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. 2021 Oct 20;12(4):408–419. doi: 10.4103/japtr.japtr_72_21

Table 3.

The Fourier transformed infrared wavenumber (per cm) of obtained cocrystals from reaction number 20-25, 41-46, and 56-61

Functional groups Wave number (per cm)
Acetone Ethyl acetate
Sil:Co
1:1		 Sil:Co
1:2		 Sil:Co
1:3		 Sil:Co
1:1		 Sil:Co
1:2		 Sil:Co
1:3
Reaction number 20-25
 Sildenafil
  Secondary amides (N-H stretching) 3332 3334 3334 3336 3336 3335
  C–H stretching 2959 2960 2961 2959 2960 2960
  C=C aromatic 1588 1588 1588 1587 1587 -
  C–N stretching 1325 - - 1324 1322 -
  SO2 symmetric 1193 1190 1190 1193 1190 1189
ASA
  C=O stretching, ester - 1755 1754 - 1753 1755
  C=O stretching, acid - 1691 1691 - 1690 1690
  C=C stretching - - - - - 1608
  C–O acid stretching - 1308 1307 - - 1307
  C–H bending - 1190 1190 - 1190 1189
Reaction number 41-46
 Sildenafil
  Secondary amides (N-H stretching) 3337 3334 3334 3336 3335 3337
  C–H stretching 2960 2959 2959 2959 2959 2959
  C=C aromatic 1587 1587 1586 1587 1587 1587
  C–N stretching 1323 1324 1323 1324 1323 1323
  SO2 symmetric 1193 1192 1192 1193 1192 1193
FMA
  C–H stretching 3081 - - - 3081 3081
  C=O - - - - 1628 1629
  COO– symmetric - - - - - -
  C–H bending 1275 1271 1271 1272 1272 1272
Reaction number 56-61
 Sildenafil
  Secondary amides (N-H stretching) 3337 3337 3332 3337 3337 3332
  C–H stretching 2960 2960 2959 2960 2960 2959
  C=C aromatic 1585 1586 1585 1585 1586 1585
  C–N stretching 1325 1324 1324 1325 1324 1324
  SO2 symmetric 1191 1192 1191 1191 1192 1191
 BZA
  Aromatic C–H stretching - - - 3332 3336 3341
  O–H stretching (carboxylic) - - - 2958 2960 2960
  C=O stretching - - - 1586 - 1587
  Aromatic C=C stretching - - - 1324 1325 1325
  C–O–H bending - - - 1192 1191 1191
  C–O stretching - - - 3071 3071 3072

Sil=Sildenafil, Co=Co-former