11.6 - bonds Strong bonds localizes the e-s producing and...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
E45 Lecture 11/6/09
Background image of page 1

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

View Full DocumentRight Arrow Icon
E=0 CB VB E g Semiconductor vs Insulator E g ≈ 1-2eV => semiconductor E g ≈ ≥ 3eV => insulator
Background image of page 2
In polymers : Strong covalent bonds along the chain and weak, van der Waals bonds between chains Intermolecular charge transfer is weak but because chains are long, not much intermolecular charge transfer is required Therefore, focus on intramolecular charge transfer
Background image of page 3

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

View Full DocumentRight Arrow Icon
Polymer with saturated chemical structure, e.g., polyethylene Tetrahedral arrangement of a.o.s sp 3 hybridization C: 1s 2 2s 2 2p 2 Sp 3 hybridization: 2s 1 p x p y p z
Background image of page 4
Polymer with saturated chemical structure, e.g., polyethylene Tetrahedral arrangement of a.o.s sp 3 hybridization C: 1s 2 2s 2 2p 2 Sp 3 hybridization: 2s 1 p x p y p z Tetrahedral bonds: Ethane: C 2 H 6 Diamond Polyethylene zig/zag
Background image of page 5

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

View Full DocumentRight Arrow Icon
Polymer with saturated chemical structure, e.g., polyethylene Tetrahedral arrangement of a.o.s sp 3 hybridization C: 1s 2 2s 2 2p 2 Sp 3 hybridization: 2s 1 p x p y p z Tetrahedral bonds: Ethane: C 2 H 6 Diamond Polyethylene zig/zag All available e - s are tied up in strong covalent
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: bonds Strong bonds localizes the e-s producing and insulator Conjugated polymers (polyacetylene) have unsaturated carbon sp 2 hybridization: sp 2 hybridization: planar bonds 120 apart p z orbital is perpendicular to plane e-in p z forms a bond with neighboring atoms p z -bond is parallel to underlying bond Resulting in double bond as in Ethylene C 2 H 4 Conjugated polymers (polyacetylene) have unsaturated carbon sp 2 hybridization: sp 2 hybridization: planar bonds 120 apart p z orbital is perpendicular to plane -bond- e-are less strongly bound than bond e-. => e-are more easily removed => conduction Polymer with saturated chemical structure, e.g., polyethylene Tetrahedral arrangement of a.o.s sp 3 hybridization C: 1s 2 2s 2 2p 2 Sp 3 hybridization: 2s 1 p x p y p z Ethane C 2 H 6 Polyethylene - zig-zag...
View Full Document

Page1 / 9

11.6 - bonds Strong bonds localizes the e-s producing and...

This preview shows document pages 1 - 9. Sign up to view the full document.

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