General Organic Chemistry PDF

Al-Tahadi University General Organic Chemistry (GRC/GR/00) Fundamental of Organic Chemistry Dr. Entesar.S. Dabous  History of Organic Chemistry Organic Chemistry: the chemistry of carbon compounds. Swedish chemist Torbern Bergman ( in 1770) was the fir...

Al-Tahadi University General Organic Chemistry (GRC/GR/00) Fundamental of Organic Chemistry Dr. Entesar.S. Dabous  History of Organic Chemistry Organic Chemistry: the chemistry of carbon compounds. Swedish chemist Torbern Bergman ( in 1770) was the first to distinguish organic compounds from inorganic compounds. Organic compounds were believed to have a vital force. Friedrich Wohler (in 1828) isolated an organic compounds from inorganic material. Organic Chemistry: definition and importance in our life Organic chemistry touches our daily lives, almost all of the reactions in living matter involve organic compounds. The major constituents of living matter e.g. nucleic acid (DNA and RNA), hormones, proteins,….etc. are organic The medicines we take and plastic containers, oil, gasoline, the paper for our books....etc. are organic materials. Organic chemistry is the study of carbon compounds. Organic compounds have carbon and with other elements hydrogen, oxygen, nitrogen, halogen,… etc. CO32-, HCO3-, CO, CO2, SCN-, CNO-, and CN- are NOT organic compounds.  Chemical Bonds - Chemical bonds: the forces attraction between any two atoms, in a molecule, to from chemical compounds which stabilize the atoms. ‫ ھﻲ اﻟﻘﻮة اﻟﺘﻲ ﺗﺮﺑﻂ اﻟﺬرات ﻟﺘﻜﻮﯾﻦ ﺟﺰﯾﺌﺎت اﻗﻞ طﺎﻗﺔ واﻛﺜﺮ اﺳﺘﻘﺮارا‬:‫اﻟﺮواﺑﻂ اﻟﻜﯿﻤﯿﺎﺋﯿﺔ‬- -Ionic bond : transfer valence electrons, electronegativity difference is greater than 2.0 The majority of ionic compounds are inorganic substances. - Covalent bond: formed when electrons are shared between two atoms. The majority of covalent compounds are organic substances Electronegativity ‫اﻟﻜﮭﺮوﺳﺎﻟﺒﯿﺔ‬ -The ability of an atom to attract a pair of electrons in a chemical bond is called its electronegative..‫ﻧﺤﻮھﺎ‬-‫ اﻟﻜﺘﺮوﻧﺎت اﻟﺮاﺑﻄﺔ‬-‫ ھﻲ ﻗﺪرة اﻟﺬرة ﻋﻠﻰ ﺟﺬب اﻟﻜﺘﺮوﻧﺎت اﻟﺘﻜﺎﻓﺆ‬: ‫اﻟﻜﮭﺮوﺳﺎﻟﺒﯿﺔ‬  Classification of Covalent bond Covalent bonding can be classified in several ways based on the number of bonds, the electronegativity difference between the atoms, ……etc. 1. Single, Double, and Triple Bonds: -Single Bonds: Involve the sharing of two electrons between two atoms, e.g., C-C, C-H, C-O, C-N. -Double Bonds: Involve the sharing of four electrons between two atoms, e.g., C=C, C=O, C=N. -Triple Bonds : Involve the sharing of six electrons between two atoms, e.g., C≡C, C≡N.  