Systematic Nomenclature
From WikidChem
Contents |
Slide 39
Kekule, in Ghent in 1865, with some associates. They discovered the structure of benzene! More about that in later slides.
[edit]Slide 40
Kekule in Bonn, sporting a crazy beard. As Kekule grew older, his sphere of influence (and lab) grew larger.
[edit]Slide 41
This slide demonstrates the consequential nature of chemistry in the later 19th century along with some slight cause-and-effect trends. As Lavoisier said, Facts, Ideas and Words were necessary for a sound and complete understanding of chemistry. Tied in to this "words" component is a consistent system for naming compounds (or, if you will, a systematic nomenclature). This nomenclature will ideally both support and logically suggest a form of notation consistent with this nomenclature. Lavoisier's "words" can be generalized to "extra-verbal" ways of conveying the compound one has in mind, for example with pictures (notation) and models.. Take, for example, ethanol in today's nomenclature. The name supports the notation (CH3CH2OH), in that it explains the molecule's notation in visible segments, and both then fit with the model, which again provides clear information about the atoms and their linking.
[edit]Slide 42
Hofmann, in his support of the radical theory, crafted a system for naming the hydrocarbon radicals. As you can see, there is a resemblance between his idea and today's system. Rather than the butyrum->butyric acid->butyl naming, however, Hofmann used the fact that butyl compounds contained four compounds to inspire the root "Quart." To that, Hofman added a vowel dependent on the number of hydrogens in the compound. A fully hydrogen saturated four-carbon compound would be "quartane," and its radical (one hydrogen less) would be "quartyl." A four-carbon compound with only eight hydrogens would be "quartene," and its radical "quartenyl." Et cetera. Really, this naming system doesn't matter a huge lot, although I suppose it could be a 4-point short answer question. What's more important is an understanding of the process that 1800s chemists were using and the logical interconnectiveness of it. Also, we can use these older nomenclature systems as a means of analyzing the roots of names we use today (particularly the -ane, -ene, -yne suffixes denoting the nature of hydrocarbon unsaturation).
