CARA MUDAH BACA SPEKTRA IR, MS, HNMR dan CNMR SENYAWA ORGANIK

Summary

In this video, Floraa Febiola explains the interpretation of infrared (IR), mass (MS), proton nuclear magnetic resonance (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR) spectra of benzoil peroxide. She discusses the chemical structure of benzoil peroxide, its molecular formula (C14H10O4), and its use as an acne treatment. The analysis includes key absorbance peaks in the IR spectrum, molecular fragmentation in the MS spectrum, and distinct signals in both the 1H NMR and 13C NMR spectra. Overall, the video offers an in-depth look into the spectral characteristics of this compound and its applications.

Takeaways

• 😀 Benzoil Peroxide (C14H10O4) is a chemical compound with medicinal uses, specifically for treating acne.
• 😀 The molecular weight of Benzoil Peroxide is 242.23 g/mol.
• 😀 The chemical structure of Benzoil Peroxide consists of 14 carbon (C), 10 hydrogen (H), and 4 oxygen (O) atoms.
• 😀 The IR spectrum reveals a weak CH aromatic stretch at 3066 cm⁻¹, indicating the presence of an aromatic CH group.
• 😀 The IR spectrum also shows carbonyl (C=O) stretches at 1785 and 1760 cm⁻¹, indicating two carbonyl groups.
• 😀 A band at 1489 cm⁻¹ in the IR spectrum suggests the presence of a C–C bond, while the 1289 cm⁻¹ peak is associated with the C=O group.
• 😀 The mass spectrum shows a molecular ion peak at m/z 242, which corresponds to the molecular weight of Benzoil Peroxide.
• 😀 A fragment ion at m/z 105 is produced by the fragmentation of a C7H5O radical from the C–O bond.
• 😀 The mass spectrum also shows fragment peaks at m/z 122 (C7H6O2) and m/z 77 (C6H5), indicating the fragmentation of the benzyl group and phenyl group.
• 😀 The 1H NMR spectrum of Benzoil Peroxide displays three distinct aromatic proton signals (a, b, c) due to the different substituent environments on the aromatic ring.
• 😀 In the 13C NMR spectrum, five signals are observed for the 14 carbon atoms, showing equivalent chemical environments for certain carbons in the structure.

Q & A

What is Benzoyl Peroxide, and what is its chemical formula?

Benzoyl Peroxide is a chemical compound used as an acne treatment. Its chemical formula is C14H10O4, and its molecular weight is 242.23 g/mol.

What are the key uses of Benzoyl Peroxide?

Benzoyl Peroxide is used as an active ingredient in acne treatment formulations due to its anti-acne properties.

What does the IR spectrum of Benzoyl Peroxide reveal?

The IR spectrum reveals various absorption bands: a weak absorption at 3066 cm⁻¹ indicating aromatic CH groups, bands at 1785 cm⁻¹ and 1760 cm⁻¹ for C=O stretching, a C–C aromatic stretch at 1489 cm⁻¹, and a CO stretch at 1289 cm⁻¹.

Why are there two absorption peaks for the C=O group in the IR spectrum?

There are two absorption peaks for the C=O group because the structure of Benzoyl Peroxide contains two C=O functionalities, resulting in two distinct absorbances.

What information does the mass spectrum provide for Benzoyl Peroxide?

The mass spectrum shows the molecular ion peak at m/z 242, corresponding to the molecular weight. It also shows fragment ions like m/z 105 from the benzoyl radical and m/z 122 from the benzoate ion.

What does the peak at m/z 77 represent in the mass spectrum?

The peak at m/z 77 represents the phenyl group (C6H5), which is a fragment formed through bond cleavage in the molecular structure of Benzoyl Peroxide.

How many signals are observed in the 1H NMR spectrum of Benzoyl Peroxide?

The 1H NMR spectrum of Benzoyl Peroxide shows three distinct signals, corresponding to protons on the aromatic ring with different environments.

What do the signals in the 1H NMR spectrum of Benzoyl Peroxide indicate?

The signals in the 1H NMR spectrum correspond to aromatic protons in different chemical environments. Signal A (8.15 ppm) is a doublet, B (7.81 ppm) is a singlet, and C (7.65 ppm) is another doublet.

What does the 13C NMR spectrum of Benzoyl Peroxide show?

The 13C NMR spectrum shows five peaks, corresponding to various carbon environments in the structure, including C=O ester groups, aromatic CH groups, and carbons in the aromatic ring.

Why is the signal at 129 ppm in the 13C NMR spectrum twice as intense as the signal at 133 ppm?

The signal at 129 ppm is twice as intense as the signal at 133 ppm because it corresponds to two CH aromatic groups in the symmetrical structure of Benzoyl Peroxide.