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C60 can be reduced to its trianion anion radical in hexamethylphosphoramide with potassium or cesium metal. The addition of water to these solutions, followed by toluene extraction, yields materials that exhibit the expected mass spectral peaks for the Birch reduction products of C 60 *3- (C60Hn). However, when cyclooctatetraene (COT) is present in the solution, the mass spectral signature for the Birch reduction products of M+@C60-COT*3- and C60-COT*3- are also found. The trianion radical of C60 reacts with COT in HMPA to yield a [2 + 2] cycloaddition product, and subsequent ring opening provides a passageway for the Cs+ or K+ counterion to the interior of the fullerene. Analogous results are not observed when the smaller metals (Na and Li) are used as the reducing agents. Only the larger alkali metal cations form tight ion pairs with the trianion of C60-COT. The tight ion association is necessary to bring the cation into a sufficiently close proximity to the trianion for the cation to proceed to the interior.

In contrast to the thermolysis of p-benzoquinone, which does not decompose until the temperature is over 800 degrees C, and then primarily yields vinylacetylene, the corresponding anion radical, precipitated from liquid ammonia [Na(+)(NH(3))C(6)H(4)O(2)(*-)], decomposes at 380 degrees C and fragments primarily into phenol, hydroquinone, ammonia, methane, carbon monoxide, hydrogen, and minor amounts of other simple compounds. When the benzoquinone is replaced with perdeuteriobenzoquinone, deuterium and hydrogen are randomly scrambled into the products, and both ND(3) and CH(4) are formed. When the hot pyrolysis container is completely sealed, preventing the escape of volatile materials, p-aminophenol, as opposed to phenol, is the major liquid product.

The C−O and C−H bonds of 18-crown-6 are activated when 18-crown-6 is complexed with the potassium salt of the benzene anion radical. Evacuated glass bulbs containing the solid anion radical salt of potassium 18-crown-6 benzene anion radical were plunged into a bath at 320 °C, resulting in mini-explosions and generating a series of compounds including dioxane, 2-methyl-1,3-dioxolane, divinyl ether, hydrogen, methane, and 15-crown-5. Deuterium labeling studies proved that all of these compounds originated from the 18-crown-6. Further, these labeling studies were an aid in discerning the mechanism of the decomposition. Benzene, 1,4-cyclohexadiene, and cyclohexene were also generated. The last two originated from the reaction of the anion radical of benzene with hydrogen.

The solid dianion salt of 1,2-di-13C-cyclooctatetraene was synthesized in order to measure the first 13C−13C NMR coupling in an aromatic annulene other than benzene and to find out if this dianion will undergo high-temperature automerizations analogous to those previously observed in the benzene system. The solid potassium salt was heated to over 600 °C for 2 h, and although decomposition with H2 and CH4 evolution takes place, there is no observable scrambling of the 13C's. The positions of the 13C's were monitored via NMR, which necessitated a rather complete understanding of the NMR couplings for the cyclooctatetraene dianion system. Interestingly, the 1JCH and 1JCC couplings for the aromatic COT2- system of 145.9 and 55.8 Hz are all quite comparable to those recently reported for the 1,2-di-13C-benzene system (158.6 and 55.8 Hz, respectively).

The solid potassium salts of the nitrobenzene anion radical [K+C6H5NO2•-(solid)] and all three nitrotoluene anion radicals were generated via the potassium reduction of the nitroaromatic in liquid ...

The addition of D 2 O to hexamethylphosphoramide solutions of the potassium salt of the [8]annulene anion radical results in the slow (days) formation of the monodeuteriated anion radical (C 8 H 7 D .- ). However, several days after a similar addition to the sodium salt solution, no C 8 H 7 D .- is present. Instead, the anion radical of [16]annulene is found. These observations led to EPR and NMR studies, which have revealed the mechanism of each process

A series of electron transfer competition reactions between several isotopically different benzophenones was established in liquid ammonia. The resulting electron transfer (A .- +B=A+B .- ) equilibrium constants were determined via EPR studies and via the physical separation of the anion radical phase from the neutral molecule phase. This anion radical-neutral molecule separation leads to a partial separation of the isotopic isomers involved due to the deviation of the equilibrium constants from unity

