1.2 Cyclic Systems
21
Table 1 (continued)
13
14
16
18
33 Heptacene e
10
15
16
34 Pyranthrene
13
14
350valene
a Exceptions from systematic numbering.
b Should really be terphenylene, quaterphenylene etc. because the direct joining of identical components (here o-phenylene) is normally indicated by bi, ter, quater etc. In
addition, this naming procedue is also applicable for higher and meta-linked representatives of this series: pentaphenylene, hexa-m-phenylene, etc.
e Can be continued accordingly: octacene, nonacene... polyacene; likewise: ... polyaphene.
Generally, many isomers are possible for fused systems and these have
to be differentiated by appropriate descriptors. To obtain these, the sides
of the parent component are labelled consecutively by italic letters a, b,
c ... tracing the locant path 1,2,3,4 ... and ignoring potential non-standard numbering. For the attached secondary components the inherent
numbering is maintained. Combination of the partial names is then
effected by intercalating the fusion locants in square brackets between the
component names. Clearly, the principle oflowest locants is to be respected
here too: first, lowest letters for the base component; second, lowest numbers for the higher order components; the sequence of numbers follows
21
Table 1 (continued)
13
14
16
18
33 Heptacene e
10
15
16
34 Pyranthrene
13
14
350valene
a Exceptions from systematic numbering.
b Should really be terphenylene, quaterphenylene etc. because the direct joining of identical components (here o-phenylene) is normally indicated by bi, ter, quater etc. In
addition, this naming procedue is also applicable for higher and meta-linked representatives of this series: pentaphenylene, hexa-m-phenylene, etc.
e Can be continued accordingly: octacene, nonacene... polyacene; likewise: ... polyaphene.
Generally, many isomers are possible for fused systems and these have
to be differentiated by appropriate descriptors. To obtain these, the sides
of the parent component are labelled consecutively by italic letters a, b,
c ... tracing the locant path 1,2,3,4 ... and ignoring potential non-standard numbering. For the attached secondary components the inherent
numbering is maintained. Combination of the partial names is then
effected by intercalating the fusion locants in square brackets between the
component names. Clearly, the principle oflowest locants is to be respected
here too: first, lowest letters for the base component; second, lowest numbers for the higher order components; the sequence of numbers follows