8'_'&_'*$_1 SM- , ,e441GS! 'i.'eMeNS $&.iiM6

Functional groups and homologous seriesNAMING ORGANICCOMPOUNDSOrganic chemistry is concerned withthe compounds of carbon. Since thereare more compounds of carbonknown than all the other elements puttogether, it is helpful to have asystematic way of naming them.

1. Identify the longest carbon chain.1 carbon = meth-2 carbons = eth-3 carbons = prop-4 carbons = but-S carbons = pent-6 carbons = hex-7 carbons = hept-8 carbons = oct-

This may come at the beginning or atthe end of the name, e.g.

alkane: only hydrogen (-H) joinedto chain =-ealcohol: -OH = -01amine: -NH2 = amino-

halogenoalkane: -X: chloro-,bromo, or iodo-

oII

aldehyde: -C-H (on the end of thechain) = -al

oII

ketone: -C - (not on the end ofthe chain) = -one

oII

carboxylic acid: -C-OH = -oicacid

2. Identify the type of bonding in thechain or ringAll single bonds in the carbonchain = -an-One double bond in the carbonchain = -en-One triple bond in the carbonchain = -yn-

3. Identify the functional groupjoined to the chain or ring.

oII

ester: -C-OR: = -oate

4. Numbers are used to give thepositions of groups or bonds alongthe chain.

Formula Name

SOME COMMON FUNCTIONAL GROUPSExamples

HI

H-C-HIH

methane

H H H HI I I I

H- C- C- C- C-HI I I IH H H H

butane

R-H alkane

H HI I

H-C-C-O-HH Hethanol

H H HI I I

H-CY-C-C-O-HH H H

propan-t-ol

R-OH alcohol

R-NH, amine~ ~ /H

H-CY-CY-N,H H H

ethylamine (aminoethane)

~ ~H -cy- cy- Br

H Hbromoethane

CI CII I

H-CY-CY-HH H

1.2·dichloroethane

R-X halogenoalkane(X = F. CI, Br, or I)

o"R-C-H aldehyde

~ //0H-C-CH 'H

ethanal

o"H3C- C - CH3

o"H3C - C - CH, - CH,- CH3

\?R-C-R' ketone

. (R' may be the sameas or different to R) propanone pentan-2-one

o"R-C-OH carboxylic acid

PH - C'o _ H

methanoic acid

ester

H 0 H HI II I I

H-C-C-O-C-C-H

H H Hethyl ethanoate

HOMOLOGOUS SERIESThe alkanes form a series of compoundsall with the general formula CnH2n+2,e.g.

methane CH4

ethane C2HS

propane C3HS

butane C4HlO

If one of the hydrogen atoms is removedwhat is left is known as an alkyl radicalR - (e.g methyl CH3-; ethyl C2Hs-)'When other atoms or groups areattached to an alkyl radical they canform a different series of compounds.These atoms or groups attached areknown as functional groups and theseries formed are all homologous series.

Homologous series have the samegeneral formula with the neighbouringmembers of the series differing by -CH2;for example the general formula ofalcohols is CnH2n+,OH. The chemicalproperties of the individual members ofan homologous series are similar andthey show a gradual change in physicalproperties.

~HH-C-HHI I I

H-C-C-C-H

H H H2-methylpropane

H O-HHI I I

H-CY-CY- cy- HH H Hpropan-z-ol

H, /HH N H HI I I I

H-c(-C-CY-CY-HH H H H

2-aminobutane

CI HI I

H-CY-CY- HCI H

1,1-dichloroethane

~ ~ //0H-C(-CY-C,

H H Hpropanal

o"H3C- CH, - C - CH,- CH3

pentan-3-one

.PC,Hs-C'O_H

propanoic acid

o"H-C-O-C3H,

propyl methanoate

Organic chemistry 61

Properties of different functional groupsBOILING POINTSAs the carbon chain gets longer the mass of the molecules increases and the van derWaals' forces of attraction increase. A plot of boiling point against number of carbonatoms shows a sharp increase at first, as the percentage increase in mass is high, but assuccessive -CH2- groups are added the rate of increase in boiling point decreases.

When branching occurs the molecules become more spherical in shape, which reducesthe contact surface area between them and lowers the boiling point.

