Pharmaceutical IR Spectroscopy Identification Flashcards

A set of vocabulary flashcards detailing the IR spectra, CAS numbers, and characteristic functional group absorption bands for various active pharmaceutical ingredients and excipients.

Key IR absorption bands at $1752.98\,\text{cm}^{-1}$ ($\nu \text{C=O}$), $1653.66\,\text{cm}^{-1}$ ($\nu \text{C=C}$), and $1110.8\,\text{cm}^{-1}$ ($\nu \text{C-O-C}$ bend / $\text{C-OH}$)

Ascorbic acid / Acidum ascorbicum (CAS: 50-81-7)

IR absorption bands showing carboxylic acid $\nu \text{OH}$ ($3400-2500\,\text{cm}^{-1}$), ester $\nu \text{C=O}$ ($1750\,\text{cm}^{-1}$), acid $\nu \text{C=O}$ ($1680\,\text{cm}^{-1}$), aromatic $\nu \text{Ar (C=C)}$ ($1604\,\text{cm}^{-1}$, $1456\,\text{cm}^{-1}$), and phenol $\text{Ar-OH}$ ($1304\,\text{cm}^{-1}$)

Acetylsalicylic acid / Acidum acetylsalicylicum (CAS: 50-78-2)

Characteristic IR absorption bands at $1678.73\,\text{cm}^{-1}$ for carboxylic acid $\nu \text{C=O}$ and a broad band around $3200-2500\,\text{cm}^{-1}$ for carboxylic acid $\nu \text{OH}$

Benzoic acid / Acidum benzoicum (CAS: 65-85-0)

IR absorption peaks at $3228\,\text{cm}^{-1}$ ($\nu \text{OH}$), $\sim 3000\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $1653\,\text{cm}^{-1}$ ($\nu \text{C=O}$), and $1244\,\text{cm}^{-1}$ ($\nu \text{C-O(H)}$)

Salicylic acid / Acidum salicylicum (CAS: 69-72-7)

IR spectrum featuring a prominent $\nu \text{OH}$ band at $3337.21\,\text{cm}^{-1}$, aliphatic $\nu \text{C-O}$ at $1045.23\,\text{cm}^{-1}$, and aliphatic $\nu \text{CH}$ bands at $3000-2850\,\text{cm}^{-1}$

Ethanol / Alcohol / Alcoholum (CAS: 64-17-5)

IR absorption peaks at $3022\,\text{cm}^{-1}$ ($\nu \text{Ar C-H}$), $2968-2861\,\text{cm}^{-1}$ ($\nu \text{CH}_3$), $1653\,\text{cm}^{-1}$ (amide $\nu \text{C=O}$), and $1128\,\text{cm}^{-1}$ ($\text{N-CH}_3$)

Aminophenazone / Aminophenazonum (CAS: 58-15-1)

IR absorption peaks for primary amine $\nu \text{NH}_2$ at $1632\,\text{cm}^{-1}$, aromatic $\nu \text{C=C}$ at $1573\,\text{cm}^{-1}$ and $1593\,\text{cm}^{-1}$, as well as ester $\text{C=O}$ and $\text{C-O-C}$ vibrations

Benzocaine / Benzocainum (CAS: 94-09-7)

IR absorption bands at $3471\,\text{cm}^{-1}$ ($\nu \text{OH}$), $3066\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $1617\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $1038\,\text{cm}^{-1}$ ($\nu \text{SO}_4^{2-}$), and $1241\,\text{cm}^{-1}$ ($\nu \text{C-N}$)

Quinidine sulfate / Chinidini sulfas (CAS: 56-54-2)

IR spectrum displaying a free $\text{OH}$ peak at $3465\,\text{cm}^{-1}$, broad H-bonded $\text{OH}$ band around $3471\,\text{cm}^{-1}$, $\nu \text{Ar (=CH)}$ at $1617\,\text{cm}^{-1}$, and $\nu \text{C-O-(H)}$ at $1026\,\text{cm}^{-1}$

Quinine hydrochloride / Chinini hydrochloridum (CAS: 130-95-0)

