2. The Nature of organic Compounds: Alkanes 有机化合物的种类:烷烃
2. The Nature of Organic Compounds: Alkanes 有机化合物的种类: 烷烃
21 Functional group:能团 Organic compounds can be grouped into families by their common structural features
2.1 Functional Groups:官能团 Organic compounds can be grouped into families by their common structural features p. 4
unctional group- collection of atoms at a site within a molecule with a common bonding pattern The group reacts in a typical way, generally independent of the rest of the molecule For example the double bonds in simple and complex alkenes react with bromine in the same way OH CH C C H Reaction site Double bond
• Functional group - collection of atoms at a site within a molecule with a common bonding pattern • The group reacts in a typical way, generally independent of the rest of the molecule • For example, the double bonds in simple and complex alkenes react with bromine in the same way
Types of functional Groups Multiple carbon-Carbon Bonds alkenes have aC-C double bond Alkynes have a C-C triple bond Arenes have special bonds that are represented as 一C≡C alternating single and Alkene Alkyne ene double c-c bonds in (aromatic ring) a SIX-membered ring
Types of Functional Groups: Multiple Carbon–Carbon Bonds • Alkenes have a C-C double bond • Alkynes have a C-C triple bond • Arenes have special bonds that are represented as alternating single and double C-C bonds in a six-membered ring
Functional Groups with Carbon Singly Bonded to an electronegative Atom Alkyl halide: C bonded to halogen(C-X) Alcohol: C bonded o of a hydroxyl group (C￥OH Ether: Two C's bonded to the same(C=0 Amine:C bonded to N(C=EN Thiol C bonded to sh group(C=Esh Sit: Two Cs bonded to same s(C羊S羊C) Bonds are polar, with partial positive charge on C(8) and partial negative charge(8-)on electronegative atom
Functional Groups with Carbon Singly Bonded to an Electronegative Atom • Alkyl halide: C bonded to halogen (C-X) • Alcohol: C bonded O of a hydroxyl group (C⺷OH) • Ether: Two C’s bonded to the same O (C⺷O⺷ C) • Amine: C bonded to N (C⺷N) • Thiol: C bonded to SH group (C⺷SH) • Sulfide: Two C’s bonded to same S (C⺷S⺷C) • Bonds are polar, with partial positive charge on C (d+) and partial negative charge (d-) on electronegative atom
Groups with a Carbon-Oxygen double Bond(carbonyl groups) Aldehyde: one hydrogen bonded to=o Ketone: two C's bonded to the c=o Carboxylic acid -OH bonded to the c=o Ester:c-o bonded to the c=o Amid e C-n bonded to the c=o Acid chloride. cl bonded to the c=o Carbonyl C has partial positive charge(8+) Carbonyl o has partial negative charge(8-)
Groups with a Carbon–Oxygen Double Bond (Carbonyl Groups) • Aldehyde: one hydrogen bonded to C=O • Ketone: two C’s bonded to the C=O • Carboxylic acid: ¾OH bonded to the C=O • Ester: C-O bonded to the C=O • Amide: C-N bonded to the C=O • Acid chloride: Cl bonded to the C=O • Carbonyl C has partial positive charge (d+) • Carbonyl O has partial negative charge (d-)
p28 2.2 Alkanes and alkyl groups Isomers烷烃和烷基:异构体 Alkanes: Compounds with C-C single bonds and C-H bonds only (no functional groups Connecting carbons can lead to large or small molecules The formula for an alkane with no rings in it must be c ha. where the number of cs is n Alkanes are saturated(.包和) with hydrogen(mo more can be adde They are also called aliphatic compounds
2.2 Alkanes and Alkyl Groups: Isomers 烷烃和烷基: 异构体 • Alkanes: Compounds with C-C single bonds and C-H bonds only (no functional groups) • Connecting carbons can lead to large or small molecules • The formula for an alkane with no rings in it must be CnH2n+2 where the number of C’s is n • Alkanes are saturated(饱和) with hydrogen (no more can be added • They are also called aliphatic compounds p.28
甲、乙、丙、 丁、戊、已、 庚、辛、壬、葵 迷以脱,以脱里
甲、乙、丙、 丁、戊、己、 庚、辛、壬、葵 迷以脱里; 以脱里
Constitutional(构造)omes Isomers that differ in how their atoms are arranged in chains are called constitutional isomers Compounds other than alkanes can be constitutional isomers of one another They must have the same molecular formula to be isomers
Constitutional(构造) Isomers • Isomers that differ in how their atoms are arranged in chains are called constitutional isomers • Compounds other than alkanes can be constitutional isomers of one another • They must have the same molecular formula to be isomers
Different carbon CH skeletons C4H10 CHoCHCH and CH3CH2CH2CH, 2-Methylpropane Butane (soutane) Different functional CH; CH2OH d CHgOCH3 groups C2H60 Ethyl alcohol Dimethyl ether Different position of NH unction OUDS CHON CHCHCH and CHOCHONH sopropvlamine Propylamine Thomson· Brooks cole