Solid state NMR interaction parameters of oxygens linking titanium and silicon in crystalline cyclic titanodiphenylsiloxanes.
17O static and magic angle spinning NMR spectra are reported from three crystalline cyclic titanodiphenylsiloxanes at magnetic fields of 5.6, 14.1, and 17.6 T. These compounds allow the NMR parameters characteristic of Ti-O-Si environments to be determined. It appears from these data that the quadrupole interaction (C(Q)) of such environments is in the range of 3-3.5 MHz and that Si-O-TiO3 sites are less shifted than Si-O-TiO5. The relatively large isotropic chemical range observed suggests that for structurally and atomically disordered titanosilicate-based materials the very highest applied magnetic field may not produce the best 17O solid state NMR spectra. There appears to be a correlation between the 17O shift and Ti-O bondlength.
Department of Physics, University of Warwick, Coventry, United Kingdom.
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Gervais
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Babonneau
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Hoebbel
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Smith
D003460:Crystallization; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012822:Silicon Dioxide / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D012833:Siloxanes; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium