IHD Formula: Degree of unsaturation

What is the IHD formula? The IHD formula (or degrees of unsaturation) (or IHD, Index of Hydrogen Deficiency) refers to the number of cycles or double or triple bonds (the latter count as two double bonds) in a compound. It can be useful in identifying the type of structure, and is calculated from the molecular … Read more

UV/vis spectroscopy

What is Ultraviolet UV and visible (UV/vis) spectroscopy? Ultraviolet UV and visible (UV/vis) spectroscopy uses radiation from the electromagnetic spectrum whose wavelength is between 100 and 800 nm (energy between 286 and 36 Kcal/mol) and its effect on organic matter, as indicated above, is to produce electronic transitions between the atomic and/or molecular orbitals of … Read more

Identification of Organic Compounds by Spectroscopy

Introduction The structural determination of an organic substance will always start with the purchase, synthesis or isolation of “a pure product” and the following aspects should be considered: Separation, isolation and purification We should therefore begin (in the most general approach) by recalling the physical methods of “separation, isolation and purification” of organic compounds: Crystallization. … Read more

Nuclear Magnetic Resonance

Introduction Before beginning to understand Nuclear Magnetic Resonance (NMR) spectroscopy, we must consider the properties of atomic nuclei that cause this phenomenon to appear. Properties of atomic nuclei The nuclei have two types of remarkable properties: Mechanical properties: which we can imagine assuming a planetary simile: The angular momentum which is due to the motion … Read more

Infrared spectroscopy

What is infrared spectroscopy? Infrared (IR) spectroscopy uses radiation from the electromagnetic spectrum whose wavelength (λ) is between 800 and 400000 nm (0.8 and 400 μ; 1 μ = 10-4 cm). Therefore, its effect on organic matter is to produce deformations of the bonds of the substance. Due to its large size, it is usually … Read more

Mass spectrometry

What is mass spectrometry (MS)? Although it is included among the spectroscopic techniques, mass spectrometry (MS) is not one of these techniques because it does not use any radiation from the electromagnetic spectrum to irradiate the sample and observe the absorption of such radiation. In EM, the sample is ionized (and therefore destroyed) using various … Read more