Prefixes — or combining forms?

With “endings” out of the way, shall we move on to “prefixes”?

In a number of IUPAC publications, the entities that are referred to as “prefixes” include

• Numerical prefixes [1], aka multiplicative prefixes [2] ‘di’, ‘tri’, ‘tetra’, etc. and ‘bis’, ‘tris’, ‘tetrakis’, etc.;
• Prefixes indicating atoms or groups, either substituents, e.g. ‘hydro’, ‘chloro’, ‘cyano’, or ligands, e.g. ‘hydrido’, ‘chlorido’, ‘cyanido’ [2];
• Prefixes ‘de’ and ‘an’ in subtractive nomenclature as well as their combinations with the names of atoms or groups, e.g. ‘dehydro’, ‘anhydro’, ‘demethyl’, ‘deoxy’, etc.;
• The ‘a’ prefixes for skeletal replacement and Hantzsch-Widman names, e.g. ‘aza’, ‘oxa’, ‘thia’, as well as their combinations with multiplicative prefixes, as in ‘dioxa’ [3];
• Geometrical and structural prefixes such as catena-, arachno-, quadro-, etc. [3];
• Configurational prefixes of inositols such as allo-, chiro-, cis-, epi-, muco-, myo-, neo- and scyllo- [4];
• Prefixes retro- and ‘apo’ in nomenclature of carotenoids [5];
• Configurational prefixes in nomenclature of carbohydrates [6];
• Prefix sn- (for stereospecifically numbered) in nomenclature of glycerol derivatives [7];
• Prefixes ‘abeo’, ‘cyclo’, ‘homo’, ‘nor’ and ‘seco’ in nomenclature of natural products [8];
• Prefix ‘poly’ and qualifiers such as branch-, net-, or star- in polymer names [9].

I like “qualifiers”. I also don’t mind saying “multiplicative prefix” or “configurational prefix” as long as we understand that they actally might be not prefixes, just like vegetarian sausages are not sausages and white chocolate is not chocolate.

Content morphemes

At this point, it might be useful to mention that morphemes could be divided into two classes: content morphemes (i.e. those that have independent meaning) and functional morphemes. All content words contain at least one content morpheme. In English, content words include nouns, adjectives, adverbs and most verbs, while functional morphemes include conjunctions, prepositions, pronouns and articles as well as affixes. These two classes are sometimes referred to as “open class” and “closed class”, respectively. New morphemes are easily added to the former and hardly ever to the latter.

Now to continue with the list that I started earlier.

6. Since chemical names consist of content words (ii), they are open-class.
7. Every content word contains at least one root (iv) which is a content (open-class) morpheme.
8. Affixes are functional (closed-class) morphemes.
9. New chemical names are formed by combining existing content morphemes with functional morphemes or adding new content morphemes.

OK? Still no objections?

Endings

First of all, let’s have a look at endings, also known as inflectional suffixes. In highly inflected languages such as Latin or Russian endings change depending on number, gender and case. In Russian, there are three noun declensions:

Case	feminine (I)		neuter (II)		masculine (II)		feminine (III)
	singular	plural	singular	plural	singular	plural	singular	plural
Nominative	кислота	кислоты	основание	основания	спирт	спирты	соль	соли
Genitive	кислоты	кислот	основания	оснований	спирта	спиртов	соли	солей
Dative	кислоте	кислотам	основанию	основаниям	спирту	спиртам	соли	солям
Accusative	кислоту	кислоты	основание	основания	спирт	спирты	соль	соли
Instrumental	кислотой	кислотами	основанием	основаниями	спиртом	спиртами	солью	солями
Prepositional	кислоте	кислотах	основании	основаниях	спирте	спиртах	соли	солях
	acid	acids	base	bases	alcohol	alcohols	salt	salts

Step back

Those of you who were reading my blog this year might have noticed that words such as “prefix”, “suffix” or “ending” are used extensively in chemical nomenclature. And those of my readers who remember (from their school days perhaps) the basics of morphology also might have been wondering whether these terms have anything to do with their counterparts in linguistics. That’s what happens when you use terms without defining them first.

Before moving any further with nomenclature, it could be helpful to clarify our terminology.

Alas, it looks like the task is more complex than I thought.