Chemistry 201 Chapter 22: Organic Compounds, Polymers and Biochemicals Sections 22.1-22.5, selected parts/examples from

1. Chemistry 201Chapter 22: Organic Compounds, Polymers and BiochemicalsSections 22.1-22.5, selected parts/examples from 22.6-22.8

2. Chapter 22 – Overall Goals Carbon-based (organic) compounds are the building blocks of life on Earth, largely due to their varied structural features. Studying organic compounds and some of their practical applications provides a relevant illustration of structure and bonding concepts at work. Familiarity with the conventions used to name and draw organic compounds (the language of organic chemistry) is crucial for interpretation of these ideas. With the information from this chapter, you will be able to: • define the types of structural isomers • describe an organic compound by naming it, describing its structure, and outlining the chemical reactions it may undergo • discuss examples where organic chemistry has been used for practical applications

3. Language of Organic Chemistry • Features of Carbon and Carbon-based compounds • Examples of bonds to carbon • Isomers • Chiral centres • Drawing and Naming Structures • Naming • Line-angle drawings • Isomer types • Describing Reactions and Properties of Molecules • Different types of arrows • Curved arrows used to show reaction mechanisms • Structural features and reactivity of functional groups

4. Language of Organic Chemistry What is Organic Chemistry? • Chemists in the 1700’s referred to compounds derived from living sources as “organic” • Until Wohler’s synthesis of urea in 1828, chemists believed that only living sources could produce organic compounds • Modern chemists describe organic chemistry as the study of carbon compounds • More than 14 million organic compounds are known (includes natural and synthetic compounds) • Compare to the roughly 100,000 known inorganic compounds urea

5. Language of Organic Chemistry Classification of Compounds All compounds Inorganic compounds Organic compounds Hydrocarbons Functionalized hydrocarbons

6. Features of carbon and carbon-based compounds • Carbon atoms form strong bonds with • other carbon atoms • other types of atoms (commonly N, O, P, or S) polymers biomolecules allotropes – graphite, diamond, fullerene

7. Features of Carbon and Carbon-based Compounds Draw a structure that corresponds to the molecular formula C5H10O • Correct answers: • Many compounds can have the same molecular formula!

8. Features of carbon and carbon-based compounds Chirality – organic compounds can be chiral • What is a chiral center? • Chirality of organic compounds is a crucial aspect of biological systems

9. Language of Organic Chemistry • Features of Carbon and Carbon-based compounds • Examples of bonds to carbon • Isomers • Chiral centres • Drawing and Naming Structures • Naming • Line-angle drawings • Isomer types • Describing Reactions and Properties of Molecules • Different types of arrows • Curved arrows used to show reaction mechanisms • Structural features and reactivity of functional groups

10. Drawing and Naming Structures • Many organic compounds have common names that you have probably heard of • Common names are not practical • Global communication • Millions of compounds • International Union of Pure and Applied Chemistry (IUPAC) nomenclature facilitates global communication about any of the millions of possible organic compounds

11. Drawing and Naming Structures • Identify the longest continuous chain of carbon atoms • The number of carbons in this chain will determine the root name of the compound • Depending on how the molecule is drawn, the longest carbon chain may not be immediately obvious

12. Drawing and Naming Structures Exact number of atoms are shown, arranged by how they are bonded together, but the bonds are not drawn in between each atom. Condensed Structural Formula Lewis structure Valence electrons are represented by dots; bonds between atoms are represented by a line. VSEPR structure Lewis structure drawn to to show the position of the atoms in 3-dimensions Line-angle drawing Bonds are represented by lines; carbon atoms are represented by corners or ends of lines; all hydrogen atoms bonded to carbon are assumed (and not shown).

13. Drawing and Naming Structures • The shape of your line-angle drawing should reflect the VSEPR geometry of the molecule line-angle drawing VSEPR geometry of highlighted atom hybridization of highlighted atom

14. Drawing and Naming Structures • Line-angle drawings including atoms other than carbon and hydrogen (heteroatoms) • H atom is replaced by an OH group • only H atoms on carbon are assumed • bond to O is shown, and H on oxygen is shown

15. Drawing and Naming Structures Re-draw the structure you drew that corresponds to the molecular formula C5H10O as a line-angle drawing • Correct answers: • Recall: Many compounds can have the same molecular formula! • Need a system of categorizing isomers based on their structures ISOMERS

16. Drawing and Naming Structures ISOMERS Compounds with same molecular formula CONSTITUTIONAL ISOMERS Different Connectivity STEREOISOMERS Same Connectivity CONFIGURATIONAL ISOMERS Different properties; cannot interconvert without breaking bonds CONFORMATIONAL ISOMERS Identical properties; can interconvert without breaking bonds GEOMETRIC ISOMERS OPTICAL ISOMERS Can be distinguished using plane-polarized light DIASTEREOMERS Non-mirror images different physical properties ENANTIOMERS Mirror images Identical physical properties

17. Language of Organic Chemistry • Features of Carbon and Carbon-based compounds • Examples of bonds to carbon • Isomers • Chiral centres • Drawing and Naming Structures • Naming • Line-angle drawings • Isomer types • Describing Reactions and Properties of Molecules • Different types of arrows • Curved arrows used to show reaction mechanisms • Structural features and reactivity of functional groups