List of Latin-script trigraphs

A number of trigraphs are found in the Latin script, most of these used especially in Irish orthography.

A

⟨aai⟩ is used in Dutch to write the sound /aːi̯/.

⟨abh⟩ is used in Irish to write the sound /əu̯/, or in Donegal, /oː/, between broad consonants.

⟨adh⟩ is used in Irish to write the sound /əi̯/, or in Donegal, /eː/, between broad consonants, or an unstressed /ə/ at the end of a word.

⟨aei⟩ is used in Irish to write the sound /eː/ between a broad and a slender consonant.

⟨agh⟩ is used in Irish to write the sound /əi̯/, or in Donegal, /eː/, between broad consonants.

⟨aim⟩ is used in French to write the sound /ɛ̃/ (/ɛm/ before a vowel).

⟨ain⟩ is used in French to write the sound /ɛ̃/ (/ɛn/ before a vowel). It also represents /ɛ̃/ in Tibetan Pinyin, where it is alternatively written än.

⟨aío⟩ is used in Irish to write the sound /iː/ between broad consonants.

⟨amh⟩ is used in Irish to write the sound /əu̯/, or in Donegal, /oː/, between broad consonants.

Trigraph (orthography)

A trigraph (from the Greek: τρεῖς, treîs, "three" and γράφω, gráphō, "write") is a group of three letters used to represent a single sound or a combination of sounds that does not correspond to the written letters combined.

Latin-script trigraphs

For example, in the word schilling, the trigraph sch represents the voiceless postalveolar fricative /ʃ/, rather than the consonant cluster */skh/. In the word beautiful, the sequence eau is pronounced /juː/, and in the French word château it is pronounced /o/. It is sometimes difficult to determine whether a sequence of letters in English is a trigraph, because of the complicating role of silent letters. There are few productive trigraphs in English such as tch as in watch, and igh as in high.

The trigraph sch in German is equivalent to the English sh and pronounced ʃ. In the Dutch language, which is closely related to German, this same trigraph is pronounced sx. In neither language is this trigraph regarded as an independent letter of the alphabet. In Hungarian, the trigraph dzs is treated as a distinct letter, with its own place in the alphabet. It is pronounced like an English "j" /dʒ/. The combination gli in Italian can also be a trigraph, representing the palatal lateral approximant /ʎ/ before vowels other than i.

Phenyl group

In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C₆H₅. Phenyl groups are closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, serving as a functional group. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry. Although often depicted with alternating double and single bonds, phenyl groups are chemically aromatic and show nearly equal bond lengths between carbon atoms in the ring.

Nomenclature

Usually, a "phenyl group" is synonymous to C₆H₅– and is represented by the symbol Ph or, archaically, Φ. Benzene is sometimes denoted as PhH. Phenyl groups are generally attached to other atoms or groups. For example, triphenylmethane (Ph₃CH) has three phenyl groups attached to the same carbon center. Many or even most phenyl compounds are not described with the term "phenyl". For example the chloro derivative C₆H₅Cl is normally called chlorobenzene, although it could be called phenyl chloride. In special (and rare) cases, isolated phenyl groups are detected: the phenyl anion (C₆H₅⁻), the phenyl cation (C₆H₅⁺), and the phenyl radical (C₆H₅^·).