CHE-310 Organic Chemistry I Dr. James Lyle; office: NSM D-323 (310) 243-3388 or 243-3376 jlyle@csudh.edu office hours: MWF: 9-10:00am & Tu: 8:00-9:00am Web page: http://chemistry.csudh.edu/ texts: Organic Chemistry, Morrison & Boyd (6th) Supplement to..., Morrison & Boyd (optional) Supplement... Model kit Grading: traditional, no curve! A=100%-93%, A-=92%-90%,B+=89%-88%, B=87%-83%,etc. Daily exams 4 exams @ 100 pts final exam homework = 100 = 400 = 100 required 600 Daily exams No make ups! Drop two lowest scores. Begin at 10:00! Daily Homework: Required! (hold until called for) Cheating: Don’t do it! The penalties are severe. Turn off all cell phones and pagers! Organic Chemistry; difficult, challenging! “memorization course” (NOT! well…maybe), body of knowledge + application of theory! How to succeed? 1. look over the text before lecture. 2. listen carefully to lectures 3. read the text (take notes) 4. do the homework (twice...?) 5. review Organic Chemistry - the study of the compounds of carbon, their properties and the changes that they undergo. Descriptive approach nomenclature syntheses reactions mechanisms ... First: review topics from gen. chem. important to o-chem. atomic structure subatomic particles: mass charge protons 1 amu +1 neutrons 1 amu 0 electrons ~0 amu -1 nucleus: protons & neutrons electron shells & subshells: electrons atomic number = number of protons in the nucleus of the atom (different for each element); Hydrogen = 1, Helium = 2, Lithium = 3,... [also the number of electrons in a neutral atom] Iron = 26 26 protons = +26 26 electrons=-26 net charge= 0 atomic mass = mass of an atom; sum of the weights of the protons & neutrons. But, not all atoms of a given element are identical. isotopes - atoms of the same element with different numbers of neutrons. examples of isotopes prot. neut. % H1 H2 1 1 0 1 99.985 0.015 C12 C13 6 6 6 7 98.89 1.11 C14 6 8 ... Cl35 17 18 75.53 Cl37 17 20 24.47 F19 9 10 100 atomic weight: weighted average mass of the atoms; combining weight... electrons => energy shells & subshells about the nucleus. shells = 1, 2, 3, 4, ... subshells = s, p, d, f orbitals = region in space where an electron of given energy is likely to be found; no more than two electrons of opposite spin per orbital (Pauli exclusion principle). maximum number of electrons per subshell: s 2 p 6 d 10 f 14 order of filling 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 6f spectral notation: 1s2,2s2,2p6… Fluorine (at.# 9) 9p/9e 1s2,2s2,2p5 Chlorine (at.# 17) 17p/17e 1s2,2s2,2p6,3s2,3p5 Bromine (at.# 35) 35p/35e 1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p5 Iodine (at.# 53) 53p/53e 1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p6,5s2,4d10,5p5 valence electrons = electrons in the outermost shell Fluorine has 7 valence elect. Chlorine has 7 valence elect. Bromine has 7 valence elect. Iodine has 7 valence elect. PERIODIC CHART OF THE ELEMENTS I VIII ┌────┐ ┌────┐ │ H │ │ He │ │ 1 │ II III IV V VI VII │ 2 │ ├────┼────┐ ┌────┬────┬────┬────┬────┼────┤ │ Li │ Be │ │ B │ C │ N │ O │ F │ Ne │ │ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │ ├────┼────┤ ├────┼────┼────┼────┼────┼────┤ │ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar │ │ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │ ├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤ │ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr │ │ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe │ │ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn │ │ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │ ├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ │ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ periodic chart of the elements metals & nonmetals families (groups) of elements alkali metals (group I) Li,Na,K,... alkaline earths (group II) Be,Mg,Ca,... halogens (group VII) F,Cl,Br,I,... noble gases (group VIII or 0) He,Ne,Ar,... group number = valence elec. Chemical bonding (classical) chemical bond: force that holds atoms together in compounds. ionic bond ~ between metals & non-metals covalent bond ~ between non-metals & non-metals definitions: ionic bond: a chemical bond formed by the transfer of valence electrons to achieve noble gas electron configurations, resulting in ions held together by electrostatic