Synthesis of salts

Salts of InCl2 and Ini2- (see Section 25.2.2.4) serve as the starting point for the synthesis of salts of [In(NCS)2], [In(NCO)2]- and [In(NCS)3]3 by metathesis in ethanol 13 the IR spectrum shows that both ligands are N-bonded in structures which are apparently bridged homopolymers in the solid state. No other pseudohalide compounds of indium(I) have been reported. 

The synthesis of salts containing this anion was first reported in 1895 by Hofmann and Wiede (4), and subsequently confirmed by... 

A more favorable synthesis of salts of the iron, cobalt and nickel carbonyl anions, which were initially prepared by disproportionation reactions of Fe(CO)5, Co2(CO)8, and Ni(CO)4 with pyridine and other amines, was found by treatment of the neutral carbonyls with alkali in aqueous or alcoholic solutions. Careful studies by Hieber revealed that Fe(CO)5 as well as Fe3(CO)12 reacted with exactly four equivalents of hydroxide ions to give the corresponding dianionic iron carbonylates (Scheme 4.4). These dianions are relatively strong bases and readily accept a proton from a water molecule to give the monoanionic hydrido carbonylates [I IFe(CO)4] and [HFe3(CO)n], respectively [36]. The related carbonylates of cobalt and manganese, [Co(CO)4] and [Mn(CO)5], were obtained by a similar way as [Fe(CO)4]2 [25]. With regard to the mechanism of Hieber s Basenreaktion , the most plausible explanation is based on an initial nucleophilic attack by the hydroxide ion at the carbon atom of a CO... 

An alternative synthesis of salts of 1, which proved to be suitable for large scale synthesis, soon followed and is outlined in equation 3 . In this approach the carbene is generated by a base-induced reaction, and under the conditions of the reaction the product... 

MSH. Only for the synthesis of salt 64 (R = R = H), was HOSA used however, the yield was about 15% [71 JCS(C)328O]. A large series of salts of type 64 was obtained by acidic cyclization of l-acylmethyl-2-(2-acetyl-hydrazino)pyridinium salts [71JCS(C)3280]. 

Recently, Ni and group [66] introduced a new type of chiral ionic liquid based on pyridinium cation having a chiral moiety tethered to a urea unit. The synthesis of salt involves a reaction of 2-aminomethyl pyridine with chiral 2-isocyanate-3-methylbutyrate and then heating in the presence of alkyl halide to form salt (Scheme 17.18). In total, nine chiral pyridinium salts were synthesized with varying amino acids. Currently, the authors are using these salts for asymmetric induction in organic transformation. 

ELECTROCHEMICAL SYNTHESIS OF SALTS OF HEXAHALODIGALLATE(II) AND TETRAHALOGALLATE(ID) ANIONS... 

SCFIEME 10.10 Synthesis of salt binding rotaxane 20 using macrocycle 17 and traceless ion pair templation. 

FIGURE 3 II Typical monomers for the synthesis of salt-responsive (co(polymers. 

Metals can also be introduced by adsorption of the elemental vapor or melt, for instance in the case of mercury or alkali metals. Adsorption of molecular "precursors such as carbonyls of iron, cobalt, nickel and molybdenum, and subsequent thermal or photochemical decomposition has become an important approach for metals that are difficult to reduce. Other ligands such as alkyls or acetylacetonates have also been used for this purpose. In all these cases, thermal decomposition carries the risk of excessive mobility of the precursors or intermediates such that agglomeration and particle formation at the external surface of the zeolite crystals can occur. Barrer has described the synthesis of salt-bearing zeolites including the famous dry synthesis of ultramarin in 1828, which is sodalite containing intercalated Na-polysulphides. Adsorption of numerous non-ionic and salt species into zeolites was also described, either as such or as precursors for oxides, hydroxides, or metals. 

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