I dislike septum bottles of anhydrous solvents from Acros; I found that the integrity of their screw-top cap with wide septa cannot be trusted. I have had a fairly good experience with Aldrich/Fluka. I keep a number of sensitive reagents and anhydrous solvents in SureSeal bottles in humid southern Florida without much problem.
Couple of comments on keeping the SureSeal-bottled compounds healthy:
1. It helps to pierce the septa only with thin needles (gauge 19, 20) whenever possible. Always put the sure-seal bottles under positive pressure of dry Ar when drawing stuff from them.
2. I use a transparent polyethylene chemical-resistant tape to re-seal the septa crown cap. I cut a 1×1 in square of the tape and affix it over the crown to cover the septa that was pierced and I compress the tape with a thumb to squeeze out air channels. (I replace the tape square with a fresh one whenever I use the bottle.) Then I put the red plastic screw cap on the taped crown and parafilm it around with double-folded parafilm strip. (The parafilm is doubled for better mechanical durability, it is stretch-wrapped and thumb compressed to seal-up tightly.) The parafilming around the bottle red cap is not overly important – but the taping the pierced septa is crucial. A suitable solvent-resistant polyethylene tape is available from VWR (cat# 11211-934).
3. Avoid commercial unstabilized anhydrous ether solvents because they don’t store well – buy the stabilized ones. In medicinal chemistry a trace of BHT is much lesser problem than peroxides. (If one does a very sensitive chemistry where BHT interferes he should not be buying anhydrous solvents anyway but distill his ether solvents from a benzophenone ketyl still)
4. Don’t buy LDA or LiHMDS because these reagents are made very easily, freshly before use – and the quality of their commercial solutions is quite atrocious. Strong bases in THF do not store well. Buy hydrocarbon solutions of NaHMDS and KHMDS. Grignards in THF are usually fine.
5. BuLi and sec-BuLi solutions in hydrocarbon are stable at RT; the air and moisture is the problem. The same goes for many commercial Grignard reagents. Don’t put stuff in fridge that does not have to be refrigerated – temperature changes cause pressure changes in the bottle and moisture condensation problem. Also, Grignards tend to crystallize in the fridge and are hard to re-dissolve afterwards. A cabinet under hood is where I store most of my organometallics.
6. I don’t like to share my septum bottles (the same goes for the needless and syringes). If there is no other alternative, I hand over my septa bottle allways together with the polyethylene tape and with explicit reminders about what to do. Then quietly watch from distance and yell if necessary.
(Org Prep Daily stats are getting close to 100k total. Thanks for reading this stuff.)