Classification of Covalent bond 2. Polar and Non-polar Covalent Bonds: Non-polar Covalent Bonds : Occur when the shared electrons are equally shared between the atoms, e.g., C-C, C-H..‫ او اﻗﻞ‬0.4 ‫ﺗﻨﺸﺄ ﺑﯿﻦ ذرﺗﯿﻦ ﻣﺘﺸﺎﺑﮭﺘﯿﻦ او ﻣﺘﻘﺎرﺑﺘﯿﻦ ﻓﻲ اﻟﻜﮭﺮوﺳﺎﻟﺒﯨﺔ وﯾﻜﻮن اﻟﻔﺮق‬ - Polar Covalent Bonds : Occur when the shared electrons are unequally shared between the atoms due to a difference in electronegativity, e.g., C-O, C-N. 1.9-0.4‫ﺗﻨﺸﺄ ﺑﯿﻦ ذرﺗﯿﻦ ﻣﺨﺘﻠﻔﺘﯿﻦ ﻓﻲ ﻗﯿﻢ اﻟﻜﮭﺮوﺳﺎﻟﺒﯿﺔ ﺑﻤﻘﺪار‬ The more electronegative atom assume a partial negative charge and the less electronegative atom a partial positive charge.  Covalence Number -The number of covalent bonds that an atom can form with other atoms. -The covalence number is equal to the number of electrons needed to fill its valance shell. Atomic Orbitals The electronic configuration of carbon ( atomic number 6) can be represented.  Atomic Orbitals An atomic orbital represents a specific region in space in which an electron is most likely to be found Atomic orbitals are designated in the order in which they are filled by the s, p, d, and f An s -orbital is spherically shaped. A p – orbital is a dumbbell -shaped Types of bonds of Organic compounds Sigma bonds (σ bonds) can be formed from  The overlap of two s atomic orbitals.  The end-on overlap of two p atomic orbitals.  The overlap of two an s atomic orbital with a p atomic orbital. Pi bonds(π bonds) can be formed from the side-side overlap between two p atomic orbitals.  Hybridization of Orbitals The combination of two or more atomic orbitals forms a new set of atomic orbitals, called hybrid orbitals” ‫ھﻮ ﻋﺒﺎرة ﻋﻦ ﻋﻤﻠﯿﺔ ﺗﺪاﺧﻞ ﺑﯿﻦ اﻻﻓﻼك اﻟﺬرة اﻟﻮاﺣﺪة اﻟﻤﺘﻘﺎرﺑﺔ ﻓﻲ اﻟﻄﺎﻗﺔ ﯾﻨﺘﺞ ﻋﻨﮭﺎ اﻓﻼك ﺟﺪﯾﺪة‬.‫ﻣﺘﺴﺎوﯾﺔ ﻓﻲ اﻟﺸﻜﻞ واﻟﻄﺎﻗﺔ‬ We deal with three types of hybrid orbitals sp3 (one s orbital + three p orbitals) sp2 (one s orbital + two p orbitals) sp (one s orbital + one p orbital) sp3 Hybrid Orbitals- Methane CH4 sp3 Hybrid Orbitals-Bonding in Methane  sp2 Hybrid Orbitals-Ethylene—C2H4 sp2 hybrid orbitals are formed from one 2s and two 2p orbitals, leaving one 2p orbital unhybridized.  sp Hybrid Orbitals- Acetylene, CH≡CH Each carbon atom is singly bonded to one hydrogen atom and triply bonded to the other carbon atom. As a result: Each carbon is linear and each carbon is sp hybrized.  