Chemistry Notes for B.Sc. and M.Sc.

  Some Important IR Regions: ü  N ear-IR region:   4 ,000 cm –1  - 13 000 cm –1 . ü  Mid-IR region: 670-4000 cm -1 Ø  Functional group region: 1450 cm –1  - 4000 cm –1 . Ø  F ingerprint  region: 67 0 cm –1  - 1450  cm –1 . ü  F ar-IR region: 1 0 cm –1  - 67 0 cm –1     Near Infra-red (NIR) Spectroscopy: ü  The near-IR extends from approximately 13,000 cm –1  - 4000 cm –1 ü  The absorption bands in the near-infrared often are overtones and combination bands of these group frequencies (of O-H, C-H and N-H) ü  The instrumentation for NIR spectroscopy, both in transmission mode and in reflectance mode, is similar to that for UV/visible spectrometers and for mid-IR spectrometry.   Applications of NIR Spectroscopy ü  Near-infrared spectroscopy is  used in astronomy for studying the atmospheres of various  stars   by detecting the  vibrational and rotational signatu...