Other homologous series show similar trends but the actual temperatures at which thecompounds boil will depend on the types of attractive forces between the molecules.The volatility of the compounds also follows the same pattern. The lower members ofthe alkanes are all gases as the attractive forces are weak and the next few members arevolatile liquids. Methanol, the first member of the alcohols is a liquid at roomtemperature, due to the presence of hydrogen bonding. Methanol is classed as volatileas its boiling point is 64.5 °C but when there are four or more carbon atoms in thechain the boiling points exceed 100°C and the higher alcohols have low volatility.

H H H H HI I I I I

H-C-C-C-C-C-HI I I I I

H H H H H b.pt 36.3"c

HI

H H-C-H H HI I I I

H-C-C- C-C-HI I I IH H H H b.pt 27.9"C

HI

H H-C-H HI I I

H-C-C- C-HI I IH H-C-H H

IH b. pt 9.5°C

Compound Formula Mr Functional group Strongest type of attraction B. pt! °C

butane C4HlO 53 alkane van der Waals' -0.5

butene C4HS 56 alkene van der Waals' -6.2

butyne C4H6 54 alkyne van der Waals' 3.1

methyl methanoate HCOOCH3 60 ester dipole:dipole 31.5

propanal CH3CH2CHO 53 aldehyde dipole:dipole 43.3

propanone CH3COCH3 53 ketone dipole:dipole 56.2

aminopropane CHFH2CH2NH2 59 amine hydrogen bonding 43.6

propan-l-ol CH3CH2CH2OH 60 alcohol hydrogen bonding 97.2

ethanoic acid CH3COOH 60 carboxylic acid hydrogen bonding 113

SOLUBILITY IN WATERWhether or not an organic compound will be soluble in water depends on the polarity of the functional group and on the chainlength. The lower members of alcohols, amines, aldehydes, ketones, and carboxylic acids are all water soluble. However, as thelength of the non-polar hydrocarbon chain increases the solubility in water decreases. For example, ethanol and water mix in allproportions, but hexan-l-ol is only slightly soluble in water. Compounds with non-polar functional groups, such as alkanes, andalkenes, do not dissolve in water but are soluble in other non-polar solvents. Propan-l-ol is a good solvent because it containsboth polar and non-polar groups and can to some extent dissolve both polar and non-polar substances.

STRUCTURALFORMULASThe difference between the empirical, molecular and structural formulas of a compound has been covered in Topic 1 -quantitative chemistry. Because the physical and chemical properties of organic compounds are determined by the functionalgroup and the arrangement of carbon atoms within the molecule, the structural formulas for organic compounds are often used.

The structural formula unambiguously shows how the atoms are bonded together. All the hydrogen atoms must be shown whendrawing organic structures. The skeletal formula showing just the carbon atoms without the hydrogen atoms is not acceptableexcept for benzene (see below). However, unless specifically asked, Lewis structures showing all the valence electrons are notnecessary. The bonding must be clearly indicated. Structures may be shown using lines as bonds or in their shortened form e.g.CH3CH2CH2CH2CH3 or CHr(CH2)rCH3 for pentane but the molecular formula CSH12 will not suffice.

H H H H H HI I I I I I

H-C-C-C-C-C-C-H

I I I I I IH H H H H H

I-C-C-C-C-C-C-

I I I I I I ostructural formula of hexanealso acceptableCH3CH2CH2CH2CH2CH3

and CH3(CH2)4CH3

skeletal formula of hexanenot acceptable as structural formula

three different ways of showing the structural formulaof benzene, all are acceptable

62 Organic chemistry

Structural isomersSTRUCTURES OF HYDROCARBONSIsomers of alkanesEach carbon atom contains four singlebonds. There is only one possiblestructure for each of methane, ethane,and propane however two structures ofbutane are possible.

These are examples of structural isomers.Structural isomers have the samemolecular formula but a differentstructural formula. They normally havesimilar chemical properties but theirphysical properties may be slightlydifferent. There are three structuralisomers of pentane.

