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Table 1 Comparison of observed and calculated vibrational modes of meropenem before degradation

From: Solid-state stability study of meropenem – solutions based on spectrophotometric analysis

IR calc/exp Raman calc/exp Band assignment
Wavenumber (cm -1 )  
575/603   O-H b in carboxylic group
635/668   O-H b in carboxylic group
653/668   def. pyrrolidine ring + C-O-H b in carboxyl group
690/705   def. pyrrolidine ring + C-O-H b in carboxyl group
695/715   breathing β-lactam ring + C=O b in dimethylcarbomoyl group
771/768   carbonyl group b in carboxylic group
  784/810 breathing β-lactam ring + C-N s between N and methyl group in dimethylcarbomoyl group
  991/959 C-C between β-lactam and dimethylcarbomoyl group + C-N in β-lactam
  994/989 C-C s in basis ring + CH3 w at pyrrolidine ring
1049/1056 1049/1056 C-C in β-lactam ring + CH t/w in trans-hydroxyethyl group
1074/1075   CH t/w in trans-hydroxyethyl group
1135/1143   CH t/w + C-N s in pyrrolidine ring
  1143/1147 CH2t and methyl t in dimethylcarbomoyl group
1160/1153   CH t in CH2 and methyl group in dimethylcarbomoyl group
1202/1188 1202/1188 C-N s in pyrrolidine ring + C-O-H b in carboxyl group
  1221/1210 C-H w at β-lactam ring
1289/1265 1289/1263 C-N s at 4 CH3 + C-H w
  1330/1307 C-C s between pyrrolidine ring and C at COH group
1375/1335   C-H w in CH in trans-hydroxyethyl group + CH w in pyrrolidine ring
1417/1388 1417/1391 C-C s between carboxyl group and pyrrolidine ring + C-N s in basis ring + C-H sc in CH3 in trans-hydroxyethyl group and methyl group
1430/1388   C-N s between CO and CH3 in dimethylcarbomoyl group
  1438/1421 C-H sc in dimethylcarbomoyl group
  1482/1459 C-H w in dimethylcarbomoyl group
  1513/1466 C-H s
1519/1448   CH3 w/sc in dimethylcarbomoyl group
1548/1500   CH3 w/sc in dimethylcarbomoyl group
1616/1549 1616/1553 C=C s in pyrrolidine ring
1751/1749, 1604   C=O s in trans-hydroxyethyl group
1818/1749, 1651 1818/1749 C=O s in carboxyl group
1887/1749   C=O s in pyrrolidine ring
  3020/2939 C-H s in dimethylcarbomoyl group
  3027/2947 C-H s in dimethylcarbomoyl group
  3052/2961 C-H s in trans-hydroxyethyl group group
  3137/2997 C-H s in methyl group
  1. Vibrational modes: s stretching, b bending, w wagging, sc scissoring, r rocking, t twisting.