Solid-state 27Al nuclear magnetic resonance investigation of three aluminum-centered dyes
Type
ArticleKAUST Department
Imaging and Characterization Core LabAdvanced Nanofabrication, Imaging and Characterization Core Lab
Date
2010-02Permanent link to this record
http://hdl.handle.net/10754/561447
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We report the first solid-state 27Al NMR study of three aluminum phthalocyanine dyes: aluminum phthalocyanine chloride, AlPcCl (1); aluminum-1,8,15,22-tetrakis(phenylthio)-29H,31H-phthalocyanine chloride, AlPc(SPh)4Cl (2); and aluminum-2,3-naphthalocyanine chloride, AlNcCl (3). Each of these compounds contains Al3+ ions coordinating to four nitrogen atoms and a chlorine atom. Solid-state 27Al NMR spectra, including multiple-quantum magic-angle spinning (MQMAS) spectra and quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) spectra of stationary powdered samples have been acquired at multiple high magnetic field strengths (11.7, 14.1, and 21.1 T) to determine their composition and number of aluminum sites, which were analyzed to extract detailed information on the aluminum electric field gradient (EFG) and nuclear magnetic shielding tensors. The quadrupolar parameters for each 27Al site were determined from spectral simulations, with quadrupolar coupling constants (CQ) ranging from 5.40 to 10.0 MHz and asymmetry parameters (η) ranging from 0.10 to 0.50, and compared well with the results of quantum chemical calculations of these tensors. We also report the largest 27Al chemical shielding anisotropy (CSA), with a span of 120 ± 10 ppm, observed directly in a solid material. The combination of MQMAS and computational predictions are used to interpret the presence of multiple aluminum sites in two of the three samples.Citation
Mroué, K. H., Emwas, A.-H. M., & Power, W. P. (2010). Solid-state 27Al nuclear magnetic resonance investigation of three aluminum-centered dyes. Canadian Journal of Chemistry, 88(2), 111–123. doi:10.1139/v09-155Publisher
Canadian Science PublishingJournal
Canadian Journal of ChemistryDOI
10.1139/V09-155ae974a485f413a2113503eed53cd6c53
10.1139/V09-155