nonaphane (see Examples 1 and 21)
PhI-2.1. Simplified Skeletal Names
A simplified skeletal name consists of the term "phane" preceded by a name specifying the structure of the simplified parent skeleton; this name is a parent for amplification but for no other operation. The simplification operation must be done in such a way that the amplificants can be expressed by amplification prefixes that are acceptable according to PhI-2.2.1.
Note: It might seem desirable to form simplified skeletal names using the usual hydrocarbon names, i.e., names ending with "ane", rather than to introduce the new ending "phane". However, it is important to have an ending that indicates the presence of a skeletal graph in which some nodes do not represent single atoms. Having "phane" as a compulsory term for all names involving simplification/amplification operations ensures that in normal hydrocarbon names, such as "hexane" or "cyclononane", all nodes will continue to represent single carbon units.
A bond order of one is assumed for all bonds expressed by a simplified skeletal name. Atoms (nodes) not identified by amplification prefixes as "superatoms" represent, by convention, carbon atoms with a bonding number ("valency") of four in accordance with the principles of organic nomenclature. In contrast to such carbon atoms, the bonding number of "superatoms" is unlimited; they never have bonds other than their skeletal bonds.
Note: In a phane parent hydride, therefore, the bonding number ("valency") of a "superatom" always equals the number of bonds connecting it to neighboring atoms of the simplified skeleton, which is clear from the phane parent name. Accordingly, since the bonding number of a superatom is unlimited, there will be simplified skeletons for which a corresponding hydrocarbon structure is not possible. In order to name such skeletons, extension of the long established principles for naming hydrocarbons in systematic nomenclature is needed. These extensions will be described in a forthcoming publication.
Superatoms of a simplified skeletal name are assigned the lowest locant or the lowest set of locants, consistent with the numbering of the skeletal class to which it belongs. The lowest set of locants is the one that has the locant with the lowest numerical value at the first point of difference when the sets are compared term by term in order of increasing value (refs. 1b, 2b).
PhI-2.1.1. Unbranched Acyclic Simplified Skeletons
The name of an unbranched acyclic simplified parent skeleton consists of a numerical term, "tri", "tetra", etc., indicating the number of nodes in the chain followed by the term "phane". The nodes of the chain are numbered consecutively from one end to the other and superatoms are given preference for low numbers.
Example:
nonaphane (see Examples 1 and 21)
In the simplified skeletal name "nonaphane", the numerical term "nona" indicates that there are nine nodes in the simplified parent skeleton and the term "phane" indicates the presence of at least one node representing a multiatomic (cyclic) structural unit. The locant set "1,3,6,9" is lower than "1,4,7,9", and is therefore correct.
PhI-2.1.2. Monocyclic Simplified Skeletons
The name of a monocyclic simplified parent skeleton consists of the prefix "cyclo", followed by the name of the corresponding unbranched acyclic simplified parent skeleton (see PhI-2.1.1). The nodes of the cyclic graph are numbered consecutively and "superatoms" are given preference for low numbers.
Note: The name "cyclopropaphane" rather than "cyclotriphane" has been used in the Beistein Handbook of Organic Chemistry (ref. 14), but neither "cyclopropaphane" nor "cyclobutaphane" is used in these recommendations.
Example:
cycloheptaphane (see Examples 6, 10 and 18)
In the simplified skeletal name "cycloheptaphane", the numerical term "hepta" indicates that there are seven nodes in the simplified parent skeleton. The term "phane" indicates the presence of at least one node representing a multiatomic (cyclic) structural unit, and the prefix "cyclo" indicates that the graph is monocyclic. The locant "1" must be assigned to a "superatom"; the locant set "1,4" is lower than "1,5" and is therefore correct.
PhI-2.1.3. Multicyclic Simplified Skeletons without Free Spiro Nodes
The name of a simplified skeleton that contains bridgehead nodes (refs. 1c, 2c), but no free spiro nodes (refs. 1d, 2d) is formed in accordance with principles of the extended von Baeyer system (refs. 1e, 2e, 15). Superatoms are given preference for low numbers.
