| A | B |
|---|
| isomers | different compounds with same formulas |
| constitutional isomers | same formula butdifferent order fo attachment |
| stereoisomers | smae molecular formulas, same connectivity, different orientations in space (ex. cis, trans isomers in cycloalkanes) |
| chiral | molecule that is not superimposable on its mirror image |
| achiral | lacks chirality |
| plane of symmetry | plane that divides an object so that one side is a reflection of the other |
| center of symmetry | point where identical components of the object are located equidistant and opposite the point along any axis |
| enantiomers | stereoisomers that are nonsuperimposable mirror images of eachother |
| stereocenter, stereogenic center | atom that has 4 different atoms or groups attached ot it |
| naming stereocenters with the R,S system | atoms bonded to stereocenter given priority based on highest atomic number (or the first difference); atoms of double bonds are doubled and triple bonds are tripled; if groups are read clockwise its R, counterclockwise is S |
| n sterocenters give ? maximum stereoisomers | 2^n |
| diastereomers | stereoisomers that are not mirror images of each other |
| meso compounds | achiral compound possessing two or more stereocenters, special symmetry (summetry that biscets the molecule into two mirror halves) that reduced the number of stereoisomers to fewer than the 2^n max |
| chiral cis and trans isomers | stereoisomers that are mot mirror images, they are diastereomers |
| enantiomers properties in achiral environments | idenitcal physical and chemical props, different rotation fo pp light |
| diastereomers in achiral or chiral environments | different physical and chemical props |
| optically acitve | compounds that rotate pp light, like all enantiomers |
| pp light | light vibrating in only parallel planespolarimeter |
| polarimeter | measures the ability of a cmpd to rotate the pp light (light source, polarizing filter, analyzing filter, sample tube) |
| props rotation depends on | concentration, legth of sample tube, temp, solvent, wavelength fo light |
| observed rotation | number of degrees through which a compound totated the pp light |
| dextrorotatory | cmpd that rotated light to the right, (+) |
| levorotatory | cmpd that rotated light to the left, (-) |
| specific rotation | observed rotation divided by (length x concentration) |
| racemic mixture | mixture of equal amounts of two enantiomers, specific rotation is 0, optically inactive, (+-) |
| optical purity | way to describe the composition of a mixture of anantiomers, specific rotation mixture / specific rotation pure x 100% |
| enantiomeric excess (ee) | percentage difference in number of moles of each enantiomer in a mixture compared with the total number of moles of both, (%R-%S) |
| resolution | separatoin fo racemic mixture into its enantiomers, by means fo diastereomeric salts (convert enantioners into two diastereomers which can be separated based on different phy/chem props with the use fo an enantiomerically pure chiral resolving agent) or enzymes as resolving agents (used as chiral chatalyts to synthesize pure enantiomers) |
| enzymes | chiral catalysts |
| stereospecific | reactions where only one enantiomer is produced |
