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For each spectrum, interpret all the significant streching frequencies above 1580 cm-10

Short Answer

Expert verified

For each spectrum all the significant stretching frequencies above 1580 cm-1 are given.

First spectrum:

1642 cm-1 : C=N stretching frequency in imine or oxime.

2900 cm-1: C-H stretching frequency in an alkane.

Second spectrum:

1626 cm-1: C=C stretching frequency in cis disubstituted alkenes.

1691cm-1: C=O stretching frequency in primary amide.

2712 cm-1: C-H stretching frequency in aldehyde as it is in the range of 2830-2695 cm-1

2814 cm-1: C-H stretching frequency of alkane.

Third spectrum

1650 cm-1: Free associated C=O .

1703 cm-1: C=O stretching frequency in aliphatic ketone.

2935 cm-1: C-H stretching frequency in alkane as it is in the range of 3000-2840 cm-1.

1604 cm-1: C=C stretching frequency in alpha, beta-unsaturated ketone.

Fourth spectrum

1742 cm-1: C=O stretching frequency in aldehydes.

3050 cm-1: C-H stretching frequency in alkane.

Step by step solution

01

For first spectrum

For this IR spectrum,

1642 cm-1: C=N stretching frequency in imine or oxim.

2900 cm-1: C-H stretching frequency in alkane.

02

For second spectrum

1626 cm-1: C=C stretching frequency in cis disubstituted alkenes.

1691cm-1: C=O stretching frequency in primary amide.

2712 cm-1: C-H stretching frequency in aldehyde as it is in the range of 2830-2695 cm-1.

2814 cm-1: C-H stretching frequency of alkane.

03

For third spectrum

1650 cm-1: Free associated C=O .

1703 cm-1: C=O stretching frequency in aliphatic ketone.

2935 cm-1: C-H stretching frequency in alkane as it is in the range of 3000-2840 cm-1.

04

For fourth spectrum

1604 cm-1: C=C stretching frequency in alpha, beta unsaturated ketone.

1742 cm-1: C=O stretching frequency in aldehydes.

3050 cm-1: C-H stretching frequency in alkane.

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Most popular questions from this chapter

Question: (a) Use the mass spectrum to propose a molecular formula. How many elements of unsaturation are there? (b) Use the IR spectrum to determine the functional group(s), if any. (c) Propose one or more structures for this compound. What parts of the structure are uncertain? If you knew that hydrogenation of the compound gives n-octane, would the structure still be uncertain? (d) Propose structures for the major fragments at 39, 67, 81, and 95 in the mass spectrum.

Chapter-9 covered a synthesis of alkynes by a double dehydrohalogenation of dihalides. A student tried to convert trans-2,5-dimethylhex-3-yne by adding bromine across the double bond and then doing a double elimination. The infrared and mass spectra of the major product are shown here.

  1. Do the spectra confirm the right product? If not, what is it?
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