The anion radicals of alkoxy-substituted cyclooctatetraenes in hexamethylphosphoramide spontaneously dimerize to form the dianions of dialkoxy-[16]annulenes. The dianions reveal the expected high-field NMR resonance for the internal protons. After electron transfer, the EPR spectra of the corresponding anion radicals reveal that only the 1,5-dialkoxy systems are formed. Further, the measured proton and (13)C spin densities show that the odd electron resides in a molecular orbital with six hydrogens in "deep" nodal positions that completely hide them from EPR detection. This MO corresponds to the nonbonding (singly occupied) MO of higher energy after splitting of the degenerate nonbonding MOs by the two-electron-withdrawing substituents. The surprising electron-withdrawing nature of the alkoxy substituents is attributed to a rather strong mixing of the sigma and pi systems in [16]annulene.

Ninhydrin (the fingerprint developing agent) spontaneously dehydrates in liquid ammonia and in hexamethylphosphoramide (HMPA) to form indantrione, which has a sufficiently large solution electron affinity to extract an electron from the solvent (HMPA) to produce the indantrione anion radical. In liquid NH(3), the presence of trace amounts of amide ion causes the spontaneous formation of an anion radical condensation product, wherein the no. 2 carbon (originally a carbonyl carbon) becomes substituted with -NH(2) and -OH groups. In HMPA, the indantrione anion radical spontaneously forms condensation products with the HMPA to produce a variety of zwitterionic radicals, wherein the no. 2 carbon becomes directly attached to a nitrogen of the HMPA. The mechanisms for the formation of the zwitterionic paramagnetic condensation products are analogous to that observed in the reaction of ninhydrin with amino acids to yield Ruhemann's Purple, the contrast product in fingerprint development. The formation of anion and zwitterionic radical condensation products from ninhydrin and nitrogen-containing solvents may represent an example of a host of analogous polyketone-solvent reactions.

N-Methoxycarbonyl-1H-azepine-2,7-dicarboxaldehyde (I) was synthesized via the SeO(2)-mediated oxidation of N-methoxycarbonyl-2,7-dimethyl-1H-azepine. The reductions of I in tetrahydrofuran with (6)Li or (7)Li resulted in anion radicals, which are tightly associated with the lithium cations. EPR and ab initio calculations both show a nonequivalency in all of the protons in I(-*),Li(+) due to the closer approach of the Li(+) to one of the carbonyls and a twist of the ester carbonyl group (slow rotation of the carbamate group) toward the Li(+). Further, as predicted by the MO calculations, I(-*),Li(+) appears to exist with the nitrogen puckered above the twisted ring system, and the lithium cation is asymmetrically complexed between the two electronegative aldehydic oxygen atoms and the carbamate carbonyl oxygen. It is also Coulombically attracted to the puckered and twisted ring system.

(S)-Verbenol was substituted onto cyclooctatetraene (COT) via an ether linkage. In tetrahydrofuran (THF), Cs(+) or Na(+) counterions are tightly ion associated with the verbenoxy-COT dianion. A cosolvent, consisting of an ibuprofen unit connected to a half crown ether, was added to the verbenoxy-COT(2)(-),M(+)(2) solutions. The intimate interaction between the chiral cosolvent (ibuprofoxymethoxyethoxyethane) and the ion-associated counterion (either Na(+) or Cs(+)) forces a chiral recognition between the verbenoxy moiety and the ibuprofoxy moiety. When a molar excess of the cosolvent is present in the dianion THF solution, separation of the cosolvent associated with the verbenoxy-COT(2)(-),M(+)(2) complex from the uncomplexed cosolvent allows partial resolution of the enantiomers of ibuprofoxymethoxyethoxyethane.

The solid anion radical salts resulting from the reductions of naphthalene, pyrene, perylene, benzo[k]fluoranthene, and biphenyl with lithium, cesium, and potassium metals were either pyrolyzed at 200-380 degrees C or irradiated with a pulsed frequency doubled Nd:YAG laser (532 nm wavelength). For both the pyrolytic and laser photolytic studies the only volatile products were hydrogen and methane. The hydrogen originated from the anionic polymerization of the anion radical. Evidence is presented that suggests that the methane results from a carbene intermediate, which in turn reacts with the H(2). Consistent with the H(2) formation, MALDS mass spectral analysis revealed the presence of dimers, trimers, and higher polymers of the polyaromatic hydrocarbon in the remaining nonvolatile products. There were considerably fewer low molecular weight oliomers produced via the laser photolysis than via the thermolysis.