Structural Formulas
From WikidChem
Contents |
Slide 26
Couper drew structural formulae not only to represent the atomic composition of molecules, but also to show the sequence of the bonded atoms (constitution).
[edit]Slide 27
Couper's structural formulae used dotted lines to represent bonds between atoms. In his representation of methanol (CH3-OH), he showed a central carbon atom bonded to three hydrogens and a hydroxyl group. His formula for ethanol (CH3CH2-OH) showed one carbon atom bonded to three hydrogen atoms, and the other carbon atom bonded to two hydrogen atoms and a hydroxyl group. Thus, these formulae were accurate in showing the constitution of the molecules-- the nature of the bonds (single, double, or triple) and the sequence of the bonded atoms.
[edit]Slide 28
A printing error resulted in the omission of a carbon-carbon bond in this formula for diethyl ether.
[edit]Slide 29
Couper recognized that C2 always behaved as a single atom, and that there were no instances in which a carbon1 with an equivalence value of 6 appeared. Thus, he changed the notation for carbon to just C, and defined it with an equivalence value of 12.
