Reference

Diazonium salts in photochemistry

Diazonium salts in photochemistry. III: Attempts to characterize aryl cations. Scaiano, J. C.; Nguyen Kim Thuan (Div. Chem., Natl. Res. Counc., Ottawa, ON K1A 0R6, Can.). J. Photochem., 23(3), 269-76 (English) 1983. CODEN: JPCMAE.Several substances with their cas registry numbers 347-46-6 and 24959-67-9 may be metioned in this study. ISSN: 0047-2670. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) Section cross-reference(s): 41, 74 Ns laser photolysis techniques were used to examine the photodecompn. of diazonium tetrafluoroborates. Only bleaching signals at the characteristic absorption wavelength of the diazonium salts were obsd.; aryl cations could not be detected directly, even for those samples with ground state triplets. CrO42- react efficiently with the protons generated in the reaction of aryl cations with water. The reaction leads to the bleaching of CrO42- and is a convenient probe to examine the behavior of aryl cations in water. Examn. of this process in the presence and absence of inorg. anions indicates that the lifetime of the Ph+ in H2O is as about or slightly shorter than 500 ps. .

How channel-like is a biological carrier? Studies with the erythrocyte anion transporter

How channel-like is a biological carrier? Studies with the erythrocyte anion transporter. Frohlich, O. (Sch. Med., Emory Univ., Atlanta, GA 30322, USA). Biophys. J., 45(1), 93-4 (English) 1984. CODEN: BIOJAU. ISSN: 0006-3495. DOCUMENT TYPE: Journal CA Section: 13 (Mammalian Biochemistry) Section cross-reference(s): 6 Anion transport across the human erythrocyte membrane is generally attributed to carrier-type transport, in which net transfer is mediated by the return conformational change of the unloaded transporter. A more complete description of the concn. dependence of net Cl- efflux from erythrocytes, however, is afforded by a model of the anion transporter as a specialized channel of very low conductance, which can undergo rapid conformational changes between 2 states. To compare the carrierlike vs. channellike properties of the anion transporter, the dependence of net efflux from red blood cells on the extracellular anion concn., the chem. nature of the transported anion, and the intracellular anion concn. were detd. If the translocation conformational change of the unloaded carrier (the slippage step) is much slower than that of the loaded transporter, Cl- net efflux should decrease to zero with increasing extracellular Cl- concn., the net efflux of other anions as a function of extracellular anion concn. should not differ from that of Cl-, and the net efflux of Cl- should not depend on the intracellular Cl- concn. Since none of these predictions was fulfilled, the carrier-mediated model of anion transport was judged inadequate. 16887-00-6 and 24959-67-9 are just another two chemicals used in this study. A tunneling mode of anion transport through a specialized 2-conformation channel is proposed to account for the observations, and the kinetic features of the model are briefly discussed. .