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Organic Chemistry. Carbon. Has 4 valence electrons Can have sp 3 hybridization where substituted groups are at 109.5 o to one another. Other hybridizations are possible. Usually shares electrons Can easily bond to itself and many other elements
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Carbon • Has 4 valence electrons • Can have sp3 hybridization where substituted groups are at 109.5o to one another. • Other hybridizations are possible. • Usually shares electrons • Can easily bond to itself and many other elements • Can make straight chains of carbons or branched chains • Can form single, double, and triple bonds to itself and to some selective other atoms • Can polymerize
Alkanes • Contain only carbon and hydrogen • Have only single bonds. • Tetrahedral geometry • Characteristic reactions • Halogenation • R-H + X2 R-X + HX • Chlorine >Bromine • Tertiary>Secondary>Primary • Combustion • R-H + O2 CO2 + H2O • Pyrolysis(cracking) • Alkane H2 + smaller alkanes + alkenes
Alkanes • Nomenclature – ending is ane. • Meth • Eth • Prop • But • Pent • Hex • Hept • Oct • Non • Dec
Alkenes • Contain only carbon and hydrogen • Have one double bond between two carbons. • The double bond makes alkenes unsaturated with respect to hydrogen. • Trigonal planar geometry • If there are two or three double bonds • Alkadiene • Alkatriene • Characteristic reactions • Addition • C=C + Y-Z C-C Y Z
Alkenes • Structural isomers are those which have the same chemical formula but differ in how the atoms are attached to one another. • A cis-isomer has the two substituted groups on the same side of the double bond. • A trans-isomer has the two • substituted groups on • opposite sides of the double • bond.
Alkenes • Characteristic Reactions • Addition of hydrogen • Addition of halogens • Addition of hydrogen halides • Addition of sulfuric acid • Addition of water
Alkenes • Nomenclature – end with ene • Eth • Prop • But • Pent • Hex • Hept • Oct • Non • Dec
Alkynes • Contain only carbon and hydrogen • Contain one triple bond between carbons • Linear geometry • Characteristic reactions of alkynes • Addition of hydrogen • Addition of halogens • Addition of hydrogen halides • Addition of water
Alkynes • Nomenclature – end with yne
Functional Groups • Hydrocarbons may have functional groups substituted for hydrogens. • Such substitutions give carbon the capacity to form many, varied compounds with different reactivities from the original hydrocarbon. • The possibilities are nearly endless.
Alkyl Halides • RX • Give the number of the carbon where the halide(s) appear. • Give the name of the halide (chloro, bromo, iodo) • Write the name of the longest chain of carbons. • C5H10Cl2 dichloropentane (must have structure to determine the numbers of carbons that are substituted)
Alcohols • ROH • Give the name of the longest chain of carbons and end with –ol. • Primary – carbon with OH is connected to one other carbon • Secondary – carbon with OH is connected to two other carbons • Tertiary – carbon with OH is connected to three other carbons • C5H11OH – pentyl alcohol or pentanol(structure needed to determine number)
Aldehydes • RCHO • Write the name of the longest carbon chain and add -al for the ending. • Remember that the functional group here must be on the last carbon in the molecule. • C5H10O - pentanal
Ketones • RCOR` • Write the name of the longest carbon chain and end with -one. • Remember that the functional group, the carbonyl (C=O) cannot be on the end of the molecule. • Example
Carboxylic Acids • RCOOH • Write the name of the longest carbon chain and end with –oic acid. • Remember that the functional group (COOH) must be on the end of the molecule. • These are organic acids and they contain one ionizable hydrogen. • Example
Esters • RCOOR` • Write the name of the group (R`) and end it with –yl. • Then write the name of the R-C group and end it with –oate. • Example
Ethers • ROR` • Write the name of one of the R groups and then the name of the other one in alphabetical order. • End with –ether. • Example
Cyclic compounds • Cycloalkanes • Cycloalkenes • Cycloalkynes • Example
Aromatic Compounds • These must contain a benzene ring. • Benzene is C6H6 and may be indicated in several different ways. • Positions on the ring may be indicated by ortho(1,2 positioning), meta(1,3 positioning), and para(1,4 positioning) prefixes. • Examples
Amines • RNH2 – primary amine • RNR` - secondary amine H • RNR` - tertiary amine R • These are organic bases. • They will combine with carboxylic acids to make amino acids, the building blocks of proteins. • Examples
Amides • RCONH2 • Write the name of the carbon chain and end with amide. • Examples
Thiols • RSH • May be primary, secondary and tertiary. • Analogs of alcohols so they will do the same reactions. • Name the longest carbon chain and maintain the ending. • Add the word thiol to it.