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Published byKeaton Cullum Modified over 2 years ago

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The Beer-Bouger-Lambert Law and max The Beer’s law: At a given the proportion of light absorbed by a transparent medium is independent of the intensity of the incident light and is proportional to the number of absorbing molecules through which the light passes. I 0 is the intensity of incident light I is the intensity of transmitted light k is the absorption coefficient l is the path length through the sample is molar extinction coefficient or molar absorptivity c is the concentration in mol/L So k ≈ c

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Changes of Absorption Maxima

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In-phase overlap region of AOs = bonding MO Out-of-phase overlap region of AOs (nodal plane) = antibonding MO AOs being combined must have similar energy and the same symmetry with respect to the internuclear axis

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= resonance energy; it becomes 0 if E A is big S = overlap integral that typically is about 0.2 E +- = (E A +- )/(1+-S) Linear Combination of AOs (LCAO)

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g = even (gerade) and u = odd (ungerade) with regard to inverion

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Penta-1,3-diene in heptane

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Absorption of alkenes

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Absorption of isolated chromophores

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