Local Structure and Near-Infrared Emission Features of Neodymium-Based Amine Functionalized Organic/Inorganic Hybrids

Abstract

Nd(3+)-based organic/inorganic hybrids have potential application in the field of integrated optics. Attractive sol-gel derived di-urea and di-urethane cross-linked poly(oxyethylene) (POE)/siloxane hybrids (di-ureasils and di-urethanesils, respectively) doped with neodymium triflate (Nd(CF(3)SO(3))(3)) were examined by Fourier transform mid-infrared (FT-IR), Raman (FT-Raman), (29)Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR) and photoluminescence spectroscopies, and small-angle X-ray scattering (SAXS). The goals of this work were to determine which cation coordinating site of the host matrix (ether oxygen atoms or carbonyl oxygen atoms) is active in each of the materials analyzed, its influence on the nanostructure of the samples and its relation with the photoluminescence properties. The main conclusion derived from this study is that the hydrogen-bonded associations formed throughout the materials play a major role in the hybrids nanostructure and photoluminescence properties.

Tuning the Photoluminescence of Silsesquioxanes with Short Substituted Urea Bridges

“…The peak close to 1 590 cm À1 corresponds to the aromatic ring and the three other peaks can be assigned to different environments of C --O groups. Comparing these spectra with those found for bridged silsesquioxanes containing urethane groups [32] or amide groups [33] (e.g., one hydrogen donor group and one hydrogen acceptor group), enabled to assign the three peaks as follows: the peak in the region 1 635-1 660 cm À1 arises from high-strength H-bonded C --O groups, the peak in the region 1 700-1 720 cm À1 corresponds to low-strength H-bonded C --O groups, and the peak in the region 1 755-1 770 cm À1 represents the non-bonded C --O groups. Table 3 gives the percentage of these bands for the different bridged silsesquioxanes.…”

“…The carbonyl band is sensitive to the specificity and magnitude of H-bonding and its deconvolution gives the fraction of free and H-bonded C --O groups of different strengths. [31][32][33] A relative comparison of the fraction of C --O groups located in different environments is possible. However, a quantitative estimation would require the knowledge of the absorption coefficients of non-bonded and bonded C --O groups.…”

Structure, thermal properties, conductivity and electrochemical stability of di-urethanesil hybrids doped with LiCF3SO3

“…D-Ut(300)-and d-Ut(600)-based di-urethanesil materials d with n=∞ 400, 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 5, 3, 2 and 1 and n=∞, 100, 40, 20, 10, 5, 3 and 1, respectively, were prepared. In agreement with the terminology adopted in previous publications [9,10,[29][30][31][32], the doped ormolytes examined were identified using the notation d-Ut(Y′)nLiCF 3 SO 3 .…”

“…Over the last two decades our group has extensively investigated di-urea and di-urethane cross-linked POE/ siloxane-based systems (designated as di-ureasils [7,8] and di-urethanenesils [9] (Scheme 1 [10]) doped with mono-, di-and trivalent cations. The two families of hybrids were identified by the notations d-U(Y) and d-Ut (Y′), where d represents di, U and Ut denote urea and urethane, respectively, and Y=600, 900 or 2,000 and Y= 300 or 600 indicate the average molecular weight of the organic precursors (corresponding to about 8.5, 15.5 or 40.5 and 6 or 13 oxyethylene repeat units, respectively) (Scheme 1a and b, respectively).…”

“…Although the optical properties of non-doped [28] and lanthanide-doped (Eu 3+ [29][30][31][32] and Nd 3+ [10]) di-urethanesils have been examined, their interest for solid state electrochemistry remains uncertain. This lack of data motivated the present work.…”