I was given this formula by my A-level teacher and was curious as to what it means. It seems to be the Greek letter phi. I have searched online and have not been successful. Any help would be greatly appreciated.

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  • $\begingroup$ Didn't you already post this then delete it when I told you the answer...? $\endgroup$ – NotEvans. Sep 8 '16 at 19:27
  • $\begingroup$ Sorry, I meant to ask what the whole of the formulas name is? I gather that the symbol is an old version of Pi but does the equation it is in have a proper name. I apologize, I worded the previous question incorrectly and to avoid any confusion I deleted it. I appreciate your previous reply and did find it helpful but unfortunately it was not the answer I was looking for, for this question but thank you anyway. $\endgroup$ – l1zzy23 Sep 8 '16 at 19:35
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    $\begingroup$ It just means any aromatic group.. it doesn't mean anything specific in the same way that R can be used for anything. I also re-iterate that it isn't used nowadays and doesn't form part of the a-level syllabus $\endgroup$ – NotEvans. Sep 8 '16 at 19:40
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    $\begingroup$ @l1zzy23 Please note that, according to IUPAC recommendations, it is generally not acceptable to use circles to indicate electron delocalization in adjacent fused rings, since such diagrams are at best ambiguous in terms of the character of the shared fusion bond between the rings. $\endgroup$ – Loong Sep 8 '16 at 20:29

According to the Graphical Representation Standards for Chemical Structure Diagrams (IUPAC Recommendations 2008), the Greek lowercase letter phi $(\phi)$ may be used to represent a phenyl group.

It is acceptable to use the Greek lowercase letter phi $(\phi)$ to represent a phenyl group. That abbreviation has a long history, and ambiguity is unlikely since that letter is rarely used for other purposes in chemical structure diagrams.

Representation of phenyl groups

Note that this traditional use is only considered “acceptable”, i.e. not “preferred”.

According to the current version of Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book), the preferred name for the hydrocarbon parent ring component is the retained name chrysene. The indicated numbering of this polycyclic hydrocarbon is is the result of the application of the specific criteria used to number fused ring systems:


Therefore, the complete name for the entire compound given in the question is 1,3,7,9-tetraphenylchrysene.


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