Thallium® bromide

The attenuated total reflectance (ATR) technique is used commonly in the near-infrared for obtaining absorption spectra of thin Aims and opaque materials. The sample, of refractive index i, is placed in direct contact with a material which is transparent in the region of interest, such as thallium bromide/thallium iodide (known as KRS-5), silver chloride or germanium, of relatively high refractive index so that Then, as Figure 3.f8... 

DTGS = deuterated triglycine sulfate KRS — 5 = mixed thallium bromide-iodide LT = lithium tantalate MCT = mercury cadmium telluride and OPO = optical parametric oscillator. 

Uses. Tballium compounds have limited use in industrial appHcations. The use of thaHous sulfate in rodenticides and insecticides has been replaced by other compounds less harmful to animals (see Insect control technology Pesticides). Tb allium sulfide has been used in photoelectric cells (see Photovoltaic cells). A thallium bromide—thallium iodide mixture is used to transmit infrared radiation for signal systems. ThaHous oxide is used in the manufacture of glass (qv) that has a high coefficient of refraction. Tb allium formate—malonate aqueous solutions (Cletici s solution) have been used in mineral separations. Many thallium compounds have been used as reagents in organic synthesis in researchlaboratoti.es. 

The organic solvent is removed by distillation under reduced pressure to give 4,4 -dimethyl-l,T-biplienyl contaminated with a small amount of bis(4-methylphenyl)thallium bromide. The crude product is dissolved in 30 ml. of benzene, and the solution is filtered through a short column of alumina (Note 7) using a total of 250 ml. of benzene as eluent. Distillation of the benzene under reduced pressure leaves 19-21 g. (80-83%) of 4,4 -dimethyl 1,1 -biphenyl as a colorless solid, m.p. 118-120° (Note 8). 

The dimensions of the alumina column arc not critical A column approximately 2 5 cm by 12 5 cm is recommended The small amount of bis(4-methylphenyl)thallium bromide formed in the reaction remains on the top of the column... 

Thallium-based devices, 23 872 Thallium-based HTS superconductors, 23 848-850. See also Tl-based superconductors Thallium bromide... 

Finally, Adzic and Wang [62], and Wang etal. [63] have studied the formation of thallium bromide on Au(lll) electrode... 

Thallium bromide-thallium 0.5-35 20,000-286 2.37 0.464 (373 K) Highly toxic, handle with care 42% TIBr,... 

Thallium iodide-thallium bromide (KRS-5) 16,000-250 2.37 Relatively soft, deforms easily warm water, ionizable acids and bases, chlorinated solvents, and amines should not be used with this ATR element... 

Metal Halides. Reacts explosively or violently with the following calcium bromide iron(III) bromide or chloride iron(II) bromide or iodide cobalt(II) chloride silver fluoride all four mercury(II) halides copper(I) chloride, bromide or iodide copper(II) chloride and bromide ammonium tetrachlorocuprate zinc and cadmium chlorides, bromides, and iodides aluminum fluoride, chloride, and bromide thallium bromide tin(II) or (IV) chloride tin(IV) iodide arsenic trichloride and triiodide antimony and bismuth trichlorides, tribromides, and triiodides vanadium(V) chloride chromium(IV) chloride manganese(II) and iron(II) chlorides and nickel chloride, bromide, and iodide.17,22"25... 

Tellurium reacted with an equimolar amount of bisfpentafluorophenyl] thallium bromide in an evacuated, sealed Pyrex tube at 190° and in three days produced bis pentafluorophenyl tellurium in 18% yield1. 

Organic compoimds that contain nitrogen in a hmctional groi shoitid not be used with plates whidi are made of thallium bromide and thallium iodide (KRS-5 plates) as they pereact with the plates. Despite these disadvantages, the tedmique is still a most usefiti one for solid ugs. The advalkali halide is very low and the quantity of compound required is small. The disks can easily be stored for reference puqx>ses or the compound can be recovered if required. 

MAIR spectroscopy at IR wavelengths was used to identify the polymers, monitor any induced structural transformations after the various treatments, and verify the freedom of the thin film from residual trapped solvent or adventitious contaminants 1, 2). A model 9 internal reflection accessory (Wilks Scientific Corp.) was used in conjunction with Beckman IR-12 and IR-7 and Perkin-Elmer 21, 257, and 457 IR spectrometers to record reflection spectra of the immediate interface of the sample which was clamped against the multiple internal reflection prisms made from the thallium bromide salt KRS-5. 

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