Organic Chemistry

Organic chemistry may be defined as the chemistry of carbon compounds. However, simple carbon-containing compounds (such as carbon monoxides, carbon dioxide and hydrogen cyanide) and carbon-containing salts (such as carbonates and cyanides) are not generally considered to be organic compounds. They are usually studied in inorganic chemistry courses. Over 96% of known chemical compounds contain carbon, these are known as organic compounds

*Differences between Organic and Inorganic Compounds In organic chemistryOrganic chemistry Properties * Study of compounds that do not contain carbon as the principal element *Usually do not contain carbon and never contain carbon-carbon or carbon- Hydrogen covalent bonds. *Contain carbon as the principle element *Contain carbon and Carbon-carbon or Carbon-Hydrogen covalent bonds *Structure *Usually dissolve in water *Usually dissolve in organic solvent *solubility *High *low*Boiling point *High *low*Melting point *Ionic bond *Covalent bond*chemical bond

CompoundOrganicInorganicCompoundOrganicInorganic CO CH 3 OH CH 4 NaHCO 3 HClC 6 H 12 O 6 NH 3 Na 2 CO 3 CO 2 K 2 Cr 2 O 7 CrSCa(OH 2 ) C2H4C2H4 Co(NO 3 ) 2 C 4 H 10 C 19 H 28 O 2 C 8 H 18 CH 3 OCH 3 Cu 2 OC 18 H 21 NO 3 Cr 2 O 3 CH 3 COOH CHCl 3 CH 3 NHCH 3 1.Using the table below, check a compound is organic or inorganic. (5 marks )

Chemical bond and valence

Valence : number of electron which place in highest shell Type of chemical bond Ionic bond Covalent bond

Ionic Bond Between atoms of metals and nonmetals with very different electronegativity Bond formed by transfer of electrons. Examples; NaCl, CaCl 2

1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na + ) and the Cl becomes (Cl - ), charged particles or ions.

COVALENT BOND bond formed by the sharing of electrons

Covalent Bond Between nonmetallic elements of similar electronegativity. Formed by sharing electron pairs Examples; O 2, CO 2, C 2 H 6, H 2 O, SiC

type of covalent bond Signal covalent bonddouble covalent bond triple covalent bond ethene Acetylene Ethane

Electron Configuration of Carbon

Why is CARBON so special? Atomic number = 6 6 protons, 6 electrons 1s 2 2s 2 2p 2 electron structure Valence of 4 electrons Need 8 electrons to fill valence shell Form 4 bonds with other atoms Can combine with 1, 2, 3 or 4 other C atoms Single, double, triple bonds Each bond consists of 1 electron from carbon & 1 electron from bonding atom

Importance of carbon atom 1.Basis for all life 2.Form stable covalent bonds to other carbon atom 3.Can form single,double and triple bond 4.Long carbon chain can be produced 5.Will bond with many other element. 1.Basis for all life 2.Form stable covalent bonds to other carbon atom 3.Can form single,double and triple bond 4.Long carbon chain can be produced 5.Will bond with many other element.

Carbon contain 2electron paired in first shell(No sharing electron) 1S 2 No sharing electron Carbon contain 4 electron in Second shell 2S 2 2P 2 No sharing electron Sharing electron Carbon atom must contain 4 electron unpaired to formation 4bond to become more stable this acure by hybridzation

Hybridization: over lab between orbital's of electron to formation new orbital contain unpaired electron formation more bond Some compound contain signal bond C c  bond Some compound contain double bond C c  bond  bond

Some compound contain trible bond C c  bond 2  bond

Type of hybridization SP 3 hybridization SP 2 hybridization SP hybridization Ethane Ethene Acetylene

SP 3 hybridization Ethane

Electron configuration of carbon only two unpaired electrons should form  bonds to only two hydrogen atoms Lead to hybridization occur occur

2s2s2s2s 2p2p2p2p Hybridization of atomic orbitals. Is overlap of the s and p orbital's occur in two steps 1 1 excite one electron

