These compounds comprise a distinct class, called aromatic hydrocarbons. A free powerpoint ppt presentation displayed as a flash slide show on id. Aliphatic fatty aromatic fragrant openchain cyclic compounds. Elucidation of the structure posed a problem the molecular formula c6h6 indicated a highly unsaturated compound double andor triple bonds but benzene. Electrophilic aromatic substitution the most characteristic reaction of aromatic compounds is electrophilic aromatic substitution, in which one of the ring hydrogens is substituted by a halogen, nitro group, sulfonic acid group, alkyl or acyl group. Benzene c 6 h 6 is the bestknown aromatic compound and the parent to which numerous other aromatic compounds are related. Study notes on mcmurry yml college of san mateo page 1 of 8 chapter 15.
Sarah tabacco, while the second half of the lectures. Aromaticity and aromatic hydrocarbons lecture notes. Four illustrative examples of aromatic compounds are shown above. That is why we require strong electrophiles for reaction. Examples of aromatic compounds chemistry libretexts. Aromatic hydrocarbons arenes there are two major classes of organic chemicals aliphatic. Heterocyclic chemistry is the branch of chemistry dealing with the synthesis, properties, and applications of heterocycles. Aromatic compounds are cyclic structures in which each ring atom is a participant in a latex\pi latex bond, resulting in delocalized latex\pi latex electron density on both sides of the ring. There are therefore 6 electrons in the circle of p orbitals. Benzene and its derivatives, many of which possess fragrance aroma. They are known as aromatic due to their pleasant smell. Aromatic hydrocarbons maharana pratap pg college hardooi. Historically, the first aromatic compound is benzene, and as its first derivatives had pleasant aromas, were called aromatic compounds.
The important fuels like petrol, kerosene, coal gas, cng, lpg etc. According to new fact, aromatic is associated with chemical stability rather than aroma. Pdf read jh sir physical chemistry notes for class 11 jee feb 12, 2020. The properties of aromatic compounds identifying aromatic compounds applying huckels rule to identify aromatic compounds skills practiced. Introduction to aromatic heterocycles and polycyclic aromatic compounds 4. A few types of aromatic compounds, such as phenol, will rea ct without a cataly st, but for ty pical benzen e derivatives wit h les s reactive substrat es, a lewis acid catalyst is required. All the carboncarbon bonds are of equal length, and all the bond angles are 120. With aromatic compounds, 2 electrons fill the lowest energy. The actual structure of benzene, however, is a resonance hybrid of these two structure usually written as. Aromatic, or partially or fully saturated this co urse will focus on aromatic systems heterocycles are important and a large proportion of natural products contain them x y x y x z carbocycle heterocycles. Aromatic compounds and aromaticity section 14 of organic chemistry notes is 11 pages in length page 141 through page 1411 and covers all youll need to know on the following lecturebook topics. When benzene is treated with an excess of chlorine under heat and pressure or with irradiation by light, six chlorine atoms add to form 1,2,3,4,5,6hexachlorocyclohexane.
The readings column refers to relevant sections in the course textbook, l. Benzene has been known since 1825 when it was first isolated by michel faraday. Presentation mode open print download current view. The sigma complex wishes to regain its aromaticity, and it may do so by either a reversal of the first step i. Download chapternotes pdf chapter 11 the pblock elements group general introduction, electronic configuration, occurrence, variation of properties, oxidation states, trends in chemical reactivity, anomalous properties of first element of the group, boron physical and chemical properties, some important compounds, borax, boric acid, boron. Aromatic compounds benzene, the most commonly known aromatic compound. Pyrrole, furan, and thiophene appear, however, to have.
The structure of benzene in the resonance hybrid, the six electrons from the three. Cbse class 11 chemistry notes chapter hydrocarbons. Download the chemistry notes for class 11 chapter available on byjus by clicking here. Next we consider a class of hydrocarbons with molecular formulas like those of unsaturated hydrocarbons, but which, unlike the alkenes, do not readily undergo addition reactions. Aromatic compounds definition, example, properties. Aromatic compounds have substantial resonance stabilization benzene is aromatic. X, y, z are usually o, n or s many pharmaceuticals. Aromaticity notes aromaticity nicotinamide adenine. Due to this connected network of latex\pi latex bonds, the rings are planar, unlike the boat or table structures typical of cycloalkanes. Our notes are easytofollow, handwritten chemistry pdf notes that combine your book and chemistry notes into one, simple, easytounderstand format. We start to see that aromatic compounds are cyclic compounds, containing a certain number of. Aromatic compounds have unusual stability that goes far beyond what is predicted by simple resonance. Compounds from fused benzene or aromatic heterocyclic rings are themselves aromatic naphthalene. The aromatic nature of benzene stabilizes it 36 kcal.
