6/12/2012 - Synthesis of Silver Iodide

One of my fellow chemists asked me if I knew where she could purchase a single silver iodide crystal, and after a while searching without an answer I looked up the synthesis of this metal compound.  The procedure is fairly simple starting with dissolving silver nitrate (AgNO₃) in water, followed with the addition of potassium iodide (KI). A yellow precipitate will form immediately containing both the α-AgI and the β-AgI crystals which can be separated through different dissolution methods.

AgNO_{3 (aq)} + KI_(aq) → KNO_{3 (aq)} + AgI_(s)

Source: O. Glemser, H. Saur "Silver Iodide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1036-7

6/11/2012 - Alkene to 1,2-Diol

Alkenes can be used in many sorts of organic reactions, and here is another use in the introduction of alcohol groups onto a molecule. A 1,2-diol is an organic molecule with two adjacent alcohol groups, as seen in the image below, and it is made through the reaction of an alkene with Osmium Tetroxide and a weak base, such as pyridine.  Then there will be a workup of water and sodium bisulfite to protinate the alcohol groups.  As seen below, highlighted in blue, the oxygen atoms come from the same osmium tetroxide molecule, resulting in the alcohol groups being syn to one another (being on the same side of the molecule).

6/9/2012 - Alkene Halohydration

Sorry for the lack of posts recently as physiotherapy has taken over my life lately and it has exhausted me to the point of falling asleep super early (unlike me).  But I thought I would continue in doing a couple basic organic reactions.  This reaction is the conversion of an alkene into a halohydrated alkane, where there is both an alcohol group and a halogen added to the carbons.  The reactants in this reaction are simply a diatomic halogen (F₂, Cl₂, Br₂, I₂) along with water which also works as the solvent.  This results in the alcohol adding to the most substituted carbon with the halogen adding to the other carbon, both anti configuration to one another.