Neutralization of an Oxytocin Derivative by 355 nm Photocleavage in High Vacuum

Controlling the charge state of biomolecules in high vacuum enables experiments in molecular physics and physical chemistry, particularly in applications of mass spectrometry, trapping and cooling, spectroscopy and matter-wave interferometry. Here we investigate the synthesis, verification and gas phase photolysis of nitrodibenzofuranmethyl aryl ether derivatives. These photocages are chosen because their absorption maximum can be tuned to near 355 nm, where intense pulsed laser light is available. We demonstrate efficient gas-phase cleavage of a photoactive nitrodibenzofuranmethyl aryl ether derivative, both free and attached to oxytocin. This enables the neutralization of a polypeptide derivative in high vacuum using a wavelength outside the absorption spectrum of natural amino acids.