Structures of alkenesEthene and propene onlyhave one possible structureeach but butene has threestructural isomers. ethene

CLASSIFICATION OF ALCOHOLS ANDHALOGENOALKANESAlcohols and halogenoalkanes may be classifiedaccording to how many R- groups and how manyhydrogen atoms are bonded to the carbon atomcontaining the functional group.

primary (on R-group bonded to C atom)

HI

R-C-OH

IH

HI

R-C-Br

IH

secondary (two R-group bonded to C atom)R may be the same as R' or different

HI

R-C-OH

IR'

HI

R-C-Br

IR'

Tertiary (three R-group bonded to C atom)

R"I

R-C-OH

IR'

R"I

R-C-Br

IR'

H H H HI I I I

H-C-C-C-C-HI I I IH H H H

butane

H H H H HI I I I I

H-C-C-C-C-C-HI J I I IH H H H H

HI

H H-C-H H HI I I I

H-C-C- C-C-HI I I IH H H H

pentane(b. pt 36.3 DC)

2-methyl butane(b. pt 27.9 DC)

propene but-1-ene

HI

H H-C-H HI I I

H-C-C- C-HI I IH H H

2-methylpropane

HI

H H-C-H HI I I

H-C-C- C-HI I IH H-C-H H

IH

2,2-dimethylpropane(b. pt 9.5 DC)

but-2-ene 2-methylpropene

NAMING STRUCTURAL ISOMERSThe naming system explained on page 61 is known as the IUPAC(International Union of Pure and Applied Chemistry) system. TheIUPAC names to distinguish between structural isomers of alcohols,aldehydes, ketones, carboxylic acids and halogenoalkanescontaining up to six carbon atoms are required.

For example, four different structural isomers with the molecularformula C6H,20 are shown.

H H H H H 0I I I I I //

H-C-C-C-C-C-C

I I I I I "HH H H H H

hexanal

HI

H-C-H

I ~ I I IH-C-C-C-C-C-H

I I I IH H H H

3-methylpentan-2-one

HI

H-C-H

H I H 0I I //H-C-C-C-C

I I I "HH HH-C-H

IH

CH3C(CH3)2CH2CHO

3,3-dimethylbutanal

HI

H-C-H

I I ~ I IH-C-C-C-C-C-H

I I I IH H H H

or CH3CH(CH3)COCH2CH3

2-methylpentan-3-one

Organic chemistry 63

AlkanesLOW REACTIVITY OF ALKANESBecause of the relatively strong C-C and C-H bonds andbecause they have low polarity, alkanes tend to be quiteunreactive. They only readily undergo combustion reactionswith oxygen and substitution reactions with halogens inultraviolet light.

COMBUSTIONAlkanes are hydrocarbons - compounds that contain carbonand hydrogen only. All hydrocarbons burn in a plentifulsupply of oxygen to give carbon dioxide and water. Thegeneral equation for the combustion of any hydrocarbon is:

CxHy + (x +~)02 -;0. xC02 +~H20

Although the C-C and C-H bonds are strong the c=o andO-H bonds in the products are even stronger so the reaction isvery exothermic and much use is made of the alkanes as fuels.

e.g natural gas (methane)

CH4(g) + 202(g) -;0. CO2(g) + 2H20(I) ~H& = -890.4 kJ mor '

gasoline (petrol)

CsH1s(l) + 12~02(g) -;0. 8C02(g) + 9H20(I) ~H& = -5512 kJ mor '

If there is an insufficient supply of oxygen then incompletecombustion occurs and carbon monoxide and carbon are alsoproduced as products.

SUBSTITUTION REACTIONSAlkanes can react with chlorine (or other halogens) in thepresence of ultraviolet light to form hydrogen chloride and asubstituted alkane, e.g. methane can react with chlorine toform chloromethane and ethane can react with bromine toform bromoethane.

H H

I uv IH-C-H + CI-CI H-C-CI + H-CI

I IH H

methane chloromethane

H H H HI I uv I I

H-C-C-H + Br-Br - H-C-C-Br + H-Br

I I I IH H H H

ethane bromoethane

64 Organic chemistry

MECHANISM OF CHLORINATIONOF METHANEThe mechanism of an organic reaction describes theindividual steps. When chemical bonds break they maybreak heterolytically or homolytically. In heterolytic fissionboth of the shared electrons go to one of the atoms resultingin a negative and a positive ion. In homolytic fission each ofthe two atoms forming the bond retains one of the sharedelectrons resulting in the formation of two free radicals. Thebond between two halogen atoms is weaker than the C-Hor C-C bond in methane and can break homolytically in thepresence of ultraviolet light.

CI2 -;0. CI' + CI'

This stage of the mechanism is called initiation.

