Introduction to organic chemistry - Download as PowerPoint

Document Sample
Introduction to organic chemistry - Download as PowerPoint Powered By Docstoc
					Introduction of Organic Chemistry



                                    1
Syllabus
 Introduction of Organic chemistry
 Classification
 Sources
 Types
 Functional Groups
  (Aldehydes,Ketone,Acids,Alccohols)
 Application
                                       2
Chemistry
 Chemistry is the study of the substances,
  specially their structure, properties,
  transformations and the energy changes
  accompanying these transformation.




                                          3
Branches
 Organic Chemistry
 Inorganic Chemistry
 Physical Chemistry




                        4
Discipline Branches of Chemistry
 Analytical Chemistry
 Industrial Chemistry
 Instrumental Chemistry
 Agriculture Chemistry
 Medicinal Chemistry



                                   5
Organic Chemistry
 The study of Carbon Compounds or better
  to say the chemistry of hydrocarbons and
  their derivatives.




                                         6
ATOMIC STRUCTURE
 Atom: Smallest indivisible particle of an
  element
 Molecule: Smallest particle of matter




                                              7
    Types of Bonding
   Ionic bonding
    – electron is fully transferred from metal to non-
      metal
    – binding is by electrostatic attraction.




                                                         8
Ionic Bonding



       Na            F
   Sodium Atom   Fluorine Atom



                                 9
   Ionic Bonding (2)



           Na                   F
         Sodium ion          Fluoride ion


Attraction between the two ions is electrostatic --
Ionic Bond
                                                      10
A SIMPLE COVALENT BOND

A pair of electrons is shared between the two bonded atoms.




               H.            .H

                                                        11
A SIMPLE COVALENT BOND

                Bonded pair




          H H

                              12
A LEWIS DIAGRAM
                     (note use of lines for bonds)
            ..
      H     O    H
            ..
                                     COVALENT
                                     BONDS
CONSTRUCTED
FROM LEWIS
DOT SYMBOLS
                  ..
       H.        .O .          .H
                  ..                          13
 DRAWING CONVENTIONS
1. A shared pair (bond) is drawn as a line.
                     C       O
2. An unshared pair is shown as a pair of dots.

                         N:
3. The diagram includes formal charges (later).

                         .. +
              H          O         H
                         H                        14
Bonding patterns


   Carbon                        4 bonds
   Nitrogen (phosphorus)    3 bonds
   Oxygen (sulfur)          2 bonds
   Halogen (F, Cl, Br, I)   1 bond
   Hydrogen                 1 bond

                                            15
Normal bonding patterns
    Carbon (4 bonds)     C           C           C       C



    Nitrogen (3 bonds)       N           N           N
     (Phosphorus)


     Oxygen (2 bonds)        O               O
      (Sulfur)


    Halogen (1 bond)             X
      (F, Cl, Br, I)


     Hydrogen (1 bond)           H

                                                             16
Common Bonding Patterns -- Cations

         +                 +         .. +
         C             N             O




                                      +
                       N +            O
                                      ..



                           +          +
                           N          O:



                           +
                           N

                                            17
Common Bonding Patterns -- Anions

                   _
        _     ..        .. _        .. _
    B         C         N
                        ..          O:
                                    ..


                               _
                          ..
                          N
                          ..
                                           18
Types of Carbons
Primary (1°) – attached to only one other carbon

Secondary (2°) – attached to two other carbons

Tertiary (3°) – attached to three other carbons

Quaternary (4°) – attached to four other carbons



                                             19
Hydrocarbons
Aliphatic
  alkanes – contain only single bonds
  (saturated)
  alkenes – contain at least one double bond
           (unsaturated)
  alkynes – contain at least one triple bond
Aromatic
  contain a benzene ring


                                               20
Hydrocarbons
 Alkanes contain only single ( ) bonds and have the
  generic molecular formula: [CnH2n+2]
 Alkenes also contain double ( + ) bonds and have
  the generic molecular formula: [CnH2n]
 Alkynes contain triple ( + 2) bonds and have the
  generic molecular formula: [CnH2n-2]
 Aromatics are planar, ring structures with alternating
  single and double bonds: eg. C6H6




                                                        21
Types of Hydrocarbons




Each C atom is tetrahedral with sp3 hybridized orbitals. They only have single bonds.




             Each C atom is trigonal planar with sp2 hybridized orbitals.
                There is no rotation about the C=C bond in alkenes.
                                                                                22
Types of Hydrocarbons



                  Each C atom is linear with sp hybridized orbitals.




