Syllabus (CHEMISTRY)

Course Type: MAJ-2

Semester: 2

Course Code: BCEMMAJ02C

Course Title: Organic Chemistry – I

(L-P-Tu): 4-2-0

Credit: 6

Practical/Theory: Combined

Course Objective: COURSE OBJECTIVE OF MAJOR - 2: The syllabus of Major -2 has been designed to provide the students with the basic ideas of bonding and hybridization and fundamental understanding of stereochemistry. The five modules consisting of valence bond theory, elect

Learning Outcome: COURSE OUTCOMES OF MAJOR – 2: CO- 2.1 Understand the valence bond theory. CO- 2.2 Understand the basics of electronic displacements. CO- 2.3 Understand the concepts of a Molecular Orbital theory. CO- 2.4 Understand the physical properties of the organic

THEORY:

BONDING AND HYBRIDIZATION IN THE LIGHT OF ORGANIC CHEMISTRY: (25L)

(i) VALENCE BOND THEORY:

Concept of hybridisation, shapes of molecules, resonance (including hyperconjugation); calculation of formal charges and double bond equivalent (DBE); orbital pictures of bonding (sp3, sp2, sp: C-C, C-N & C-O systems and s-cis and s-trans geometry for suitable cases).

(ii) ELECTRONIC DISPLACEMENTS: Inductive effect, field effect, mesomeric effect,resonance energy; bond polarization and bond polarizability; electromeric effect; steric effect, steric inhibition of resonance.

(iii) MO THEORY: qualitative idea about molecular orbitals, bonding and antibonding interactions, idea about σ, σ*, π, π *, n – MOs; basic idea about Frontier MOs (FMO); concept of HOMO, LUMO and SOMO; interpretation ofchemical reactivity in terms of FMO interactions; sketch and energy levels of πMOs of acyclic p orbital system (C=C, conjugated diene, triene, allyl andpentadienyl systems) ii) cyclic p orbital system (neutral systems: [4], [6]-annulenes; charged systems: 3-,4-,5-membered ring systems); Hückel’s rules for aromaticity up to [10]-annulene (including mononuclear heterocyclic compounds up to 6-memberedring); concept of antiaromaticity and homoaromaticity; non-aromatic molecules; Frostdiagram; elementary idea about α and β; measurement of delocalization energies interms of β for buta-1,3-diene, cyclobutadiene, hexa-1,3,5-triene and benzene.

(iv) PHYSICAL PROPERTIES: Influence of hybridization on bond properties: bond dissociation energy (BDE) and bond energy; bond distances, bond angles; concept of bond angle strain (Baeyer’s strain theory); melting point/boiling point and solubilityof common organic compounds in terms of covalent & non-covalent intermolecular forces; polarity of molecules and dipole moments; relative stabilities of isomeric hydrocarbons in terms of heat of hydrogenation, heat ofcombustion and heat of formation.

BASIC STEREOCHEMISTRY-I: (20L)

Bonding geometries of carbon compounds and representation of molecules: Tetrahedral nature of carbon and concept of asymmetry; Fischer, sawhorse, flyingwedgeand Newman projection formulae and their inter translations.

2. Concept of chirality and symmetry: symmetryelements and point groups (Cv, Cnh, Cnv, Cn, Dh, Dnh, Dnd, Dn, Sn(Cs,Ci); molecular chirality and centre of chirality; asymmetric and dissymmetric molecules; enantiomers and diastereomers; concept of epimers; concept of stereogenicity, chirotopicity and pseudoasymmetry; chiral centres and number of stereoisomerism: systems involving 1/2/3-chiralcentre(s) (AA, AB, ABA and ABC types).

3. Relative and absolute configuration: D/L and R/S descriptors; erythro/threo and meso nomenclature of compounds; syn/anti nomenclatures for aldols; E/Z descriptors for C=C, conjugated diene, triene, C=N and N=N systems; combination of R/S- and E/ Z- isomerisms: Optical activity of chiral compounds: optical rotation, specific rotation and molar rotation; racemic compounds, racemisation (through cationic, anionic, radical intermediates and through reversible formation of stable achiral ntermediates); resolution of acids, bases and alcohols via diastereomeric salt formation; optical purity and enantiomeric excess; invertomerism of chiral trialkylamines.

GENERAL REACTION MECHANISM-I: (15L)

1. Mechanistic classification: ionic, radical and pericyclic (definition and example);reaction type: addition, elimination and substitution reactions (definition andexample); nature of bond cleavage and bond formation: homolytic and heterolytic bond fission, homogenic and heterogenic bond formation; curly arrow rules inrepresentation of mechanistic steps; reagent type: electrophiles and nucleophiles(elementary idea); electrophilicity and nucleophilicity in terms of FMO approach.

2. Reactive intermediates: carbocations (carbenium and carbonium ions), carbanions,carbon radicals, carbenes: generation and stability, structure using orbital picture andelectrophilic/nucleophilic behavior of reactive intermediates (elementary idea).

READING REFERENCES:

1. Clayden, J., Greeves, N. & Warren, S. Organic Chemistry, Second edition, Oxford University Press, 2012.
2. Smith, J. G. Organic Chemistry, Tata McGraw-Hill Publishing Company Limited.
3. Nasipuri, D. Stereochemistry of Organic Compounds, Wiley Eastern Limited.
4. Morrison, R. N. & Boyd, R. N. Organic Chemistry, Dorling Kindersley (India) Pvt. Ltd. (Pearson Education).
5. Finar, I. L. Organic Chemistry (Volume 1), Dorling Kindersley (India) Pvt. Ltd., (Pearson Education).
6. Fleming, I. Molecular Orbitals and Organic Chemical Reactions, Reference/Student Edition, Wiley, 2009.
7. James, J., Peach, J. M. Stereochemistry at a Glance, Blackwell Publishing, 2003.
8. Robinson, M. J. T., Stereochemistry, Oxford Chemistry Primer, Oxford University Press, 2005.

PRACTICALS:

1. Separation

Based upon solubility, by using common laboratory reagents like water (cold, hot),dil. HCl, dil. NaOH, dil. NaHCO3, etc., of components of a binary solid mixture; purification of any one of the separated components by crystallization and determination of its melting point. The composition of the mixture may be of the following types: Benzoic acid/p-Toluidine; p-Nitrobenzoic acid/p- Aminobenzoic acid; p-Nitrotolune/p-Anisidine; etc.

2. Determination of boiling point

Determination of boiling point of common organic liquid compounds e.g., ethanol, cyclohexane, chloroform, ethyl methyl ketone, cyclohexanone, acetylacetone, anisole, crotonaldehyde, mesityl oxide, etc. [Boiling point of the chosen organic compounds should preferably be less than 160°C]

3. Identification of a Pure Organic Compound

Solid compounds: oxalic acid, tartaric acid, citric acid, succinicacid, resorcinol, urea, glucose, cane sugar, benzoic acid and salicylic acidLiquid Compounds: formic acid, acetic acid, methyl alcohol, ethyl alcohol,acetone, aniline, dimethylaniline, benzaldehyde, chloroform and nitrobenzene.

REFERENCES FOR PRACTICALS:

1. Bhattacharyya, R. C, A Manual of Practical Chemistry.
2. Vogel, A. I. Elementary Practical Organic Chemistry, Part 2: Qualitative Organic Analysis, CBS Publishers and Distributors.
3. Mann, F.G. & Saunders, B.C. Practical Organic Chemistry, Pearson Education (2009).

4. Furniss, B.S., Hannaford, A.J., Smith, P.W.G., Tatchell, A.R. Practical Organic Chemistry,5th Ed., Pearson (2012).