title: Optical spectra of a novel polyoxometalate occluded within modified MCM-41.
abstract: The novel polyoxometalate ([(Eu2PW10O38)4(W3O8(H2O)2(OH)4)]22-), also referred to herein as Eu8P4W43, has been immobilized inside the channels of MCM-41 mesoporous molecular sieve material by means of the incipient wetness method. For proper host-guest interaction, amine groups were introduced into the system as a result of an aminosilylation procedure. A stable and integrated Eu8P4W43 polyoxometalate was shown to be formed inside the channels of the modified MCM-41. The products were characterized by XRD, UV-vis absorption, emission, Raman excitation, Raman, and 31P solid-state NMR measurements. Infrared and Raman spectra of the polyoxometalate/MCM-41 composite systems are interpreted as showing spectral shifts due to site induced electrostatic interactions. The photoluminescent behavior of the composite at room temperature indicates a characteristic Eu3+ emission pattern corresponding to 5D0- 7F(J) transitions. A strong photoluminescence suggests the potential utility of the polyoxometalate as a luminescent material.
authors.affiliation: Center for Analysis of Structures and Interfaces (CASI), Department of Chemistry, The City College of The City University of New York (CUNY), New York, New York 10031, USA.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Haiquan
authors.initials: H
authors.lastname: Guo
authors.forename: Wenlin
authors.initials: W
authors.lastname: Huang
authors.forename: Tatyana
authors.initials: T
authors.lastname: Polenova
authors.forename: Lynn C
authors.initials: LC
authors.lastname: Francesconi
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Akins
mesh_terms: D000538:Aluminum Silicates; D002850:Chromatography, Gel; D007202:Indicators and Reagents; D049449:Luminescence; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D010777:Photochemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D017973:Tungsten Compounds / Q000138:chemical synthesis*; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D007202:Indicators and Reagents; C509968:MCM-41; D017973:Tungsten Compounds; D012822:Silicon Dioxide; C011934:mica