Reference

Voltammetric characterization of micro- and submicrometer-electrode arrays of conical shape for electroanalytical use

All Rights Reserved. Voltammetric characterization of micro- and submicrometer-electrode arrays of conical shape for electroanalytical use. Daniele, Salvatore; De Faveri, Eddy; Kleps, Irina; Angelescu, Anca ( Department of Physical Chemistry, University of Venice, Venice 30123, Italy). Electroanalysis, 18(18), 1749-1756 (English) 2006 Wiley-VCH Verlag GmbH & Co.In this study， 7440-06-4 and 14282-91-8 are also used. KGaA. CODEN: ELANEU. ISSN: 1040-0397. DOCUMENT TYPE: Journal CA Section: 72 (Electrochemistry) Section cross-reference(s): 79 Densely packed micro- and submicrometer electrode arrays of platinum and gold (the nominal no., N, of electrodes in each array varies between 225 and 3600) are fabricated by photolithog. technique and vapor deposition processes of metal films. The electrodes are conical-shaped and only their apexes are exposed to the electrolytic soln. The electrode arrays were characterized electrochem. in Ru(NH3)6Cl3 aq. solns. by using cyclic voltammetry at low scan rates, to establish the no. of electrochem. active electrodes (Nac) in each array; the geometric characterization was performed by SEM. All the studied arrays provide steady-state voltammograms, indicating diffusionally independent behavior of each microelectrode. The no. of microelectrodes that are active in the fabricated arrays depends on microelectrode d. In particular, for the arrays with N = 3600 and N = 225, the fraction of active sites is ~45% and 90%, resp. The anal. performance of some of the Pt version of the arrays is tested in hydrogen peroxide solns., allowing verifying that linear calibration plots over the concn. range (0.1-20 mM) were obtained. This dynamic range is larger than that typically recorded at smooth polycryst. platinum electrodes (0.5-5 mM), and the better performance is attributed to both the higher aspect ratio of the cone geometry and the higher mass transport assocd. to each microelectrode of the array. Reproducibility (within 3.5%, relative std. deviation) and long-term stability (within 5%, relative std. deviation, after 8 h continuous use) of the electrode systems are satisfactory. A low detection limit, based on the signal to noise ratio equal to 3, of 0.05 mM is found, which is adequate for a rapid monitoring of H2O2 in real samples and industrial processes. .

Studies involving labile vitamin B1 metal complexes

Studies involving labile vitamin B1 metal complexes. Part III. Preparation and general mechanism for the formation of complexes of the general formula M*(NH3)6MX5. Adeyemo, Adegboye (Dep. Chem., Univ. Ibadan, Ibadan, Nigeria). J. Chem. Soc. Pak., 8(4), 455-9 (English) 1986. CODEN: JCSPDF. ISSN: 0253-5106. 107444-38-2 and 14282-91-8 are also in the experiment. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Reactions of labile vitamin B1 (H2LCl2) metal complexes M(H2L)Cl4.H2O (M = Hg, Cd, Zn) with Ru(NH3)6Cl3 in aq. medium (1:1 molar ratio) yielded Ru(NH3)6MCl5. These new compds. were characterized by elemental analyses and IR spectra. The rationale for the particular geometry assumed by the MCl53- complex ions is discussed. .