Na amalgam

Until comparatively recently only vanadium had a significant coordination chemistry and even so the majority of its compounds are easily oxidized and must be prepared with air rigorously excluded. The usual methods are to use VCI3 as the starting material, or to reduce solutions of vanadium(V) or (IV) electrolytically. However, the reduction of pentahalides of Nb and Ta by Na amalgam or Mg, has facilitated the expansion of Nb " and Ta " chemistry particularly with S-and P-donor ligands. 

Tetraruthenium cluster complexes have been synthesized by the reaction of [ Ru(Cl)(P(OMe)3)2 2(/t-Cl)2(/t-S2)] with Mg, Na, or Na amalgam (Scheme 67). The removal of the terminal chlorine atoms from... 

Table 19.7 contains data of Hamed and Nuns [21] for the cell Ag, AgCl, NaCl(m2 = 4), Na(amalgam)-Na(amalgam), NaCl(m2 = 0.1), AgCl, Ag in which both sodium amalgams have the same composition. 

TABLE 19.7. Potentials for AgCl, Na(amalgam) Cells at Several Temperatures... 

Hydrocinnamic Acid or 3-Phenylpropionic Acid, C6HsCH2CH2COOH mw 150.17, crystals, mp 46° si sol in w sol in ale or eth. Prepd by the reduction of cinnamic acid with Na-amalgam... 

V sol in w sol in ethanol and py. Prepn is by redn (hydrogenation) of D-xylose either cata-lytically or by using Na amalgam or by an electrolytic process. Nitration of xylitol yields an expl syrup, Xylitolpentanitrate. C5 H7Ns 015 mw 377.17 N 18.57% OB to C02 +6.36%... 

Fig. 17.48. The reduction of an alkyl aryl sulfone to an alkane. The preparation of the alkyl aryl sulfone (top) is followed by a reduction with Na amalgam (right and bottom).

Yb KIO3 Acid medium, YbCl3 reduced by Na amalgam gives yellow colour - [65]... 

Oxalic acid and napthoresorcinol Yb3+ reduced by Na amalgam gives red colour 3 [66]... 

This is the rarest oxidation state for technetium. The IR spectrum of a solution prepared by the addition of Na amalgam to [Tc2(CO)10] in THF showed two v(CO) bands at 1911 and 1865 cm-1, which were assigned to the carbonyl anion [Tc(CO)5] by comparison with the spectra of [M(CO)5] (M = Mn, Re). Solutions of Na[Tc(CO)5] in THF undergo the expected reactions, including the formation of volatile [HTc(CO)5] on treatment with H3P04 (45). The [Tc(CO)5]- anion has been used as a nucleophile for the preparation of mixed-metal decacar-bonyls (46) by reactions such as... 

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