Addition reactions of benzene derivatives reactions of aromatic compounds chlorination. Polycyclic aromatic hydrocarbons pahs are a class of hazardous organic compounds consisting of three or more fused benzene rings in linear, angular, and cluster arrangements. In addition, a recent monograph on general heterocyclic. Aromatic hydrocarbons are compounds that contain a benzene ring. Pdf download resonance chemistry inorganic hand written. Each corner of the hexagon has a carbon atom with a hydrogen attached. King chapter 18 electrophilic aromatic substitution i. The dashed lines inside the hexagon in the resonance hybrid of benzene. Form elemental analysis and molecular mass determination, it was found that the molecular formula of benzene is c 6 h 6 indicating high unsaturation. Students practice the following skills in these assessments. We have both general chemistry notes and organic chemistry notes. Three of the twenty amino acids used to form proteins the building blocks of life are aromatic compounds and all five of the nucleotides that make up dna and rna sequences are all aromatic compounds. Aromatic compounds are unsaturated hydrocarbon ring structures that exhibit special properties, including unusual stability, due to their aromaticity. This website is created solely for jee aspirants to download pdf, ebooks, study materials for.
Aromatic hydrocarbon, are hydrocarbons containing sigma bonds and delocalized pi electrons between carbon atoms in a ring. Hunter, department of chemistry, youngstown state university chemistry 1506. Heterocyclic compoundsare organic compounds that contain a ring structure containing atoms in addition to carbon, such as sulfur, oxygen or nitrogen, as the heteroatom. Aromatic, antiaromatic, homoaromatic and nonaromatic compounds. Chemistry notes download handwritten pdf chemistry notes. These hindi notes on aromatic compounds for chemistry will help you prepare well for iit jee and neet and also help to quickly revise the entire syllabus.
In real life, many aromatic compounds have an odor, however, there are some compounds that are chemically aromatic, but do not have a distinct smell. If you dont understand this structure, it is explained in full in two pages. This collection is very useful for jee candidates to crack their. Hydrocarbons alkanes, alkenes, alkynes and aromatics benzene, the prototypical aromatic hydrocarbon is a six membered ring composed of six sp2 hybridized carbon atoms in a plane and sharing 6 pi electrons. All of the organic substances we have looked at so far have been aliphatic benzene belongs to the aromatic class. Aromatic hydrocarbon an overview sciencedirect topics. The six carbons of benzene are joined in a ring, having the planar geometry of a regular hexagon in which all of the cc bond distances are equal. Aromatic compounds and aromaticity solomons 6 edition. Organic chemistry notes aromatic compounds and aromaticity. Properties of aromatic compounds introduction to chemistry. This section contains notes used to supplement the lectures for the course. Aromatic compounds are broadly divided into two categories.
Aromaticity and electrophilic aromatic substitution. Aromatic compounds are unsaturated compounds having alternate double and single bonds in one or more planar rings of atoms benzene, a hexagon, is the simplest aromatic compound aromatic compounds have delocalized electrons called pi electrons that provide overall stability to these compounds criteria for aromaticity includes that the compound is planar, cyclic. Visit, hydrocarbons class 11 notes to learn about the different types of hydrocarbons along with examples. Aromatic compounds 23 i general notes 23 ii aromatic hydrocarbons 23 iii substituted aromatic hydrocarbons 24 2 a. Aromatic hydrocarbon compounds are hydrocarbons containing one or more aromatic rings, such as the singlering benzene as well as the multiring systems. So aromatic is used for series containing benzene ring. Aromaticity reactions of benzene and substituted benzenes format.
Alkenes, alkynes, and aromatic compounds hydrocarbons with multiple bonds outline. Naming aromatic compounds aromatic compounds are cyclic hydrocarbons containing a benzene structure. Pdf download pradeep kshetrapal sir genius notes feb, 2020. Some lecture notes apply to multiple class sessions. Petroleum and natural gas are the major sources of aliphatic hydrocarbon while coal is an important source of aromatic hydrocarbons. Reactions of aromatic compounds part 2 bsc chemistry notes. Ppt aromatic compounds powerpoint presentation free to. However, benzene does undergo addition reactions in contrast to unsaturated hydrocarbons, although it mainly undergoes substitution reactions. Aromatic compounds facts alevel chemistry revision notes.
Needless to say, aromatic compounds are vital to us in many aspects. The sp2 hybridized ring atoms are connected by brown bonds, the. Aromatic compounds are also vital to the biochemistry of all living things. Lecture handouts organic chemistry i chemistry mit. All of the organic substances we have looked at so far have been aliphatic. Hunters class section 2 notes page 129 20002002, dr. Download in free pdf hydrocarbons are composed of carbon and hydrogen. Chemistry 106 lecture notes examination 2 materials. Reactions of aromatic compounds rutgers university. Aromatic compounds may undergo addition if forcing conditions are used. All aromatic compounds are based on benzene, c 6 h 6, which has a ring of six carbon atoms and has the symbol. The aromatic hydrocarbons are the subject of this tutorial. Chemistry 106 lecture notes examination 2 materials chapter 16.
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