Tetrahedral silicon-centered imidazolyl derivatives: Promising candidates for OLEDs and fluorescence response of Ag (I) ion

A series of novel tetrahedral silicon-centered imidazolyl derivatives, Bis(4-(imidazol-1-yl)phenyl)dimethylsilane (1), Tri(4-(imidazol-1-yl)phenyl)methyl silane (2), Bis(4-(imidazol-1-yl)phenyl)diphenylsilane (3), Tri(4-(imidazol-1-yl)phenyl)phenylsilane (4), [Bis(4-(imidazol-1-yl)phenyl)](4-bromophenyl)phenylsilane (5) and [Tri(4-(imidazol-1-yl)phenyl)](4-bromophenyl)silane (6) have been synthesized and characterized by FTIR, ¹H NMR, ¹³C NMR and mass spectroscopy. They all display high thermal stability, are fluorescent with emission in the region of violet to blue, and possess large HOMO-LUMO energy gaps ranging from 4.9585 to 5.1879 eV, which could be potentially used as blue emitters or hole blocking materials in OLEDs. Moreover, the metal ion titrations based on Ag (I) and compounds 1-4 reveal that these ligands show distinguishable fluorescence response with increasing of Ag (I) ions.