Fused Ring and Bridged Fused Ring Nomenclature
(IUPAC Recommendations 1998)

Appendix 1

Continued from References

Continue with Appendix 2

Appendix 1

Hydrocarbon parent components in order of decreasing seniority.

1Polyphenylene (C6)m .C2mcf. 33 (m > 8)(see FR-2.1.5)
2Polynaphthylene (C6)2k .C2kcf. 25 (k > 4)(see FR-2.1.6)
3Polyacene (C6)ncf. 39 (n > 10)error details(see FR-2.1.2)
4Polyaphene (C6)ncf. 31 or 35 (n > 10)error details(see FR-2.1.3)
5Polyhelicene (C6)ncf. 32 (n > 9)(see FR-2.1.7) Note a
6Nonaphenylene (C6)9.C18cf. 33 (m = 9)(see FR-2.1.5)
7error details
8Decacene (C6)10cf. 39 (n = 10)error details(see FR-2.1.2)
9Decaphene (C6)10cf. 31 (n = 10)(see FR-2.1.3)
10Ovalene (C6)10
11Decahelicene (C6)10cf. 32 (n = 10)(see FR-2.1.7) Note a
12Octaphenylene (C6)8.C16cf. 33 (m = 8)(see FR-2.1.5)
13Tetranaphthylene (C6)8.C8cf. 25 (k = 4)(see FR-2.1.6)
14Nonacene (C6)9cf. 39 (n = 9)error details(see FR-2.1.2)
15Nonaphene (C6)9cf. 35 (n = 9)(see FR-2.1.3)
16Nonahelicene (C6)9cf. 32 (n = 9)(see FR-2.1.7) Note a
17Heptaphenylene (C6)7.C14cf. 33 (m = 7)(see FR-2.1.5)
18Octacene (C6)8cf. 39 (n = 8)error details(see FR-2.1.2)
19Octaphene (C6)8cf. 31 (n = 8)(see FR-2.1.3)
20Pyranthrene (C6)8
21Octahelicene (C6)8cf. 32 (n = 8)(see FR-2.1.7) Note a
22Hexaphenylene (C6)6.C12cf. 33 (m = 6)(see FR-2.1.5)
23Heptacene (C6)7cf. 39 (n = 7)error details(see FR-2.1.2)
24Heptaphene (C6)7cf. 35 (n = 7)(see FR-2.1.3)
25Trinaphthylene (C6)7(see FR-2.1.6)

Three naphthalene
systems - hence k = 3

26Coronene (C6)7
27Heptahelicene (C6)7cf. 32 (n = 7)(see FR-2.1.7) Note a
28Rubicene (C5)2.(C6)5
29Pentaphenylene (C6)5.C10cf. 33 (m = 5)(see FR-2.1.5)
30Hexacene (C6)6cf. 39 (n = 6)error details(see FR-2.1.2)
31Hexaphene (C6)6(see FR-2.1.3)

six rings hence n = 6

32Hexahelicene (C6)6(see FR-2.1.7) Note a

six rings hence n = 6

33Tetraphenylene (C6)4.C8(see FR-2.1.5)

four benzene rings hence m = 4

34Pentacene (C6)5cf. 39 (n = 5)error details (see FR-2.1.2)
35Pentaphene (C6)5(see FR-2.1.3)

five rings hence n = 5

36Perylene (C6)5
37Picene (C6)5
38Pleiadene (C6)3.C7
39Tetracene (C6)4(see FR-2.1.2) Note b

four rings hence n = 4

40Tetraphene (C6)4cf. 35 (n = 4)error details(see FR-2.1.3)
41Chrysene (C6)4
42Pyrene (C6)4
43Triphenylene (C6)4
44Aceanthrylene C5.(C6)3
45Acephenanthrylene C5.(C6)3
46Fluoranthene C5.(C6)3
Note c
47Anthracene (C6)3Note a
48Phenanthrene (C6)3Note d
(1H-form shown)
(9H-form shown)
51Acenaphthylene C5.(C6)2
52Biphenylene C4.(C6)2Note e
53s-Indacene(C5)2.C6Note e
54as-Indacene(C5)2.C6Note e
55Polyalene (Cn)2 (n > 6)Heptalene (n = 7) shown
(see FR-2.1.4)
56Azulene C5.C7
57Naphthalene (C6)2
(1H-form shown)
59Pentalene (C5)2(see FR-2.1.4)
60Polyalene (Cp)2cf. 50 (p = 3 or 4)(see FR-2.1.4)
61[p]AnnuleneCp (p > 6)Note f
62Benzene C6
63[p]AnnuleneCp (p < 6)Note g


a. Non-standard numbering.

b. Formerly called naphthacene which is still used by CAS and Beilstein.

c. CAS and Beilstein includes trindene (cyclopenta[e]-as-indacene).

d. Non-standard orientation, hence non-standard numbering.

e. In the previous edition of these rules (rule A-21.1, ref 3) indacene was preferred to biphenylene. This is now reversed to follow FR-2.3.c (see also Table 20, ref 3a).

f. These names only apply for a parent component; otherwise cycloalka is used as a fusion prefix (see FR-2.1.1).

g. Only [5]annulene may be used as a parent e.g. cyclobuta[1,2:3,4]di[5]annulene. The prefix cycloalka- is used for attached components (see FR-2.1.1).

References for this Section

3. IUPAC Nomenclature of Organic Chemistry, Sections A and B, 1st edition, 1958; 2nd edition, 1966; 3rd edition (combined with section C), 1971; 4th edition (combined with sections C, D, E, F and H), 1979.

3a. A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993, Blackwell Scientific Publications, 1993.

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