Each C--C bond is the same length; shorter than a C-C bond: longer than a C=C bond.
           The concept of resonance is used to explain this phenomena.       23
Alkanes
1 meth    methane   CH4
2 eth     ethane    C2H6
3 prop    propane   C 3 H8
4 but     butane    C4H10
5 pent    pentane   C5H12
6 hex     hexane    C6H14
7 hept    heptane   C7H16
8 oct     octane    C8H18
9 non     nonane    C9H20
10 dec    decane    C10H22
                             24
                     Naming Alkanes
           C1 - C10 : the number of C atoms present in the chain.




                                                                -
                                                                -
                                                                -
                                                                -




Each member C3 - C10 differs by one CH2 unit. This is called a homologous series.
             Methane to butane are gases at normal pressures.
             Pentane to decane are liquids at normal pressures.           25
26
Nomenclature of Alkyl Substituents




                                     27
navedmalek@yahoo.co.in   28
          Constitutional Isomers
   Substances which have the same molecular
    formula but a different structural formula.

   Isomers differ in connectivity.




                                                  29
30
• A compound can have more than one name, but a
 name must unambiguously specify only one compound
    A C7H16 compound can be any one of the following:




                     navedmalek@yahoo.co.in             31
Functional Groups
   An atom or group of atoms which makes an organic
    compound reactive and decides its functions (properties)
    is called a Functional group.
   In an organic compound, the alkyl group determines the
    physical properties whereas the functional group
    determines the chemical properties of the compound.
   A Functional group can be introduced by displacing
    hydrogen of the hydrocarbon.
   The functional groups are directly attached to the carbon
    of the organic compound.




                                                           32
The basic structure of testosterone (male hormone) and estradiol
  (female hormone) is identical.

 Both are steroids with four fused carbon rings, but they differ in the
  functional groups attached to the rings.
 These then interact with different targets in the body.




                                                                       33
 6 functional groups, all hydrophilic
 In a hydroxyl group (-OH), a hydrogen atom forms a polar covalent bond
  with an oxygen which forms a polar covalent bond to the carbon skeleton.



     Because of these polar covalent bonds hydroxyl groups improve the
      water solubility of organic molecules.
     Organic compounds with hydroxyl groups are alcohols and their names
      typically end in -ol.




                            navedmalek@yahoo.co.in                    34
A carbonyl group (-CO) consists of an oxygen atom joined to the carbon
   skeleton by a double bond.

 If the carbonyl group is on the end of the skeleton, the compound is an
  aldelhyde.
 If not, then the compound is a ketone.
 Isomers with aldehydes versus ketones have different properties.




                                                                      35
A carboxyl group (-COOH) consists of a carbon atom with a
  double bond with an oxygen atom and a single bond to a hydroxyl
  group.

   Compounds with carboxyl groups are carboxylic acids.
   A carboxyl group acts as an acid because the combined
    electro-negativities of the two adjacent oxygen atoms increase
    the dissociation of hydrogen as an ion (H+).




                                                             36
An amino group (-NH2) consists of a nitrogen atom attached to two
   hydrogen atoms and the carbon skeleton.

   Organic compounds with amino groups are amines.
   The amino group acts as a base because amino groups can pick up
    a hydrogen ion (H+) from the solution.
   Amino acids, the building blocks of proteins, have amino and
    carboxyl groups.




                                                                    37
A sulfhydryl group (-SH) consists of a sulfur atom bonded to a
  hydrogen atom and to the backbone.

   This group resembles a hydroxyl group in shape.
   Organic molecules with sulfhydryl groups are thiols.
   Sulfhydryl groups help stabilize the structure of proteins.




                                                                  38
A phosphate group (-OPO32-) consists of phosphorus bound to four
  oxygen atoms (three with single bonds and one with a double
  bond).

   A phosphate group connects to the carbon backbone via one
    of its oxygen atoms.
   Phosphate groups are anions with two negative charges as two
    hydrogens have dissociated from the oxygen atoms.
   One function of phosphate groups is to transfer energy
    between organic molecules.




                                                            39
Functional Groups




           navedmalek@yahoo.co.in   40
Functional Groups




           navedmalek@yahoo.co.in   41
        Classes of Organic Compounds
R       H                      R     X                        R     OH
    Alkane                         Alkyl Halide                    Alcohol

R       O       R'             R      NH2
    Ether                          Amine

R               R              O                                  O
    C       C             R    C      H                     R     C       R'
R               R
    Alkene                    Aldehyde                            Ketone

        O                      O                                  O

R       C       OH        R    C      O     R'              R     C       NH2
    Carboxylic Acid           Ester                               Amide



R       C       C    R'                                 R    C        N
                               navedmalek@yahoo.co.in                           42
    Alkyne                                                  Nitrile
ALCOHOL FUNCTIONAL GROUP




