Nitrogen" Suppt. Vol. B 1 describes the compounds of nitrogen with noble gases and, in the major part, binary compounds composed of one nitrogen atom and hydrogen. Nitrogen hydrogen compounds with two and more nitrogen atoms are covered in "Nitrogen" Suppt. Vol. 82. There is some information on various nitrogen-noble gas species, to a large extent because of the interest in their bonding behavior. Experimental data have been obtained chiefly for some singly charged cations, particularly those formed by argon Like ArN + and ArNi. The existence of others has only been established by mass spectrometry. The binary compounds of nitrogen and hydrogen comprise NH, NH , NH , NH , the corre 2 4 5 sponding ions, and some adducts. NH and NH1 are not treated. The predominant part 3 of the volume covers the description of the molecules NH and NH . 8oth species are present 2 in photolytic processes in the atmosphere. They play an essential role in combustion systems regardless of whether the nitrogen stems from the nitrogen-containing fuel or from the air. Thus, much work has been devoted to the understanding of the nitrogen chemistry in combustion and in the atmosphere. The production and detection methods as weiL as the reactions have been comprehensively described. ln addition detailed information is given on the spectral behavior, the knowledge of which is important for detecting the mole cules and for studying their kinetics.
The volume describes all compounds that consist of bromine and fluorine and/or chlorine and may additionally contain noble gases, hydrogen, oxygen, and nitrogen. The description of chemical and physical properties of binary compounds between bromine and fluorine takes up most of the volume, because this class of compounds includes BrF3 and BrF5 which have considerable technical interest. Especially the the oxidizing and fluorinating properties of BrF3 make it a convenient reactant for the preparation of inorganic fluorides. On the other hand, the diatomic molecule BrF is well-characterized by spectroscopic methods, but its chemistry is less known because of its instability. Other neutral species, such as Br2F, Br2F2, BrF2, and BrF6, only exist in matrices at low temperatures, and the existence of BrF4 and BrF7 is even doubted. Some of the ions, including BrF2+, BrF2-, Br3F10-, BrF4+, BrF4-, BrF6+, and BrF6-, can be stabilized as salts.
This volume deals with binary nitrogen-hydrogen compounds having two, three, or more nitrogen atoms (with the exception of hydrazine) and with compounds composed of nitrogen, hydrogen, and noble gases. The important species containing two nitrogen atoms, N2H, N2H+, N2H2, and N2H3 are described in the first part of this volume. Next, chains and cycles consisting of three nitrogen atoms are covered. Among them hydrogen azide or hydrozoic acid, HN3, is the most extensively studied nitrogen-hydrogen compound described in this volume. With increasing number of nitrogen atoms, the thermochmical stability declines. There is, however, a considerable amount of information on molecules with up to nine linked nitrogen atoms. Several of these binary nitrogen-hydrogen compounds could only be isolated in the form of organic derivatives. In that case, data available for the organic derivatives were included if they were characteristic for the particular unsubstituted N-H parent compound.
The volume describes the chemical and physical properties of the approximately 80 known bromine compounds and ions which contain oxygen and/or nitrogen, and which may include hydrogen as well. The class of bromine-oxygen and bromine-oxygen-hydrogen compounds comprises several well-known species. Their description accounts for approximately three-quarters of the volume. The BrO radical and the BrO3 ion are the most and best studied among all binary bromine-oxygen species. BrO was recently recognized to play a role in some reaction sequences depleting the ozone concentration in the stratosphere. Bromate-ion-driven chemical oscillator systems have attracted much interest in recent decades. Thus data on single reaction steps which involve BrO3, BrO2, and the oxoacides of bromine - HBrO, HBrO2, and HBrO3 - are reviewed in detail; a comprehensive description of the oscillating systems, however, is beyond the scope of this volume. The remaining one-quarter of the volume is devoted to bromine-nitrogen and bromine-nitrogen-oxygen compounds. Bromine azide and nitrosyl bromide are the most comprehensively studied of these, accounting for almost half of this section.
The volume covers the interactions and compounds of gold with noble gases, hydrogen, oxygen, nitrogen, fluorine, and chlorine. Along with the expanding use of gold in recent years, for example in electronics and in aerospace equipment, there has been an impressive series of advances in the chemistry of gold compounds and of discoveries of unusual oxidation states. Hydrogen forms a nonstoichiometric solid phase, AuHn at high pressures with a maximum value of n=0.43. Hydrides such as AuH exist only in the gaseous state. The predominant oxide is that of gold(III), Au2O3. The lower-valent oxides Au2O and AuO form during anodic oxidation of gold. There still is no evidence for definite gold(I) and gold(II) fluorides, whereas AuF3 is stable below 500oC, while it is immediately decomposed by water. The first pentavalent gold compound, (Xe2F11)AuF6, was synthesized in the early 1970's. Later, a number of new Auv compounds were prepared, among them AuF5. The highest oxidation state of gold ever realized is +7 in the recently synthesized AuF7. The major portion of this volume deals with gold chlorine-compounds. Solid AuCl has a polymeric structure with Au and Cl atoms forming zigzag chains, while the gaseous compound consists of dimeric Au2Cl2 molecules. AuCl2, which was first thought to be a compound of gold(II), actually is a mixed-valence gold(I)-gold(III) compound with the net formula Au4Cl8. The crystal structure of AuCl3 comprises discrete, planar Au2Cl6 molecules. The most important water-soluble gold compounds are the tetrachloroauric acid, HAuCl4, and its sodium and potassium salts, easy to obtain by dissolution of gold in aqua regia. They are used besides AuCl3 to prepare nearly all other gold compounds, mostly in solution via the tetrachloroaurate (III) ion ÄAuCl4Ü-.
Thank you for visiting our website. Would you like to provide feedback on how we could improve your experience?
This site does not use any third party cookies with one exception — it uses cookies from Google to deliver its services and to analyze traffic.Learn More.