Wavelength (cm⁻¹)

Assignments

L-Arginine

Maleic acid

L-Arginine maleate dihydrate

3359

-

3375

NH₂ asymmetric stretching

2925

2924

2951

CH₃ asymmetric stretching

1679

-

1677

NH₃ asymmetric deformation

1619

1637

1627

COO⁻ asymmetric stretching

1556

-

1512

NH₃ deformation

1377

1376

1389

COO⁻ symmetric stretching

1362

1367

1358

C-CH in plane deformation

1333

-

1312

CH bending

1186

-

1166

rocking

1139

-

1111

CN stretching

847

863

868

COO⁻ rocking

771

786

796

CH rocking

713

-

708

NH₂ out of plane bending

623

633

661

CH₂ rocking

561

-

573

COO⁻ wagging

493

489

503

COO rocking