A phenyl group (Ph or C6H5) is the term used for a benzene ring directly attached to a substituent, such as in triphenylphosphine (C6H5)3P or phenyl alcohol (PhOH, a.k.a. “phenol”). Do not confuse with benzyl (Bn), which is the substituent C6H5CH2– ! (e.g. benzyl alcohol, C6H5CH2OH).