Pharmacy Gyan

        CONFORMATIONAL ANALYSIS

Different spatial arrangements of atom in a molecule which are readily interconvertable by rotation of single bond are configuration.
Configuration represent confirmer which are readily inter convertible to they are not be separated.


The study of existence of configuration in molecule and their physical and chemical property is k/as CONFIRMATION ANALYSIS.

The structure of confirmers is of 2 types

1.STAGGERD -: When tarsinal angle b/w 2 atom molecule is 60°.

2.ECLIPSED -: Group of front and rear carbon overlap.

Confirmational analysis

         Conformational analysis in ethane

*In the structure of ethane 3 hydrogen is bonded with both carbon
*In the special arrangements with bond is rotated 60° then total six types of structure is obtained in which three is staggered from and three is eclipsed from.


        Conformational analysis in butane

*In the structure of n-butane hydrogen and 1 methyl group is present on both carbon.
*During conformational analysis after reaction of 60° in each time total 6 structure is formed in which full staggered is 1,fully eclipsed 1 , partial staggered 2 and portial eclipsed 2.

                 
                Energetic in n-butane

* In the confirmational analysis total 6 structure are form in which 3 is staggered from and other 3is edipsed.
* In staggered from no steric hindrance occurs so they are stable and their energy is low.
* But in the case of eclipsed from bilky group are comes closer and dur to steric hindrance their stability is reduce and potential energy is increase.


Conformational analysis in cyclohexane 

Cyclohexane is a cyclic compound which show confirmational analysis by rotation or straining of bonds Mohr and Sachse in 1890-91 gives the idea of confirmational analysis in cyclohexane.
*After angel stain cyclohexane show 2 form of structure.


*The chair form is rigid and where it is trans form into boat form same angulr deformation is Nesserey.
*The energy barrier in this process is about 9-11 kd/mole.
*This value is large enough for each confirmation to retain its identity.
*The chair and boat form are triangle stain but because of difference in staining strain and border a position state the 2 form are different in energy content.

   
                   Energy in cyclohexane

*When chair form structure of cyclohexane is convert into boat form then they change into total five structure-
1. Chair
2. Half chair
3. Twisted boat
4. Half boat
5. Boat
*They energy of chair from is highest becoz this is similar to the eclipsed form.
*The energy of boat form is very less is about to 1.5 kcl.


Stereo isomerism in biphenyl compound ( Atrop isomerism) 

*Those single bonded compound in which 2 cyclic group are bulky group present,  they also show restricted rotation, that way these compound biphenyl also show stereo isomerism.
* Stereo isomerism in biphenyl compound is also k/as atrop isomerism.
* The term atrop isomerism consist of 3 words.
A + Trop + isomerism
A means NON
TROP means TERM
*It means those isomerism which can not tern into another axis.
     
              Atrop isomerism in biphenyl



*There are basically 2 condition for spoeing atrop isomerism.
1. There should be any functional group or atom at the ortho position.
2. The group or atom should not be simiiat position 1 and 2,and 3 and 4.
*Diphenyl compound can be diverded into 2 equal half so they can be symmetrical if there is no any group at ortho position.

*But when different atom or group is attached with ortho position then will be asymmetrical and show atrop isomerism.

Stereospecific and steroselective reaction

*Those chemical reaction after which a stereo compound is form which is either may be destroyed or levo then this is called stereospecific reaction.
*In this type of reaction both dextro and levo compound can be synthesized in different proportion.



             Stereo selective reaction

These chemical reaction after which only one dextro or one levo compound is form and which is 100% selective they are called Stereo selective reaction.

               Geometrical isomerism 

The isomerism which due to restricted or forzen rotation about a bond in a molecular is k/as Geometrical isomerism.

Pharmacygyan by NITESH VISHWKARMA

The rotation either about a double bond or about single bond or in a cyclic compound can be seen.

Geometrical isomerism is exhibited by variety of compound lile
--- Compound Containing a double bond
(C=C) (C=N) (N=N)


Compound containing cyclic structure homocyclic Or hetrocylic.


Compound having restricted rotation about a single bond. Due to steric hindrance in biphenyl compound.


CONDITION FOR GEOMETRICAL ISOMERISM
A compound will show geometrical if it fulfill following three conditions.

1- There should be atleast one double bond            b/w and carboy, carbon and nitrogen.
2- There should be restricted rotation in                  double bond.
3- There should be at lest one similar group             b/w both double bond carbon.

NOMENCLATURE OF GEOMETRICAL ISOMERISM

GEOMETRICAL ISOMERISM can be nomenclature by 3 method -:

1. Cis- trans nomenclature
2. E and Z nomenclature
3. Syn and Anti nomenclature

1. CIS TRANS NOMENCLATURE

*There should be atleast one double bond b/w C=C, C=N.
*There should be restricted rotation in double bond.
*Tere should be atleast one similar group b/w both double bond carbon.
*If the similar atom are group is present on the same axis an both carbon then it is called CIS ISOMER and if they are present on opposite axis then they are TRANS ISOMER.


2. E and Z NOMENCLATURE

*There should be atleast one double bond b/w carbon and C, C and N or N and N.
*Four atoms or group which are held with both carbon should be different.
*There should be restricted in rotation.  E and Z is the derived from two Jarmon words -:

Z – ZUSSAMAN – CIS (SOME SIDE)
E – ENTEGGEN – TRANS (OPPOSITE SIDE)

EXAMPLE –
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3. SYN – ANTI NOMENCLATURE

*This kind of isomerism is shown by those compound which have atleast one  C=N OR N=N.

It is of two types

1. SYN – SAME  SIDE – CIS
2. ANTI – OPPOSITE – TRANS

*If the heigher polar group is present on the same side of carbon and nitrogen atom then it is called SYN and if height polar group are present an opposite side then is called ANTI.

*Determination of configuration of geometrical isomerism.

There are a number of method to determine the configuration of geometrical isomerism. 

1. Physical method
2. Cyclisation method
3. Conversion method 

1.Physical method -: The melting point and intently of absorption of cis isomer are lower than trans.
* The boiling point solubility heat of combution heat of hydrogenation, densiy, reflective index, dipole movement and dissociation constant of cis are greater then trans isomer.
By the comparison of above there physical properties we can determine the configuration of isomers.

2.Cyclisation Method -: Intermolecular reaction are more likely to occurs the closer together are the reaction group in the molecular, cis isomer undergoess the cyclisation reaction bit the trans isomer does not go for cyclisation reaction.

Ex. Malic acid after dehydration gives a cyclic compound maloc anhydride but fumaric acid do not gives dehydrated reaction so molic acid is cis isomer and feumeriv acid is trans isomer.

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3.Conversion method -: In this method unkown compound is convert compound after chemical reaction conversion method we can configuration of compound.

Ex. If tri chloro erotenic after oxidation gives fumeric acid then it is trans and if it gives malic acid then it is cis isomers.

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                                             COLLOIDAL DISPERSION

Dispersion medium – A dispersion system is define as a system during which dispersed particles is distributed uniformly thought-out dispersing phase .

Colloidal dispersion- System during which dispersed particles size range 1nm to 1um is distributed uniformly thought out the dispersing phase are called as colloidal dispersion.

Pharmacygyan by Nitesh Vishwkarma

                                              Classification of colloidal dispersion

S.N.	DISPERSION MEDIUM	DISPERSED PHASE	EXAMPLES
1	GAS	LIQUID	FOG
2	GAS	SOLID	SMOKE
3	LIQUID	GAS	FOAM(ARESOAL)
4	LIQUID	SOLID	COLLOIDAL GOLD IN WATER
5	LIQUID	LIQUID	OIL GLOBULES OR WATER GLOBULES
6	SOLID	GAS	SOLID FOAM
7	SOLID	LIQUID	MINIRAL OIL IN WATER
8	SOLID	SOLID	COLLOIDAL GOLD IN GLASS