Isohexane cas 64742-49-0 and cas 107-83-5 - differences

[Mr Good Cat]

I did my base extraction rescently. Two kinds of isohexane were used: cas 64742-49-0 and cas 107-83-5.

I really don't like this isohexane cas 64742-49-0 as it has higher boiling range 70/85 than cas 107-83-5, and I have strong feeling its ebulioscopic constant is some higher as well. But this time my isohexane cas 107-83-5 was over, so I had to separate the same batch with two different solvents.

What I noticed, at the point when solvent evaporated almost completely, some yellowish tint appeared in the part separated with cas 64742-49-0. At the same time, the part separated with cas 107-83-5 remains pure transparent.
Unfortunately I didn't take photos at this time, but you can believe I say truth.

By next days I was thinking what is the reason of such difference. There were two options: either isohexane cas 64742-49-0 has a natural property to become yellowish while heated, or it dissolves some organic impurities that become yellowish while heated.

So today I did a simple test: I put 500 ml of isohexane cas 64742-49-0 in the beaker and evaporated it till 15 ml remained. It is still pure transparent: no yellowish tint.

As both batches were from the same flast, there is no other way, but completely obvious: isohexane cas 64742-49-0 dissolves some organic side products insoluble in case of isohexane cas 107-83-5 used.

 

[Osmosis Vanderwaal]

What does Cas the website say is the difference, have you compared?

 

[Mr Good Cat]

Not a lot of information on cas 64742-49-0, but what i got, it is a fraction of naptha. No molecular formula, the same as petroleum ether I guess, but more cheap fraction: "64742-49-0 is identified in the product MSDS as hydrotreated light petroleum distillates comprising ≥ 90% C5-C7 hydrocarbons, n-alkanes, isoalkanes, and < 5% n-hexane,"
But cas 107-83-5 is another compound called 2-methylpeptane.
Both used as solvents.

 

[Osmosis Vanderwaal]

2-methylpeptane is a mixture of 2-methylpentane and 2-methylheptane. 2-methylpentane is isohexane.
So basically the second Cas# is the reagent grade and the first distilled petroleum oils

 

[Mr Good Cat]

Exactly, but in terms of application, cas 64742-49-0 is less suitable. This is what I want to say.

Sorry, mistaken spelling. Cas 107-83-5 is another compound called 2-methylpentane, for sure.

 

[Osmosis Vanderwaal]

There is chemical, 2-methylpeptane, like I said it's a mixture of the pentane and the hexane. That's what I read anyway . There's also a petroleum company with a patent on "peptane".