Key IR absorption bands including $\nu \text{SO}_4^{2-}$ at $1025\,\text{cm}^{-1}$, $\nu \text{Ar (=CH)}$ at $1618\,\text{cm}^{-1}$, alkene $\text{=CH}$ at $1472\,\text{cm}^{-1}$, and $\nu \text{C-N}$ at $1242\,\text{cm}^{-1}$

Quinine sulfate / Chinini sulfas (CAS: 804-63-7)

IR spectrum characterized by $\nu \text{OH}$ at $3348.78\,\text{cm}^{-1}$, $\nu \text{CH}$ at $2952.48\,\text{cm}^{-1}$, $\nu \text{C-O}$ stretching at $1074.16\,\text{cm}^{-1}$, and $\text{C-Cl}$ stretching at $810.92\,\text{cm}^{-1}$

Chloral hydrate / Chlorali hydras (CAS: 302-17-0)

IR absorption bands at $3270.68\,\text{cm}^{-1}$ ($\nu \text{OH}$), tertiary alcohol $\text{C-O}$ stretching at $1143.58\,\text{cm}^{-1}$, and $\text{C-Cl}$ stretching bands at $829.241\,\text{cm}^{-1}$ and $784.886\,\text{cm}^{-1}$

Chlorobutanol / Chlorobutanolum (CAS: 57-15-8)

IR absorption peaks at $3524\,\text{cm}^{-1}$ ($\nu \text{OH}$), $3046\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $1272\,\text{cm}^{-1}$ ($\nu \text{C-O-C}$), and $1070\,\text{cm}^{-1}$ ($\nu \text{C-O(H)}$)

Codeine hydrochloride / Codeini hydrochloridum (CAS: 5916-29-0)

Key IR features including $\nu \text{C-O-C}$ at $1262\,\text{cm}^{-1}$, $\text{C-O}$ stretching at $1117\,\text{cm}^{-1}$, $\nu \text{C-O(H)}$ at $1061\,\text{cm}^{-1}$, and aromatic $\nu \text{Ar (C=C)}$ vibrations

Codeine phosphate / Codeini phosphas (CAS: 41444-62-6)

IR absorption bands at $3110.62\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $2955.38\,\text{cm}^{-1}$ ($\nu \text{CH}_3$), $1692.23\,\text{cm}^{-1}$ and $1643.05\,\text{cm}^{-1}$ ($\nu \text{C=O}$), and $1545.67\,\text{cm}^{-1}$ ($\nu \text{Ar (C=C)}$)

Caffeine / Coffeinum (CAS: 58-08-2)

IR spectrum characterized by bands for $\nu \text{CH}$ ($2940-2836\,\text{cm}^{-1}$), amine $\text{-C-N-C-}$ / $\nu \text{NH}^+$ at $2755\,\text{cm}^{-1}$, and $\text{N-H}$ bending at $1589\,\text{cm}^{-1}$

Ephedrine hydrochloride / Ephedrini hydrochloridum (CAS: 299-42-3)

IR absorption bands for $\nu \text{OH}$ ($3500-3200\,\text{cm}^{-1}$), $\nu \text{Ar (=CH)}$ ($3039\,\text{cm}^{-1}$), aryl-alkyl $\text{C-O-C}$ ($1270\,\text{cm}^{-1}$), and $\text{C-OH}$ bend ($1047\,\text{cm}^{-1}$)

Ethylmorphine hydrochloride / Ethylmorphini hydrochloridum (CAS: 125-30-4)

IR spectrum displaying strong bands for $\nu \text{OH}$ at $3520.42\,\text{cm}^{-1}$ and $3397.96\,\text{cm}^{-1}$, $\nu \text{CH}$ at $2990-2899\,\text{cm}^{-1}$, and $\nu \text{C-O}$ stretching at $1048.12\,\text{cm}^{-1}$

Fructose / Fructosum (CAS: 57-48-7)

