Resonance Structures


by Woopydalan
Tags: resonance, structures
Woopydalan
Woopydalan is offline
#1
Feb4-13, 08:16 PM
P: 746
Hello,

I am having difficulty discerning which resonance structures are considerable enough to include and which are so unimportant that they should be discarded. There seems to be no general rule on this that I can find, so I was wondering if such a rule existed or if someone can lead me in the right direction.
Phys.Org News Partner Chemistry news on Phys.org
Space-tested fluid flow concept advances infectious disease diagnoses
New, more versatile version of Geckskin: Gecko-like adhesives now useful for real world surfaces
Researcher develops novel wastewater treatment fabric
Ygggdrasil
Ygggdrasil is offline
#2
Feb4-13, 09:17 PM
Other Sci
Sci Advisor
P: 1,342
http://www.chem.ucla.edu/harding/tut...p_res_str.html
Woopydalan
Woopydalan is offline
#3
Feb4-13, 09:28 PM
P: 746
Thanks, that cleared a lot of things up (though they need to spell check and grammar check that article again)!!

DrDu
DrDu is offline
#4
Feb5-13, 01:51 AM
Sci Advisor
P: 3,372

Resonance Structures


Rule number 5 is debatable. In general, two one electron bonds are more stable than one two-electron bond due to electronic repulsion.
Especially, what do they mean with their example?
How can structure 1 have 3 unpaired electrons? Either the electrons combine to total spin 1/2, then the molecule is already described by structures II and III, or the electrons combine to spin 3/2, then structure I corresponds to an excited state of the molecule which won't mix in structures II and III.
In the case of oxygen you also don't need molecular orbital considerations to show that triplet oxygen is more stable than singlet oxygen. Especially two three electron bonds are more stable than one two electron bond and one four electron bond. This was already shown in 1937 by Wheland and Lennard-Jones http://pubs.rsc.org/en/content/artic...f/tf9373301499


Register to reply

Related Discussions
Resonance structures you don't see Biology, Chemistry & Other Homework 1
Resonance Structures Chemistry 5
Resonance Structures Biology, Chemistry & Other Homework 3
resonance structures Biology, Chemistry & Other Homework 4
Resonance Structures Biology, Chemistry & Other Homework 2