The trihalides of nitrogen

NF3 is the most stable of the trihalides of nitrogen, being the only one to have a negative value of (Table 14.5). It is a colourless gas which is resistant to attack by acids and alkalis, but is decomposed by sparking with H2 (equation 14.54). The resistance towards hydrolysis parallels that observed for the carbon tetrahalides Section 13.8). 

NF3 is the most stable of the trihalides of nitrogen, being the only one to have a negative value of A[H° (Table 15.5). 

The trihalides of nitrogen provide sharp contrasts in their stability and reactivity. NF3 is a stable gas that resists hydrolysis by water, NCI3 is an unstable liquid that decomposes explosively and hydrolyzes readily, andNBr3 is very unstable and decomposes explosively even at very low temperatures. Pure NI3 has not been isolated. Crystals resulting from the action of iodine on ammonia are represented by the formula NI3 NH3. This unstable adduct, often prepared for chemical demonstrations, can be exploded by the slightest tickling with a feather. 

The trihalides of nitrogen are all known, but tend to be rather unstable. 

When looking for other molecules with lone electron-pairs that perhaps will combine these electrons with d electrons of platinum metals, there are, first of all, the trihalides of the nitrogen-phosphor group of elements. Complexes formed from chlorides of the platinum... 

Boron trihalide adducts of 4-methylpyridine show halogen exchange behavior similar to that of the adducts of trimethylamine 10), and isolation of individual mixed-halogen species is feasible here too. The stability of nitrogen-donor adducts of the mixed boron trihalides parallels the stability of nitrogen-donor adducts of BH2X and BHX2 which have been more extensively studied 19, 153,156). 

Trihalides of nitrogen with fluorine and chlorine can be isolated, but with bromine and iodine only the ammonia complexes, NBr3(NHg)g and Nl3(NH3), are known. 

A convenient apparatus for this transfer from the ampul is shown in Fig. 116. The frozen ampul, the neck of which is scored by a scratch mark, is attached to the frit arm by thick-walled rubber tubing, and the complete apparatus is evacuated. The scored portion of the neck extends inside the wider-bore frit arm. The apparatus is filled with nitrogen, and the ampul is allowed to warm until the methyltitanium trihalide has melted and dissolved in its oc-... 

Halogens. Halogens react with ammonia to yield haloamines. The eventual trihalides formed can react with excess ammonia to produce unstable ammoniates, which can decompose to give ammonium salt and nitrogen. This reaction has some implication for water purification using chlorine as disinfectant. Aqueous solutions of chloramine, NHjCl, are formed by the reaction of aqueous ammonia and chlorine or hypochlorite solutions ... 

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