IR spectrum showing prominent bands for $\nu \text{OH}$ at $3398.92\,\text{cm}^{-1}$ and $3253.32\,\text{cm}^{-1}$, $\nu \text{CH}$ at $2942.84-2890.77\,\text{cm}^{-1}$, and ring/C-O modes around $1048.12\,\text{cm}^{-1}$

Glucose / Glucosum (CAS: 50-99-7)

IR absorption peaks at $3034\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $2955\,\text{cm}^{-1}$ ($\nu_{\text{as}} \text{CH}_2$), and $1735\,\text{cm}^{-1}$ (ester $\nu \text{C=O}$)

Homatropine methylbromide / Homatropini methylbromidum (CAS: 80-49-9)

IR spectrum characterized by sulfonamide $\nu \text{S=O}$ bands at $1332\,\text{cm}^{-1}$, $1163\,\text{cm}^{-1}$, and $1148\,\text{cm}^{-1}$, along with $\nu \text{C-Cl}$ at $774\,\text{cm}^{-1}$

Hydrochlorothiazide / Hydrochlorothiazidum (CAS: 58-93-5)

IR spectrum showing carbohydrate absorption bands for $\text{OH}$, $\text{CH}$, $\text{C-C}$, and $\text{C-O}$, with distinctive $\text{CH/CH}_2$ bending modes at $1423\,\text{cm}^{-1}$ and $1339\,\text{cm}^{-1}$

Lactose / Lactosum (CAS: 63-42-3)

IR absorption peaks for amide $\nu \text{NH}$ at $3245\,\text{cm}^{-1}$ and $1661\,\text{cm}^{-1}$, $\nu_{\text{as}} \text{CH}_3$ at $2967\,\text{cm}^{-1}$, and aromatic $\nu \text{Ar (C=C)}$ bands at $1594\,\text{cm}^{-1}$ and $1488\,\text{cm}^{-1}$

Lidocaine / Lidocainum (CAS: 137-58-6)

IR spectrum characterized by Amide I peak at $1656\,\text{cm}^{-1}$, $\nu_{\text{as}} \text{CH}_3$ at $2904/2796\,\text{cm}^{-1}$, and aromatic $\nu \text{Ar (C=C)}$ bands at $1625\,\text{cm}^{-1}$, $1593\,\text{cm}^{-1}$, and $1497\,\text{cm}^{-1}$

Metamizole sodium / Dipyrone / Metamizolum natricum (CAS: 68-89-3)

IR absorption peaks at $3376\,\text{cm}^{-1}$ ($\nu \text{OH}$), $3054\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), phenolic $\text{O-H}$ bending at $1313\,\text{cm}^{-1}$, and aromatic $\nu \text{Ar (C=C)}$ at $1648\,\text{cm}^{-1}$, $1503\,\text{cm}^{-1}$, and $1473\,\text{cm}^{-1}$

Morphine hydrochloride / Morphini hydrochloridum (CAS: 52-26-6)

IR absorption bands at $3069\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), carboxylate $\nu \text{C=O}$ at $1650\,\text{cm}^{-1}$, $\nu \text{C=C}$ at $1578\,\text{cm}^{-1}$, $1482\,\text{cm}^{-1}$, $1458\,\text{cm}^{-1}$, and ortho-disubstituted ring peak at $740\,\text{cm}^{-1}$

Sodium salicylate / Natrii salicylas (CAS: 54-21-7)

IR spectrum characterized by aromatic $\nu \text{Ar (=CH)}$ at $3070-3025\,\text{cm}^{-1}$, carboxylate $\nu \text{C=O}$, aromatic $\nu \text{Ar (C=C)}$ at $1406\,\text{cm}^{-1}$, and monosubstituted aromatic C-H bending at $844\,\text{cm}^{-1}$ and $678\,\text{cm}^{-1}$

Sodium benzoate / Natrii benzoas (CAS: 532-32-1)

IR absorption bands for methoxy groups $\nu \text{OCH}_3$ ($2965\,\text{cm}^{-1}$, $2936\,\text{cm}^{-1}$, $2840\,\text{cm}^{-1}$), aromatic $\nu \text{Ar (C=C)}$ ($1633\,\text{cm}^{-1}$, $1606\,\text{cm}^{-1}$, $1509\,\text{cm}^{-1}$, $1485\,\text{cm}^{-1}$), and aryl-alkyl ether $\nu_{\text{as}} \text{C-O-C}$ ($1279\,\text{cm}^{-1}$)

