**Analysis:** * **Region 4000-2500 cm⁻¹:** * Peaks at 2846, 2913, 2944, 2978 cm⁻¹: Assigned to C-H stretching vibrations (symmetric and asymmetric) of aliphatic -CH₂- and -CH₃ groups. * Peak at 3031 cm⁻¹ (weak, broad): Consistent with =C-H or aromatic C-H stretching. * **Numerous sharp/broad weak peaks from 3136 to 3988 cm⁻¹:** This pattern is highly atypical for common organic functional group fundamentals. These peaks likely represent **overtone/combination bands** (e.g., from aromatic ring vibrations) and/or **hydrogen-bonded O-H or N-H stretches** from strongly associated species (e.g., carboxylic acid dimers, polyols, amines). The very weak intensity suggests these are not primary functional group stretches but secondary features. The sharpness of some peaks (e.g., 3296, 3540, 3671 cm⁻¹) may indicate "free" or weakly associated O-H/N-H groups in a specific environment. * **Region 1800-1500 cm⁻¹:** * Peak at 1734 cm⁻¹ (medium, broad): Characteristic of C=O stretching of an **ester, carboxylic acid, or aldehyde**. The breadth suggests possible hydrogen bonding. * Peak at 1637 cm⁻¹ (medium, sharp): Likely C=C stretching of an **alkene or aromatic ring**, or possibly a conjugated carbonyl. Could also be from adsorbed water (H-O-H bending). * Peak at 1557 cm⁻¹ (medium, broad): Possibly N-H bending (amide II) or asymmetric stretching of a carboxylate ion (COO⁻). * **Region 1500-1000 cm⁻¹ (Fingerprint Region):** * Peaks at 1416, 1472 cm⁻¹: C-H bending vibrations (scissoring) of -CH₂- and -CH₃ groups. * Peak at 1367 cm⁻¹: Symmetric bending of -CH₃ or O-H in-plane bending. * Peaks at 1257, 1290 cm⁻¹: C-O stretching of esters, phenols, or carboxylic acids; also C-N stretching possible. * **Dominant peaks at 1096 (strong, broad), 1132 (strong, sharp), 1180 (strong, broad):** Strongly indicate **C-O-C stretching vibrations** (asymmetric) typical of **ethers, esters, or polyols**. The breadth of 1096 and 1180 cm⁻¹ suggests a polymeric or highly hydrogen-bonded network involving C-O groups. * Peak at 956 cm⁻¹ (medium, broad): Could be =C-H out-of-plane bending (alkenes) or P-O-C/P-OH stretching if organophosphorus compounds are present. * **Region below 1000 cm⁻¹:** * Peaks at 802, 730, 669 cm⁻¹ (strong/medium, broad): Characteristic of **aromatic C-H out-of-plane bending** vibrations, indicating a substituted benzene ring (likely 1,4- or 1,2,4-substitution patterns based on 802 and 730 cm⁻¹). The 669 cm⁻¹ peak may also involve C-S or C-Cl stretching. * **Anomalous Peaks (2500-2200 cm⁻¹):** * Peaks at 2372, 2503 cm⁻¹ (weak): These are in the region for P-H, S-H, or C≡C-H stretches, but are very weak. More likely, they are **combination bands** from lower-frequency fundamentals (e.g., aromatic ring vibrations) or artifacts (e.g., atmospheric CO₂ at ~2345 cm⁻¹).
**Conclusions/Inferences:** 1. **Primary Functional Groups Present:** The spectrum is dominated by signals from: * **Aromatic rings** (C-H
This discussion presents an infrared spectral analysis combining
automated interpretation with reference comparison to support
functional group identification and structural assessment.
FTIR Spectrum Interpretation Summary
Comparative Analysis Conclusion
AI-assisted Interpretation Conclusion
**Data → Analysis → Conclusions/Inferences**
**Data:**
Provided FTIR peaks (cm⁻¹, relative intensity, shape): 669 (0.71, strong, broad), 730 (0.62, medium, sharp), 802 (0.73, strong, broad), 956 (0.62, medium, broad), 1096 (1.00, strong, broad), 1132 (0.91, strong, sharp), 1180 (0.99, strong, broad), 1257 (0.65, medium, sharp), 1290 (0.44, medium, sharp), 1367 (0.47, medium, sharp), 1416 (0.51, medium, broad), 1472 (0.44, medium, sharp), 1557 (0.59, medium, broad), 1637 (0.41, medium, sharp), 1734 (0.65, medium, broad), 2372 (0.24, weak, broad), 2503 (0.21, weak, sharp), 2738 (0.20, weak, broad), 2760 (0.21, weak, sharp), 2846 (0.34, medium, sharp), 2913 (0.27, weak, broad), 2944 (0.12, weak, sharp), 2978 (0.18, weak, sharp), 3031 (0.19, weak, broad), 3136-3988 (multiple weak, sharp/broad peaks).
