PPT-Aromatic compounds

14351436 20142015 Learning Objectives Understand the resonance description of structure of benzene Understand the hybridization in benzene Understand the relation between the stability of benzene and resonance energy. 15-8. Benzene undergoes substitution reactions with electrophiles.. Electrophiles attack benzene by substituting for a hydrogen atom, not addition to the ring.. Under the conditions of this type of reaction, ordinary non-aromatic conjugated polyenes would polymerize rapidly.. Dr. . Sheppard. CHEM . 2412. Summer 2015. Klein (2. nd. ed. .) . sections. : 18.1, 18.2, 18.8, 18.3, 18.4, 18.5. Aromatic Compounds. Originally distinguished because of smell. Then noticed trends in reactivity. The painkiller morphine is obtained from opium, the dried sap of unripe seeps of the poppy . P. apaver. . somniferum. Amines are relatives of ammonia and are usually classified as primary, secondary or tertiary. (. Benzene. ). 140 pm. 140 pm. 140 pm. 140 pm. 140 pm. 140 pm. All C—C bond distances = 140 pm. Benzene. empirical formula. = CH. 140 pm. 140 pm. 140 pm. 140 pm. 140 pm. 140 pm. . 146 pm. 134 pm. page 1 Aromatic Compounds Historically, benzene and its first derivatives had pleasant aromas, and were called aromatic compounds. Structure of Benzene Kekul Orbitals. Natural gas?. Fig. 11.1. Aliphatic Hydrocarbon Structure Comparison. Bonding and Geometry. of Two-Carbon Molecules . 11.1 Structure and Physical. . Properties. Bitter almonds are the source of the aromatic compound benzaldehyde. Sources of Benzene. Some Facts About Benzene. Reacts mainly by substitution. Friedrich August Kekule’. The Orbital Model for Benzene. 15-5. Molecules containing several fused benzene rings are called . polycyclic benzenoid. or . polycyclic aromatic hydrocarbons. (. PAHs. ).. Common names are used for these systems, since there is no simple naming system for them.. Dr. . Shatha. I . Alaqeel. 108 . Chem. Learning Objectives. By the end of chapter four the students will:. Understand the resonance description of structure of benzene. Understand the hybridization in benzene. Newehy. Chemistry Department, College of Science, King Saud University. http://fac.ksu.edu.sa/melnewehy. Aromatic . Compounds. The Structure of Benzene Ring. - . Benzene. is . the . parent hydrocarbon of . 240 . Chem. 1. The expressing . aromatic compounds . came to mean . benzene. . and derivatives of benzene. .. . Structure of Benzene: Resonance Description. C. 6. H. 6. It contains a six-membered ring and three additional degrees of unsaturation.. The Discovery of Benzene. Benzene was discovered in . 1825. by the English chemist . Michael Faraday . (Royal Institution). Faraday called this new hydrocarbon “. bicarburet. of hydrogen”.. Faraday isolated benzene from a compressed illuminating gas that had been made by . Arenium Ion Mechanism . Some Aromatic Electrophilic Substitution Reactions Viz. Nitration, Sulphonation, Halogenation, Friedel- Crafts Reaction. Orientation & Reactivity in Mono Substituted Benzene. D. r. . Zamir G Khan . Assistant Professor . H R Patel Institute of Pharmaceutical Education and Research Shirpur, Dist. Dhule, (M.S) 425405. Copyright @ Mr. Z G Khan. 2. If benzene is 1,3,5-cyclohexatriene as .