Energy drink consumption has been anecdotally linked to the development of adverse cardiovascular effects in consumers, although clinical trials to support this link are lacking. The effects of Red Bull energy drink on cardiovascular and neurologic functions were examined in college-aged students enrolled at Winona State University. In a double-blind experiment where normal calorie and low calorie Red Bull were compared to normal and low calorie placebos, no changes in overall cardiovascular function nor blood glucose (mg/dL) were recorded in any participant (n = 68) throughout a 2-h test period. However, in the second experiment, nine male and twelve female participants subjected to a cold pressor test (CPT) before and after Red Bull consumption showed a significant increase in blood sugar levels pre- and post Red Bull consumption. There was a significant increase in diastolic blood pressure of the male volunteers immediately after submersion of the hand in the 5 degrees C water for the CPT. Under the influence of Red Bull, the increase in diastolic pressure for the male participants during the CPT was negated. There were no significant changes in the blood pressure of the female participants for the CPT with or without Red Bull. Finally, the CPT was used to evaluate pain threshold and pain tolerance before and after Red Bull consumption. Red Bull consumption was associated with a significant increase in pain tolerance in all participants. These findings suggest that Red Bull consumption ameliorates changes in blood pressure during stressful experiences and increases the participants' pain tolerance.

Redox radical chain reactions of trivalent organophosphorus compounds (PZ3) with diaryliodonium (Ar2l+) and triarylsulfonium (AraS-1") salts to give arylphosphonium (ArP+Zg) salts and iodoarenes (Arl) or diaryl sulfides (At2S) are reported. The key propagation step in these SrnI reactions is a single-electron reduction of the onium salts by intermediate phosphoranyl radicals (ArÉZa). The observation of competitions between solvent molecules and phosphine establishes the intermediacy of free aryl radicals and allows estimates of rate constants for addition of p-tolyl radicals to triphenylphosphine (k » 3 X 108 M"1 s-1) and to trimethyl phosphite (k « 2 x 10® M-1 s-1). The intermediate phosphoranyl radicals can also partition between competitive reaction pathways; the aryltributylphosphoranyl radical, ArPBua, for example, partitions between unimolecular a-cleavage of butyl radical and chain-propagating electron transfer to diaryliodonium salt. The relative amounts of these two pathways allows an estimate of the rate constant for electron transfer, Aset = 4 X 109 M-1 s'1.Phosphoranyl radicals (Z4P*) are well-known species, often characterizable by ESR spectroscopy.2 Most of the

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A discovery-based Grignard experiment for a secondyear undergraduate organic chemistry course is described. The exclusive Grignard reagent formed by the reaction of 1-bromo-4fluorobenzene (1) with Mg is 4-fluorophenylmagnesium bromide (2), which is treated with either benzophenone or CO 2 to produce the corresponding fluorinated alcohol (3) or benzoic acid (4), respectively. The use of a dihalogenated Grignard reagent requires students to discern its reactivity for synthesis. Students predict the chemoselectivity of Grignard reagent formation based on the C−X bond energies of 1 and investigate their predictions by analysis of 1 H, 13 C, and 19 F NMR, EI−MS, and IR data of 3 and 4. Empirical parameters and DFT calculations are used to predict the 1 H and 13 C NMR chemical shifts of 4 and the hypothetical brominated analogue.