N-Halides

Explosive Properties. N trifluoride is the most stable of the N halides, but it can detonate in the presence of hydrazoic acid (Ref 13) or org compds (Ref 10). Ozone, which is one by-prod of the electrolysis of Amm bifluoride, was found by Ruff and coworkeis to cause violent expins in the reaction vessels and gas lines. They found that the ozone could be removed by passing the off-gas thru pyrolusite, thus reducing considerably the expin hazard (Ref 1). It also decomps explosively above 100° (Ref 2)... 

Most compounds R3EX can be described as essentially ionic, exhibiting structures that exhibit directed n(halide) - a (E- C) contacts between pyramidal R3E+ cations and X- anions.3... 

Synthesis of 2,6-Bis(imino)pyridine Iron(n) and Cobalt(n) Halides... 

One of the drawbacks of the Sandmeyer reaction is the number of competing side reactions leading to the formation of biaryls, azo compounds and phenols. A recent procedure to maximise the yield of aryl halide involves treatment of the arylamine with t-butyl nitrite and anhydrous copper(n) halide (the chloride or the bromide) in acetonitrile at 65 °C.28 The method is illustrated by the preparation of p-chloronitrobenzene (Expt 6.73) the overall reaction may be represented as ... 

Grignard reagents, prepared from alkyl halides, react with a mercury(n) halide that contains the same halogen as the reagent to form alkyl mercury(n) halides ... 

Under similar conditions, 2-D coordinated polymers of some other 1-alkyltetrazoles 31 were synthesized using copper(ll), iron(ll), and nickel(n) halides and nitrates <2002IC6468, 2002ICA(335)61, 2003M255, 2003ICA(350)57, 2003JCD3628>. In these complexes, halide and nitrate anions are included in the inner coordination sphere. 

Hydrazine forms68 a 2 1 complex with eobalt(ii) bromide Co(N2H4)Br2,2H20 and phenylhydrazine forms69 2 1 complexes with all cobalt(n) halides. The latter seem to be octahedral in the solid state but dissolve in acetone to give blue solutions with characteristic pseudotetrahedral electronic spectra. 

The formation of hydrated cobalt(n) complexes of pyridine carboxylic acids and the subsequent thermal decomposition to lower hydrates has been documented.82,83 Cobalt(n) halides react with 6-methylpicolinic acid (6-mpaH), picolinic acid (paH), nicotinic acid (naH), and pyridine-2,6-dicarboxylic acid (2,6-py) to form Co(6-mpa) (6-mpaH)X (X = Cl, Br, or NCS), Co(naH)nX2 (n = 2, X = Cl, Br n = 3, X = NCS), and Co(pa)(paH)X, EtOH (X = Cl, Br, or NCS) which are all probably octahedral.83 6-Methylpicolinic acid also formed Co(6-mpaH)4X2,2HX (X = Cl or Br) which were formulated [(6-mpaH)2H]2[CoX4], since the electronic spectra show absorptions characteristic of tetrahalogenocobaltate(n) ions.83... 

The open-chain quadridentate thioether, l,2-bis(o-methylthiophenylthio)ethane (33), forms a trans-octahedral [CoLI2] complex, readily decomposed by donor solvents. Other cobalt(n) halides did not react with (33), and no cobalt(n) complexes formed with the 1,3-propane or 1,4-butane analogues.168... 

Looking at Fig. 5.32, it can be seen that there is a fairly significant fit. The anions, particularly those of the group n halides, are not very consistent with the Stokes-Einstein relation. However, their poorer fit is offset by the better Stokes-Einstein behavior of the cations. The relatively good fit of the cations tempts one to conclude that there is a particular reason for the deviations of the anions. Some attempts have been made... 

All four mercury (n) halides are known, and their properties are hsted in Table 5. All can be prepared by the direct combination of the appropriate halogen with mercury metal. Except for the fluoride, which has bonds that are predominantly ionic in character, they are characterized by relatively low-melting and boiling points and display surprising solubility in organic solvents such as acetone. Their coordination chemistry has been reviewed. A summary of the structural features of the crystalline mercury(II) halides is given in Table 6. 

The Sn-S, Sn-Se, and Sn Te bonded compounds are less reactive than Sn-O bonded species, e g. towards water. Reactions proceed with a variety of electrophilic reagents (e.g. alkyl halides, halogens, and snlfur(n) halides). 

Organoytterbium(n) halides provide higher 1,2-selectivity in reactions with a,3-unsaturated aldehydes and ketones than their Grignard counterparts, although yields are sometimes low (equation 93). - ... 

Structural and IR Data for [Tc N] Halide Complexes and Some [Tc 0] ANALOGS... 

In the reduction of dienes and polyenes, combinations of a metal hydride and transition metal halides can also be used. Sodium borohydride and cobalt(n) halides were applied in the selective reduction of unsatnrated carbon-carbon double bonds . LiAlIU, in the presence of Zr -, Ti" - or -halides, is a selective reducing agent of dienes . The following reactions were carried out with sodium borohydride and iodine (equation 28) . 

---