1 2008 Lecture 8 9 Alkynes - Chem 2203/2207 Test 1: Tuesday...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chem 2203/2207 Test 1: Tuesday Oct 7, 11:30 -1:00 Surnames A –M Theatre B Surnames N- Z ME 4499 (West entrance, closest to the Unicentre, two floors up staircase) 1 Note: Sample Tests are posted. Test 1 covers all lecture material including alkynes. Check http://http-server.carleton.ca/~pbuist/ Alkynes 2 Chapter 8 Alkynes (Acetylenic Hydrocarbons) 1) Introduction, Nomenclature 2) Hybridization 3) Physical Properties 3 4) Chemistry The Carbon-Carbon Triple Bond • Found in some bioactive natural products 4 Polyacetylenic Fatty Acids Echinacea extracts contain diacetylenic fatty acid derivatives 5 1. Introduction to Alkynes • General formula for monoalkyne: C n H 2n-2 • 2 degrees of unsaturation • Recall: Degrees of Unsaturation calculation: • (Max # hydrogens - Obs # hydrogens )/ 2 6 • For monoalkynes with n carbons: (2n+2 )- (2n-2 ) = 2 2 For acetylene, C 2 H 2 : ((2 . 2) +2 ) - ((2 . 2) -2 )/2 = 2 H C C H Ethyne = Acetylene 7 Isomers of C H 2 C 3 H 4 family 8 H C C CH 3 C H 2 CH 2 C CH C H allene cyclopropene propyne Nomenclature H C C H Ethyne (acetylene) ropyne C n H 2n-2 9 H C C CH 3 C H 3 C C CH 3 H C C CH 2 CH 3 Propyne 1-butyne (terminal alkyne) 2-butyne (internal alkyne) 2. Geometry (Hybridization) • sp hybridization = linear sp 3 09 H 10 H H H H sp 2 120 ° vs. 109 ° vs. H H sp 180 ° H H H Hybridization: sp Orbitals • Carbon 2 s orbital hybridizes with a single p orbital giving two sp hybrids – two p orbitals remain unchanged • sp orbitals are linear, 180°apart on x-axis • Two orthogonal p orbitals lie on the y-axis and on the z-axis 11 Hybridization: sp Orbitals and the Structure of Acetylene • In acetylene, each Carbon atom is sp hybridized and has 4 valence electrons, three of which are used to form a triple ond consisting of 1 sigma bond and 2 pi 12 bond consisting of 1 sigma bond and 2 pi bonds. • The remaining electron on each carbon is used to bond to a hydrogen atom. Making Ethyne (Acetylene) using sp Hybrid Orbitals 13 + 2 H . H C C H CC Triple Bond from two sp Hybrid Orbitals and a p orbital • Two sp hybrid orbitals from each C form sp – sp σ bond....
View Full Document

Page1 / 47

1 2008 Lecture 8 9 Alkynes - Chem 2203/2207 Test 1: Tuesday...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online