Following are infrared spectra of methylenecyclopentane and 2,3-dimethyl-2-butene, Assign each compound its correct spectrum. Micrometers 25 is ma Transmittance (5) 10 MOD Wavenumber(cm) Micrometers 100 Transmittance (5) So 10 OD 1300 Wavenumber(cm)
The following are IR spectra for the compounds: methylenecyclopentane and 2,3-dimethyl-2-butene.
Assign each compund its IR spectra
The Correct Answer and Explanation is :
Based on the provided infrared (IR) spectra and the chemical structures of methylenecyclopentane and 2,3-dimethyl-2-butene, we can assign each compound to its corresponding spectrum.
Methylenecyclopentane:
Methylenecyclopentane is a cyclic compound featuring a methylene group (–CH₂–) attached to a cyclopentane ring. In its IR spectrum, a prominent absorption band is observed between 900–880 cm⁻¹, corresponding to the out-of-plane bending vibrations of the C–H bonds in the methylene group. This strong absorption is characteristic of 1,1-disubstituted alkenes, where the methylene group is directly attached to the ring.
2,3-Dimethyl-2-butene:
2,3-Dimethyl-2-butene is an alkene with two methyl groups attached to the second carbon of a butene chain. Its IR spectrum exhibits a strong absorption band between 840–800 cm⁻¹, attributed to the out-of-plane bending vibrations of the C–H bonds in the methyl groups. This absorption is typical for trisubstituted alkenes, where the methyl groups are positioned on the same carbon atom of the double bond.
By analyzing these characteristic absorption bands, we can confidently assign each compound to its respective IR spectrum.