Cyanide complex of 1,3,5-trinitrobenzene in nonaqueous solvents

The initial reversible interaction of 1,3,5-trinitrobenzene and cyanide ion has been studied spectrophotometrically in a number of nonaqueous solvents and found to result in the formation of a complex containing 1,3,5-trinitrobenzene and cyanide ion in a 1:1 ratio. At 25.3 °C, the equilibrium constants for complex formation (K) and the molar extinction coefficients (ϵ) of the complex were found to be 1.44 ± 0.15 × 10 5  l mole −1 and 2.24 ± 0.05 × 10 4  l mole −1 cm −1 and 3.35 ± 0.35 × 10 5  l mole −1 and 2.24 ± 0.05 × 10 4  1 mole −1 cm −1 respectively for acetone and chloroform solutions. The second-order rate constant governing formation of the complex in chloroform was found to be 2.25 × 10 2  l mole −1 s −1 at 25.0 °C. On the basis of the visible and infrared absorption data obtained for the complex in chloroform and 1,2-dimethoxy-ethane, the complex is considered to be a Meisenheimer-type complex rather than a "charge-transfer" complex.