De Castro-Martins

Ti02, Ti02 on silicalite, and Ti-exchanged ZSM-5 show no electrochemical activity under the same conditions, suggesting that the nature and coordination state of the electroactive sites are characteristic of Tiiv in TS-1. A carbon electrode modified with TEOT undergoes reduction and oxidation processes at 0.62 and 0.71 V versus SCE, values only 60 mV different from those of TS-1. This indicates a close similarity between Tiiv in TEOT and Tiiv in TS-1 in both compounds the Ti,v ions are tetrahedrally coordinated by O and isolated from other TiIV ions (de Castro-Martins el al., 1993 ). 

The characterization of the high-Ti-content TS-1 synthesized by the modified method was also attempted by using cyclic voltammetry, which distinguishes between framework Tilv and extra-framework Ti02. The results (Fig. 17) indicate that while the maximum current intensity increases linearly up to 2% Ti content, no further increase is observed beyond this value. The same maximum value is obtained when TS-1 is synthesized by the conventional method. From this result, it is concluded that the limit for Tiiv in framework position in silicalite-1 corresponds to about x = 0.025 and that the excess titanium introduced with the modified method is not in framework positions (de Castro-Martins et al., 1994). 

Fig. 17. Maximum anodic electrochemical current as a function of titanium content of samples synthesized by the classical method [TS-1(1) to TS-1 (4)] and by the modified procedure of Thangaraj el at. [TS-1 (5) to TS-1 (7)]. (From de Castro-Martins el al., Zeolites, 14, 1994, pp. 130-136. Reprinted with permission from the Publisher.)...

De Castro-Martins, S., Tuel, A., and Ben faaril, Y. 1994. Characterization of titanium sili-calites using cyclic voltammetry. In Zeolites and Related Microporous Materials State of the Art 1994. Weitkamp, J., Karge, H.G., Pfeifer, H., and Holderich, W., Eds. Studies in Surface Science and Catalysis. 84, 501-508. 

J. T. Vanderslice and G. R. Beecher, Comments on the Paper by Gomez-Nieto, Luque de Castro, Martin, and Valc rcel. Talanta, 32 (1985) 334. 

Prado, V. F., Martins-Silva, C., de Castro, B. M., lima, R. F., Barros, D. M., Amaral, E., et al. (2006) Mice deficient for the vesicular acetylcholine transporter are myasthenic and have deficits in object and social recognition. Neuron 51, 601-612. 

V. Fernandez-Perez, J. Tapiador, A. Martin and M.D. Luque de Castro, Innov. Food Sci. Emerging Technol., 5 (2004) 361. 

Rodrigo E, San MiUan JCR, Heras M, Pinera C, Fresnedo F, Sanz De Castro S, Martin De Francisco YM, Arias AL. Posterior leukoencephalopathy in erythropoietin induced hypertensive encephalopathy. Neurologica 1999 19 360-4. 

M.A. Gomes-Neto, M.D. Luque de Castro, A. Martin, M. Valcarcel, Prediction of the behaviour of a single flow-injection manifold, Talanta 32 (1985) 319. 

Martins M, Vilas-Boas M, de Castro B, Hilhnan AR, Freire C (2005) Electrochim Acta 51 304-314... 

I Martin, G., Castro, B., Martin, M. Chemie Physique.-Etude par Resonance Magnetique Nucleaire de Quelques Composes Chlores a Functionnels. Compt. Rend. 261, 395 (1965). 

Acknowledgments. We thank Direccion General de Investigacion Cientffica y Tecnica (DGICYT), Ministerio de Education y Cultura (SPAIN) for financial support. We are grateful to Dr. Ana M. Martin Castro and M. Teresa Aranda for their help in preparing the manuscript. 

Fernandez Perez, F.J., Garcia Montes, J.M., Castro Laria, L., Martin Guerrero, J.M., Jimenez Saenz, M., Herrerias Gutierrez, J.M. Valor de la ecografia en el diagnostico de la hipertension portal. Rev. Esp. Enferm. Dig. 1998 90 806-812... 

Castro, A.A.J.F. and Martins, F.R., Cerrados do Brasil e do Nordeste caracteriza9ao, area de ocupa9ao e considera9oes sobre a sua fitodiversidade, Pesq. Eoco, Sdo Luis, 7 (9), 147, 1999. 

Rubio, D., Garcia-Castro, J., Martin, M. C., De La Fuente, R., Cigudosa, J. C., Lloyd, A. C., and Bernad, A. 2005. Spontaneous human adult stem cell transformation. Cancer Res, 65,3035-9. 

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