Complexation reactions between methylthymol blue and Fe , A l ,Ga , 1n a nd TI ions have been studied in buffer aqueous solutions of pH 5.0 at 2S°C by a spectrophotometric technique. The conditional stepwise stability constants of the resulting 1:l and 1:2 (metal-to-ligand) complexes were determined from the absorbance-mole ratio data at three different wavelengths of the visible sp...

We determine optical absorption cross sections of single-wall carbon nanotubes for visible light copolarized and cross polarized with respect to the nanotube axis. The need for perfectly aligned ensembles in absorbance measurements is eliminated by using Raman scattering to measure the nematic order parameter in magnetically aligned nanotube suspensions. The absorbance data allow the first quan...

The UV-visible diode array spectrophotometer is a work-horse instrument for many laboratories. This article provides simple data acquisition and control routines in Microsoft QuickBasic for a HP-8452A diode array spectrophotometer interfaced to an IBM PC/XT/AT, or compatible, microcomputer. These allow capture of full spectra and measure absorbance at one or several wavelengths at preset time i...

A spectrophotometric study concerning the interactoin between iodine and bromine with tetrabutylammonium iodide (TBAI), tetrabutyl- ammonium bromide (TBABr) and cryptand 222 (C222) has been performed in dichloromethane solution at 25°C. The results are indicative of the formation of TBA+X3- and  C222X+X3-  t...

Absorbance spectra were measured by microspectrophotometry in retinal rods of sand gobies (Pomatoschistus minutus) from four allopatric populations (Baltic Sea, Swedish west coast, English Channel and Adriatic Sea). Mean (+/- S.E.M.) wavelengths of maximum absorbance (lambda(max)) were 508.3+/-0.5 nm, 505.4+/-0.2 nm, 506.2+/-0.3 nm and 503.0+/-0.3 nm, respectively. Pairwise comparison between t...

Aromatic constituents of cell walls limit the feeding value of forages, but information is lacking on the sites and types of these constituents that retard biodegradation. A series of cell types in stems and leaf blades of a normal (N) and a brown midrib (bmr) mutant line of pearl millet (Pennisetum glaucum (L) R Br) were analyzed by UV absorption microspectrophotometry from freeze-dried bulk w...

complexation reactions between methylthymol blue and fe , a l ,ga , 1n a nd ti ions have been studied in buffer aqueous solutions of ph 5.0 at 2s°c by a spectrophotometric technique. the conditional stepwise stability constants of the resulting 1:l and 1:2 (metal-to-ligand) complexes were determined from the absorbance-mole ratio data at three different wavelengths of the visible spectra. the o...

4 Chemical Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306 4.1 Elemental Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 4.2 Molecular Size Distribution and Charge . . . . . . . . . . . . . . . . . . . . . . 309 4.3 Spectral Absorbance and Fluorescence . . . . . . . . . . . . . . . . . . . . . . . 311 4.4 Infrared Spectra . . . . ....

Pyrene mediated noncovalent attachment of a chlorophyll derivative, pyro-pheophorbide a, to a soluble single wall carbon nanotube is reported and the resultant CD, UV-Vis absorbance, fluorescence and 1H NMR spectra are discussed.

We evaluated the dye 4',5'-dimethyl-5-(and -6-) carboxyfluorescein (Me2CF) for determining the intracellular pH(pHi) of isolated, perfused proximal tubules of the salamander. The intracellular absorbance spectrum, corrected for the intrinsic absorbance of the tubule, was obtained once per second. The dye was incorporated into tubule cells by exposing them to the membrane-permeable precursor 4',...