2s2s2s2s 2p2p2p2p mix orbitals 1s 3P + = SP 3

H.. C.. H H H....  bond

SP 2 hybridization Ethene

2s2s2s2s 2p2p2p2p Hybridization of atomic orbitals. Is overlap of the s and p orbitals occur in TWO steps 1 excite one electron

2s2s2s2s 2p2p2p2p.. 2 mix orbitals 1s + 2p = sp 2

sp 2 Orbital Hybridization 2 sp 2 p HH H H σσ σ σσ cc Π

Π σσσσσσ

SP hybridization Ethane

sp Hybridization and Bonding in Acetylene Acetylene

2s2s2s2s 2p2p2p2p Hybridization of atomic orbitals. Is overlap of the s and p orbitals occur in three steps 1 1 excite one electron

2s2s2s2s 2p2p2p2p. 2 2 mix orbitals. 1S 1P SP

sp Orbital Hybridization 2 sp 2 p HH σ σ σ c c Π Π

Classification of organic chemistry by functional group

Hydrocarbon : These compound which contain carbon and hydrogen

classification hydrocarbon Aliphatic Aliphatic Aromatic Aromatic alkanes alkanes Cyclo alkanes Cyclo alkanes Alkenes Alkenes Alkyenes Alkyenes Benzene Benzene

The IUPAC Nomenclature of Alkanes IUPAC "International Union of Pure and Applied Chemistry" names  The IUPAC system is based upon a series of rules which enable us to explain the structure of a compound from its name.  We should start by learning the names of 10 simplest straight chain alkanes.

i- Locate the longest continuous chain of carbon atoms

ii- Indicate the position of a side chain(replacement group) by the lowest possible number. replacement group

√ x

CH 4 –H ( Methane)  CH 3 - = (methyl ) CH 3 CH 3 ( ethane )  CH 3 CH 2 - = ethyl CH 3 CH 2 CH 3 (Propane)  CH 3 CH 2 CH 2 - = Propyl Replace ane from alkane to yl replacement group may be alkyl group or another atom(Halogen) alkyl group) contain from hydrogen atom removed from alkane

The substituent groups are listed alphabetically

When two or more substituents are identical, indicate this by the use of the prefixes di-, tri-, tetra-, and so on.

Physical Properties of alkane Non polar molecule No soluble in water Low melting point Low boiling point first four members (C1–C4 )are gases C5-C17are liquids and above C17 are solid

Chemical Properties of alkane Hydrogenation of alkanes: Reduction of alkyl haled 1-hydrolysis Girgnard reagent R-X +Mg  RMgX +H 2 O  R-H CH 3 CL + Mg  CH 3 MgCL+H2O  CH 4 Preparation of alkane

Reduction by metal and acid R-X +Zn+ H +  R-H+Zn +2 +X - CH 3 CH 2 CL +Zn +2 +H +  CH 3 CH 3 +Zn +2 +X - Reaction of alkane CH3 –CH-CH3 CH3 CL 2 CH3 CH3 –CH-CH2CL + CL CH3 –CH-CH3 CH3 HALOGENATION ISO BUTANE ISO BUTYL CHLORIDETERT BUTYLCHLORIDE

Reduction by metal and acid Reaction of alkane CH 3 –CH 2 -CH 3 Br 2 CH 3 –CH 2 -CH 2 Br + Br CH3 –CH-CH3 HALOGENATION Propane 1Bromo Propane2Bromo Propane

. Alkenes are unsaturated hydrocarbon, they contain a carbon-carbon double bond which general formula.

Nomenclature: Count the number of carbon atoms in the longest continuous carbon chain containing the double bond Change the ending from –ane by –ene Indicate the position of the double bond by the lowest possible number CH2 = CH - CH2 - CH3 1butene CH3CH=CHCH3 2 butene

Alkynes Alkynes contain a carbon-carbon triple bond, these compounds they have the general formula C n H 2n-2

Nomenclature: Count the number of carbon atoms in the longest continuous carbon chain containing the triple bond Change the ending from –ane by –yne Indicate the position of the triple bond by the lowest possible number