Example:
bicyclo[8.6.0]hexadecaphane (see Example 7)
In the simplified skeletal name "bicyclo[8.6.0]hexadecaphane", the prefix "bicyclo" indicates that there are two rings. The bridge descriptor describes the ring structure in terms of a sixteen-membered main ring [8 + 6 + 2 (the bridgehead nodes)] with a bridge consisting of a bond, i.e., zero nodes, which divides the main ring into an eight-membered and a ten-membered ring. The numerical term "hexadeca" denotes the presence of sixteen skeletal nodes and the term "phane" indicates that at least one node represents a multiatomic (cyclic) structural unit. The locant set "1,10,12" is lower than "1,10,15", and is therefore correct.
PhI-2.1.4. Multicyclic Simplified Skeletons with Spiro Nodes but No Bridgehead Nodes
The name of a multicyclic simplified skeleton with "free spiro unions" (refs. 1d, 2d) but no bridgehead nodes (refs. 1c, 2c) is formed according to the normal rules for naming spiro hydrocarbons having only monocyclic components (refs. 1f, 1g, 2f, 2g, 16).
PhI-2.1.4.1. Monospiro Simplified Skeletons
The name of a simplified skeleton having a single free spiro node linking two monocyclic simplified skeletons is formed according to the normal rules for naming monospiro hydrocarbons having only two monocyclic components (refs. 1f, 2f, 16). Superatoms are given preference for low numbers.
Example:
spiro[5.7]tridecaphane (see Example 15)
In the simplified skeletal name "spiro[5.7]tridecaphane", the term "spiro" indicates that there is one free spiro union. The ring descriptor describes the ring structure in terms of a six-membered ring [5 + 1 (the spiro node)] and an eight-membered ring [7 + 1 (the spiro node)]. The numerical term "trideca" denotes the presence of thirteen skeletal nodes and the term "phane" indicates that at least one node represents a multiatomic (cyclic) structural unit. The locant set "3,6,8" is lower than "3,6,12", and is therefore correct.
PhI-2.1.4.2. Linear Unbranched Multispiro Simplified Skeletons
The name of a simplified skeleton consisting of an unbranched linear arrangement of monocyclic simplified skeletons each connected by a free spiro union is formed according to the normal rules for naming dispiro and polyspiro hydrocarbons having only monocyclic components (refs. 1g, 2g, 16). Superatoms are given preference for low numbers. Branched multispiro simplified sleletons are possible beginning with trispiro systems. In reference 16, the use of spiro atom locants as superscripts is recommended for all spiro systems consisting of only monocyclic components beginning with trispiro. These locants distinguish between unbranched and branched systems.
Example:
spiro[5.2.2.612.39.26]tricosaphane (see Example 17)
In the simplified skeletal name "trispiro[5.2.2.612.39.26]tricosaphane", the term "spiro" preceded by the numerical term "tri" indicates the presence of three free spiro unions. The ring descriptor describes the ring structure in terms of, in order, a terminal six-membered ring [5 + 1 (the spiro atom)], another six-membered ring [2 + 2 (the second and sixth numbers) + 2 (the spiro atoms)], a seven-membered ring [2 + 3 (the third and fifth numbers) + 2 (the spiro atoms)], and a seven-membered terminal ring [6 + 1 (the spiro atom)]. The superscript locants indicate that the fourth, fifth, and sixth segments between the spiro atoms terminate at the spiro atoms with the locants 12, 9, and 6, respectively. The numerical term "tricosa" denotes the presence of twenty-three skeletal nodes and the term "phane" indicates that at least one node represents a multiatomic (cyclic) structural unit. The locant set "3,6,9,12,15" is lower than "3,6,9,12,16" and is therefore correct.
PhI-2.2. Amplification Prefixes
An amplification prefix specifies a multiatomic (cyclic) unit of structure that replaces a node of a simplified skeleton, thereby identifying a "superatom". Amplification prefixes are immediately followed by the simplified skeletal name forming an inseparable unit, the phane parent name. In the terminology of published IUPAC rules and recommendations for naming organic compounds, such prefixes are called "nondetachable" (refs. 1h, 2h). Phane nomenclature requires a separate amplification prefix for each ring or ring system in the structure.
PhI-2.2.1. Parent Hydride Names for Deriving Amplification Prefix Names
PhI-2.2.1.1. An amplification prefix name is derived from a name for a cyclic parent hydride. The latter includes monocycles and polycycles with the maximum number of noncumulative double bonds ["mancude" (ref. 17) systems] (refs. 1i, 2i, 18), bridged fused ring systems (refs. 1j, 2j, 18), saturated monocycles (refs. 1k, 2k, 19), saturated bicycloalkanes and polycycloalkanes (von Baeyer ring systems) (refs. 1e, 2e, 15), and spiroalkanes (refs. 1f, 1g, 2f, 2g, 16). Numbering of the cyclic parent hydride from which the amplification prefix is derived is retained.