Papaverine hydrochloride / Papaverini hydrochloridum (CAS: 61-25-6)

IR absorption peaks at $3321\,\text{cm}^{-1}$ ($\nu \text{OH}$), $3160\,\text{cm}^{-1}$ ($\nu \text{NH}$), $1650\,\text{cm}^{-1}$ (Amide I), $\nu \text{C-O(H)}$ at $1257\,\text{cm}^{-1}$, and para-disubstituted ring peak at $807\,\text{cm}^{-1}$

Paracetamol / Acetaminophen / Paracetamolum (CAS: 103-90-2)

IR spectrum with $\nu \text{Ar (=CH)}$ at $3092\,\text{cm}^{-1}$, $\nu \text{CH}_3$ at $2989\,\text{cm}^{-1}$ and $2963\,\text{cm}^{-1}$, Amide I at $1658\,\text{cm}^{-1}$, and aromatic ring peak at $769\,\text{cm}^{-1}$

Phenazone / Antipyrine / Phenazonum (CAS: 60-80-0)

IR absorption peaks for $\nu \text{NH}$ ($3303\,\text{cm}^{-1}$), $\nu \text{Ar (=CH)}$ ($3166\,\text{cm}^{-1}$, $3081\,\text{cm}^{-1}$), carbonyl $\nu \text{C=O}$ bands at $1766\,\text{cm}^{-1}$ (N-CO-N) and $1679\,\text{cm}^{-1}$ (N-CO-C), and $\nu \text{C-N}$ at $1249\,\text{cm}^{-1}$

Phenobarbital / Phenobarbitalum (CAS: 50-06-6)

IR absorption bands for primary aromatic amine $\nu \text{Ar-NH}_2$ at $3347\,\text{cm}^{-1}$, $3313\,\text{cm}^{-1}$, and $3206\,\text{cm}^{-1}$, ester $\nu \text{C=O}$ at $1692\,\text{cm}^{-1}$, aromatic $\nu \text{Ar C=C}$ at $1644\,\text{cm}^{-1}$, $1604\,\text{cm}^{-1}$, $1519\,\text{cm}^{-1}$, and aryl-aliphatic ester $\nu_{\text{as}} \text{C-O-C}$ at $1270\,\text{cm}^{-1}$

Procaine hydrochloride / Procaini hydrochloridum (CAS: 51-05-8)

IR absorption peaks at $3320.82\,\text{cm}^{-1}$ ($\nu \text{OH}$), $3231.15\,\text{cm}^{-1}$ ($\nu \text{NH}^+$), $3094.23\,\text{cm}^{-1}$ ($\nu \text{ArCH}$), $1274.72\,\text{cm}^{-1}$ ($\nu \text{C-O}$), and $1213.97\,\text{cm}^{-1}$ ($\nu \text{C-N}$)

Pyridoxine hydrochloride / Pyridoxini hydrochloridum (CAS: 58-56-0)

IR absorption peaks at $3186\,\text{cm}^{-1}$ ($\nu \text{OH}$, lowered due to hydrogen bonding), $\nu \text{C-OH}$ at $1294\,\text{cm}^{-1}$, $1166\,\text{cm}^{-1}$, $1145\,\text{cm}^{-1}$, and ortho-disubstituted ring deformation at $770\,\text{cm}^{-1}$

Resorcinol / Resorcinum (CAS: 108-46-3)

IR spectrum with multiple $\nu \text{OH}$ bands at $3560.0\,\text{cm}^{-1}$, $3381.6\,\text{cm}^{-1}$, $3323.7\,\text{cm}^{-1}$, $\nu \text{C-H}$ at $2970.8-2913.0\,\text{cm}^{-1}$, $\nu \text{C-C/CO/COC}$ at $1115.6\,\text{cm}^{-1}$, and $\nu \text{C-O}$ at $1049.1\,\text{cm}^{-1}$

