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Organic chemistry - Coggle Diagram
Organic chemistry
Benzene(C6H6)
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they have delocalised electrons, equal bond lengths, and the benzene ring has a distinctive structure
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the stability of the benzene ring is due to the delocalisation of electrons in the conjugated system
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A benzene ring in which one hydrogen atom has been substituted by another group is
known as the phenyl group. The phenyl group has the formula –C6H5.
ethers
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Ethers are commonly used as solvents since they are relatively inert chemically and will
dissolve many organic compounds.
Methoxymethane and methoxyethane are soluble in water. Larger ethers are insoluble in
water due to their increased molecular size.
smaller chain gives first name (methoxy, ethoxy) and surname is given by larger chain (methane, ethane)
amines
they are organic derivatives of ammonia where one or more hydrogens has been replaced by an alkyl group, and can be classified as primary, secondary or tertiary depending on how many hydrogens have been replaced by alkyl groups
they are named by first naming the alkyl groups alphabetically,(ethyl, methyl) then -amine
they can react with carboxylic acids to form an alkylammonium salt, which can then be heated to form an amide
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alkenes
geometric isomers can occur when there is restricted rotation around a carbon to carbon double bond or a carbon to carbon single bond in a cyclic structure
they can be labelled as -cis or -trans, depending on whether the substituent groups are on the same side (cis) or different sides (trans) of the bond with restricted rotation
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they have differences in physical properties, such as melting point and boiling point
optical isomers occur in compounds in which four different groups are attached tetrahedrally around a central carbon (chiral carbon or chiral centre)
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they have identical chemical properties, except when in chiral environments such as those found in biological systems (only one optical isomer is usually present)
they have identical physical properties, except for their effect on plane-polarised light (they rotate it by the same amount in different directions)
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when mixed in equal amounts they are optically inactive as their effect on plane-polarised light cancels out (racemic mixture)
Molecules that have the same molecular formula but different structural formulae can be regarded as isomers
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Steroisomers
Stereoisomers occur when the order of the bonding in the atoms is the same but the spatial arrangement of the atoms is different in each isomer. There are two types of steroisomer, geometric and optical
monohaloalkanes
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classified as primary, secondary or tertiary depending on how many alkyl groups are attached to the carbon which is attached to the halogen
nitriles
can be formed from monohaloalkanes by a nucleophilic substitution reaction, with NaCN or KCN
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mechanisms
An Sn1 mechanism is a nucleophilic substitution reaction with one species in the rate determining step, and which occurs in a minimum of two steps via a trigonal planar carbocation intermediate
An Sn2 mechanism is a nucleophilic substitution reaction with two species in the rate determine step, which occurs in a single step via a single five-centred, trigonal bipyramid transition state
primary monohaloalkanes undergo Sn2 mechanisms, but due to steric hindrance, tertiary monohaloalkanes undergo Sn1 as a step is first needed to free space for the nucleophile to attack
Nucleophiles
Nucleophiles are negatively charged ions or neutral molecules that are electron rich, that are attracted to atoms bearing a partial positive (delta positive) or a full positive charge
Examples: Cl- , Br- , OH- , CN- , NH3 and H2O
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Electrophiles
Electrophiles are positively charged ions or neutral molecules that are electron deficient, and attracted to atoms bearing a partial negative (delta negative) or a full negative charged
examples: H+, NO2+ and SO3
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