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EXAMPLE 8 Bis-[(2,3-butanedione dioximato)(1-)N,N'](2-ethoxy-carbonylethyl)-(pyridine)cobalt(III), Agent 6, was prepared by the following method. A mixture of cobaltous chloride hexahydrate (11.9 g), and dimethylglyoxime (11.6 g) was dissolved, with stirring, in deaerated 90% ethanol (200 ml) under nitrogen. The following deaerated reagents were then added in sequence: sodium hydroxide (4 g in 25 ml water), pyridine (4 g), ethyl acrylate (5 g), sodium hydroxide (1 g in +-6 ml water). The resultant mixture was stirred for 5 minutes and then poured into water (500 ml) containing acetic acid (2.5 ml). The Agent was recovered by extraction of the aqueous mixture with methylene chloride, evaporation of the extract, and recrystallization of the residue from aqueous methanol. Treatment of MMA (1.9 g) with Agent 6 at 60 C. by the method of Example 4 yielded a mixture of oligomers consisting of dimer (0.8 g), trimer (0.6 g), plus higher oligomers.
EXAMPLE 16 Aquo(ethyl)(acacen)cobalt(III), Agent 16, was prepared by the following method. Cobaltous chloride hexahydrate (4.8 g) was dissolved in 20 ml of deaerated water under nitrogen. 4.5 g of (acacen), prepared by condensation of acetylacetone (2 mol) and ethylene diamine (1 mol), was then added, followed by sodium hydroxide (1.6 g). The mixture was heated, with stirring, until the suspended solid turned to a yellow-orange colour. The mixture was then cooled, the intermediate, (acacen)cobalt(II) filtered off under nitrogen and washed on the filter with warm deaerated water (10 ml), and then dried in-vacuo over calcium chloride. The air-sensitive anhydrous chelate (4.5 g) was dissolved in anhydrous tetrahydrofuran maintained under argon. Sodium amalgam (0.38 g sodium in 5 g mercury) was added, and the mixture stirred vigorously for 2 hours, then cooled to -10 C. Ethyl bromide (1.4 m) was added and the mixture stirred for 15 minutes, then decanted from the amalgam residues into water (100 ml). Agent 16 separated as brown crystals when the tetrahydrofuran was stripped under vacuum at 20 C.; it was purified by dissolution in acetone and crystallization on addition of water to the resultant green solution. Agent 16 crystallizes with water as the axial base; the water is eliminated when the Agent is dissolved in organic solvents. A labile orange-colored adduct is formed when a small quantity of pyridine is added to the green solution of Agent 16 or its chelate precursor. Agent 16 is stable in air, although loss of the ethyl group and oxidation of the residue occurs on prolonged storage at ambient temperatures. Treatment of MMA with Agent 16 using the method of Example 4 yielded poly(MMA) with molecular weight with 9,700 and polydispersity of 2.3. A similar treatment of addition of pyridine (8 mg) yielded polymer with molecular weight of 8,600, compared to the molecular weight of 18,000 obtained by treatment in the absence of the Agent or pyridine.
EXAMPLE 6 A one-liter glass flask equipped with a stirrer, a dropping funnel with a gas introduction conduit, a reflux condenser with a calcium chloride tube, and a thermometer was charged with 212 grams (2.0 moles) of purified ethylbenzene, 4.0 grams (0.17 mole) of metallic sodium, and 2.9 grams (0.02 mole) of cumene hydroperoxide while introducing argon gas through the gas introduction conduit, and the resulting mixture was heated to 135 C. Then 208 grams (2.0 moles) of purified styrene were added dropwise thereto with stirring over 2 hours while maintaining the temperature of the reaction system at 135 C. After dropwise addition was completed, the reaction mixture was further stirred while heating for 1 hour and then cooled to room temperature. An excess of metallic sodium was decomposed by dropping methanol in small portions while stirring. Introduction of argon gas was stopped, and the contents were transferred to a separating funnel and then washed with water. The aqueous layer was removed, and the remaining oily layer was analyzed by gas chromatograpy. This gas chromatographic analysis showed that 96.6 grams (0.94 mole) of 1,3-diphenylbutane was formed. The yield was 47 mole %.
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