Sucrose / Saccharum (CAS: 57-50-1)

IR bands for primary amine $\nu \text{NH}$ at $3375.78\,\text{cm}^{-1}$, sulfonamide $\nu \text{NH}$ at $3270.6\,\text{cm}^{-1}$ (or $3220.6\,\text{cm}^{-1}$), carbonyl/amide $\nu \text{C=O}$ at $1684.52\,\text{cm}^{-1}$, and $\text{SO}_2$ bands at $1377.89\,\text{cm}^{-1}$ and $1142.62\,\text{cm}^{-1}$

Sulfacetamide sodium / Sulfacetamidum natricum (CAS: 127-56-0)

IR absorption bands for guanidine $\delta \text{NH}$ at $1613\,\text{cm}^{-1}$ and $1525\,\text{cm}^{-1}$, asymmetric $\text{SO}_2$ stretching ($\nu_{\text{as}} \text{SO}_2$) at $1229\,\text{cm}^{-1}$, symmetric $\text{SO}_2$ stretching ($\nu_{\text{s}} \text{SO}_2$) at $1125\,\text{cm}^{-1}$, and para-disubstituted ring peak at $819\,\text{cm}^{-1}$

Sulfaguanidine / Sulfaguanidinium (CAS: 57-67-0)

IR absorption bands at $3152\,\text{cm}^{-1}$, $3113\,\text{cm}^{-1}$, and $3029\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $2826\,\text{cm}^{-1}$ ($\nu \text{CH}_3$), carbonyl $\nu \text{C=O}$ at $1661\,\text{cm}^{-1}$, and $\nu \text{C=C} / \nu \text{C-N}$ at $1592\,\text{cm}^{-1}$

Theobromine / Theobrominum (CAS: 83-67-0)

Key IR absorption bands at $3119\,\text{cm}^{-1}$ ($\nu \text{Ar (=CH)}$), $2982\,\text{cm}^{-1}$ ($\nu \text{CH}_3$), two carbonyl $\nu \text{C=O}$ bands at $1704\,\text{cm}^{-1}$ and $1660\,\text{cm}^{-1}$, and ring $\text{C-N-C}$ / $\delta \text{CH}_3$ bands at $1562\,\text{cm}^{-1}$, $1483\,\text{cm}^{-1}$, $1440\,\text{cm}^{-1}$

Theophylline / Theophyllinum (CAS: 58-55-9)

IR absorption spectrum showing secondary amine $\nu \text{N-H}$ at $3373.85\,\text{cm}^{-1}$, amine salt $\nu \text{NH}^+$ / $\nu \text{CH}$ at $2412.51\,\text{cm}^{-1}$, ester $\nu \text{C=O}$ at $1690.3\,\text{cm}^{-1}$, and aryl-aliphatic ester $\nu_{\text{as}} \text{C-O-C}$ at $1270\,\text{cm}^{-1}$

Tetracaine hydrochloride / Tetracaini hydrochloridum (CAS: 136-47-0)

IR absorption spectrum displaying broad $\nu \text{NH}_3^+$, $\nu \text{OH}$, $\nu \text{NH}$ bands, aromatic C-H at $3073\,\text{cm}^{-1}$ and $3015\,\text{cm}^{-1}$, pyrimidine ring $\nu \text{C=N}$ at $1649\,\text{cm}^{-1}$, aromatic $\nu \text{Ar (C=C)}$ at $1603\,\text{cm}^{-1}$ and $1539\,\text{cm}^{-1}$, and $\nu \text{C-O(H)}$ at $1041\,\text{cm}^{-1}$

Thiamine hydrochloride / Thiamini hydrochloridum (CAS: 67-03-8)

IR spectrum identified by characteristic absorption peaks including $2802.06\,\text{cm}^{-1}$, $1149.37\,\text{cm}^{-1}$, $1001.84\,\text{cm}^{-1}$, $786.815\,\text{cm}^{-1}$, and $713.533\,\text{cm}^{-1}$

Urea / Ureum (CAS: 57-13-6)