Note: Ring systems with names that include fusion prefixes, such as "benzo" in "benzo[a]acridine, and bridge prefixes, such as "ethano'' in "9,10-ethanoanthracene" are approved names for deriving amplification prefix names. Thus, fusion and bridging prefixes are not used with phane parent hydride names.
PhI-2.2.1.2. Names with "hydro" prefixes, such as "9,10-dihydroanthracene", or subtractive endings, such as "ene" in "cyclohexene", are not used to derive names for amplification prefixes. "Spirobi-" names, such as "1,1'-spirobi[indene]", spiro ring systems with at least one fused or polycycloalkane component, such as "spiro[1,3-dioxolane-2,1'-indene]", ring assembly names, such as "2,2'-binaphthalene", and ring names containing traditional skeletal replacement ("a") prefixes, such as "oxa", "aza", "sila" in names like 1-azabicyclo[2.2.2]octane and 5-silaspiro[4.5]decane are also not approved for forming amplification prefix names.
PhI-2.2.1.3. The term "parent hydride name" excludes names with substitutive suffixes, such as "ol", "one", "oic (acid)", and "ylium", from use for deriving amplification prefix names. Similarly, names with substitutive prefixes, such as "ethyl" or "dibromo", are excluded, as are functional class names and conjunctive names, such as "benzyl chloride" and "benzeneacetic acid", respectively.
PhI-2.2.1.4. Names corresponding to substituted rings or ring systems, such as "toluene" and "styrene", or functional parent compounds, such as "anisole" and "aniline", are not acceptable for derivation of amplification prefix names. However, names of stereoparent hydrides, such as "gonane" and "morphinane", are acceptable.
PhI-2.2.1.5. Names corresponding to partially hydrogenated fused ring systems, such as "indane" and "chromane", are not acceptable for derivation of amplification prefix names. Modifications of the state of hydrogenation are made to the complete phane name and not to individual component names; this methodology will be described in a subsequent set of recommendations.
PhI-2.2.2. Formation of Amplification Prefix Names
The name of an amplification prefix is formed by adding the letter "a" to the name of the corresponding parent hydride, with elision of the final letter "e", if present, for example, "benzena", "furana", "pyridina", "piperidina", "pyrrola", "pyrrolidina", and "1-benzothiophena".
PhI-2.2.3. Order of Citation of Amplification Prefixes
The order of citation of two or more amplification prefixes in a phane parent name is determined by the order of seniority of rings and ring systems. Six criteria, with illustrative examples, are listed here. A full comprehensive order is under review by the Commission.
All heterocycles are senior to carbocycles:
pyridine > phenanthreneA heterocycle with a heteroatom as early as possible in the following list is preferred:
pyrrolidine > furan > thiophene
A ring system with the greater number of rings is preferred:
quinoline > pyridinephenanthrene > naphthalene > benzene
A ring or ring system with the greater number of atoms in the largest individual ring at the first point of difference is preferred:
naphthalene > indenepyridine > 1,2-oxazole
A ring or ring system with the greater number of heteroatoms of any kind is preferred:
pyrimidine > pyridine1,2,5-oxadiazole > pyrrole
A ring or ring system in the lower state of hydrogenation is preferred:
pyridine > piperidinebenzene > cyclohexane
PhI-2.2.4. Multiple Identical Amplificants
Amplificants occuring more than once in a phane parent skeleton are described by an appropriate multiplicative term, either "di", "tri", etc., or "bis", "tris", etc., prefixed to the name of the amplificant. It is not necessary that the identical amplificants also have identical attachment locants.
PhI-2.2.4.1. The multiplicative terms "di","tri", etc., are used in front of simple amplification prefix names.
Examples:
pyrimidinatripyridinanonaphane (see Example 1)(not pyrimidinapyridinapyridinapyridinanonaphane)
dibenzenacycloheptaphane (see Example 10)
(not benzenabenzenacycloheptaphane)
PhI-2.2.4.2. The multiplicative terms "bis", "tris", etc., are used before an amplification prefix when it it begins with a multiplicative term, as in "bicyclo[2.2.2]octane", "1,3-dioxole", and "4,7-dinorgonane" or it begins with a name component that could be preceded by a multiplicative prefix indicating a multiple occurrence of that name component, as in "1,4-oxazine", "2-benzoxepine", and "1,4-methanonaphthalene".
