{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Rules of the Day 4-15 - the pi electrons in low energy...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Rules of the Day 4-15-09 1. Featured Golden Rule of Chemistry: 7. Pi electrons prefer to be delocalized over as many adjacent sp 2 hybridized atoms (or sp hybridized atoms in some cases) as possible, and aromaticity is the most stable form of pi electron delocalization. Pi electrons cannot delocalize onto or through sp 3 hybridized atoms since an sp 3 atom has no 2p orbital available. 2. According to the Huckel definition of aromaticity, monocyclic molecules will be aromatic if they are 1) flat , 2) all the ring atoms are sp2 hybridized (sp in rare cases) and 3) there are 4n + 2 pi electrons , where n = 0,1,2,3,4,5,6 ....... 3. The 36 kcal/mol extra stability (unreactivity) of aromatic species derives from putting all
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: the pi electrons in low energy molecular orbitals that extend over the sp2 hybridized ring atoms. These molecular orbitals involve overlap (in phase and out of phase) of the 2p orbitals on the sp2 hybridized ring atoms. 4. Aromaticity stabilizes ions and atoms in molecules exist in hybridization states that maximize aromatocit y . The lone pair on a ring atom will be in a 2p orbital if that leads to aromaticity . This explains why pyridine is much more basic than pyrrole. You will need to understand this before the next test....
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern