Sensitization of Er3+ infrared photoluminescence embedded in a hybrid organic-inorganic copolymer containing octahedral molybdenum clusters

Abstract

Luminescent hybrid copolymers are obtained by copolymerizing in bulk methylmethacrylate with a methacrylic acid (MAC) solution containing [n-Bu 4N]2[Mo6Br8(MAC)6], and aliquots of an Er(TMHD)3 complex (TMHD for 2,2,6,6-tetramethyl-3,5- heptanedione) solution. This leads to novel homogeneous and transparent hybrid materials in which the Er3+ infrared luminescence at 1.55 μm, a standard wavelength for telecommunication applications, is up to six time more intense in the presence of Mo6 clusters when samples are irradiated at 476.5 nm. This work demonstrates the outstanding potential of Mo6 clusters, compounds obtained by high-temperature solid-state synthesis, in the design of functional hybrid materials via soft chemistry routes. Integrating Er3+ ions in a hybrid Mo6-PMMA hybrid matrix enables the sensitization of its IR photoluminescence upon irradiation anywhere in the octahedral metallic cluster absorption band. Meanwhile, it causes a noticeable decrease of the Mo6 red luminescence. Mo6 clusters being covalently linked to polymer strands, the hybrid material shows excellent aging behavior, leaving promising perspectives for telecom applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.