摘要：

Electron spin resonance was measured at room temperature in a mixture of TiCl4 and Al(C2H5)2Cl in heptane. No resonance could be demonstrated in the precipitate. At room temperature the concentration of unpaired electrons reaches its maximum value in approx. 10 minutes. At an Al/Ti ratio less than one the concentration of unpaired electrons remains for some hours at a constant value of about 4.6 × 103 times the initial concentration of aluminium compound, a value which is only slightly dependent on the initial titanium concentration. At higher temperatures or at an Al/Ti ratio greater than one the number of unpaired electrons also reaches a maximum, but decreases afterwards. The concentration of unpaired electrons appeared to be highly governed both by the TiCl3 precipitate formed and by other substances, such as water, alcohol, carbon tetrabromide and oxygen.

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