Infrared absorption frequencies salts

The sparingly water-soluble triethylammonium saltofBi2H122-is readily converted to the highly water-soluble sodium salt. A carefully weighed sample of the triethylammonium salt is treated with an exactly equivalent amount of standardized aqueous sodium hydroxide. The mixture is heated to effect solution and then boiled to expel the free triethylamine until the vapors are no longer basic. Evaporation to dryness then leaves a crystalline hydrate of Na2Bi2Hi2. The anhydrous salt is obtained by drying at 100°/1 n for 24 hours and has characteristic infrared absorption frequencies as a Nujol mull (exclusive of any frequencies coincident with Nujol) at 2470 (s), 1010 (w), 1070 (m), 770 (w), 727 (m),710 (m),and 700 (m) cm. 1... 

Table 2.12 Infrared absorption frequencies (cm of [N2H5(Hoda)] and [(N2H5)2oda] salts (Hoda = hydrogen-oxydiacetate and oda = oxydiacetate).

The elegant approach to the problem is to investigate spectra of water and salt solutions. The appearance of a concentration-dependent absorption band would indicate a likely region for radiation in order to cause precipitation. A partial investigation of the infrared absorption of saline water was not conclusive as to the existence of concentration-dependent bands. It is also possible that such bands may exist at radio frequencies, and these should be studied. 

The cesium and tetramethylammonium salts are white crystalline compounds, air-stable and nonhygroscopic. The cesium salt is soluble in acetone and hot water, insoluble in tetrahydrofuran. The tetramethylammonium salt has partial solubility in acetone or dimethylformamide, but is insoluble in water or methanol. The infrared spectra of the salts (Nujol and hexa-chlorobutadiene mulls) contain major absorption bands at the indicated frequencies ... 

The cream-colored ligand salt is soluble in acetone, nitromethane, and acetonitrile but insoluble in water and alcohols. The ligand salt is a biunivalent electrolyte in acetonitrile and nitromethane. The infrared spectrum of this material shows several characteristic bands a broad N—H stretcliing frequency at 3300 cm , a broad intense absorption in the double-bond region at 1600 cm, and bands due to hexafluorophosphate at 860 and 560 cm. The PMR spectrum in nitromethane shows five types of proton resonances as expected singlet methyl at 5 2.41, broad methylene at 5 3.83, doublet vinyl at 6 6.38 and 5 6.58, complex vinyl near 5 8.0, and broad NH at 6 7.6. 

Figure 6. Infrared spectra of ammonium nickel Tutton salt doped with 4% deuterium. Top Absorption spectra. Between 2260 and 2364 cm "1 lie the four N—D stretching bands of the NH3D+ ion, above 2380cm 1 the O—D stretching bands of HOD. Bottom Difference spectra before and after IR laser irradiation at the frequencies as indicated by arrows. (Adapted from Fei et al. [105].)...

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