Hydrogen bromide thiocyanate

Acetophenone Formaldehyde Hydrogen bromide Potassium thiocyanate... 

When the cyclization procedure, using hydrogen bromide, is applied to a-cyanoalkyl thiocyanates (152), the salts of 2-bromo-4-amino-thiazoles (153) can be obtained in excellent yield.105 Most of these salts... 

The reaction of methylene bis-thiocyanate (LI) with hydrogen bromide affords the imidoyl bromide LII in high yield ( ). 

The hitherto-synthesized derivatives are substituted on the nitrogen, with the exception of the hydrogen bromide adducts VIII of thiocyanates which have recently been synthesized by Allenstein and Quis ( ). 

Recently Allenstein and Quis ( ) investigated the addition of hydrogen halides to thiocyanates. While with hydrogen chloride only labile adducts have been observed, hydrogen bromide adds to methyl- and phenylthio-cyanate to afford 2 1 adducts, for which structure XX has been assigned on the basis of infrared spectroscopy ( ). 

The 1-chloroformimidates and the 1-chlorothioformimidates are in general liquids or low-melting solids, which can be purified by vacuum distillation. In contrast, 1-bromothioformimidates, obtained as hydrobromides from thiocyanates and hydrogen bromide, or from isothiocyanates and hydrogen bromide, are hygroscopic salt-like compounds which are difficult to handle. 

Amino silanes react to produce phosphonous amides MeP (NR2)2 (7.179), and silver cyanide or thiocyanate produces the corresponding cyano derivative (6.168). Hydrogen bromide displaces chlorine to give methylphosphonous dibromide (6.169). 

Several investigations have demonstrated the possibility or probability of the existence of persistent five- or six-co-ordinate intermediates in the associative pathway for nucleophilic substitution. Examples include the reactions of [AuClJ with thiocyanate and with A-cyclohexylthiobenzamide and of cw-[Pt(N02)2-(NHs)2] with hydrogen bromide. The behaviour of stable five-co-ordinate compounds has been examined with a view to treating them as models for such transient intermediates in associative substitution at four-co-ordinate complexes (see Section 3). A thorough and unusually extensively referenced molecular orbital treatment of... 

The combined (S + Au)-sensitization usually is applied during the manufacture of the emulsion, but sensitization can be achieved also by bathing a coated S-sensitized emulsion in an aurous thiocyanate solution before exposure (161). Reduction sensitization can be combined with (S + Au)-sensitization under some conditions. Collier (162) found that reduction sensitization either before or after (S + Au)-sensitization increased both sensitivity and fog in a l-ym octahedral grain silver bromide emulsion. The largest increase in sensitivity and lowest increase in fog were achieved when reduction sensitization was applied after the S+Au. Hydrogen hypersensitization likewide is effective (108) and can produce large increases in sensitivity for some emulsions. 

Figure 3. Selectivity pattern of an ISE based on ionophore 2. The electrode was exposed to the following anions salicylate (1), thiocyanate (2), nitrite (3), perchlorate (4), iodide (5), benzoate (6), bromide (7), bicarbonate (8), hydrogen phosphate (9), nitrate (10), chloride (11), sulfate (12). (Reproduced with permission from ref. 10. Copyright 1989 Alan R. Liss.)...

It has also been found in literature [84] that iodide ions, I- bromide ions, Br and azide ions, N3, inhibit the corrosion of metallic iron in acid solution. On the other hand, the presence of hydrogen sulfide ions, HS- thiosulfate ions, S2O2 and thiocyanate ions, SCN, accelerate the corrosion of metallic iron in acidic solution [84]. 

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