Harjinder Kaur
Sep 15
Why is there an increase in lambda max (in nm) value of the compounds: CH4 (125), CH3CH2CH3 (135), cyclopropane (190)?
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ChatGPT
Sep 15
The increase in lambda max value of the compounds CH4, CH3CH2CH3, and cyclopropane can be attributed to the increasing size and complexity of the molecules.
In general, larger and more complex molecules tend to have higher lambda max values because they have more electrons and more possible electronic transitions. This results in a wider range of energy levels and therefore a higher lambda max value.
CH4 is a simple molecule with only one carbon atom and four hydrogen atoms. It has a lambda max value of 125 nm because it has a limited number of electrons and electronic transitions.
CH3CH2CH3, also known as propane, is a larger molecule with three carbon atoms and eight hydrogen atoms. It has a lambda max value of 135 nm, which is higher than that of CH4 because it has more electrons and electronic transitions.
Cyclopropane is a cyclic hydrocarbon with three carbon atoms. It has a lambda max value of 190 nm, which is higher than that of both CH4 and CH3CH2CH3 because of its unique structure and increased complexity compared to the linear hydrocarbons.
Overall, the increase in lambda max value of these compounds can be attributed to the increasing size and complexity of the molecules, which results in a wider range of energy levels and electronic transitions.
In general, larger and more complex molecules tend to have higher lambda max values because they have more electrons and more possible electronic transitions. This results in a wider range of energy levels and therefore a higher lambda max value.
CH4 is a simple molecule with only one carbon atom and four hydrogen atoms. It has a lambda max value of 125 nm because it has a limited number of electrons and electronic transitions.
CH3CH2CH3, also known as propane, is a larger molecule with three carbon atoms and eight hydrogen atoms. It has a lambda max value of 135 nm, which is higher than that of CH4 because it has more electrons and electronic transitions.
Cyclopropane is a cyclic hydrocarbon with three carbon atoms. It has a lambda max value of 190 nm, which is higher than that of both CH4 and CH3CH2CH3 because of its unique structure and increased complexity compared to the linear hydrocarbons.
Overall, the increase in lambda max value of these compounds can be attributed to the increasing size and complexity of the molecules, which results in a wider range of energy levels and electronic transitions.
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Google Gemini AI
Sep 15
The increase in lambda max (in nm) value of the compounds can be attributed to the following reasons:
1. Increase in Conjugation: As the number of conjugated double bonds increases, the lambda max value also increases. Conjugation lowers the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), resulting in a longer wavelength of absorption. In the given compounds, cyclopropane has no conjugation, while CH3CH2CH3 has one conjugated double bond. Hence, cyclopropane has a lower lambda max value (190 nm) than CH3CH2CH3 (135 nm).
2. Ring Strain: Ring strain in cyclopropane causes a distortion of the C-C-C bond angles, which affects the electronic structure of the molecule. The strained C-C bonds in cyclopropane result in a higher energy HOMO, leading to a shorter wavelength of absorption (190 nm) compared to CH4 (125 nm) and CH3CH2CH3 (135 nm).
3. Hybridization: The hybridization of the carbon atoms also influences the lambda max value. In CH4, the carbon atom is sp3 hybridized, while in CH3CH2CH3, the carbon atoms involved in the double bond are sp2 hybridized. Sp2 hybridization allows for more efficient overlap of p-orbitals, leading to a lower energy gap and a longer wavelength of absorption. Hence, CH3CH2CH3 has a higher lambda max value (135 nm) than CH4 (125 nm).
In summary, the increase in lambda max value from CH4 to CH3CH2CH3 to cyclopropane is primarily due to the increased conjugation in CH3CH2CH3 and the ring strain in cyclopropane.
1. Increase in Conjugation: As the number of conjugated double bonds increases, the lambda max value also increases. Conjugation lowers the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), resulting in a longer wavelength of absorption. In the given compounds, cyclopropane has no conjugation, while CH3CH2CH3 has one conjugated double bond. Hence, cyclopropane has a lower lambda max value (190 nm) than CH3CH2CH3 (135 nm).
2. Ring Strain: Ring strain in cyclopropane causes a distortion of the C-C-C bond angles, which affects the electronic structure of the molecule. The strained C-C bonds in cyclopropane result in a higher energy HOMO, leading to a shorter wavelength of absorption (190 nm) compared to CH4 (125 nm) and CH3CH2CH3 (135 nm).
3. Hybridization: The hybridization of the carbon atoms also influences the lambda max value. In CH4, the carbon atom is sp3 hybridized, while in CH3CH2CH3, the carbon atoms involved in the double bond are sp2 hybridized. Sp2 hybridization allows for more efficient overlap of p-orbitals, leading to a lower energy gap and a longer wavelength of absorption. Hence, CH3CH2CH3 has a higher lambda max value (135 nm) than CH4 (125 nm).
In summary, the increase in lambda max value from CH4 to CH3CH2CH3 to cyclopropane is primarily due to the increased conjugation in CH3CH2CH3 and the ring strain in cyclopropane.
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