Chemically bonded metallic (Eu, Tb, Zn) hybrid materials through sulfide linkage: Molecular construction, physical characterization and photophysical properties

In this paper, a kind of aromatic carboxylic acid of sulfhydryl group (2-mercaptonicotinic acid) is modified with four silane crosslinking reagents (3-methacryloyloxypropyltrimethoxysilane (S1), 3-glycidoxypropyltrimethoxysilane (S2), 3-aminopropyltrimethoxysilane (S3), and 3-(triethoxysilyl)propylisocyanate (S4)) to achieve four new kinds of functionalized molecular bridge (Pi (i = 1–4)). Subsequently, four molecular bridges and lanthanides (europium and terbium) or zinc ions have been assembled via chemical bonds through a sol–gel (cohydrolysis and copolycondensation) process with inorganic precursor (tetraethoxysilane, TEOS), resulting in four novel series of chemically bonded hybrid materials which named as Ln (Zn)–Mi (i = 1–4). The coordinated bonding makes metal ions evenly dispersed in a stable hybrid system. The intramolecular energy transfer process between lanthanide ions and the molecular bridges take place within these molecular-based hybrids and especially the luminescent quantum efficiency of them are determined, suggesting that the hybrid material systems derived from different molecular bridges present different luminescence efficiencies.

Graphical abstractSulfhydryl group (2-mercaptonicotinic acid) is modified with four silane crosslinking reagents to achieve four new kinds of functionalized molecular bridge (Pi (I = 1–4)). Subsequently, four novel series of chemically bonded hybrid materials which named as Ln (Zn)–Mi (I = 1–4) have been assembled via chemical bonds.Figure optionsDownload full-size imageDownload as PowerPoint slide