Photochromic systems are important due to their industrial applications in variable optical transmission
materials and optobioelectronic devices. For such applications, the organic photochromic compounds involved
are usually incorporated in polymers, liquid crystalline materials, or other convenient host matrices [1, 2]. Herein,
a photochromic compound, (E)-1-(cyclopropyldiazenyl)naphthalen-2-ol (show in Figure 1), which was
synthesized by a published method [3] and characterized, was isolated in a cryogenic argon matrix and its
structure as well as UV-induced phototransformations were characterized by IR spectroscopy. The structures of
the starting compound and of the generated photoproducts were identified by comparison of their experimental IR
spectra with the spectra theoretically calculated at the DFT (B3LYP)/6-311++G(d,p) level for several possible
tautomeric and rotameric forms.Fundação para a Ciência e a Tecnologia (FCT
