Boron compounds nomenclature

Another type of anion, confined for practical purposes to boron compounds, has no unshared electrons at the anionic site, and must be thought of as being formed by addition of hydride to a boron atom (or other atom with an incomplete valence shell). Such structures were not anticipated at the time general heterocyclic nomenclature was developed, and they are only recently being fitted into systematic nomenclature (lUPAC Provisional Recommendation 83.2). Proposals for a suffix to indicate such structures are under consideration (1982). 

The nomenclature of boron compounds involves some intricacies. IUPAC rules allow the terms borabenzene or borinine for 2 the older name borin has become obsolete with the recent revision of the extended Hantzsch-Widman system (6). Anions 4 are termed boratabenzene ions an alternative would be borininate instead of the earlier borinate (7). 

Nomenclature. The naming of sodium perborate, one of the most important commercial boron compounds, has long been confused. The tetrahydrate has more recently come to be called the hexahydrate. The crystallographically derived names are used to avoid confusion. The commercial or common names are also given. 

In Chapter 2, the use of a bonds for one special bonding that occurs in one particular boron compound, which was called "diborane", was introduced. An examination of other boron compounds and the nomenclature associated with them is now undertaken. First of all, it should be noted that despite that boron has three electrons in its outer shell and that a trigonal planar bonding pattern is common in molecules such as BF3, etc., the simplest hydride of boron that is normally encountered is not BH3. To the contrary, under normal conditions of temperature and pressure, not only is the smallest boron hydride a dimer, but also two distinct diboron hydride molecules are encountered. 

In conformity with the convention that terminal hydrogen atoms are significant and that the longest chain in this molecule is four atoms long, the simpler name B1B is eschewed. In a manner similar to the methyl group not being represented by a triple underscore, rather being nomenclated as 1 1H, no terminal double underscored boron atoms will be encountered in the proposed nomenclature. Note, however, that there is not a similar limitation for cyclic boron compounds. 

Council of the American Chemical Society, Inorg.Chem., "The Nomenclature of Boron Compounds", 7 (1968) 1945. 

Names used in this cumulative Subject Index for Volumes XVI and XVII, as well as in the text, are based for the most part upon Nomenclature of Inorganic Chemistry, Definitive Rules 1970 Report of the Commission on the Nomenclature of Inorganic Chemistry of the International Union of Pure and Applied Chemistry, Butterworths, London, 1971 [see Pure Appl. Chem. 27(1), 1-110] also on the Tentative Rules of Organic Chemistry—Section D and Nomenclature of Inorganic Boron Compounds [Commission on Nomenclature of Inorganic Chemistry, IUPAC, published in Pure Appl. Chem. 30(3 -4), 683 - 710 (1972)]. All of these rules have been approved by the ACS Committee on Nomenclature. Conformity with approved organic usage is also one of the aims of the nomenclature used here. 

The nomenclature of boron compounds is now at about the same stage as was that of the silicon compounds when the silicon nomenclature was developed. An advisory committee of the Nomenclature Committee of the ACS Division of Organic Chemistry has been studying this problem (5) and expects to present a comprehensive report soon. 

The general formula for boric acid esters is B(OR)2. The lower molecular weight esters such as methyl, ethyl, and phenyl are most commonly referred to as methyl borate [121 -43-7] ethyl borate [130-46-9J, and phenyl borate [1095-03-0] respectively. Some of the most common boric acid esters used in industrial appHcations are Hsted in Table 1. The nomenclature in the boric acid ester series can be confusing. The lUPAC committee on boron chemistry has suggested using trialkoxy- and triaryloxyboranes (5) for compounds usually referred to as boric acid esters, trialkyl (or aryl) borates, trialkyl (or aryl) orthoborates, alkyl (or aryl) borates, alkyl (or aryl) orthoborates, and in the older Hterature as boron alkoxides and aryloxides. CycHc boric acid esters, which are trimeric derivatives of metaboric acid (HBO2), are known as boroxines (1). 

The nomenclature of boron hydride derivatives has been somewhat confusing and many inconsistencies exist in the Hterature. The stmctures of some reported boron hydride clusters are so compHcated that only a stmctural drawing or graph, often accompanied by explanatory text, is used to describe them. Traditional nomenclature systems often can be used to describe compounds unambiguously, but the resulting descriptions may be so long and unwieldy that they are of Htde use. The lUPAC (7) and the Chemical Abstract Service (8) have made recommendations, and nomenclature methods have now been developed that can adequately handle nearly all clusters compounds however, these methods have yet to be widely adopted. Eor the most part, nomenclature used in the original Hterature is retained herein. 

When a boron atom of a borane is replaced by a heteroelement, the compounds are called carbaboranes, phosphaboranes, thiaboranes, a2aboranes, etc, by an adaptation of organic replacement nomenclature. The numbering of the skeleton in heteroboranes is such that the heteroelement is given the lowest possible number consistent with the conventions of the parent borane. Thus C2B2H is dicarba- /(9j (9-pentaborane(5) and could occur as the 1,2-, 2,3-, or 1,5-isomeric forms (l,2-dicarba- /(9j (9-pentaborane(5) [23777-70-0] 2,3-dicarba- /(9j (9-pentaborane(5) [30396-61-3] and... 

Boron Hydrides and Related Compounds," in, G. L. Leigh, ed., Nomenclature of Inorganic Chemist, Becommendations 1990, lUPAC, Oxford, UK, 1990, Chapt. I-ll. 

A remarkable variety of compounds in the Ca-(B,C,N) system has opened a window for research in related fields. With the elements boron, carbon and nitrogen, substance classes such as borocarbides, boronitrides, and carbonitrides can be considered to contain anionic derivatives of binary compounds B4C, BN, and C3N4. Until now, most compounds in these substance classes have been considered to contain alkali, alkaline-earth, or lanthanide elements. Lanthanide borocarbides are known from the work of Bauer [1]. Lanthanide boronitrides represent a younger family of compounds, also assigned as nitridoborates [2] following the nomenclature of oxoborates. 

Wade electron counting rules borane-like cluster nomenclature. On initially studying compounds such as boranes (boron hydrides) and carboranes (or carbaboranes boron—carbon hydrides), Wade (1976) proposed a number of rules which have then been extended to several compounds and which relate the number of skeletal electrons with the structure of deltahedral clusters. A polyhedron which has only A-shaped, that is triangular, faces is also called a deltahedron. 

Thus organometallic compounds can be named by an additive or a substitutive process. Additive nomenclature is applicable to all organometallic compounds, but substitutive nomenclature is arbitrarily restricted to names of derivatives of specific metals, the elements of Groups 14, 15, 16 and 17, and boron. 

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