Organic Chemistry I

GENERAL OBJECTIVES:

1. Understand the application of spectrophotometric techniques in the identification of organic compounds

2. Understand the chemistry of monosubstituted aromatic compounds and compare their reactions with those of their aliphatic analogues.

3. Understand the principles of organic reaction mechanism applied to aromatic systems.

1.1 List the frequency range of UV radiation.

1.2 Explain the effect of the interaction of UV light with organic compounds (electronic transitions).

1.3 Explain electronic transitions in terms of molecular orbital theory (p-p* and n-p*)

1.4 State wavelength in S.I. units.

1.5 State intensity of band as (E)

1.6 Explain that the wavelength of maximum absorption is called λmax and the intensity of absorption at λmax is Emax.

1.7 Give and be able to use the BeerLambert law relating absorbance to concentration.

1.8 Describe the relationships between structures and wavelength of maximum absorption

1.9 Explain the use of UV spectrum in identification of unsaturated linkages, chromophores and aromatic systems.

1.10 Explain the interaction of infra-red electromagnetic radiation with organic molecules.

1.11 Explain how the interaction of infra-red radiation with organic molecules gives rise to stretching, bending, vibration and wagging of the molecules.

1.12 Assign absorption frequencies to the following functional groups: - OH; -OR; -NH2; -X-C; HC=0; C=O;

1.13 Assign absorption frequencies to the following functional groups: alkene, alkyne, nitrile,

1.14 Explain how the “finger print’ region between 1450 - 650 cm-1 is unique for any compound.

1.15 Explain how the substituent groups attached to a functional group affects the absorption frequency of the functional group e.g. ketones, esters, amides, conjugated carbonyls, substituted aromatic compounds, etc.

1.16 Interpret the spectrum of a known compound.

1.17 Explain the effect of the interaction of radio frequency spectrum of electro magnetic waves on the nuclei of atoms.

1.18 Explain the concept of magnetic moments to the nuclei of the following atoms H11; N157; F199; P3915 and C136.

1.19 Explain the theory of NMR.

1.20 Explain the term chemical shift with particular attention to chemical shift values for H1.

1.21 Understand that chemical shift is affected by the electronic environment of the nucleus - deshielding and shielding effects.

1.22 Identify chemical shifts for different types of protons e.g. -OH, - CH2, -Ar-H, etc.

1.23 Know the characteristic chemical shift ranges for common functional groups.

1.24 Understand and be able to predict equivalence of hydrogen atoms in a molecule.

1.25 State the scales adopted for H1 nmr spectrum.

1.26 Explain the use of integration of H1 nmr signals.

1.27 Describe the following:

(a) Use of TMS.

(b) Spin-spin splitting.

(c) Coupling constant in assigning structure to a compound.

1.28 Be aware of some complications in spin-spin splitting:

(a) second order effects

(b) coupling to nonequivalent neighbours

(c) exchangeable hydrogens

(d) self-decoupling of halogen neighbours

1.29 Assign structures to compounds using nmr spectra.

1.30 Explain how a mass spectrometer distinguishes between ions of different mass to charge (m/e ratio).

1.31 Explain the concept of mass spectrometry.

1.32 Identify fragmentation patterns of molecules e.g. for CH4 as CH3 +, CH2+, CH+ and C+ having m/e = 15, 14, 13 and 12.

1.33 Identify parent ion in the mass spectrum of a compound.

1.34 Write possible fragmentation pattern or simple organic compounds e.g. CH3-CH2-CH3.

1.35 Describe the structure of a compound using fragmentation pattern and parent ion.

1.36 Explain X-ray diffraction technique as a means of determining the structures of crystalline complex organic molecules.

1.37 Describe the application of X-ray diffraction in the determination of structures of organic molecules.

1.38 State and use Bragg equation.

1.39 Understand the production of an X-ray diffraction pattern from a crystal

1.40 Understand the conversion of an X-ray diffraction pattern into a map of electron density.

1.41 Understand, in general terms, the interpretation of X-ray diffraction pattern to give a model of the organic molecule making up the crystal.

2.1 State the general formulae for monosubstituted aromatic compounds.

2.2 Describe the physical and chemical properties of monosubstituted aromatic compounds.

2.3 State IUPAC names for monosubstituted aromatic compounds.

2.4 Know how to prepare monosubstituted aromatic compounds (by halogenation, nitration, sulphonation, alkylation, acylation) from non-substituted aromatic compounds

2.5 Compare reactions of monosubstituted aromatic compounds with non-aromatic compounds

2.6 List uses of monosubstituted aromatic compounds.

3.1 Describe the following types of reactions, encountered in organic chemistry - addition, elimination, substitution and re-arrangement reactions.

3.2 Explain the following:

(a) Inductive effects

(b) Mesomeric and

(c) Electromeric

3.3 Identify ortho, para and meta positions on a monosubstituted aromatic compound.

3.4 Explain the term electophiles and nucleophiles.

3.5 Describe the mechanism of electrophilic aromatic substitution and nucleophilic aromatic substitution.

3.6 Explain the mechanism of aromatic electrophilic substitution with respect to the following:

(a) Halogenation of benzene

(b) Nitration of benzene

(c) Sulphonation of benzene

(d) Friedel craft reactions.

3.7 Draw diagrams of Energy against reaction co-ordinate for the above reactions and relate the shape of the Energy curves to the mechanism of the reaction (i.e. label the diagram)

3.8 List examples of ortho-para directing and meta directing groups.

3.9 List the differences between electrophilic aromatic substitution and nucleophilic aromatic substitution.

3.10 List other reactions of aromatic hydrocarbons like addition and oxidation reactions.

3.11 Describe SN1 and intermediate complex mechanism to aromatic nucleophilic substitution.

3.12 Know selected reactions of arenes: (oxidation of alkyl side chains, reduction of benzylic alcohols and ketones, chlorination of toluene)

3.13 Know selected reactions of aromatic substituents (reduction of the nitro group, oxidation of amino)