Prefixes acids

Chemical formulas describe the simplest atom ratio (empirical formula), actual atom number (molecular formula), and atom arrangement (structural formula) of one unit of a compound. An ionic compound is named with cation first and anion second. For metals that can form more than one ion, the charge is shown with a Roman numeral. Oxoanions have suffixes, and sometimes prefixes, attached to the element root name to indicate the number of oxygen atoms. Names of hydrates give the number of associated water molecules with a numerical prefix. Acid names are based on anion names. Covalent compounds have the first word of the name for the element that is leftmost or lower down in the periodic table, and prefixes show the number of each atom. The molecular (or formula) mass of a compound is the sum of the atomic masses in the formula. Molecules are depicted by various types of formulas and models. 

The same nomenclature has been adopted for amino-acids, the configurational family to which the a-carbon atom belongs being denoted by the prefixes d- and L-. 

Double bonds m the mam chain are signaled by the ending enow acid and their position IS designated by a numerical prefix Entries 6 and 7 are representative carboxylic acids that contain double bonds Double bond stereochemistry is specified by using either the cis-trans or the E-Z notation... 

It IS understood that a amino acids occur as their l stereo isomers unless otherwise indicated The d notation is explicitly shown when a D amino acid is present and a racemic amino acid is identified by the prefix dl... 

Systematic names formed by applying the principles of substitutive nomenclature are single words except for compounds named as acids. First one selects the parent compound, and thus the suffix, from the characteristic group listed earliest in Table 1.7. All remaining functional groups are handled as prefixes that precede, in alphabetical order, the parent name. Two examples may be helpful ... 

When side chains of two or more different kinds are attached to a cyclic component, only the senior side chain is named by the conjunctive method. The remaining side chains are named as prefixes. Likewise, when there is a choice of cyclic component, the senior is chosen. Benzene derivatives may be named by the conjunctive method only when two or more identical side chains are present. Trivial names for oxo carboxylic acids may be used for the acyclic component. If the cyclic and acyclic components are joined by a double bond, the locants of this bond are placed as superscripts to a Greek capital delta that is inserted between the two names. The locant for the cyclic component precedes that for the acyclic component, e.g., indene-A - -acetic acid. 

Acid Anhydrides. Symmetrical anhydrides of monocarboxylic acids, when unsubstituted, are named by replacing the word acid by anhydride. Anhydrides of substituted monocarboxylic acids, if symmetrically substituted, are named by prefixing bis- to the name of the acid and replacing the word acid by anhydride. Mixed anhydrides are named by giving in alphabetical order the first part of the names of the two acids followed by the word anhydride, e.g., acetic propionic anhydride or acetic propanoic anhydride. Cyclic anhydrides of polycarboxylic acids, although possessing a... 

The bivalent radical —NH— linked to two identical radicals can be denoted by the prefix imino-, as well as when it forms a bridge between two carbon ring atoms. A trivalent nitrogen atom linked to three identical radicals is denoted by the prefix nitrilo-. Thus ethylenediaminetetraacetic acid (an allowed exception) should be named ethylenedinitrilotetraacetic acid. 

Acyl derivatives, RCO—NH—OH and HjN—O—CO—R, are named as A-hydroxy derivatives of amides and as O-acylhydroxylamines, respectively. The former may also be named as hydroxamic acids. Examples are A-hydroxyacetamide for CH3CO—NH—OH and O-acetylhydrox-ylamine for HjN—O—CO—CH3. Further substituents are denoted by prefixes with O- and/or A-locants. For example, C5H5NH—O—C2H5 would be O-ethyl-A-phenylhydroxylamine or A-ethox-ylaniline. 

Trivial acid names are formed by changing the endings -oic acid or -ic acid to -onitrile. For example, CH3CN is acetonitrile. When the —CN group is not the highest priority group, the —CN group is denoted by the prefix cyano-. 

