1 research outputs found
Hybridization between Periodic Mesoporous Organosilica and a Ru(II) Polypyridyl Complex with Phosphonic Acid Anchor Groups
A new
method for the hybridization of a rutheniumÂ(II) polypyridyl complex
([RuÂ(bpy)<sub>2</sub>((CH<sub>2</sub>PO<sub>3</sub>H<sub>2</sub>)<sub>2</sub>-bpy)]<sup>2+</sup> (<b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup>: bpy =2,2′-bipyridine; (CH<sub>2</sub>PO<sub>3</sub>H<sub>2</sub>)<sub>2</sub>-bpy =2,2′-bipyridine-4,4′diÂ(metylphosphonic
acid)) with biphenylene-bearing periodic mesoporous organosilica <b>(Bp–PMO</b> made from 4,4′bisÂ(triethoxysilyl)Âbiphenyl
[(C<sub>2</sub>H<sub>5</sub>O)<sub>3</sub>Si-(C<sub>6</sub>H<sub>4</sub>)<sub>2</sub>-SiÂ(OC<sub>2</sub>H<sub>5</sub>)<sub>3</sub>]) was developed.
Efficient and secure fixation of the rutheniumÂ(II) complex with methylphosphonic
acid groups (<b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup>) in the mesopores of <b>Bp–PMO</b> occurred.
This method introduced up to 660 μmol of <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> in 1 g of <b>Bp–PMO</b>. Two modes of adsorption of <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> in the mesopores of <b>Bp–PMO</b> were observed: one is caused by the chemical interaction between
the methylphosphonic acid groups of <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> and the silicate moieties of <b>Bp–PMO</b> and the other is attributed to aggregation of
the <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> complexes. In the case of the former mode, adsorbed <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> (up to 80–100
μmol g<sup>–1</sup>) did not detach from <b>Bp–PMO</b> after washing with acetonitrile, dimethylformamide, or even water.
Emission from the excited biphenylene (Bp) units was quantitatively
quenched by the adsorbed <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> molecules in cases where more than 60
μmol g<sup>–1</sup> of <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> was adsorbed, and emission from <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> was
observed. Quantitative emission measurements indicated that emission
from approximately 100 Bp units can be completely quenched by only
one <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> molecule in the mesopore, and photons absorbed by approximately
400 Bp units are potentially accumulated in one <b>RuP</b><sub><b>2</b></sub><sup><b>2+</b></sup> molecule