Heats of formation of disodium and dipotassium cyclooctatetraenide

Reduction and oxidation of annulenes

“…Measurement of the heats of combustion, generally applied toward that goal, are not practical for organometallic compounds,332 mainly due to their air sensitivity. In order to circumvent that problem, one can calorimetrically measure the heats of reaction of the alkali metal salts of 32- 54,333 and 72-322 with water. For the sake of comparison acene dianions (e.g., anthracene) have also been included.…”

Anion radical solvation enthalpies

“…Subtracting -108 from the enthalpy of the reaction shown in eq 4 yields a value of -60 kcal/mol for the solvation enthalpy of AN™• in HMPA, eq 5. This is much more exothermic than was '•8 -* "• μ Afí°= -60 ± 6 (5) expected. Although HMPA is known to be an excellent solvent for anion radical formation with alkali metals due to its ability to solvate cations,13 it has long been believed that anions remain practically unsolvated in this solvent due to steric hindrance around the electropositive phosphorus center.14 This is clearly not the case.…”

“…The possibility of the evolution of hydrogen gas from the reaction of the solvated anthracene anion radical with water was eliminated by pumping any gaseous products into a calibrated gas buret with a Toepler pump as previously described. 5 The fact that no gas phase products could be detected means that at least 99.9% of the reaction leads to protonation of the anthracene anion radical.5 THF and HMPA solutions of the anthracene anion radical were sealed into evacuated thin-walled glass bulbs, which were placed into the cell of a Parr solution calorimeter and broken under 100 mL of deoxygenated water with a push rod. The change in the temperature of the calorimeter is due to the heat of reaction of the anion radical with water and the heat of aquation of the HMPA or THF.…”

Metal atom synthesis of iron diene phosphite complexes

“…The only product isolated was a dark red, thermally unstable material containing no phosphite ligands. This material was 45 based on its mass spectrum, complex NMR, and analogy to the previously reported20 complex 46. Fe Fe 45 46 with 1,3,5-cyclohepta triene.…”