Molecular Bond Theory

[Guest Nerddoc]

Hey All,

 

Great forum you all got going on here. I just joined recently and already have a question that the chem buffs here might be able to answer. I just finished reading about the Molecular bond Theory...you know, Bonding MOs and Antibonding MOs etc. Could someone explain how to write the molecular structure based on Bonding and Antibonding MOs? Also, when the txtbk says that the Schordinger wave functions of two atoms overlap in phase or out of phase, is that permanent overlap? If so, how does that occur. Thanks, guys.

 

 

-Nerddoc

[Horza2002]

Typically when you writting out the electronic structure, you number the orbitals and then fill them up. So for dihydrogen you would have:

 

1[math]\sigma[/math][math]^{2}[/math] because you have two electrons in the first sigma bond.

 

Then taking for exxample diberylium you would have

 

1[math]\sigma[/math][math]^{2}[/math] 1[math]\sigma[/math][math]^{*2}[/math] because you have two electrons in the first sigma bond and two in the first antisigma bond (* referes to an antibonding). This actually shows why diberlieium doesnt exists, the overal bond order is 0.

 

Then you again repeat the process for say dinitrogen

 

1[math]\sigma[/math][math]^{2}[/math] 1[math]\sigma[/math][math]^{*2}[/math] 2[math]\sigma[/math][math]^{2}[/math] 2[math]\sigma[/math][math]^{*2}[/math] 1[math]\pi[/math][math]^{4}[/math] 3[math]\sigma[/math][math]^{2}[/math]

 

http://www.meta-synthesis.com/webbook/39_diatomics/diatomics.html

 

This site helped me when I was learning about MO theory. Note the numbers after the greek letters are supposed to be superscript but I couldnt get them to work!

 

Sorry I dont understand what your asking for the second part of your questions.

[Guest Nerddoc]

Typically when you writting out the electronic structure, you number the orbitals and then fill them up. So for dihydrogen you would have:

 

1[math]\sigma[/math][math]^{2}[/math] because you have two electrons in the first sigma bond.

 

Then taking for exxample diberylium you would have

 

1[math]\sigma[/math][math]^{2}[/math] 1[math]\sigma[/math][math]^{*2}[/math] because you have two electrons in the first sigma bond and two in the first antisigma bond (* referes to an antibonding). This actually shows why diberlieium doesnt exists, the overal bond order is 0.

 

Then you again repeat the process for say dinitrogen

 

1[math]\sigma[/math][math]^{2}[/math] 1[math]\sigma[/math][math]^{*2}[/math] 2[math]\sigma[/math][math]^{2}[/math] 2[math]\sigma[/math][math]^{*2}[/math] 1[math]\pi[/math][math]^{4}[/math] 3[math]\sigma[/math][math]^{2}[/math]

 

http://www.meta-synthesis.com/webbook/39_diatomics/diatomics.html

 

This site helped me when I was learning about MO theory. Note the numbers after the greek letters are supposed to be superscript but I couldnt get them to work!

 

Sorry I dont understand what your asking for the second part of your questions.

 

Hi horza,

 

Thanks a lot for your help. The site looks like a very useful resource, thank you very much.