Bivalent Sulfur. The prefix thio, placed before an affix that denotes the oxygen-containing group or an oxygen atom, implies the replacement of that oxygen by sulfur. Thus the suffix -thiol denotes — SH, -thione denotes —(C)=S and implies the presence of an =S at a nonterminal carbon atom, -thioic acid denotes [(C)=S]OH [(C)=0]SH (that is, the O-substituted acid and the 5-substi-... 

The prefix thioxo- is used for naming =S in a thioketone. Sulfur analogs of acetals are named as alkylthio- or arylthio-. For example, CH3CH(SCH3)OCH3 is l-methoxy-l-(methylthio)ethane. Prefix forms for -carbothioic acids are hydroxy(thiocarbonyl)- when referring to the O-substituted acid and mercapto(carbonyl)- for the S-substituted acid. 

Organosulfur Halides. When sulfur is directly linked only to an organic radical and to a halogen atom, the radical name is attached to the word sulfur and the name(s) and number of the halide(s) are stated as a separate word. Alternatively, the name can be formed from R—SOH, a sulfenic acid whose radical prefix is sulfenyl-. For example, CH3CH2—S — Br would be named either ethylsulfur monobromide or ethanesulfenyl bromide. When another principal group is present, a composite prefix is formed from the number and substitutive name(s) of the halogen atoms in front of the syllable thio. For example, BrS—COOH is (bromothio)formic acid. 

Sulfur Acids. Organic oxy acids of sulfur, that is, —SO3H, —SO2H, and —SOH, are named sulfonic acid, sulfinic acid, and sulfenic acid, respectively. In subordinate use, the respective prefixes are sulfo-, sulfino, and sulfeno-. The grouping —SO2—O—SO2— or —SO—O—SO is named sulfonic or sulfinic anhydride, respectively. 

Peroxo- Group. When used in conjunction with the trivial names of acids, the prefix peroxo- indicates substitution of —O— by —O—O—. 

Replacement of Oxygen by Other Chalcogens. Acids derived from oxoacids by replacement of oxygen by sulfur are called thioacids, and the number of replacements are given by prefixes di-, tri-, and so on. The affixes seleno- and telluro- are used analogously. 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

The nitroparaffins are named as derivatives of the corresponding hydrocarbons by usiag the prefix "nitro" to designate the NO2 group (1), eg, 1,1-dinitroethane, CH2CH(N02)2- The salts obtained from nitroparaffins and the so-called nitronic acids are identical and may be named as derivatives of either, eg, sodium salt of i7ti-nitromethane, or sodium methanenitronate [25854-38-0]. 

Ternary compounds are also named by citing the more electropositive constituent first. The various oxidation states of the more electropositive element are designated by a system of prefixes and terminations added to a stem characteristic of the element, except in the case of coordination compounds (qv). Examples are as follows (see Chlorine oxygen acids and salts) ... 

Some elements form acids with more than four oxidation states, requiring other combinations of prefixes and suffixes intermediate... 

There are two broad classes of organic peroxyacids peroxycarboxyUc acids, R[C(0)00H], where R is an alkyl, aralkyl, cycloalkyl, aryl, or heterocycHc group and n = 1 or 2, and organoperoxysulfonic acids, RSO2—OOH. PeroxycarboxyUc acids are commonly named by adding the prefix peroxy to the parent acid as in peroxypropionic acid. The prefix per- is accepted only for the weU-estabHshed products, ie, performic, peracetic, and perbenzoic acids. 

This article uses the former nomenclature. Organoperoxysulfonic acids are named by inserting peroxy in the sulfonic acid name, eg, cyclohexaneperoxysulfonic acid [74232-61 ]. For diacids, the prefixes monoperoxy- or diperoxy- are used, eg, monoperoxysuccinic acid and diperoxyisophthahc acid [1786-87 ]. 

Carbonates are indexed in Chemicaly hstracts under carbonic acid, esters. Symmetrical diesters have the prefix di or bis. Unsymmetrical diesters are listed with the two radicals following each other. For example, ethyl phenyl carbonic diester is C2H OCOOC H. Table 6 Hsts commonly used carbonates, their Chemicaly hstracts Service Registry Number, and formulas. 

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