Metal hydride nitrogen hydrides

Indeed, Mann s studies initiated an explosion of interest in transition metal phosphine chemistry. Chatt was Mann s student, and it is interesting to reflect that Chatt employed transition metal salts as a means of derivatising tertiary phosphines. Little did they realise how this area would expand Chatt s influence on metal-phosphine chemistry was profound, and out of it sprung the employment of phosphine complexes as tools for investigations into metal hydrides, nitrogen fixation, the stabilisation of unusual oxidation states, synthesis of metal alkyls and aryls, and the immense practical area of homogeneous and heterogen-... 

The mechanism of this reaction is complex and may vary with the number of alkyl groups on the amide nitrogen. However, the first step is certainly the same as in the other reductions by metal hydrides the hydride adds to the carbonyl to give an alkoxide that is coordinated to a metal (Fig. 18.43). Now, the metal oxide is lost with formation of an iminium ion. There are several possible ways to describe the formation of the iminium ion, but once it is produced, reduction by the metal hydride to give the amine is sure to be rapid. 

Nitriding Metals or Metal Hydrides. Metals or metal hydrides may be nitrided using nitrogen or ammonia. Pure metal powders or pure metal hydride powders yield nitride products that are nearly as pure as the precursors. 

Phosphorus compounds exhibit an enormous variety of chemical and physical properties as a result of the wide range ia the oxidation states and coordination numbers for the phosphoms atom. The most commonly encountered phosphoms compounds are the oxide, haUde, sulfide, hydride, nitrogen, metal, and organic derivatives, all of which are of iadustrial importance. The hahde, hydride, and metal derivatives, and to a lesser extent the oxides and sulfides, are reactive iatermediates for forming phosphoms bonds with other elements. Phosphoms-containing compounds represented about 6—7% of the compound hstiugs ia Chemical Abstracts as of 1993 (1). 

Potassium 3-aniinopropylaniide [56038-00-7] (KAPA), KNHCH2CH2CH2-NH2, pX = 35, can be prepared by the reaction of 1,3-diaminopropane and potassium metal or potassium hydride [7693-26-7] (57—59). KAPA powder has been known to explode during storage under nitrogen in a drybox, and is therefore made in situ. KAPA is extremely effective in converting an internal acetylene or aHene group to a terminal acetylene (60) (see Acetylene-DERIVED chemicals). 

The reduction of iminium salts can be achieved by a variety of methods. Some of the methods have been studied primarily on quaternary salts of aromatic bases, but the results can be extrapolated to simple iminium salts in most cases. The reagents available for reduction of iminium salts are sodium amalgam (52), sodium hydrosulfite (5i), potassium borohydride (54,55), sodium borohydride (56,57), lithium aluminum hydride (5 ), formic acid (59-63), H, and platinum oxide (47). The scope and mechanism of reduction of nitrogen heterocycles with complex metal hydrides has been recently reviewed (5,64), and will be presented here only briefly. 

Newton s second law, L0 nickel, 49, 665 nickel arsenide structure, 201 nickel surface, 189 nickel tetracarbonyl, 665 nickel-metal hydride cell, 520 NiMH cell, 520 nitrate ion, 69, 99 nitration, 745 nitric acid, 629 nitric oxide, 73, 629 oxidation, 549 nitride, 627 nitriding, 208 nitrite ion, 102 nitrogen, 120, 624 bonding in, 108 configuration, 35 photoelectron spectrum, 120... 

R.E. Lyleu. P. S. Anderson, The Reduction of Nitrogen Heterocycles with Complex Metal Hydrides, Advances in Heterocyclic Chemistry, Vol. 6, S. 45, Academic Press, New York 1966. 

One, two, or all three double bonds of certain aromatic nitrogen heterocycles can be reduced with metallic hydrides such as NaBH4 or LiAlH. For a review, see Keay, J.G Adv. Heterocycl. Chem., 1986, 39, 1. 

Imine formation is an important reaction. It generates a C-N bond, and it is probably the most common way of forming heterocyclic rings containing nitrogen (see Section 11.10). Thns, cycliza-tion of 5-aminopentanal to A -piperideine is merely intramolecular imine formation. A further property of imines that is shared with carbonyl groups is their susceptibility to reduction via complex metal hydrides (see Section 7.5). This allows imines to be... 

Most reactions of bromine are highly exothermic which can cause incandescence or sudden increase in pressure and rupture of reaction flasks. There are a number of cases of explosions documented in the literature. (NFPA. 1986. Fire Protection Guide on Hazardous Materials, 9th ed. Quincy, MA National Fire Protection Association) Reactions of liquid bromine with most metals (or any metal in finely divided state), metal hydrides, carbonyls and nitrides can be explosive. Many oxides and halides of nonmetals, such as nitrogen triiodide or phosphorus trioxide, react explosively or burst into flame in contact with liquid bromine. 

---