related problems must be considered in individual products. Bromine, chlorine, and antimony add to the smoke of a fire, while phosphorus and water do not, and some metal oxides can actually reduce it. Toxicity of combustion gases is a major concern but the main problem is that oxidation of carbon compounds in an enclosed space—indoors— produces carbon monoxide, no matter whether the carbon compounds are wood or plastics. Other problems include the cost of flame-retardants, difficulties in processing, and loss of mechanical or thermal properties. 

Oxidizer, Poison, Corrosive SAFETY PROFILE Poisonous and corrosive. Very reactive, a powerful oxidizer. Explosive or violent reaction with organic materials, water, acetone, ammonium halides, antimony, antimony trichloride oxide, arsenic, benzene, boron, bromine, carbon, carbon monoxide, carbon tetrachloride, carbon tetraiodide, chloromethane, cobalt, ether, halogens, iodine, powdered molybdenum, niobium, 2-pentanone, phosphoms, potassium hexachloroplatinate, pyridine, silicon, silicone grease, sulfur, tantalum, tin dichloride, titanium, toluene, vanadium, uranium, uranium hexafluoride. 

---