Interaction of the Mu-cyclohexadienyl radical with metallic (Au, Pt) nanoparticles in mesoporous silica

[摘要] μSR and ALCR techniques have been used to investigate the structure and dynamics of the Mu-cyclohexadienyl radical interacting with Au and Pt metal nanoparticles (MNPs) supported in mesoporous silica (SBA-15). Surprisingly, coherent precession signals are observed and the isotropic hyperfine coupling constants are almost the same in loaded and unloaded samples, implying that the electronic structure of MuC6H6 is only weakly perturbed by the presence of the MNPs. We propose the observed radicals are shielded from the metallic surfaces by a benzene coating on the MNPs. The Δ1 resonance is observable in MNP-loaded samples at higher temperatures than in the unloaded SBA-15. This is attributed to stronger binding of MuC6H6 to the benzene coated MNPs.

[发布机构] Department of Chemistry, University of British Columbia, Vancouver; BC; V6T 1Z1, Canada^1;TRIUMF CMMS, 4004 Wesbrook Mall, Vancouver; BC; V6T 2A3, Canada^2;Department of Chemistry and Biochemistry, California State University, Fullerton; CA; 92831, United States^3;Department of Physics and Astronomy, University of British Columbia, Vancouver; BC; V6T 1Z1, Canada^4;Rutherford Appleton Laboratory, Swindon; SN2 1SZ, United Kingdom^5;Physik-Department, Technische Universität München, James-Franck-Strasse 1, Garching bei München; 85748, Germany^6

[关键词] Isotropic hyperfine coupling constant;Mesoporous Silica;Metallic surface;Structure and dynamics