Solvents

 

Solvents - more than just organic intermediates

 

Aliphatic nitriles are one of the most important products we have added to the portfolio at AlzChem. Based on more than 40 years’ experience with aromatic intermediates, over the past few years we have established the syntheses is of a range of aliphatic nitriles from the laboratory to technical scale production. These compounds are of interest not only as organic synthetic building blocks for pharmaceuticals, agrochemicals and polymers; but also in particular because of their suitability as dipolar aprotic solvents. In this regard, acetonitrile, which stands at the front of this chain, has recently been the focus of attention. During the global shortage of this important solvent in 2009, the advantages of AlzChem‘s direct synthesis became increasingly clear – complete independence from the acrylonitrile process. Thanks to a sophisticated in-house distillation technique, this standard solvent is now available in three qualities (NITRALZ® solvent grade, anhydrous, HPLC grade). Additionally, the longer-chain or branched intermediates are also attracting increasing attention as specialty solvents. Thanks to the broad spectrum of their physical and chemical properties, such as melting and boiling point, dipole moment, dielectric constant etc., suitable solvents can be chosen for each particular requirement profile. In addition, decanonitrile already exhibits a distinctive surface activity. The following diagram, which shows for each compound the particular liquid range as function of the dielectric constant, should make the selection easier. The aromatic benzonitrile is used as the reference.

 

 

Did you know…?

Nitriles are also used as valuable fragrances and scents. For example, the aliphatic decanonitrile conveys a walnut type of smell while p-methoxybenzonitrile has a very pleasant coumarin fragrance that brings to mind the smell of hay or woodruff. More than 50 derivatives, especially higher molecular derivatives, have now been characterized in terms of their olfactory properties. The advantage of these compared to other classes of aromatic substances, in particular such as aldehydes, is the much greater durability of the nitrile function. In addition, a less pronounced sensitising effect of nitriles generally offers better skin tolerance. Your favorite scent may well contain a nitrile of some description, because a perfumer often composes a complete work of art from up to several hundred scent components [ref. V.G. Yadav, Pafai Journal 1994, 16, 29-42].