Tests of emotional reactivity have been used in a broad range of basic and applied research and have been primarily concerned with how rearing conditions, particularly environmental enrichment, can affect reactivity. However, assessment of how emotional reactivity can be altered during testing procedures and how it affects behaviors such as exploration is relatively uncommon. The present study assessed the explorative responses of Northern bobwhite quail (Colinus virginianus) neonates under conditions of either elevated or attenuated emotional reactivity during a maze task. Measures of emotional reactivity were compared with measures of exploration to determine their relationship with one another. Chicks that were highly emotionally reactive were generally less willing to explore during the maze task than chicks that were less emotionally reactive. Results indicate that levels of emotional reactivity and approach/avoidance motivation play a role in the speed and amount of exploration that is likely to occur in novel environments.

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Ph. D.

The oxidation of arsenic(III) by chromium(VI) requires the postulation of uncommon oxidation states as reactive intermediates. The possible intermediates of chromium are the divalent, tetravalent, and pentavalent states. Recently arsenic(IV) has been postulated as a reactive intermediate in certain oxidations of As(III). A detailed study of the reaction rate law in various solutions has been carried out in order to determine the nature of the intermediates found in the Cr(VI)-As(III) reaction. The effects of hydrogen ion and buffer concentrations have been determined. The mechanism postulated depends upon the solution in which the reaction occurs. The kinetics of the chromium(VI)-arsenic(III) reaction have been measured in perchloric acid solutions, acetic acid solutions, acetic acid-acetate buffers, ammonium nitrate solutions, and dihydrogen phosphatemonohydrogen phosphate buffers. The rate laws are: Perchloric Acid - -d[Cr(VI)]/ dt = [k₀ + k_H[H⁺] + k_H² [H⁺]²] (K’ [As (III)][Cr(VI)])/(l+K’[As(III)]) Acetic Acid-Acetate Buffers - -d[Cr(VI)]/ dt = [k₀ + k_HOAc[HOAc]} (K’ [As (III)][Cr(VI)])/(l+K’[As(III)]) Acetic Acid - -d[Cr(VI)]/ dt = [k₀ + k’_HOAc[HOAc]] (K’ [As (III)][Cr(VI)])/(l+K’[As(III)]) H₂PO₄⁻- HPO₄⁻² Buffers - -d[Cr(VI)]/ dt = (kK”[As(III)][Cr(VI)][H₂PO₄⁻])/(1+k”[H₂PO₄⁻]) Ammonium Nitrate Solutions - -d[Cr(VI)]/ dt = k₂ [As(III)][Cr(VI)] The reaction studied was the oxidation of As(III) by Cr(VI} according to the stoichiometry 3 As(III) + 2 Cr(VI) = 3 As(V) + 2 Cr (III) Rate data were obtained spectrophotometrically and by iodometric titration depending upon the region being investigated. At high As(III)-low Cr(VI), the Cr(VI) concentration was followed as a function of time at 350 mu using a Beckman DU spectrophotometer. The validity of Beer's law with respect to Cr(VI) was checked. At low As(III)-high Cr(VI), the unreacted As(III) concentration was determined by iodometric titration. In phosphate buffers, the HCrPO₇⁻² complex is indicated as an oxidizing agent. In the other systems, the following mechanism is consistent with the experimental facts. As(III) + HCrO₄⁻ [stacked right and left arrows with K above] As(III) · HCrO₄ As (III), As(III) · HCrO₄⁻ [right arrow with kₒ above] products, rate determining As(III) · HCrO₄⁻ + HOAc [right arrow with K_HOAc above] products, rate determining As(III) · HCrO₄⁻ + H⁺ [right arrow with k_H] products, rate determining In perchloric acid, H₂CrO₄is indicated as participating in the oxidation by the following steps: HCrO₄⁻ + H⁺ [stacked right and left arrows with Kₐ above] H₂CrO₄, ₂CrO₄ + As(III) [stacked right and left arrows with K above] As(III) · H₂CrO₄ The decomposition of As(III}•H₂CrO₄ is also acid catalyzed. In the mechanism described above, the products of the rate determining steps are arsenic(V) and chromium(IV). The existence of chromium(IV) is supported by the induced oxidation of ferrocyanide by the As(III)-Cr(VI) reaction. The chromium(IV) reacts immediately with chromium(VI) to form chromium(V) which can oxidize As(III) to As(V) directly. This is in agreement with the experimentally observed stoichiometry and accounts for the use of K' in the rate laws where K’ is actually 2K. The value of K is obtained from plots of 1/k_m versus 1/As(III). The value of K which describes all data reported is 17.2 1.mole⁻¹. In all three systems, perchloric acid, acetic acid, and acetic acid-acetate, the same kₒ is obtained. The specific rate constant for the acetic acid catalysis is 1.99 x 10⁻³ 1.⁻² mole² sec.⁻¹. Comparison of k"_HOAc terms for acetic acid and acetic acid-acetate solutions shows that k”_HOAc for the acid solution is larger than that for the buffers. This difference is explained on the basis of a medium effect. / Doctor of Philosophy