Free radicals contain an unpaired electron and are highlyreactive. When the chlorine free radicals come into contactwith a methane molecule they combine with a hydrogenatom to produce hydrogen chloride and a methyl radical.

H3C-H + CI' -;0. H3C' + CI'

Since a new radical is produced this stage of the mechanismis called propagation. The methyl free radical is alsoextremely reactive and reacts with a chlorine molecule toform the product and regenerate another chlorine radical.This is a further propagation step and enables a chainreaction to occur as the process can repeat itself.

CH3 + CI2 -;0. CH3-CI + CI'

In theory a single chlorine radical may cause up to 10000molecules of chloromethane to be formed. Terminationoccurs when two radicals react together.

}CI' + CI' -;0. CI2CH3 + CI' -;0. CH3CICH3 + CH3 -;0. C2H6

termination

Further substitution can occur when chlorine radicals reactwith the substituted products. For example:

HI

CI-C-H

IH

HI

+ CI'-CI-C'+ HCII

H

H HI I

then CI-C' + C12- CI-C-CI + CI'I IH H dichloromethane

The substitution can continue even further to producetrichloromethane and then tetrachloromethane.

The overall mechanism is called free radical substitution.[Note that in this mechanism hydrogen radicals H' are notformed.]

AlcoholsCOMBUSTIONEthanol is used both as a solvent and as a fuel. It combusts completely in a plentiful supply of oxygen to give carbon dioxide andwater.

C2HsOH(I) + 302(g) ~ 2C02(g) + 3Hp(l) ilH" = -1371 k] mol:"

Ethanol is already partially oxidized so it releases less energy than burning an alkane of comparable mass. However, it can beobtained by the fermentation of biomass so in some countries it is mixed with petrol to produce 'gasohol' which decreases thedependence on crude oil.

The general equation for an alcohol combusting completely in oxygen is:

CnH(2n+l)0H + (2n-1)02 -- nC02 + (n+ 1)H20

OXIDATION OF ETHANOLEthanol can be readily oxidized by warming with an acidified solution of potassium dichromate(VI). During the process theorange dichromate(VI) ion Cr207

2- is reduced from an oxidation state of +6 to the green Cr3+ ion. Use is made of this in simplebreathalyser tests, where amotorist who is suspected ofhaving exceeded the alcohollimit blows into a bag containingcrystals of potassiumdichromate(VI).

H H H 0I ,;-

H- c-cI -,

H H

H 0I ,;-

H- c- C~ '0- H

I Ic- c-c -OH

I IH H

ethanol(,wine')

ethanol ethanoic acid('vinegar')

Ethanol is initially oxidized to ethanal. The ethanal is then oxidized further to ethanoic acid.

Unlike ethanol (b. pt 78.5 °C) and ethanoic acid (b. pt 118°C) ethanal (b. pt 20.8 °C) does not have hydrogen bonding betweenits molecules, and so has a lower boiling point. To stop the reaction at the aldehyde stage the ethanal can be distilled from thereaction mixture as soon as it is formed. If the complete oxidation to ethanoic acid is required, then the mixture can be heatedunder reflux so that none of the ethanal can escape.

OXIDATION OF ALCOHOLSEthanol is a primary alcohol, that is the carbon atom bonded to the -OH group is bonded to two hydrogen atoms and one alkylgroup. The oxidation reactions of alcohols can be used to distinguish between primary, secondary, and tertiary alcohols.

All primary alcohols areoxidized by acidified potassiumdichromate(VI), first toaldehydes then to carboxylicacids.

HI

R -C-OHIH

oR-C:H

primary alcohol aldehyde carboxylic acid

Secondary alcohols are oxidizedto ketones, which cannotundergo further oxidation.

HI

R-C-OHI

R'O

Cr2072-/H+

o"R-C-R'

secondary alcohol ketone

RI

R' -C-OHIR'

Tertiary alcohols cannot beoxidized by acidifieddichromate(VI) ions as they haveno hydrogen atoms attacheddirectly to the carbon atom containing the -OH group. It is not true to say that tertiary alcohols can never be oxidized, as theyburn readily, but when this happens the carbon chain is destroyed.

tertiary alcohol

66 Organic chemistry

AlkenesADDITION REACTIONSThe bond enthalpy of the C=C double bond in alkenes has a value of 612 k] mol:". This is less than twice the average value of348 k] mol' for the C-C single bond and accounts for the relative reactivity of alkenes compared to alkanes. The most importantreactions of alkenes are addition reactions. Reactive molecules are able to add across the double bond. The double bond is saidto be unsaturated and the product, in which each carbon atom is bonded by four single bonds, is said to be saturated.