PhI-2.3. Superatom Locants and Amplificant Attachment Locants
After the simplified skeletal name and the amplification prefix names have been determined, the phane parent hydride name is completed by adding the locants for the superatoms (see PhI-1.3) and the attachment locants (see PhI-1.5). These locants are cited before an amplification prefix; the superatom locant is cited first followed by the attachment locants enclosed in parentheses. Specific locants are determined from the numbering procedures given in PhI-3.
In the phane parent hydride name 3(5,2)-pyridina-1(3,1)-piperidina-6(3,1)-naphthalenacyclononaphane (see Example 2), the locants "3", "1" and "6" are superatom locants and the locants in parentheses, "(5,2)", "(3,1)" and "(3,1)", are the respective attachment locants for the three amplificants.
PhI-2.3.1. Superatom Locants
Superatom locants specify the nodes of the simplified skeleton that are replaced by the amplificants specified by the amplification prefixes. Superatom locants are assigned the lowest locants (refs. 1b, 2b) of the phane parent skeleton consistent with the numbering of the class to which it belongs (see PhI-2.1.1 through PhI-2.1.4). An amplification prefix preceded by a multiplicative term indicating the presence of like amplificants requires the appropriate number of superatom locants, which are cited in ascending numerical order.
In the phane parent hydride name 1(1,3),4(1,4)-dibenzenacycloheptaphane (see Example 10), the numerical prefix "di" requires the two superatom locants "1" and "4" which appear in the order "1, 4", each in front of the appropriate parenthetical attachment locants (see PhI-2.3.2).
When like amplificants also have identical attachment locants as described in PhI-2.3.2.1, below, their attachment locants are arranged in ascending numerical order of the first cited corresponding superatom locant.
In the phane parent hydride name 1,9(1),3,5,7(1,4)-pentabenzenanonaphane (see the name in step 1, Example 21), the identical attachment locant sets "(1,4)" for three of the five benzene amplificants are cited only once and follow the superatom locant set "3,5,7"; the two terminal benzene amplificants with the same attachment locant "(1)" are cited only once and follow the superatom locant set "1,9".In the phane parent hydride name 3,15(1,4),6(1,4,2,5),9(1,2,5,4),12(1,5,2,4)-pentabenzenatrispiro[5.2.2.612.39.26]tricosaphane (see Example 17), the numerical prefix "penta" requires five superatom locants, 3,6,9,12,15. In order to show that amplificants "3" and "15" have the identical attachment locant set "(1,4)", they are placed, in ascending order, before this attachment locant set, i.e., 3,15(1,4). See also Example 1.
PhI-2.3.2. Attachment Locants
The locants enclosed in parentheses in a phane parent hydride name are the attachment locants of the amplificant whose position in the phane parent skeleton is specified by a preceding superatom locant. The specific order of the attachment locants in the set describes precisely how their respective amplificant is attached to the rest of the phane parent skeleton. Amplificants retain the locants of the cyclic parent hydride from which they are derived (see PhI-2.2.1.1).
PhI-2.3.2.1. Identical attachment locant sets for multiple identical amplificants are cited only once in a name; they follow the set of superatom locants corresponding to the identical amplificants.
In the phane parent hydride name 4(5,2),12(3,5)-dipyridina-1,8(1,3,5)-dibenzenabicyclo[6.6.0]tetradecaphane (see Example 11), the identical locant sets for the two benzene amplificants "(1,3,5)" are cited only once and follow the superatom locant set "1,8"; the nonidentical attachment locant sets "(5,2)" and "(3,5)" for the two pyridine amplificants must be cited separately.
PhI-2.3.2.2. The locants in an attachment locant set are arranged so that of any two locants the one cited first is adjacent to the lower locant of the phane parent skeleton.
In the phane parent hydride name 1(4)-pyrimidina-3,6(5,2),9(3)-tripyridinanonaphane (see Example 1), the arrangement of the locants in the attachment locant set "(5,2)" for superatoms "3" and "6" indicate that the attachment locant "5" is adjacent to locants "2" and "5" of the phane parent skeleton, respectively.
