Thiocyanates, preparations listed

According to an O.S. amendment sheet, the procedure as described [1] is dangerous because the reaction mixture (dicyanodiamide and ammonium nitrate) is similar in composition to commercial blasting explosives. This probably also applies to similar earlier preparations [2]. An earlier procedure which involved heating ammonium thiocyanate, lead nitrate and ammonia demolished a 50 bar autoclave [3], TGA and DTA studies show that air is not involved in the thermal decomposition [4], Explosive properties of the nitrate are detailed [5], An improved process involves catalytic conversion at 90-200°C of a molten mixture of urea and ammonium nitrate to give 92% conversion (on urea) of guanidinium nitrate, recovered by crystallisation. Hazards of alternative processes are listed [6],... 

The sodium salt of these acids may be used to prepare aqueous solutions of indicators. Other examples of redox indicators include starch, potassium thiocyanate, methylene blue, and phenosafranine. Some selected general indicators in redox titrations are listed in Table 1.6.3. The properties of starch as an indicator in iodometric titration are discussed in the following section. 

All the examples reported so far appear to contain N-bonded thiocyanate groups and to dissociate readily in solution. Thus, [ScL3](NCS)3 (L = bipy or phen) has been prepared and characterized 223). Treatment with warm EtOH gives [ScL2(NCS)2](NCS) where the formulation is supported by conductivity measurements (in CHgCN or CH3NO2) and infrared mull spectra in aqueous solutions the coordinated NCS is displaced 223, 225, 464). Other mixed liquid complexes of these metals with NCS are listed in Table XX. A 1 1 adduct is formed between 1,3,5-trinitrobenzene and several lanthanide thiocyanates. No... 

Materials. Origin and characteristics of the cellulose samples used are listed in Table I. The low molecular weight cellulose sample A, was prepared from American Enka rayon by hydrolysis in 4 M HCl for 15 minutes and then washed with an eluotropic series of solvents. Sheets of samples C and D were shredded in a Wiley Mill (40 mesh) before use. Sample B, with degree of polymerization DP) of 210, was used in this study except where noted. Ammonium thiocyanate (Witco Chemical) was dissolved in condensed anhydrous ammonia (Air Products). Unless otherwise noted, all chemicals were ACS reagent grade. 

Analogous investigations were performed by Madeja et al. [Ma 76] with the mixed complex consisting of the hydrogen-bond containing nickel(II) macrocyclic complex (I) and thiocyanate ion. The equilibrium constants determined in solutions prepared with various donor solvents are listed in Table 4.8. By comparison with Table 4.7, it can be seen that, with the exception of acetonitrile, the stability of the thiocyanate complex is higher than that of the iodide complex in every solvent this... 

Methods of preparation of selenocyanates are entirely analogous to those of thiocyanates, and the papers listed at the end of this section include examples of methods. The previously unknown compound PhTeCN is formed in only low yield from PhTeTePh and KCN, but in high yield through reductive cyanation of ArTeClj and by the general route from ArTeBr with KCN. ... 

This chapter comprises organotin compounds having a pseudohalogen group linked to tin. Aside from (iso)cyanides, (iso)cyanates (iso)thiocyanates and azides reported in the Main Volume, a number of novel derivatives are added. These include (iso)selenocyanate-NCSe, fulminate-CN 0 and N-derivatives of dicyanamide-N(CN)2 and tricyanomethane-N C C(CN)2 The compounds listed in Tables 158 and 159 are prepared by the following methods. 

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