, /

C=C/ -,

unsaturated

+ x-vx yI I

-C-C-I I

saturated

Addition reactions include the addition of hydrogen, bromine, hydrogen halides, and water.

H BrI I

H-C-C-HI I

H Hbromoethane

(halogenoalkane)

H HI I

H-C-C-HI I

H H(alkane)

Br BrI I

H-C-C-HI IH H

IIUSES OF ADDITIONREACTIONS1. Bromination

Pure bromine is a red liquid but it hasa distinctive yellow/orange colour insolution. When a solution of bromineis added to an alkene the product iscolourless. This decolorization ofbromine solution provides a useful testto indicate the presence of an alkenegroup.

2. HydrationEthene is an important product formedduring the cracking of oil. Althoughethanol can be made from thefermentation of starch and sugars,much industrial ethanol is formedfrom the addition of steam to ethene.

3. HydrogenationThe addition of hydrogen tounsaturated vegetable oils is usedindustrially to make margarine.Hydrogenation reduces the number ofdouble bonds in the polyunsaturatedvegetable oils present in themargarine, which causes it to becomea solid at room temperature.

HBr H H, /

C=C/ ,

H H

H20(H2S04 catalyst)

1,2-dibromoethane(dihalogenoalkane)

H OHI I

H-C-C-HI IH H

(alcohol)

IIADDITION POLYMERIZATIONUnder certain conditions ethene can also undergo addition reactions with itselfto form a long chain polymer containing many thousands (typically 40 000 to800 000) of carbon atoms.

H H, /

n C=C/ ,

H H.f CH2 - CH2-lnpoly(ethene)

(also known aspolythene)

ethene

These addition reactions can be extended to other substituted alkenes to give awide variety of different addition polymers.

e.g. H CIn 'C= C/ .f CH2 - CHCI tn

/ <,

H Hpoly(chloroethene)

chloroethene (also known as polyvinylchloride, PVC)

F F-, / + CF2 - CF2 tnn C=C/ -,

F Fpoly(tetrafluoroethene), PTFE

tetrafluoroethene (also known as Teflon or 'non-stick')

Organic chemistry 65

Substitution reactions and reaction pathwaysSUBsnTunONREAcnONSOFHALOGENOALKANESBecause of the greater electronegativity of the halogen atom compared with the carbon atom halogenoalkanes have a polarbond. Reagents that have a non-bonding pair of electrons are attracted to the carbon atom in halogenoalkanes and a substitutionreaction OCcurs. Such reagents are called nuc/eophiles

A double-headed curly arrow represents the movement of a pairof electrons. It shows where they come from and where theymove to.

MECHANISM OF NUCLEOPHILIC SUBSTITUTION

Primary halogenoalkanes (one alkyl group attached tothe carbon atom bonded to the halogen)e.g. the reaction between bromoethane and warm dilutesodium hydroxide solution.

C2HSBr + OH- -- C2HsOH + B,

The experimentally determined rate expression is:rate = k[C2HsBr)[OH-)

The proposed mechanism involves the formation of atransition state which involves both of the reactants.

fHO-/--t-B]-- r + Br"-, /1'"

CH, H HO H CH,

Because the molecularity of this single-step mechanism istwo it is known as an SN2 mechanism (bimolecularnucleophilic substitution).

Tertiary halogenoalkanes (three alkyl groups attachedto the carbon atom bonded to the halogen)e.g. the reaction between 2-bromo-2-methylpropane andwarm dilute sodium hydroxide solution.

The experimentally determined rate expression for thisreaction is: rate = k[C(CH

3)3Br)

A two-step mechanism is proposed that is consistent with thisrate expression.

slow

fast

In this reaction it is the first step that is the rate determiningstep. The molecularity of this step is one and the mechanismis known as SN1 (unimolecular nucleophilic substitution).

The mechanism for the hydrolysis of secondaryhalogenoalkanes (e.g 2-bromopropane CH

3CHBrCH

3) is

more complicated as they can proceed by either SN1 or SN2pathways or a combination of both.