Note: If the adjacent node of a phane parent skeleton is a superatom, the real adjacent atom is another attachment atom, which has its own superatom locant and attachment locant set. This superatom locant is considered first (the corresponding attachment locant is important in particular cases, which will be discussed in a later set of recommendations).
(1) International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, R. Panico, W. H. Powell and Jean-Claude Richer (Senior Editor), Blackwell Scientific Publications, Oxford, 1993, 190 pp. (a) R-1.2.2.1, p. 23; R-2.3.3.2, p. 43; R-5.5.4.3, p. 95. (b) R-0.2.4.2, p. 17. (c) R-2.4.2.1, especially footnote 29, p. 49. (d) R-2.4.3, p. 51. (e) R-2.4.2, pp. 49-51. (f) R-2.4.3.1, pp. 51-2. (g) R-2.4.3.2, p. 52. (h) R-0.1.8, p. 10. (i) R-2.3.1.2, p. 39; R-2.3.3 (in part), pp. 40-4; R-2.4.1, pp. 44-9. (j) R-2.4.1.2, p. 46. (k) R-2.3.1.1, p. 39; R-2.3.3 (in part), pp. 40-4. (m) R-9.3, p.182. (n) R-2.3.3.2, p. 43. (o) R-2.4.2, pp. 49-51.
(2) International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, 1979 Edition, J. Rigaudy and S. P. Klesney eds., Pergamon Press, Oxford 1979, 559 pp. (a) B-4, pp. 68-70; C-0.6, pp. 123-7; D-1.6, pp. 334-6; D-5.17, p. 388; D-6.71, pp. 419-20. (b) A-2.6, p. 10, footnote; C-13.11(e), p. 99, footnote; D-4.14, p. 374, footnote. (c) A-31.1, p. 31, especially its footnote. (d) Spiro hydrocarbons, p. 37, especially its footnote. (e) A-31.1 and A-31.2, p. 31; A-32, pp. 32-4. (f) A-41.1 and A-41.2, p. 38. (g) A-41.6, p. 39. (h) C-16.11, p. 108. (i) A-11.3, pp. 16-17 (benzene); A-21 and A-22, pp. 20-7; B-2 (in part) and B-3, pp. 55-68. (j) A-34, pp. 35-7; B-15 (in part), pp. 75-6. (k) A-11.1, p. 16; B-2.12 (in part), pp. 62-3; D-4.21, p. 375; D-4.51 (in part), pp. 378-9. (m) Appendix, Table I, pp. 459-60. (n) B-14 (in part), p. 75. (o) B-10.1, p. 72.
(14) Beilstein Handbook of Organic Chemistry, Fourth Edition, 5th Supplementary Series, Vol. 17/2, p. 318; Vol. 18/5, p. 405; and Vol. 19/11, pp. 499-500; Springer-Verlag, Berlin.
(15) International Union of Pure and Applied Chemistry. Division of Organic Chemistry. Commission on Nomenclature of Organic Chemistry, "Extension and Revision of the von Baeyer system for Naming Polycyclic Compounds (Including Bicyclic Compounds)", in preparation.
(16) International Union of Pure and Applied Chemistry. Division of Organic Chemistry. Commission on Nomenclature of Organic Chemistry, "Extension and Revision of the Nomenclature for Spiro Compounds", in preparation.
(17) International Union of Pure and Applied Chemistry. Division of Organic Chemistry. Commission on Nomenclature of Organic Chemistry. Commission on Physical Organic Chemistry, "Glossary of Class Names of Organic Compounds and Reactive Intermediates Based on Structure (Recommendations 1995)", Pure Appl. Chem. 1995, 67, 1307-75.
(18) International Union of Pure and Applied Chemistry. Division of Organic Chemistry. Commission on Nomenclature of Organic Chemistry, "Nomenclature of Fused and Bridged Fused Ring Systems (Recommendations 1998)", Pure Appl. Chem. 1998, 70, 143-216.
(19) International Union of Pure and Applied Chemistry. Organic Chemistry Division. Commission on Nomenclature of Organic Chemistry, "Revision of the Extended Hantzsch-Widman System of Nomenclature for Heteromonocycles (Recommendations 1982)", Pure Appl. Chem. 1983, 55, 409-16. (a) Table 1, p. 413.
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