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Organometallic Grignard Reagent
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ChapterOrganometallic compounds are compounds that contains a carbon metal bond. You are already familiar with some organometallic compound like sodium acetylide (NaC==CH) and alkyl lithium which has an ionic bond between carbon and sodium or carbon and lithium. But simply having a metal and carbon in the same compound is not sufficient for classification as organometallic. Sodium methoxide (NaOCH3), for example, is not an organometallic compound ; sodium is not bonded directly with carbon atom.Preparation of organomagnesium : Grignard ReagentsThe most important organometallic reagents in organic chemistry are organomagnesium compounds. They are called Grignard reag
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Nucleophilic Substitution Reaction
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ChapterMechanism of bimolecular (SN2) nucleophilic substitution [Mechanism & Kinetics] An SN2 reaction proceeds with complete stereo chemical inversion.SN2 reaction decreases with stearic hinderance and increases by presence of nonprotic solvent for example DMF and DMSO. SN2 reaction decreases in the presence of protic solvent like CH3OH, C2H5OH, HF etc.As the size of alkyl group increases than chemical reactivity towards SN2 decreases.As the size of alkyl group increases sterichindrance comes into play so reactivity decreases.
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Alkynes
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ChapterGeneral formula of alkynes is CnH2n–2They are more acidic then alkene and alkane because they have sp hybridised carbon atom which is more elctronegative.Preparation PropertiesAlkynes resemble alkanes and alkenes in their physical properties. They share with those other hydrocarbons the properties of low density and low water-solubility. They are nonpolar and dissolve readily in typical organic solvents such as alkanes, and diethyl ether. Alkynes generally have slightly higher boiling points than the corresponding alkanes and alkenes due to more polar character. Normally they are colourless and odourless gas - acetylene is also colourless and odour
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Alkyl Halides
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ChapterTrihalogen DerivativesThe general formula of trihalogen derivative is CHX3These are also called HALOFORMS.Preparation(i) Haloform test is given by compounds having –COCH3 group.CH3COOH cannot give haloform test due to resonance and does not contain pure COCH3 group.C6H5COC6H5 Benzophenone does not give haloform test due to absence of –COCH3 group. 2-alkanol but cannot give haloform test because it is inert towards first step oxidation. Acetoacetic ester even though contains –COCH3 group but does not give haloform test due to active methylene group in the molec
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Alkanes Paraffins
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chapterGeneral formula of alkanes is Cn H2n+2They are also called paraffins (parum = Little + affinis = reactivity).They may have no bond polarity and does not contain in the molecule so known as saturated hydrocarbons.Preparation(i) From Grignard reagentRMgX alkyl magnesium halide (other examples of RMgX type molecules are RLi and R2Cd)This reaction is known as Zere wittinoff’s method for estimation of active hydrogen in the molecule. Active hydrogen is the one which is attached to a highly electronegative element. eg., N,O,S etc. Hydrogen attached to alkyl groups like —CH3, —C2H5 are never active due to less electronegativity of ‘C&rsquo
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Alkadienes and Cycloalkanes
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ChapterGeneral formula of alkadienes is CnH2n–2Preparation of alkadienes(i) Dehydrogenation of butane(ii) Pyrolysis of Cyclo alkenes This reaction is known as Retro Diels – Alder reaction.(iii) Dehydration of diols(iv) Dehydrohalogenation by alc. KOH (v) From HCHOProperties of alkadienes(a) In 1,3- Butadiene all carbons are in sp2 hybridisation.(b) 1,3- Butadiene undergo resonance so that it undergo electrophilic addition reaction at both 1,2-and 1,4- position of molecule.(c) In Butadiene C2 – C3 bond length is 1.48 Å which is less than C – C bond length of ethane while C1–C2 or C3 – C4 bond length is 1.37 Å which is s
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Stereo Chemistry
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ChapterMolecules that are attached to four different groups a, b, d and e are chiral.A tetrahedral carbon that is attached to four different group is known as a chiral centre, a chiral carbon atom, an asymmetric centre or an asymmetric carbon atom. Now a days a more modern term stereogenic centre is used.It we have to find, the presence of a stereogenic centre in a given molecule then we have to check if it is chiral. For example C-2 is stereogenic centre in 2-butanol. A stereogenic centre has four different groups. (a) In 2-chloropentane, C-2 satisfies this requirement. (b) None of the carbons in 3-bromopentane have four different substituents, and so none of i
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Isomerism
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IntroductionThe existence of two or more compounds with same molecular formula but different properties (physical, chemical or both) is known as isomerism; and the compounds themselves are called isomers. The term was given by Berzelius. The difference in properties of two isomers is due to the difference in the arrangement of atoms within their molecules. Isomerism may be of two types:Structural isomerismWhen the isomers differ only in the arrangement of atoms or groups within the molecule, without any reference to space, these are known as structural isomersand the phenomenon asstructural isomerism.Thus the structural isomers have the same molecular formula, but p
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Fundamentals of organic chemistry
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IntroductionBREAKING OF A COVALENT BOND Breaking of a covalent bond between two atoms can take place mainly in two alternative ways, viz. homolytic and heterolytic fissions depending upon the relative electronegativity of the two concerned atoms and medium of reaction.(i) Homolytic fissiontakes place when the two atoms (say A and B) are usually of similar electronegativity(ii) Heterolytic fissiontake place when the two atoms (A and B) are of different electronegativities. It may again take place in two different ways.(a)When A is more electronegative than B(b)When B is more electronegative than AIt is important to note that homolytic fission requires much less energ
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Common names and geneva system
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IntroductionIUPAC (Geneva System of Nomenclature)(i) Regular pattern of naming ide chain + alk + (-)ane or (=)ene or (=)yne + suffix of main functional group 1C Math 4C But 2C Eth 5C Pent 3C Prop 6C Hex (ii) Selection of LPCC ( longest possible carbon chain)The longest possible chain is numbered from one side to the other by Arabic numerals, the direction being so chosen as to given the lowest numbers possible to the side chains. When series of locants containing the same number of terms are compared term by term,
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Alcohols,diols and triols
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Preparation(1) Hydrolysis of alkyl halides This reaction is useful only with reactants that do not undergo E2 elimination readily. It is really used for the synthesis of alcohols where alkyl halides are primary in nature. (2) Reaction of Grignard reagents with aldehydes and ketones A method that allows for alcohol preparation with formation of new carbon bonds. Primary, secondary, and tertiary alcohols can all be prepared and stepping up to two carbon atom also can takes place by the help of cyclic epoxides.