The reaction of sodium azide with 2-p-chloro- and 2-p–methoxyphenyl–3,4,5-triphenyl–2,4-cyclopentadien– Iâ one was studied to determine if the substituent would have any appreciable effect on the product distribution of the corresponding l,5,7,8–tetraphenyl-2,3,4–triazabicyclo[3.3.0]octa-2,7-dien-6-ones and the 3,4,5,6–tetraphenyl–2(lH)â pyridinones that were formed by an acid catalyzed rearrangement. It was found that the chloro substituent had no effect on the reaction. The methoxy substituent had a moderate effect in that the product arising from the stabilized intermediate cation was favored by a ratio of approximately 3 to l. The two simple linear analogs studied were l,2,3,3–tetraphenyl-2-propen-l-one and 3,4,4-triphenyl-3–buten–2â one. These compounds did not react with azide, presumably due to charge delocalization. Also studied as a cyclic analog was 2,7-diphenyltropone which did not react due to the aromatic character of the tropone ring system. A reaction did occur with diphenylcyclopropenone to give an unidentified product. However, the reaction did not take place in the same fashion as for the tetracyclones. / Master of Science

This work involves a three part study concerning the synthesis and reactivity of quinodimethanes, the determination of reduction potentials of electrophilic olefins, and the crystal structure determination of a new charge transfer complex. Treatment of p-xylylene dicyanide (10) with NaH and dimethyl carbonate in glyme yielded a,a'-bis(methoxycarbonyl)-p-xylylene dicyanide (11a), 82% yield. Oxidation of 11a with N-chlorosuccinimide and triethyl amine in acetonitrile at 0° gave 7,8-di(methoxycarbonyl)-7,8-dicyanoquinodimethane (12a), 64% yield, d. 268°. This quinodimethane homopolymerizes spontaneously and forms a Wurster complex with tetramethyl-p-phenylenediamine and a blue-black CT-complex with tetrathiafulvalene. Cyclic voltammetry reduction potentials (E^(Red)(,p)) UV absorptions and ¹H-NMR chemical shift data of 22 olefins compounds were measured. The sequence for the ability to stabilize the ethylenic radical anion was found to be (diagram omitted) > -CN >-CO₂CH₃ > Cl > Br > H as expected. An inverse relationship between chemical reactivity and reduction potential was found for tetramethyl ethylenetetracarboxylate (25) and the triester derivative (33). Although 25 has a lower E^(Red)(,p) (-1.30v) than 33, it is less reactive toward polymerization. A linear correlation of E^(Red)(,p) and Hammett substituent constants was seen for the substituted maleic anhydrides and cyanofumarates. No correlations were seen for sterically crowded derivatives of 33. The crystal structure of tetrathiafulvalinium dimethyl dicyanofumarate was determined from a single crystal X-ray study. The crystal belongs to the monoclinic space group P2₁/C with two complexes per unit cell with cell constants a = 11.075(2) Å, b = 11.615(3) Å, c = 6.623(4) Å, α = 95.7°(16), V = 847.6(9) ų. The structural parameters have been refined to convergence, R = 0.0492 and R(,w) = 0.0614.

No description available.

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