Characteristics of different hybrids Hybrids and some molecular parameters Example #1 Example #2 More Examples  Home assignment 1-The hybridization of C atoms in C–C single bond of HC≡C–CH═CH2 is (a) sp-sp2 (b) sp2-sp2 (c) sp-sp3 (d) sp2-sp3 2- The bond between C atom (1) and C atom (2) in compound involves, respectively, the hybrid orbitals (a) sp2 and sp2 (b) sp3 and sp (c) sp and sp2 (d) sp and sp Types of Organic Reactions There are many types of organic reaction: Addition Reactions Elimination Reactions Substitution Reactions I-Addition Reactions Addition reaction: two molecules combine to give one molecule. It occurs in alkenes and alkynes ( double or triple bond is broken) Reactants are added to the carbon atoms in these bonds. ‫‪Examples‬‬ ‫‪.‬تفاعل اإلضافة‪:‬‬ ‫‪1-‬‬ ‫ يتضمن تفاعل اإلضافة إضافة مواد جديدة إلى املركب غير املشبع‪ ،‬مما يؤدي إلى تحويله إلى مركب‬ ‫ال‪ ،‬في تفاعل اإلضافة إلى األلكينات )التي تحتوي على روابط مزدوجة( أو األلكاينات )التي تحتوي‬‫مشبع‪.‬مث ً‬ ‫على روابط ثالثية(‪ ،‬تتم إضافة مواد مثل الهيدروجني‪ ،‬الهالوجينات‪ ،‬أو األحماض‪ ،‬مما يؤدي إلى تحويل الروابط‬ ‫املتعددة إلى روابط مفردة‪ ،‬مما يجعل املركب مشبًعا أكثر‪.‬‬ ‫‪2.‬‬ ‫‪2-‬‬  ‫‪II- Elimination Reactions‬‬ ‫تفاعل الحذف‪:‬‬ ‫ يتضمن تفاعل الحذف إزالة مجموعة أو ذرتني من املركب املشبع‪ ،‬مما يؤدي إلى‬ ‫‪ Elimination Reaction: removal of a molecule from two adjacent carbon‬‬ ‫تكوين مركب غير مشبع‪.‬على سبيل املثال‪ ،‬في تفاعل الحذف من األلكانات‪ ،‬يمكن إزالة‬ ‫املاء أو الهيدروجني لتكوين األلكينات أو األلكاينات‪.‬‬ ‫‪atoms. Ex. Preparation of alkene or alkyne.‬‬ ‫‪ -‬ھﺬا اﻟﺘﻔﺎﻋﻞ ﺗﺤﺬف ذرﺗﺎن ) او ﻣﺠﻤﻮﻋﺘﺎن( ﻣﻦ ذرﺗﯿﻦ ﻛﺮﺑﻮن ﻣﺘﺠﺎروﻧﯿﻦ ﻓﯿﻨﺸﺄ ﻣﺮﻛﺐ ﻏﯿﺮ ﻣﺸﺒﻊ‪.‬‬ ‫‪ Two groups X and Y are removed.‬‬ ‫‪ Two σ bonds are broken, and a π bond is formed between adjacent‬‬ ‫‪atoms.‬‬ ‫ ‬  Examples 1- 2-  III- Substitution Reactions Substitution Reaction: a reaction in which an atom or group of atoms is replaced by another atom or group of atoms. ‫ ﺣﯿﺚ ﺗﺰاح ذرة او ﻣﺠﻤﻮﻋﺔ ﻣﺮﺗﺒﻄﺔ ﺑﺬرة اﻟﻜﺮﺑﻮن وﯾﺤﻞ ﻣﺤﻠﮭﺎ ذرة او‬:(‫ﺗﻔﺎﻋﻼت اﻻﺣﻼل ) اﻻﺳﺘﺒﺪال‬.‫ﻣﺠﻤﻮﻋﺔ اﺧﺮى‬  Reagent Types There are basically two types of reagents in organic chemistry: 1- The nucleophilic (Nu-,Nu) is electron rich species and donates electron pairs to electron deficient species : ‫ اﻟﻜﻮاﺷﻒ اﻟﻨﯿﻮﻛﻠﯿﻮﻓﯿﻠﯿﺔ‬. 1 ‫ھﻲ ﻛﻮاﺷﻒ ﻟﺪﯾﮭﺎ اﻟﻘﺪرة ﻋﻠﻰ ﻣﻨﺢ او اﻋﻄﺎء اﻻﻟﻜﺘﺮوﻧﺎت ) إﻧﮭﺎ ﻏﻨﯿﺔ ﺑﺎﻹﻟﻜﺘﺮوﻧﺎت ( اي اﻧﮭﺎ ﻗﻮاﻋﺪ‬ ‫ ﻣﻤﻜﻦ ان ﺗﻜﻮن ﺳﺎﻟﺒﺔ او ﻣﺘﻌﺎدﻟﺔ ﻣﺜﻞ‬,‫ﻟﻮﯾﺲ‬ ‫‪Reagent Types‬‬ ‫‪ 2- Electrophiles( E+,E) are electron deficient species and can accept‬‬ ‫‪an electron pair from electron rich species.‬‬ ‫‪.-2‬اﻟﻛواﺷف اﻹﻟﻜﺘﺮوﻓﯿﻠﯿﺔ‪:‬‬ ‫ھﻲ ﻛﻮاﺷﻒ ﻟﺪﯾﮭﺎ اﻟﻘﺪرة ﻋﻠﻰ اﺳﺘﻘﺒﺎل اﻻﻟﻜﺘﺮوﻧﺎت ) ﻓﻘﯿﺮة اﻟﻜﺘﺮوﻧﯿﺎ( اي اﻧﮭﺎ اﺣﻤﺎض ﻟﻮﯾﺲ‬ ‫وﯾﻤﻜﻦ ان ﺗﻜﻮن ﻣﻮﺟﺒﺔ او ﻣﺘﻌﺎدﻟﺔ ﻣﺜﻞ‬