Fabrication and photoluminescence of molecular hybrid films based on the complexes of 8-hydroxyquinoline with different metal ions via sol–gel process

A kind of monomer (abbreviated as HQ-TESPI) was prepared by modifying 8-hydroxyquinoline (abbreviated as HQ) with 3-(triethoxysilyl)-propyl isocyanate (abbreviated as TESPI) through the hydrogen transfer nucleophilic addition in this study. Then the monomer was used to coordinate with the metal ions (Al3+, Zn2+, Eu3+, Tb3+) according to the complexation theory. On the other hand, the monomer was simultaneously used to occur hydrolysis and condensation together with tetraethoxysilane (abbreviated as TEOS) to form silica-based organic–inorganic hybrid thin films (abbreviated as Al-HQ-TESPI, Zn-HQ-TESPI, Eu-HQ-TESPI and Tb-HQ-TESPI, respectively) by the means of spin-coating technology. The resultant thin films showed characteristic photoluminescence originated from the modified 8-hydroxyquinolinates. The target materials exhibit strong green-colored fluorescence (Al-HQ-TESPI), cyan-colored fluorescence (Zn-HQ-TESPI) and olivine-colored fluorescence (Eu-HQ-TESPI, Tb-HQ-TESPI). These hybrid thin films can be prospected to be used in the field of photoluminescence.