| geometric isomerism | A form of isomerism displayed by unsaturated or ring compounds where free rotation about a bond (usually a carbon-carbon bond) is restricted; e.g., the isomerism of a cis-or trans-compound as in oleic acid and elaidic acid. Compare: cis-, entgegen, trans-, zusammen. (05 Mar 2000) |
|---|---|
| stereochemical isomerism | The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (12 Dec 1998) |
| structural isomerism | Isomerism involving the same atoms in different arrangements; e.g., butyric acids, leucine and isoleucine, glucose and fructose. (05 Mar 2000) |
| isomerism | A condition in which several chemical compounds have the same molecular formula (have the same number and type of atoms) but, because those atomsare arranged differently in each, they all have different chemical properties. (09 Oct 1997) |
| optical isomerism | Stereoisomerism involving the arrangement of substituents about an asymmetric atom or atoms (usually carbon) so that there is a difference in the behaviour of the various isomers with regard to the extent of their rotation of the plane of polarised light. Compare: stereoisomerism. (05 Mar 2000) |
| cis-trans isomerism |
Compounds with double bonds, or alicyclic rings can exhibit isomerism, due to the attached groups lying above or below the plane of the oduble bond or ring. The "cis" compound is the one with the groups on the same side of the bond, and the "trans" has the groups on the opposite sides. The different isomers have different physical and chemical properties. Examples are fumaric acid/maleic acid and 1,3-dimethylcyclohexane - see below:
Ãâó: www.ch.ic.ac.uk/vchemlib/mol/glossary/
|
|---|
Á¦Ç°¸í |
ÆÇ¸Å»ç |
º¸ÇèÄÚµå | ¼ººÐ/ÇÔ·® | ±¸ºÐ/º¸Çè±Þ¿© |
|---|
Á¦Ç°¸í |
ÆÇ¸Å»ç |
º¸ÇèÄÚµå | ¼ººÐ/ÇÔ·® | ±¸ºÐ/º¸Çè±Þ¿© |
|---|