If you like us, please share us on social media.
The latest UCD Hyperlibrary newsletter is now complete, check it out.

GeoWiki.png
ChemWiki: The Dynamic Chemistry E-textbook > Wikitexts > UC Davis > UCD Chem 124A: Kauzlarich > ChemWiki Module Topics > sp3 Hybridization

MindTouch
Copyright (c) 2006-2014 MindTouch Inc.
http://mindtouch.com

This file and accompanying files are licensed under the MindTouch Master Subscription Agreement (MSA).

At any time, you shall not, directly or indirectly: (i) sublicense, resell, rent, lease, distribute, market, commercialize or otherwise transfer rights or usage to: (a) the Software, (b) any modified version or derivative work of the Software created by you or for you, or (c) MindTouch Open Source (which includes all non-supported versions of MindTouch-developed software), for any purpose including timesharing or service bureau purposes; (ii) remove or alter any copyright, trademark or proprietary notice in the Software; (iii) transfer, use or export the Software in violation of any applicable laws or regulations of any government or governmental agency; (iv) use or run on any of your hardware, or have deployed for use, any production version of MindTouch Open Source; (v) use any of the Support Services, Error corrections, Updates or Upgrades, for the MindTouch Open Source software or for any Server for which Support Services are not then purchased as provided hereunder; or (vi) reverse engineer, decompile or modify any encrypted or encoded portion of the Software.

A complete copy of the MSA is available at http://www.mindtouch.com/msa

sp3 Hybridization

Table of Contents

 

Introduction

The term “sp3 hybridization” refers to the mixing character of one 2s-orbital and three 2p-orbitals to create four hybrid orbitals with similar characteristics. In order for an atom to be sp3 hybridized, it must have an s orbital and three p orbitals.

From wave function to the visual representation:

Four equivalent sp3 hybrid orbitals, resulting from the combination of one s atomic orbital and three p atomic orbitals, can then describe by four new wave functions (equations 1 – 4)

ψ(sp3) = 0.5 ( ψ2s + ψ2px + ψ2py + ψ2pz)      (1)

ψ(sp3) = 0.5 ( ψ2s + ψ2px - ψ2py - ψ2pz)        (2)

ψ(sp3) = 0.5 ( ψ2s - ψ2px - ψ2py + ψ2pz)        (3)

ψ(sp3) = 0.5 ( ψ2s - ψ2px + ψ2py - ψ2pz)        (4)

Plotting any of these four wave functions gives a picture representation of a sp3 orbital. Each hybrid orbital consists of a large lobe and a small lobe, pointing in two opposite direction (figure 1).

sp3 1.jpg

The Bond Angle is 109.5o:

When the graphs of the four wave functions are combined, the resulting picture shows the tetrahedral arrangement of the four sp3 hybrid orbitals around the central atom. Because of the tetrahedral molecular geometry, the calculate bond angles between 1 and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, and 3 and 4 approximately equal 109.5o (figure 2).

sp3 2.jpg

The Energy level and election population:

All four sp3 hybrid orbitals are delocalized—they occupy the same energy level; however, they are higher in energy than the 2s orbital and lower in energy than the 2p orbital (figure 3).

Just like any other atomic orbital, each sp3 hybrid orbital can house 2 elections.

sp3 3.jpg

S-character and the stability of the anion:

Each sp3 orbital has 1 part of s-character to 3 parts of p-character. In other words, it has 25% s-character and 75% p-character. Since the s orbital is closer to the nucleus and thus lower in energy than the p orbital, the electrons of sp3 hybridized species are held farther from the nucleus than those in sp2 (33% s-character) and sp (50% s-character) hybridized species. The closer the electrons are to the nucleus, the more stable they are. Therefore, when bearing the negative charge, sp3 species are less stable than sp2 and sp species. Put differently, sp3 species are less likely to get deprotonated (leaving a pair of electron behind).

Hybridization and bond length/bond strength:

The greater the s-character, the closer the electrons are held to the nucleus, the shorter the bond, and the stronger the bond. Thus, sp3 hybridized atoms form longer and weaker bonds than those of sp2 and sp hybridized.

References

  1. Brown W H, Foote C S, Iverson B L, Anslyn E V. Organic Chemistry, 5th Ed. Brooks/Cole Cengage Learning 2009, 2005.

Problems

1. Which of the (*) carbons is/are sp3 hybridized

problem 2.png

 

2. Draw the energy diagram for the orbitals of sp3 hybridzied carbon and nitrogen. Then fill in the correct number of electron.

3. Indicate the hybridization of oxygen in each molecule

problem 3.png

 

4. Which nitrogen atom(s) is/are sp3 hybridized

problem 1.png

 

5. Describe the bonding scheme of CH4.

 

 

 

 

Answers:

1. a and b

2. Just like the energy diagram in fig.3.
For carbon, each sp3 orbital has 1 electron. For nitrogen, the first sp3 orbital has 2 electrons, then one electron for each of the remaining three

3. All of them (Don't for get the elctron pairs)

4. a and d

5. Carbon has four half-filled sp3 hybrid orbitals. Each orbital overlaps with a partially filled 1s atomic orbital of hydrogen to form 4 sigma bonds. To visualize, hydrogen atoms are placed at the four corner of the tetrahedron.

Contributors

Quynh Nhu Nguyen

You must to post a comment.
Last Modified
10:17, 2 Oct 2013

Tags

Classifications

(not set)
(not set)

Creative Commons License Unless otherwise noted, content in the UC Davis ChemWiki is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. Permissions beyond the scope of this license may be available at copyright@ucdavis.edu. Questions and concerns can be directed toward Prof. Delmar Larsen (dlarsen@ucdavis.edu), Founder and Director. Terms of Use