**Analysis:**
* **Region 4000-2500 cm⁻¹:**
* Peaks at 2846, 2913, 2944, 2978 cm⁻¹: Assigned to C-H stretching vibrations (symmetric and asymmetric) of aliphatic -CH₂- and -CH₃ groups.
* Peak at 3031 cm⁻¹ (weak, broad): Consistent with =C-H or aromatic C-H stretching.
* **Numerous sharp/broad weak peaks from 3136 to 3988 cm⁻¹:** This pattern is highly atypical for common organic functional group fundamentals. These peaks likely represent **overtone/combination bands** (e.g., from aromatic ring vibrations) and/or **hydrogen-bonded O-H or N-H stretches** from strongly associated species (e.g., carboxylic acid dimers, polyols, amines). The very weak intensity suggests these are not primary functional group stretches but secondary features. The sharpness of some peaks (e.g., 3296, 3540, 3671 cm⁻¹) may indicate "free" or weakly associated O-H/N-H groups in a specific environment.
* **Region 1800-1500 cm⁻¹:**
* Peak at 1734 cm⁻¹ (medium, broad): Characteristic of C=O stretching of an **ester, carboxylic acid, or aldehyde**. The breadth suggests possible hydrogen bonding.
* Peak at 1637 cm⁻¹ (medium, sharp): Likely C=C stretching of an **alkene or aromatic ring**, or possibly a conjugated carbonyl. Could also be from adsorbed water (H-O-H bending).
* Peak at 1557 cm⁻¹ (medium, broad): Possibly N-H bending (amide II) or asymmetric stretching of a carboxylate ion (COO⁻).
* **Region 1500-1000 cm⁻¹ (Fingerprint Region):**
* Peaks at 1416, 1472 cm⁻¹: C-H bending vibrations (scissoring) of -CH₂- and -CH₃ groups.
* Peak at 1367 cm⁻¹: Symmetric bending of -CH₃ or O-H in-plane bending.
* Peaks at 1257, 1290 cm⁻¹: C-O stretching of esters, phenols, or carboxylic acids; also C-N stretching possible.
* **Dominant peaks at 1096 (strong, broad), 1132 (strong, sharp), 1180 (strong, broad):** Strongly indicate **C-O-C stretching vibrations** (asymmetric) typical of **ethers, esters, or polyols**. The breadth of 1096 and 1180 cm⁻¹ suggests a polymeric or highly hydrogen-bonded network involving C-O groups.
* Peak at 956 cm⁻¹ (medium, broad): Could be =C-H out-of-plane bending (alkenes) or P-O-C/P-OH stretching if organophosphorus compounds are present.
* **Region below 1000 cm⁻¹:**
* Peaks at 802, 730, 669 cm⁻¹ (strong/medium, broad): Characteristic of **aromatic C-H out-of-plane bending** vibrations, indicating a substituted benzene ring (likely 1,4- or 1,2,4-substitution patterns based on 802 and 730 cm⁻¹). The 669 cm⁻¹ peak may also involve C-S or C-Cl stretching.
* **Anomalous Peaks (2500-2200 cm⁻¹):**
* Peaks at 2372, 2503 cm⁻¹ (weak): These are in the region for P-H, S-H, or C≡C-H stretches, but are very weak. More likely, they are **combination bands** from lower-frequency fundamentals (e.g., aromatic ring vibrations) or artifacts (e.g., atmospheric CO₂ at ~2345 cm⁻¹).
**Conclusions/Inferences:**
1. **Primary Functional Groups Present:** The spectrum is dominated by signals from:
* **Aromatic rings** (C-H
This discussion presents an infrared spectral analysis combining automated interpretation with reference comparison to support functional group identification and structural assessment.