University:
Brigham Young University
Course:
CHEM 102 | Concepts of Chemistry
Academic year:

2023
Views:

322

Pages:

9
Author:

InterstellarInsight

R-S Nomencleature:- This nomencleatine is goveren by CIP roule (Cahn. Ingold, Prelog) on Priority rule. They suggest a Simple Procedure to assign a Configuration interm of Prefix R and 's fore an optically active Compound. Following steps are involved for R-s nomencieature:- Step-1 Arrirange all the four different groups or atoms of Chiral Carbon atorm in their priority order. Step-2 Aftere the arrangement, assign a no. to each off atom on groups. (a) The atom with highest atomic no. get the highest Priority while the atom with lowest atomic no. least Priority. get the (b) If the ist atom of two or more groups are Tame. then the relative Priority is determine by Comparing the and are even 3rd atom of nespective group. (C) Treiple bond will get more double and fingle bond. Priority than followed by (d) If the atoms are isotope of Same element, then the atom with higher mass no. get lighen Preionity. Step-3 → It the groups are arranged and rotation is Clockwise from highest Priority group to lowest Priority group, then it is called R-Configuration on Rectus- Configuratiom (Rigut) Ite Bimilarly the → rotation is anticlockwise then it is Called 5- Configuration ore Sinister-Configuration (Left) Prochirality- A Carbon atom bonded to two identical group (a, a) and two different groups (b,c) is called Pro-chiral Carbon atorn because of One group a' is reeplaced by another group d ie. different from a, bec. - Then the Carton become Chiral. This Property of Prochoral Carben atom is called Prochorality. Replacement of hydrogeo Ha by Br leads to a chical Compound with S-configuration, then ho is called Pro-s. Similarly, replacement of hydrogeo He by Br Leads to a Chiral Compound with R-Confd, then the is called Pro-R. Racemisation:- When two enant fomer of a substance are mixed in exactly equal amount, then the mixture is optically inactive. This is because, When PPL is Passed througle its aqueous solution, then notation due to One isomen in One direction Cancel the rotation due to othere isomern in opposite direction. Such an optically inactive mixture is Called racemic Mixture on racemic modification & is represented by de ort. This Phenomenon is called as racemisation). Resolution of Racemic mixture;- The repanation of racemic mixture into its two enantiomern, is called resolution. Method of resolution of racemic mixture care- a) Mechanical method Biochemical method Chemical method 4) kinetic method e) Selective adsorption method Specific Rotation :- Specific rotation of a Compound is defined as the rotation Produced by Compound when PPL is Passed through One decimeter of the Bolution having conc 1 g/ml at 20c using Bodium ligut. [x] = Observed angle of cotation D l x c degree Where. &= Observed augle of rotation in dey I = length of sol in don. C = Conc of son in gorans t = Temperature employed D: Wavelength of D-Line of sudiwon (58134)