**Analysis (Peak Assignments based on standard FTIR ranges):** * **701, 784 cm⁻¹:** Aromatic C–H out-of-plane bending vibrations (substitution pattern indeterminate from these peaks alone). * **887, 962 cm⁻¹:** C–H out-of-plane bending (alkenes) or C–O stretching vibrations. * **1083 cm⁻¹:** C–O stretching (alcohols, ethers) or potentially C–N stretching. * **1182, 1225 cm⁻¹:** Strong, broad bands indicative of C–O stretching (phenolic, carboxylic acid, ester) and/or O–H in-plane bending. * **1389 cm⁻¹:** Strong, sharp band characteristic of O–H in-plane bending (phenolic) or symmetric stretching of carboxylate (COO⁻) group. C–H bending (alkane) is less likely given intensity/sharpness. * **1452 cm⁻¹:** C–H bending (alkane or aromatic) or O–H bending. * **1539 cm⁻¹:** Strong, sharp band strongly indicative of N–O asymmetric stretching (nitro compound, NO₂) or C=C stretching (conjugated, aromatic). N–H bending (amide II) is possible but less common at this exact wavenumber. * **1622 cm⁻¹:** Strong, broad band primarily assigned to O–H bending of water (adsorbed) and/or C=O stretching (conjugated ketone, quinone, or carboxylate). C=C stretching (aromatic) typically contributes here. * **2155 cm⁻¹:** Weak, sharp band characteristic of C≡C or C≡N stretching (alkyne or nitrile). * **3269 cm⁻¹:** Medium, broad band definitive for O–H stretching (hydrogen-bonded, carboxylic acid, phenol, or alcohol). * **3529, 3565, 3624 cm⁻¹:** Weak, sharp bands in the region for free (non-hydrogen-bonded) O–H or N–H stretching.
**Conclusions/Inferences:** 1. **Confirmed Functional Groups Present:** * **Hydroxyl Groups (O–H):** Confirmed by the broad ~3269 cm⁻¹ (H-bonded) and sharp peaks ~3529-3624 cm⁻¹ (free). The strong, broad bands at 1182, 1225 cm⁻¹ and sharp band at 1389 cm⁻¹ support phenolic O–H or carboxylic acid O–H involvement. * **Aromatic Rings:** Confirmed by C–H out-of-plane bending below 900 cm⁻¹ and contribution to the 1622 cm⁻¹ band. * **Carbonyl Group (C=O):** [Inference] Likely present, conjugated. The strong, broad 1622 cm⁻¹ band is consistent with a conjugated ketone, quinone, or carboxylate C=O stretch overlapping with aromatic C=C and O–H bending. A distinct, isolated C=O stretch above 1680 cm⁻¹ is absent. * **Nitro Group (NO₂) or Conjugated C=N/C=C:** [Inference] The strong, sharp 1539 cm⁻¹ band is highly suggestive of an aromatic nitro group (asymmetric N–O stretch). Alternatively, it could arise from a highly conjugated system. * **Alkyne or Nitrile (C≡C / C≡N):** [Inference] The weak, sharp 2155 cm⁻¹ band indicates a terminal alkyne or a nitrile group is likely present in minor amounts.
2. **Probable Compound Class:** The spectrum is complex, indicating a polyfunctional molecule. The combination suggests a **polyhydroxy-aromatic compound** (phenolic/flavonoid-like backbone) possibly substituted with **nitro (-NO₂)** and/or **cyano (-C≡N)** groups, or containing conjugated enone/quinone moieties. The presence of both strong H-bonded and free O–H bands indicates multiple hydroxyls in different chemical environments.
3. **Data Limitations:** The exact structure cannot be determined. The absence of a strong, isolated carbonyl stretch >1680 cm⁻¹ and the overlap in the 1500-1650 cm⁻¹ region complicate definitive assignment of carbonyl type and nitro group confirmation without complementary data (e.g., NMR, elemental analysis). The weak sharp peaks ~3529-3624 cm⁻¹ require confirmation to rule out artifacts.