       R –O H

                           43
Classification
 Monohydric Alcohols
 Polyhydric Alcohols
  - Dihydric Alcohols (Ethylene Glycol)
  - Trihydric Alcohols (Glycerol)




                                          44
Monohydric Alcohols
 Devided in Primary, Secondary and tertiary
  alcohols.
 CH3OH, CH3CH2OH
 Methanol          Ethanol
 CH3CH(OH)CH3
 Isopropyl Alcohol
 CH3C(OH)(CH3)
   t-Butyl Alcohol




                                               45
Physical Properties
 Lower     are   colorless,   neutral   substances    with
  characteristic sweet alcoholic smell and burning taste.
  Higher are waxy solids.
 Lower are readily soluble in water & organic solvents but
  it decreases as M.W. increases.
 B.P. are higher than corresponding alkanes. e.g.
  Methanol-338 K and Methane-112K




                                                         46
Preparation of Alcohol
 By Hydrolysis
  R-X + NaOH→ R-OH + NaX
 By Hydration
  CH2=CH2 → CH3CH2OH
 Hydrolysis of Esters
  CH3COOC2H5 → CH3COOH + C2H5OH
 Reduction of Aldehyde/Ketone
  CHO/C=O → 1-Alcohol/2-alcohol
 Grignard Reagent
  R-Mg-X →R-O-MgX →R-OH

                                  47
Chemical properties
 Displacement of –OH gr. By Halogen(X)
  R-OH + HX → RX + H2O
 Action of Alkali Metals
  2ROH + 2Na → 2RONa + H2
 Dehydration
  C2H5OH → CH2=CH2 + H2O
 Oxidation of Alcohol(K2Cr2O7/H2SO4)
  1-alcohol → Aldehyde → Acid
 Reduction of Alcohols(Red P )
  C2H5OH + 2HI → CH3CH3+H2O + I2

                                          48
    METHANOL

             Methanol (methyl alcohol) or wood alcohol
             a. Made by the destructive distillation of wood
             b. Or by… CO + 2H2  CH3OH
    H        c. Used as a solvent
H
    C   OH   d. Possible replacement for gasoline
H            e. Forms formaldehyde in body causing blindness




                                                       49
    ETHANOL

                 Ethanol (ethyl alcohol) or grain alcohol
                 a. Made from the fermentation of grain, fruit, or sugar
    H   H        b. C6H12O6 + yeast  2C2H5OH + CO2
    C
        C
            OH   c. The alcohol that is in beverages
H
    H            d. Added to automotive fuels – 10% as gasohal
        H
                 e. 1 pint of pure alcohol will kill most people
                 f. caused deterioration of the liver, memory loss
                    and is harmful to unborn babies

                                                                50
ISOPROPYL ALCOHOL


     OH       Isopropyl alcohol (rubbing alcohol)
 H        H
    C C       a. Alcohol used for cuts and cleaning
H C H    H
   H   H      b. Will not be absorbed by the skin
              c. Toxic if taken internally
              d. Sold as a 70% solution – 140 proof

                                               51
 Ethylene glycol


              Ethylene glycol
              a. Used for antifreeze in cars
H    H
H C C H       b. Very sweet tasting
              c. Toxic – caused kidney failure and death
HO   OH
      H   H               O O
     H C C H    Liver                           CaC2O4
                          C C         Kidney
     HO   OH            HO    OH
                        Oxalic acid            Calcium Oxalate

                                                                 52
  GLYCEROL


          Glycerol
  H  H H  a. Used in lotion to keep skin soft
H C C C H b. Food additive that keeps cookies soft
          c. Can add to nitric acid to form nitroglycerin
 HO OH OH    Nitroglycerin (nitro) taken to relieve angina
              heart pain




                                                        53
Carbonyl Compounds
If an oxygen atom is attached to carbon by a double bond
the functional group –C=O is called carbonyl group.




                                                           54
ALDEHYDE

           O
      R C H
               55
Physical Properties
 Formaldehyde is a gas at room temp. All other members
  are colorless liquids at ordinary temp. The higher
  members are solids.
 Lower aldehydes have unpleasant smell but as one goes
  up in the series the smell becomes more fruity. Ketones
  are generally pleasant smelling liquids.
 Solubilities
 Lower members are highly soluble in water. Solubilities
  decreases with increasing molecular mass.
 B.P. are higher than those of non polar alkanes.
 B.P. of aldehydes/Ketones are lower than the B.P. of
  alcohols.

