By Emil Lawton
I arrived at Rocketdyne in December of the year that Sputnik was launched. I had been hired as the inorganic, synthesis chemist to replace a young organic chemist who had resigned. The Research Division had several excellent physical chemists and thermodynamicists and they had figured out that compounds containing the N-F bond could serve as excellent rocket propellant oxidizers.
The young chemist had got as far as setting up a system for fluorinating urea safely and had obtained a yellow, fuming corrosive liquid. It could not be contained in glass but was stable in polyethylene bottles. My job was to prove that there were compounds containing N-F bonds in the mixture, extract and identify them. I asked one of the theoreticians where the desired bonds would absorb in the IR. By analogy to NF3 he predicted about 9.8 microns. (Remember, this was in the days before micrometers.) So why had they not gotten the IR spectra? The liquid instantly attacked the salt windows. They had tried coating the windows with paraffin wax but if the coating was thin, the liquid pin-holed through. If they made it thick enough to protect the NaCl windows, the windows were no longer transparent. CaF2 windows were available then, but cut off before 9 microns.
That evening I went home and we had just gotten some shirts back from the laundry. They were wrapped in the then new polyethylene film. Hmm, I thought, they can make this disposable by making them thin. Thin, thin – I thought. The next morning I brought some of the film into the lab, heating a scissors in a flame, I found that I could make small bags which could contain the yellow liquid. Squeezing the bags with the liquid gave us the spectra at the proper frequency. But if there were N-F bonds there, they should be oxidizing. A drop oxidized iodide to iodine.
My boss pulled back a report that was going to the sponsor, Naval Research Laboratory, and added the new data to the report. Back came a temporary extension of the project with enough funds to hire an assistant. It was then I found out that the sponsor was about to terminate the program but gave us a temporary lease on life. During this time we isolated difluoramine and N, N difluorourea. We were off and running and this led to my being promoted, and eventually getting a research team to supervise.