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Acid derivatives
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IntroductionNucleophilic Substitution : Alkyl vs. AcylAs we have said, nucleophlic substitution takes place much more readily at an acyl carbon than at saturated carbon. Thus, toward nucleophilic attack acid chlorides are more reactive than alkyl chlorides, amides are more reactive than amines and esters are more reactive than ether.It is, of course, the carbonyl group that makes acyl compounds more reactive than alkyl compounds. Nucleophilic attack (SN2) on a tetrahedral alkyl carbon involves a badly crowded transition state containing pentavalent carbon ; a bond must be partly broken to permit the attachment of the nucleophile : Nucleophilic attack on a
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Solid State
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A solid is defined as that form of matter which possesses rigidity and due to which possesses a definite volume and a definite shape. – The solids can be classified into - (a) Amorphous solids (b) Crystalline solids The solids which do not have any definite shape geometrically are called AMORPHOUS (Morpha = form) solids. Infact these have a random and disordered arrangement of atoms. These solids are also called –super cooled liquids– and are without sharp melting points i.e., these have –short r
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ELECTROCHEMISTRY
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Chemistry: Physical Chemistry ChapterIn mid, 17808 anatomist Luigi Galvani (Italy) was studying effects of atm. electric discharge. One day, in his garden, he fastened bross hooks b/w spinal cord of dissected frof and iron railing. He should that frog's leg began twitching wildly. He interpreted as animal electricity.In 1777, Alessandro volta repeated Galvani's famous experiments with decapitated frogs ole interpreted that twitches were due flowing of current b/w two dissimilar metals connected moist flesh of frog's leg.In 1801 volta awarded by Napolean a gold his discovery.Faraday achieved scientific prominence of his own for Istlaw of Electrochemistry,
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APPLICATION OF DERIVATIVES
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IntroductionHistory of calculus is very old since 200 BC Bhaskara in 12thcentury develop a no. of ideas that led to development of Rolle's Theorem. He was also first to define notion of derivative as a limit.Leibniz & Newton pulled these ideas further. Newton was first to apply calculus to general physics. These great scholar developed fundamental theorem of calculus.Today, calculus is used in every branching of physical sciences, in computer science, in statistics and in engineeerings, in economics, business etc.Derivative as rate of change: If variable quantity y is function of t i.e. y = f(t), then small change in time y in y Average rate of change =
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DIFFERENTIABILITY
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INTRODUCTIONFor many years the path in which planets were revolving round the sun was not known. After many years of observation Kepler conducted that planets move around the sun in elliptical orbits. But he could not give logical reasoning for his claim. But once Newton and Leibniz gave the fundamental theorem of calculus, the reasoning for this and many more things became quiet clear. Since then differential calculus has proved itself to be indispensable in development of mathematics and physics sciences.In this section
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LIMITS AND CONTINUITY
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INTRODUCTION To find limit of a function is an interesting concept where it may be possible that value of the function does not exist at a point but we try to find the value in the neighbourhood of the point. We will talk about this in more detail in the chapter. In the other part of the chapter we will discuss continuity of a function which is closely related to the concept of limits. There are some functions for whi
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3-D GEOMETRY
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IntroductionThree dimensional geometry developed accordance to Einsteins field equations. It is useful in several branches of science like it is useful in Electromagnetism. It is used in computer alogorothms to construct 3D models that can be interactively experinced in virtual reality fashion. These models are used for single view metrology. 3-D Geometry as carrier of information about time by Einstein. 3-D Geometry is extensively used in quantum & black hole theory.Section Formula:(1)Integral division: If R(x, y, z) is point dividing join of P(x1, y1, z1) & Q(x2, y2, z3) in ratio of m : n.Then, x =, y =, z =(2)External division: Coordinates of point
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HYPERBOLA
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IntroductionHyperbola is a very important lonic section. It has a wide use in further engineering courses. Hyperbola is a very special curve which is very rarely seen in day to day life. The new concepts such as touching the curve at infinity fills us with a great excitement to read this chapter, so enjoy the curve named hyperbola by getting into the chapter and feel the touch of the line to the line to the curve at infinity. DEFINATION:The locus of point which moves in a plane such that its distance from a fixed point called focus is e times (e > 1) its distance from a fixed line called directrix. EQUATION OF HYPERBOLAThe standard equation of hyperbola is
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