attraction. covalent bond: chemical bond formed by the sharing of valence electrons to achieve noble gas electron configurations. ionic bond example: sodium chloride sodium = Na, atomic # 11 1s2,2s2,2p6,3s1 neon = Ne, atomic # 10 1s2,2s2,2p6 if Na loses 1 elect. then it will have a noble gas elect. config. like Ne but will be charged, +1 ( 11p/10e ). => Na+ sodium ion chlorine = Cl, atomic # 17 1s2,2s2,2p6,3s2,3p5 argon = Ar, atomic # 18 1s2,2s2,2p6,3s2,3p6 if chlorine can gain an electron it will have a noble gas electron config. like argon but will be charged -1 (17p/18e) Clsodium chloride = NaCl or Na+Cl- covalent bonds Lewis Dot representations . . Be . .. :..Cl. Ne . .C . . .. . O... H H2O = .. H:O ..:H see homework! review your gen chem text! CO2 .. .. :O::C::O: .. .. :O=C=O: N2 :N:::N: HCN H:C:::N: H-CN: H2CO .. H:C::O: .. H .. H-C=O: | H :NN: atomic orbitals s p d etc. hybrid atomic orbitals s + p + s + p + p => 3 sp2 s + p + p + p => 4 sp3 => 2 sp hybrids + Hybrid atomic orbitals: sp = linear; 180o B A B sp2 = trigonal; 120o B A B B sp3 = tetrahedral; 109.5o B A B B B VSEPR (valence shell electron pair repulsion) prediction of hybridization number of ligands (X) plus number of unshared pair of valence electrons (E) equals number of orbitals needed what type of hybrid orbitals are needed eg. H2O => .. H:.. O:H or .. H—O—H .. 2 ligands + 2 lone pair = 4 orbitals AX2E2 sp3 tetrahedral, 109.5o H H O water is a bent molecule with bond angles of 105o VSEPR AX2 sp 180o linear AX3 sp2 120o trigonal AX2E sp2 ~120o or “bent” AX4 sp3 109.5o tetrahedral AX3E sp3 ~109.5o or “pyramidal AX2E2 sp3 ~109.5o or “bent” We can use the VSEPR method to predict the shape and bond angles for simple covalent molecules. SHAPE is important! review gen chem text! Do the homework!!!!! PERIODIC CHART OF THE ELEMENTS I VIII ┌────┐ ┌────┐ │ H │ │ He │ │ 1 │ II III IV V VI VII │ 2 │ ├────┼────┐ ┌────┬────┬────┬────┬────┼────┤ │ Li │ Be │ │ B │ C │ N │ O │ F │ Ne │ │ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │ ├────┼────┤ ├────┼────┼────┼────┼────┼────┤ │ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar │ │ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │ ├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤ │ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr │ │ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe │ │ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn │ │ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │ ├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ │ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ Polarity Covalent bonds are polar when the two atoms sharing electrons have different electronegativities. eg. H—Cl δ+ δ- a charge separation or a dipole gives a polar bond. O2 .. .. :O=O: has a non-polar bond Representation of dipoles using vectors a) magnitude = length b) direction = positive negative A molecule will be non-polar if the vector sum of the bond dipoles is zero; eg. they cancel one another. A molecule with be polar if the vector sum of the bond dipoles is non-zero. Determining polarity of covalent molecules: 1. Lewis dot structure 2. VSEPR hybridization shape of the molecule 3. dipoles for polar bonds 4. vector sum of the bond dipoles 5. vector sum = 0 non-polar molecule 6. vector sum 0 polar molecule CO2 :O=C=O: sp linear vector sum = 0 non-polar molecule H2O .. H—O—H .. H O H AX2E2 sp3 vector sum 0 polar molecule! tetrahedral (bent) CH3OH Both C & O are sp3 hybridized. The bond dipole vectors do not cancel each other and the molecule is polar. NB: must know shape to determine polarity! H C H O H H Intermolecular forces. Attractions between molecules. ionic attractions (very strong) Na+ClCl-Na+ dipole-dipole attractions H—Br Br—H hydrogen bonding ( H attached to N,O,F ) H—O----H—O | | H H van der Waals (London forces) (weak) Br—Br Br—Br intermolecular attractions strongest ionic attractions dipole-dipole / hydrogen bonding van der Waals weakest ionic bonds => ionic attractions polar covalent => dipole-dipole attractions non-polar covalent => van der Waals Cl2 non-polar covalent => van der Waals CO2 non-polar covalent => van der Waals H2O polar covalent => dipole-dipole & Hydrogen bonding CH4 non-polar covalent => van der Waals KBr ionic bonding => ionic attractions bonding => shape => polarity => physical properties physical properties: melting point boiling point solubility The stronger the intermolecular forces the higher the mp/bp. Ionic substances have significantly higher mp/bp than do covalent substances. [note: mp/bp also increase with increasing size.] Prediction of mp/bp (relatively high or low?): mp bp Mg(OH)2 ionic => ionic attractions 350oC -- CH3OH polar => dipole-dipole + H-bond -94oC 65oC CH2O polar => dipole-dipole -920C -21oC CH3CH3 non-polar => van der Waals -183oC –89oC Solubility “like dissolves like” ~ water soluble? must be ionic or highly polar + H-bond (hydrophilic) ~ water insoluble? must be non-polar or weakly polar (hydrophobic) Most organic compounds are water insoluble! Acids/Bases historic: acids – from L. acidus = “sour” sour taste react with metals H2 react with bases water + salts change litmus red react with limestone CO2 examples: HCl, H2SO4, HNO3, HClO4 historic: bases - bitter taste soapy feel react with acids water + salts change litmus blue examples: NaOH, Al(OH)3, K2CO3, NaHCO3 Lowry-Brønsted Acid - a substance that donates a proton (H+) in a chemical reaction. Lowry-Brønsted Base – a substance that accepts a proton (H+) in a chemical reaction. CH3MgBr + NH3 CH4 + Mg(NH2)Br base NaOH base acid + H2SO4 acid acid H2O acid base + NaHSO4 base Lewis Acid – a substance that accepts an electron pair in a chemical reaction to form a covalent bond. Lewis Base – a substance that donates an electron pair in a chemical reaction to form a covalent bond. BF3 + :NH3 Lewis - + F3B:NH3 Lowry-Brønsted Rule: acid/base reactions must run “down hill.” stronger acid/base weaker acid/base H2SO4 + H2O stronger stronger acid base H2O + weaker acid NH3 weaker base HSO4- + weaker base NH4+ + stronger acid (note direction of reactions) H3O+ weaker acid OHstronger base Within a period of the periodic chart, acid strength increases with increasing electronegativity: CH4 < NH3 < H2O < HF Within a family of elements, acid strength increases with increasing size: HF < HCl < HBr < HI PERIODIC CHART OF THE ELEMENTS I VIII ┌────┐ ┌────┐ │ H │ │ He │ │ 1 │ II III IV V VI VII │ 2 │ ├────┼────┐ ┌────┬────┬────┬────┬────┼────┤ │ Li │ Be │ │ B │ C │ N │ O │ F │ Ne │ │ 3 │ 4 │ │ 5 │ 6 │ 7 │ 8 │ 9 │ 10 │ ├────┼────┤ ├────┼────┼────┼────┼────┼────┤ │ Na │ Mg │ │ Al │ Si │ P │ S │ Cl │ Ar │ │ 11 │ 12 │ │ 13 │ 14 │ 15 │ 16 │ 17 │ 18 │ ├────┼────┼────┬────┬────┬────┬────┬────┬────┬────┬────┬────┼────┼────┼────┼────┼────┼────┤ │ K │ Ca │ Sc │ Ti │ V │ Cr │ Mn │ Fe │ Co │ Ni │ Cu │ Zn │ Ga │ Ge │ As │ Se │ Br │ Kr │ │ 19 │ 20 │ 21 │ 22 │ 23 │ 24 │ 25 │ 26 │ 27 │ 28 │ 29 │ 30 │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Rb │ Sr │ Y │ Zr │ Nb │ Mo │ Tc │ Ru │ Rh │ Pd │ Ag │ Cd │ In │ Sn │ Sb │ Te │ I │ Xe │ │ 37 │ 38 │ 39 │ 40 │ 41 │ 42 │ 43 │ 44 │ 45 │ 46 │ 47 │ 48 │ 49 │ 50 │ 51 │ 52 │ 53 │ 54 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Cs │ Ba │ La │ Hf │ Ta │ W │ Re │ Os │ Ir │ Pt │ Au │ Hg │ Tl │ Pb │ Bi │ Po │ At │ Rn │ │ 55 │ 56 │ 57 │ 72 │ 73 │ 74 │ 75 │ 76 │ 77 │ 78 │ 79 │ 80 │ 81 │ 82 │ 83 │ 84 │ 85 │ 86 │ ├────┼────┼────┼────┼────┼────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ │ Fr │ Ra │ Ac │ │ │ │ 87 │ 88 │ 89 │104 │105 │ └────┴────┴────┴────┴────┘ ┌────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐ │ Ce │ Pr │ Nd │ Pm │ Sm │ Eu │ Gd │ Tb │ Dy │ Ho │ Er │ Tm │ Yb │ Lu │ │ 58 │ 59 │ 60 │ 61 │ 62 │ 63 │ 64 │ 65 │ 66 │ 67 │ 68 │ 69 │ 70 │ 71 │ ├────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┼────┤ │ Th │ Pa │ U │ Np │ Pu │ Am │ Cm │ Bk │ Cf │ Es │ Fm │ Md │ No │ Lr │ │ 90 │ 91 │ 92 │ 93 │ 94 │ 95 │ 96 │ 97 │ 98 │ 99 │100 │101 │102 │103 │ └────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘ Which is the stronger acid? H2O or H2S? oxygen & sulfur are in the same family and sulfur is bigger: H2S > H2O What is the order of base strength? F- Cl- Br- I- in the halogen family base strength decreases with increasing size: F- > Cl- > Br- > I- Will H2O react with NaSH as shown below? H2O + NaSH NaOH + WA H2S SA no, H2O < H2S Will the following reaction proceed as shown? HI + NaCl SA yes, HI > HCl HCl WA + NaI Isomers - different compounds with the same molecular formula. example: C2H6O CH3CH2OH CH3OCH3 ethyl alcohol dimethyl ether bp 78oC bp –24oC H H H C C O H H H H H H C O C H H H