[tensor]

So I made the sodium phenoxide of BHT in THF by adding BHT to sodium metal. The solution was clear at first, but then turned yellow. I stripped all of the solvent to leave mostly a white precipitate. Over the course of a day or so standing in a sealed Schlenk flask, the solid is now a blueish color. All manipulations were done by Schlenk techniques with dry solvents.

What could be happening?

[rkaminski]

First, do an NMR. Are you sure that the flask was sealed properly or your solvents were fully dried?