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:**
Peak (cm⁻¹) / Height (a.u.) / Intensity & Shape:
701 / 0.45 / medium, sharp
784 / 0.27 / weak, sharp
887 / 0.33 / weak, sharp
962 / 0.50 / medium, sharp
1083 / 0.44 / medium, sharp
1182 / 0.84 / strong, broad
1225 / 0.84 / strong, broad
1389 / 0.68 / strong, sharp
1452 / 0.58 / medium, sharp
1539 / 0.87 / strong, sharp
1622 / 1.00 / strong, broad
2155 / 0.12 / weak, sharp
3269 / 0.55 / medium, broad
3529 / 0.12 / weak, sharp
3565 / 0.14 / weak, sharp
3624 / 0.15 / weak, sharp
**Analysis (Peak Assignments based on standard FTIR ranges):**
* **701, 784 cm⁻¹:** Aromatic C–H out-of-plane bending vibrations (substitution pattern indeterminate from these peaks alone).
* **887, 962 cm⁻¹:** C–H out-of-plane bending (alkenes) or C–O stretching vibrations.
* **1083 cm⁻¹:** C–O stretching (alcohols, ethers) or potentially C–N stretching.
* **1182, 1225 cm⁻¹:** Strong, broad bands indicative of C–O stretching (phenolic, carboxylic acid, ester) and/or O–H in-plane bending.
* **1389 cm⁻¹:** Strong, sharp band characteristic of O–H in-plane bending (phenolic) or symmetric stretching of carboxylate (COO⁻) group. C–H bending (alkane) is less likely given intensity/sharpness.
* **1452 cm⁻¹:** C–H bending (alkane or aromatic) or O–H bending.
* **1539 cm⁻¹:** Strong, sharp band strongly indicative of N–O asymmetric stretching (nitro compound, NO₂) or C=C stretching (conjugated, aromatic). N–H bending (amide II) is possible but less common at this exact wavenumber.
* **1622 cm⁻¹:** Strong, broad band primarily assigned to O–H bending of water (adsorbed) and/or C=O stretching (conjugated ketone, quinone, or carboxylate). C=C stretching (aromatic) typically contributes here.
* **2155 cm⁻¹:** Weak, sharp band characteristic of C≡C or C≡N stretching (alkyne or nitrile).
* **3269 cm⁻¹:** Medium, broad band definitive for O–H stretching (hydrogen-bonded, carboxylic acid, phenol, or alcohol).
* **3529, 3565, 3624 cm⁻¹:** Weak, sharp bands in the region for free (non-hydrogen-bonded) O–H or N–H stretching.
**Conclusions/Inferences:**
1. **Confirmed Functional Groups Present:**
* **Hydroxyl Groups (O–H):** Confirmed by the broad ~3269 cm⁻¹ (H-bonded) and sharp peaks ~3529-3624 cm⁻¹ (free). The strong, broad bands at 1182, 1225 cm⁻¹ and sharp band at 1389 cm⁻¹ support phenolic O–H or carboxylic acid O–H involvement.
* **Aromatic Rings:** Confirmed by C–H out-of-plane bending below 900 cm⁻¹ and contribution to the 1622 cm⁻¹ band.
* **Carbonyl Group (C=O):** [Inference] Likely present, conjugated. The strong, broad 1622 cm⁻¹ band is consistent with a conjugated ketone, quinone, or carboxylate C=O stretch overlapping with aromatic C=C and O–H bending. A distinct, isolated C=O stretch above 1680 cm⁻¹ is absent.
* **Nitro Group (NO₂) or Conjugated C=N/C=C:** [Inference] The strong, sharp 1539 cm⁻¹ band is highly suggestive of an aromatic nitro group (asymmetric N–O stretch). Alternatively, it could arise from a highly conjugated system.
* **Alkyne or Nitrile (C≡C / C≡N):** [Inference] The weak, sharp 2155 cm⁻¹ band indicates a terminal alkyne or a nitrile group is likely present in minor amounts.
2. **Probable Compound Class:** The spectrum is complex, indicating a polyfunctional molecule. The combination suggests a **polyhydroxy-aromatic compound** (phenolic/flavonoid-like backbone) possibly substituted with **nitro (-NO₂)** and/or **cyano (-C≡N)** groups, or containing conjugated enone/quinone moieties. The presence of both strong H-bonded and free O–H bands indicates multiple hydroxyls in different chemical environments.
3. **Data Limitations:** The exact structure cannot be determined. The absence of a strong, isolated carbonyl stretch >1680 cm⁻¹ and the overlap in the 1500-1650 cm⁻¹ region complicate definitive assignment of carbonyl type and nitro group confirmation without complementary data (e.g., NMR, elemental analysis). The weak sharp peaks ~3529-3624 cm⁻¹ require confirmation to rule out artifacts.
This discussion presents an infrared spectral analysis combining automated interpretation with reference comparison to support functional group identification and structural assessment.