Propyne

My presentation about PROPYNE

1. Propyne By Lê Hà Minh Châu,Tô Phạm Quỳnh Mai Introduction Physical properties Chemical properties Preparation Applications

2. Introduction

3. Introduction Chemical formula: C3H4 Structure: Name: + IUPAC name: Prop-1-yne + Common names: Propyne , Methylacetylene .

4. Physical properties

5. Physical properties Title Properties Molar mass 40.0639 g/mol Appearance Colorless gas Odor Sweet Density 0.53 g/cm 3 Melting point − 102.7 °C (170.5  K) Boiling point −23.2 °C (250.0 K)

6. Chemical properties

7. 1. Addition reaction A  triple bond  adition  reaction can take place in two stages Markovnikov’s   law : The rich get richer. Similar to addition reaction of alkenes 1 pi bond becomes 2 sigma bonds. Usually exothermic

8. a) Halogenation (X2) Cl2 and Br2 add to alkynes to form vinyl dihalides . May add syn or anti, so product is mixture of cis and trans isomers. Difficult to stop the reaction at dihalide .

9. b) Hydrohalogenation (HX) Markovnikov ’s   law : H  atoms of hydrogen halides into  atoms C double bind more H atoms. HCl , HBr , and HI add to alkynes to form vinyl halides. If two moles of HX is added, product is a geminal dihalide .

10. c) Hydrogenation (H2)

11. d) Hydration (H2O) Mercuric sulfate in aqueous sulfuric acid adds H-OH to one pi bond with a Markovnikov orientation, forming a vinyl alcohol ( enol ) that rearranges to a ketone . Hydroboration -oxidation adds H-OH with an anti- Markovnikov orientation, and rearranges to an aldehyde .

12. 3. Substitution reaction Substitution on the  alkyne  reaction involves the release of H atoms bound to the C C bond at the end of the chain of   alkyne CH≡ C-CH3 + AgNO3/NH3 → Ag-C ≡- C-CH3↓ + NH4NO3     silver asetilid e             

13. 4. Oxidation reaction a, KMnO 4 Dilute, neutral solution of KMnO4 O xidizes alkynes to a diketone . Warm, basic KMnO4 cleaves the triple bond. Ozonolysis , followed by hydrolysis cleaves the triple bond.

14. 4. Oxidation reaction b, Combustion reaction Combustion  propyne  with a limited amount of  O 2 ,  CO or C will result in: C 3 H 4 (g)  +   4 O 2 (g )            3 CO 2 (g)  +   2H 2 O(g )

15. Preparation

16. Preparation T he separation reaction of dihalogen in the solution of base and alcol T wo times dehydrogenation of propane

17. Applications

18. Applications a, Use as a rocket fuel L ess toxic A dvantageous  for craft intended for  low Earth orbital operations b, Organic chemistry O rganic synthesis U sed to synthesize vitamin E

19. Thank you for listening!