W2013CHM2311 Part 4a Notes

W2013CHM2311 Part 4a Notes - CHM2311 Introduc0on to...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
CHM2311’ Introduc0on’to’Structure’&’Bonding’ Part’4’ Molecular’Orbital’Theory’
Image of page 1

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

View Full Document Right Arrow Icon
Models’of’Covalent’Bonding’ Lewis’formalism;’atoms’seek’an’inert’gas’conFgura0on.’ C H H H H Lewis’ V alence’ S hell’ E lectron’ P air’ R epulsion’( VSEPR )’Theory.’Pairs’of’electrons’avoid’one’another’ like’charges’on’a’sphere. H C H H H VSEPR’ V alence’ B ond’( VB )’Theory.’Combina0ons’of’atomic’orbitals’provide’electron’pair’bonds.’ Hybrids’ orient’electron ’pairs . C VB’Theory ’ M olecular’ O rbital’( MO )’Theory.’Energy’levels’within’molecules.’ MO’Theory ’
Image of page 2
Models’of’Covalent’Bonding’ C H H H H Lewis’ H C H H H VSEPR’ V alence’ B ond’( VB )’Theory.’Combina0ons’of’atomic’orbitals’provide’electron’pair’bonds.’ Hybrids’ orient’electron ’pairs . C M olecular’ O rbital’( MO )’Theory.’Energy’levels’within’molecules.’ Quantum’mechanical’models’for’bonding’describe’electrons’as’waves.’ VB’Theory ’ MO’Theory ’
Image of page 3

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

View Full Document Right Arrow Icon
VB’Theory’and’MO’Theories’ The’Main’Diferences’ In VB theory we hybridize atomic orbitals (add/subtract them) on same atom to direct electron pairs. In MO theory we add/subtract atomic orbitals on diferent atoms create orbitals that span two or more atoms. C MO theory provides us with an Au±au type descrip²on oF energy levels in molecules. Hybrids on diferent atoms are then mul²plied together. Pictorially easy, mathema0cally complex.
Image of page 4
Models’of’Covalent’Bonding’ C H H H H Lewis’ H C H H H VSEPR’ C VB’Theory ’ MO’Theory ’ Localized bonding models: Lewis Theory, Valence Bond Theory Electrons’in’a’bond’ are’considered’to’be’ localized’between’the’two’atoms’that’are’joined’by’the’bond.’ The’electrons’stay’between’those’atoms;’they’can’NOT’change’loca0ons’and’they’ do not move around the molecule .’ Delocalized bonding models: Resonance Theory, Molecular Orbital Theory Electrons’in’a’molecule’are’no’longer’considered’as’belonging’to’a’speciFc’atom.’They’are’not’stuck’ in’ any’ given’ loca0on.’ Rather,’ all’ electrons’ belong’ to’ the’ molecule’ as’ a’ whole,’ and’ can’ move’ throughout’the’molecule.’
Image of page 5

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

View Full Document Right Arrow Icon
Molecular’Orbital’Bonding’Models’ General ProperBes: Molecular’orbitals’(MO)’are’similar’in’many’ways’to’atomic’orbitals’(AO).’They’are’ the’solu0ons’to’the’wave’equa0on’for’molecules.’ Exact’solu0ons’to’the’wave’equa0ons’for’molecules’are’difficult’to’Fnd’(e.g.’dealing’ with’e - -e - ’interac0ons),’but’several’methods’of’Fnding’approximate’solu0ons’exist.’ Ha Hb e 1 e 2 ra 1 rb 1 rb 2 ra 2 r 12 R The Schrodinger equa?on revisited… + + + + Λ Ν Μ Ξ Π Ο h m e ra rb ra rb r R 8 1 1 1
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the 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