                                                       56
Chemical Properties
   Addition Across C=O bond
    CH3CHO + HCN            CH3CH(CN)OH             CH3CH(OH)COOH
    Acetaldehyde              Cyanohydrins             2-hydroxy propanoicAcid
    -
   Addition of Grignard Reagent
    HCHO + CH3MgBr          HCH(OMgBr)CH3              CH3CH2OH + Mg(OH)Br
   With Hydroxyl Amine
    CH3CHO + H2NOH                         CH3CH=N-OH + H2O
   With Hydrazine (Phenyl Hydrazine)
    CH3CHO + H2NNH2                     CH3CH=NNH2 + H2O
   Oxidation
    CH3CHO                         CH3COOH
   Reduction (Pt / Ni)

    CH3CHO + H2                CH3CH2OH


                                                                        57
FORMALDEHYDE



        Formaldehyde
  O     a.   Soluble in water
        b.   40% solution is called formaline
H C H   c.   Used in some plastic manufacturing
        d.   Makes a good disinfectant



                                            58
BENZALDEHYDE


      Benzaldehyde
      a. called synthetic oil of almond
      b. used as flavoring – maraschino cherries
O     c. used in perfumes
C H




                                           59
Ketones

              O
              C
          R       R

                      60
  ACETONE

                                                 O
Acetone                                          C
a. Made from Isopropyl alcohol
                                           H3C       CH3
                                 O
       OH
                  -H             C
   H3C CH   CH3            H3C       CH3



b. Used as a solvent for fats, rubber, plastics, and varnishes
c. Used as fingernail polish remover
d. Will not mix with water
Washes water off of glassware after cleaning
                                                           61
CARBOXYLIC ACID




      O
 R    C    OH     R COOH

                       62
Physical Properties
   The first nine mono carboxylic acids are colorless liquids, while
    the higher ones are colorless wax like solids.
   Solubility: The first four (formic, acetic, propeonic, butiric) are
    soluble while fifth (valeric) is slightly soluble and acids above
    six carbon are insoluble in water.
   B.P. & M.P.: They have abnormally high b.p., even higher than
    those of alcohols of similar molecular weights.




                                                                    63
Chemical Properties
Reaction with alkalies
R-COOH + NaOH                       R-COONa + H2O
Decarboxylation
CH3COOH + NaOH           soda lime   CH3COONa + H2O
CH3COONa + NaOH           sodalime   CH4 + Na2CO3
Reduction
R-COOH       LiAlH4/ 2H2         R-CH2OH
Reaction with Carbonates
R-COOH + Na2CO3                        R-COONa + H2O + CO2
Dehydration
2R-COOH                     R-COOCOCH3 + H2O
                         Acid Anhydride




                                                             64
FORMIC ACID



                               O
                         H     C      OH
   Formic Acid
   a. Irritant to skin
   b. Part of the venom in ants, bee’s, or wasps


                                                   65
ACETIC ACID




    O         The acid in vinegar
CH3 C   OH




                                    66
    BENZOIC ACID



                            O
                            C     OH

Benzoic acid
Used to make benzene type compounds in organic synthesis



                                                    67
ESTERS

         O
     R C O
           R



               68
O
        Apricot (pentyl buterate)
    O




                              69
O

    O   Orange (Octyl acetate)




                          70
   O
CH3 C O   Jasmine (benzyl acetate)




                               71
     O
     C O CH3   Wintergreen (methyl salicylate)

OH




                                            72
ETHER


    R O R

            73
DIETHYL ETHER

        O


Diethyl ether
a. Used as a solvent
b. Used for thinning paints
c. Boils at 36 C (dries quickly)
d. Used as anesthetic or as a drug
e. Dissolves organic compounds readily
f. Reacts with oxygen to form unstable peroxides

                                                   74
TERT-BUTYL ETHER


               CH3
       CH3 O C CH3
               CH3

  Tert-butyl ether (MTBE)
  a. Gasoline additive
  b. Reduces CO emissions
  c. Replaced lead as the antiknock compound
                                         75
    ETHYLENE OXIDE




          Ethylene Oxide
          a. Very toxic gas
          b. Used in the formation of ethylene glycol
          c. Ethylene glycol is used in antifreeze and in polyester fibers.
H     H
  C C H
H
   O



                                                                   76
AMINES
            R
          H N       primary
            H
   H            R
 H N        R N      secondary
   H            H
 amonia     R
          R N       tertiary
            R
                                 77
       H
CH2 CH2 N   Amphetamine (stimulant drug)
       H




                                   78
H
N   Analine (used in dyes)
H




                        79
   CH3   Dimethyl amine
CH3 N    used in volcanizing rubber, tanning hydes
         and making of soaps
   H




                                              80
         CH2CH3
                  Triethyl amine
CH3CH2   N        attracts insects
         CH2CH3   warning agent in natural gas




                                          81

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:48
posted:7/27/2012
language:English
pages:81