Halides and Cyanides

Ironfm).—Halides and Cyanides. The results of a spectroscopic and potentiometric study on the KCl-FeCl3 system are best explained in terms of the equilibria  

Herbcr and H. Werner, Synth. React. Inorg. Metal-Org. Chem., 1975,5,381. 

Kuroda, S. Goto, and Y. Yano, Chem. Letters, 1975,1085. 

Inomota, T. Takeuchi, and T. Moriwaki, Bull. Chem. Soc. Japan, 1976,49,1568. 

The FeCla-MQ (M = Li, Rb, or Cs) systems have also been studied. FeAlCl is formed by heating iron and aluminium in a chlorine stream or heating FeCl3 and anhydrous Reaction of (N2Hg)FeF5 with excess XeF gives the antiferro- 

Similar reactions with NO were also briefly reported. CU2O reacts with aqueous KI to give Culj and CuIJ.  

The reaction of K3[Cu(CN)J with CuS04,6H20 gives the mixed Cu Cu complex, [Cu Cu2(CN)4],5H20. The structure of the similar complex, 

822 Y Xakeda, T. Hashino, H. Miyamoto, F. Kanamuru, S. Kume, and M. Koizumi, J. Inorg. Nuclear Chem., 1972, 34, 1599. 

X-Ray structural studies on LaFe(CN)6,3H20 show that [FeCh]-octahedra are linked by CN-bridges to nine-co-ordinate [LaN6(H20)3] units.253 Oxidation of [Fe(CN)(,]3 ionsbyhydroxylamine is catalysed by [(edta)Fe]3+ and aquo-copper(n) species, but pentacyanoaquoferrates and other secondary reaction products are not significant catalysts.254 

Feitknecht, R. Giovanoli. W. Michaelis, and M. Miillcr, Helv. Chim. Acta. 1973. 56. 2847. 1,2 M. Kiyama and T. Takada. Bull. Client. Soc. Japan, 1973, 46. 1680. 

---

Reaction between alkyl halides and cyanide ion Elimination of water from N-alkylformamides Reduction of isocyanates... 

The conversion of benzaldoxime [157] into benzonitrile and benzamide by catalytic amounts of potassium halides and cyanide has also been attributed to proton abstraction by the anion (Rasmussen, 1977). Nucleophilic addition was thought to be unlikely, since the anion reactivities in (26) in acetonitrile with... 

Copper(i).—Halides and Cyanides.cation, [Me2N=CH2] , which has been reported previously by Eschenmoser (Symposium on Stereochemistry, Sheffield, 1970) is potentially useful in stabilizing low-valent metal complexes, and its reaction with Cu(CO)Cl has been examined. The results are outlined in Scheme 9. 

The preparation of nitriles by SN2 reactions between alkyl halides and cyanide ion has been mentioned previously (Section 8-7F) and this is the... 

The complications which result from the hydrolysis of alkali metal cyanides in aqueous media may be avoided by the use of non-aqueous solvents. The one most often employed is liquid ammonia, in which derivatives of some of the lanthanides and of titanium(III) may be obtained from the metal halides and cyanide.13 By addition of potassium as reductant, complexes of cobalt(O), nickel(O), titanium(II) and titanium(III) may be prepared and a complex of zirconium(0) has been obtained in a remarkable disproportion of zirconium(III) into zirconium(IV) and zirconium(0).14 Other solvents which have been shown to be suitable for halide-cyanide exchange reactions include ethanol, methanol, tetrahydrofuran, dimethyl sulfoxide and dimethylformamide. With their aid, species of different stoichiometry from those isolated from aqueous media can sometimes be made [Hg(CN)3], for example, is obtained as its cesium salt form CsF, KCN and Hg(CN)2 in ethanol.15... 

Electronic spectra of square-planar halides and cyanides... 

Fig. 10.44. The structures of Gilman cuprates in halide- and cyanide-free solution dimer-to-monomer conversion. The dimer is a contact ion pair and occurs in diethyl ether. The monomer is a solvent-separated ion pair and occurs in the more solvating ethers THF (with the stoichiometry mentioned) and DME, respectively. (DME stands for 1,2-dimethoxyethane since DME is a bidentate ligand, the stoichiometry given in this figure does not apply only two DME molecules are bound per lithium).

Bach, S. B. H., and Ault, B. S., Infrared matrix isolation study of the hydrogen-bonded complexes between formaldehyde and the hydrogen halides and cyanide, J. Phys. Chem, 88, 3600-3604 (1984). 

In principle, these complexes undergo a one-electron oxidation and two successive one-electron reductions. The potential and reversibility of the oxidation step depend very much on the axial ligand E. Oxidation of halide and cyanide complexes is followed by rapid loss of the oxidized axial ligand [130, 131] ... 

In addition to complex halides and cyanides, the metals form many ammines. Organic compounds of nitrogen, arsenic, sulphur, selenium and tellurium arc other possible ligands. Many complexes with bidentate ligands are known. The various types of isomerism are common thus Pd(NH3)2Cl2 occurs as the pink [Pd (NH3)4] [PdCy and as the yellow cis and trans isomers ... 

Selenocyanates (RSeCN), which are employed for the synthesis of selenides and selenoesters, are usually derived from selenenyl halides and cyanide ion (or silyl cyanate) [38 k, 40]. Alkylation of potassium selenolate (KSeCN) with alkyl halides is an alternative means of preparation of aliphatic selenocyanates (Scheme 15.13)... 

Stannylsilane (51) reacts selectively with fluoride ion on the silicon site, generating stannyl anion, which can cleave vinyl and aryl iodides under very mild conditions to give vinyl and aryl anions, respectively. Likewise, other halides and cyanide ions attack selectively at the harder silicon site of 51, chemoselectivity of which can be explained on the basis of HSAB theory. An application of the stannyl anion chemistry for the synthesis of (-)-cephalotaxine (56) via spirocyclization is shown in Scheme 3.28 [31]. 

---