Tin IV nitride

Tin(rV) nitride, Sn3N4, was first isolated in 1999 from the reaction of Snl4 with KNH2 in liquid NH3 at 243 K followed by annealing the solid product at 573 K. Su3N4 adopts a spinel-type structure, related to that of y-Si3N4 described above. Tin(IV) nitride is the first nitride spinel that is stable under ambient conditions. 

The Pb ion does not exist in aqueous solution, and the value of °(Pb /Pb +) given in Table 14.1 is for the halfreaction 14.93 which forms part of the familiar lead-acid battery (see equations 14.3 and 14.4). For half-reaction 14.93, the fourth-power dependence of the half-cell potential upon [H ] immediately explains why the relative stabilities of Pb(II) and Pb(IV) depend upon the pH of the solution (see Section 8.2). 

for example, Pb02 oxidizes concentrated HCl to CI2, but CI2 oxidizes Pb(II) in alkaline solution to Pb02. It may be noted that thermodynamically, Pb02 should oxidize water at pH = 0, and the usefulness of the lead-acid battery depends on there being a high overpotential for O2 evolution. 

Yellow crystals of Pb(S04)2 may be obtained by electrolysis of fairly concentrated H2SO4 using a Pb anode. However, in cold water, it is hydrolysed to Pb02, as are Pb(IV) acetate and [NH4]2[PbCl6] (see Section 14.8). The complex ion [Pb(OH)g] forms when Pb02 dissolves in concentrated KOH solution, but on dilution of the solution, Pb02 is reprecipitated. 

The following terms were introduced in this chapter. Do you know what they mean  

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In discussing bonds formed between the group 14 elements and nitrogen, two compounds of particular importance emerge cyanogen, C2N2, and silicon nitride. Tin(IV) nitride has recently been prepared. 

BN Na,P SnCh SnCh HCl boron nitride trisodium phosphide sodium phosphide tin dichloride tin tetrachloride hydrogen chloride tin(II) chloride tin(IV) chloride stannous chloride stannic chloride borazon... 

Tin nitride Sn3N4 is obtained by thermal decomposition of the product of reaction from liquid ammonia and tin(IV) chloridct, and also by atomization of a tin cathode in an atmosphere of nitrogen. Sn3N4 is reported stable to water, but to form tin(IV) chloride and ammonium chloride on attack by hydrochloric acid. 

Hardness vs. Composition. Hardness varies with composition as shown in Fig. 1The hardness of the interstitial nitrides of Group IV (TiN, ZrN, and presumably HfN) reaches a maximum at stoichiometry while the maximum hardness of the nitrides of Group V (NbN, TaN, and presumably VN) occurs before stoichiometry is reached. A similar behavior is observed for the corresponding carbides (see Fig. 4.5 of Ch. 4). 

The existence of ternary carbides and nitrides was discussed in Ch. 4, Sec. 5.0. As shown in Fig. 11.6, TiN has complete mutual solubility witii the other nitrides of Groups IV and V while mutual solubility with the... 

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