Filtration of sodium sulfate what was used to dry this dilute solution of an iodoacetic acid ester in dichloromethane.
The iodoacetic acid slightly decomposed to give a little iodine what colored the whole solution as seen on the picture.
Iodoacetic/bromoacetic/chloroacetic acid esters are highly effective lachrymators (from lacrima meaning “tear” in Latin) the worst is the iodoacetic acid based esters but chloroacetates are also compounds what are not the best to work with. Even milligrams of iodoacetate esters could make anyone cry in no time.
9:30 pm • 19 October 2014 • 71 notes • View comments
Chlorination with 500 g phosphorous pentachloride.
PCl5 is a highly toxic, corrosive ect. yellow solid and a pretty well working reagent. When adding it to ethers it could chlorinate the carbon by turning into the also highly toxic, corrosive ect. phosphorous trichloride what could be distilled out from the reaction mixture.
The problem starts when not everything reacted and you want to distill the products. PCl5 sublimes quite easily at 160 °C, so after the distillation you could easily end up with phosphorous pentachloride dissolved in everything.
Note: PCl5 reacts with water violently to form highly toxic phosphorous oxychloride:
PCl5 + H2O → POCl3 + 2 HCl
What will give ortho-phosphoric acid and hydrochloric acid upon standing in water:
O=PCl3 + 3 H2O → O=P(OH)3 + 3 HCl
9:30 pm • 18 October 2014 • 50 notes • View comments
Recrystallization of 2-chloro-5-nitrobenzoic acid from water.
9:30 pm • 17 October 2014 • 259 notes • View comments
Distillation of a slightly decomposed perfluoroalkyl iodide.
Upon standing alkyl halides, especially iodides could decompose to give elemental iodine and a lot unwanted stuff. From time to time these decomposition products could be removed with fractional distillation if we are enough lucky. In this case a little iodine was left in distillate (as seen on the pictures).
Did you know that Perflubron (perfluorooctyl bromide) has been used in liquid breathing in premature infants with respiratory distress since oxygen dissolves pretty well in these perfluorinated compounds.
9:30 pm • 16 October 2014 • 82 notes • View comments
A small cylinder of hydrogen fluoride with 340 g or 360 liter of HF in it. More than enough to kill someone.
Hydrogen fluoride is a colorless gas what can be liquefied quite easily, with a little ice and water, since its boiling point is 19.5 °C. The gas or its solution in water (hydrofluoric acid) attacks glass, so it could be only stored in steel or plastic. The reaction with silicates (glass) produces silicon tetrafluoride what is a low boiling point ( 4 °C), highly reactive compound and hexafluorosilicic acid.
SiO2 + 4 HF → SiF4(g) + 2 H2O
SiO2 + 6 HF → H2SiF6 + 2 H2O
Hydrogen fluoride is the only hydrohalic acid that is not considered a strong acid, i.e. it does not fully ionize in dilute aqueous solutions. When the concentration of HF approaches 100% (like in the gas cylinder on the picture), the acidity increases dramatically because of homoassociation: 3 HF is in equilibrium with H2F+ + FHF−
Once absorbed into blood through the skin, it reacts with blood calcium and may cause cardiac arrest. In the body, hydrofluoric acid reacts with the ubiquitous biologically important ions Ca2+ and Mg2+. Hydrofluoric acid exposure is often treated with calcium gluconate, a source of Ca2+ that sequesters the fluoride ions. So if anyone works with this, always have a lot calcium gluconate solution somewhere close.
9:30 pm • 15 October 2014 • 117 notes • View comments
If something is worth to publish in the scientific literature, than this is it. A compound what could be polymerized by gentle oxidation to give conductive nano wires what has an insulating layer on them. Pretty interesting and really-really new.
This compound is dissolved in the bottom organic, dichloromethane layer.
9:30 pm • 14 October 2014 • 119 notes • View comments
3 different compound but same reaction conditions. Every flask contains 25 cm3 4M sodium hydroxide and a little alcohol for better solubilization. It should hydrolyze every ester what was in these these flasks.
Every reaction is under a sulfuric acid filled gas bubbler to see, that does the carboxylic acids decompose to CO2 or I’m lucky and they survive these conditions.
9:30 pm • 13 October 2014 • 97 notes • View comments
After a long day in the lab. This amount of glassware was used in the lab just for my experiments, in this case for small scale reactions.
Let’s wash them and end this week.
9:30 pm • 12 October 2014 • 51 notes • View comments
The best pics from the blog could be purchased at Society6 now with a free worldwide shipping for the art prints. The print above is a “SMALL” print, what means a 19” x 13” size and could be bought for $55.
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Short note: just a few hours left from the promotion!
6:59 pm • 12 October 2014 • 38 notes • View comments
These crystals are the first results of a several month long work, they are a quite special substituted pyrrole what could be polymerized quite easily and it will give a conductive polymer.
Even through the crystals have a slight brownish coloration, they are perfectly pure, according to the NMR analysis.
9:30 pm • 11 October 2014 • 199 notes • View comments