REACTION PATHWAYS'rx~rk,"'halogenoalkane ~ alkene ---- .•• poly(alkene)

J/--_. trihalogenoalkane

tetrahalogenoalkane

alcohol ----_....... aldehyde----. carboxylic acid

ketone

H OHH2S04 I I

• HC-C-C-CH3 I I 3

H Hbutan-2-ol

Using the scheme on the left which summarizes the organicreactions in the text, it is possible to devise reactionpathways. These should involve no more than two stepsand should include the reagents, conditions and relevantequations.

e.g. to convert but-2-ene to butanone

Step 1. Heat but-2-ene in the presence of H2S0

4as a

catalyst to form butan-z-ol

but-2-ene

Step 2. Oxidize butan-z-nl to but-2-ene by warming withacidified potassium dichromate(VI) solution

H OHI I

HC-C-C-CH3 I I 3

H H

H °W/Cr20/- I II• HC-C-C-CH

3 I 3

H

butan-2-one

Organic chemistry 67

lm Identifying and naming more functional groupsAMINES (R-NH2)IUPAC accepts several different ways of naming amines.The most straightforward system is to prefix the longest chainalkane by the word amino- with the location of the NH2-

group being indicated. For example, 2-aminopentane and 1-aminohexane. It is also correct to call them by the longestalkane with the suffix -amine e.g. pentan-2-amine. If thenumber of carbon atoms is small (one, two or three) then theold names of methylamine, ethylamine and propylaminetend to be used rather than aminomethane, aminoethaneand aminopropane. IUPAC accepts 1-butylamine, 1-butanamine and 1-aminobutane for CH3CH2CH2CH2NH2'

H NH H H HI I 2 I I I

H-C-C-C-C-C-H

I I I I IH H H H H

H H H H H HI I I I I I

H-C-C-C-C-C-C-NHI I I I I I 2H H H H H H

2-aminopentane(or pentan-2-amine)

1-aminohexane(or hexan-1-amine)

For secondary amines the main name of the amine is takenfrom the longest carbon chain attached to the nitrogen atom.The other chain is prefixed as an alkyl group with thelocation prefix given as an italic N. Examples includeN-methylethanamine and N-ethylpropanamine. Tertiaryamines conatin two prefixes with an italic N, for exampleCH3CH2N(CH3)2 is N,N-dimethylethanamine.

N-methylethanamine N-ethylpropanamine N,N-dimethylethanamine

AMIDES (R-CO-NH2)Amides are named after the longest carbon chain (whichincludes the carbon atom in the functional group) followedby -amide. For example, ethanamide and2-methylpropanamide. Secondary amides are named ratherlike amines in that the other alkyl group attached to thenitrogen atom is prefixed by an N, e.g., N-methylethanamide

oII

CHlC-NH2

H H 0I I II

H-C-C-C-NH

~ I 2

H-C-H

IH

ethanamide 2-methylpropanamide N-methylethanamide

68 Organic chemistry

.~.u •• .uu. •• uu•• ~ •• o. __uua_ •• .mu. •• n~=-IIL.~.~ESTERS (R-COO-R')Esters take their IUPAC name from the acid and alcohol

• from which they are derived. The first part of the ester isnamed after the R- group from the alcohol. There is then aspace followed by the name for the carboxylic acid anion.For example, methyl ethanoate, ethyl propanoate andpropyl methanoate.

H 0 HI II I (H3(H2(OO(H2(H3

• H-(-(-O-(-H

I IH H ethyl propanoate

methyl ethanoate 0II

propyl methanoate

~1 __ ~b- .•i~'~DEI.

NITRILES (R-CN)Nitriles used to be called cyanides so that C2HsCN wasknown as ethyl cyanide. IUPAC bases the name on thelongest carbon chain (which includes the carbon atom of

• the nitrile group) with the word -nitrile is added to thealkane. For example, the IUPAC name for C2HsCN ispropanenitrile. Ethanenitrile has the formula CH3CN, andbutanenitrile the formula C3H7CN.

H H HI I I

H-C-C-C NH-C-C=N

I I IH H H

H H HI I I

H-C-C-C-C N

I I IH H H

propanenitrile ethanenitrile butanenitrile

•