Question

Spectroscopid Analysuts 호 Prot, Zuhncky deoded io analyse a whaleystaline solid left behind by a student one aftomoon. By using mass spectrometry, be igured out that the molecular weight or the axilpound wins 70 밂mol. Prot Zuhncky also n and obtained the folkowing IR and 1H-NMR spectra. Based on this nformation, determine the structure of this unknown by determining the moleculsr formula first them determining the straciure by using the spec- tra below Info on the 'H-NMR: The peaks at -2.0 and 25 ppm are triplets The peaks at-3.5 and-3.8 ppm are singlets

please help me with this. I am not good at reading the IR charts.

Answer 1

Structure:

${\color{Blue} \mathbf{HO-CH_2-CH_2-C\equiv C-H}}$

$\mathbf{Fw=79\frac{g}{mol}}$

H-RMN Analize:

At -OH (singlet, integrate 1H⁺)

First -CH₂- look to left -O- and rigth -CH₂-, so: first -CH₂- (triplet, integrate 2H⁺)

Second -CH₂- look to left -CH₂- and rigth -C $\equiv$ -, so: second -CH₂- (triplet, integrate 2H⁺)

At - $\equiv$ CH- (singlet, integrate 1H⁺)

IR Analize:

At 3300cm^-1 show -OH bond stretch.

At 3000cm^-1 show - $\equiv$ CH- bond stretch.

At 2800cm^-1 show -CH₂- bond stretch.

At 2300cm^-1(aprox) show -C $\equiv$ C- bond stretch.

Answer 2

Structure:

${\color{Blue} \mathbf{HO-CH_2-CH_2-C\equiv C-H}}$

$\mathbf{Fw=79\frac{g}{mol}}$

H-RMN Analize:

At -OH (singlet, integrate 1H⁺)

First -CH₂- look to left -O- and rigth -CH₂-, so: first -CH₂- (triplet, integrate 2H⁺)

Second -CH₂- look to left -CH₂- and rigth -C $\equiv$ -, so: second -CH₂- (triplet, integrate 2H⁺)

At - $\equiv$ CH- (singlet, integrate 1H⁺)

IR Analize:

At 3300cm^-1 show -OH bond stretch.

At 3000cm^-1 show - $\equiv$ CH- bond stretch.

At 2800cm^-1 show -CH₂- bond stretch.

At 2300cm^-1(aprox) show -C $\equiv$ C- bond stretch.