ANION INDUCED REGULATION OF THE ABSORPTION MAXIMUM OF THE TWENTY TWO CARBON ANALOG OF THE JV‐RETINYLIDENE‐n‐BUTYLAMMONIUM CATION*

This study was undertaken to further investigate the way in which the counter anion controls the Λmax of the absorption spectrum of compounds similar to N‐retinylidene‐n‐butylammonium salts (NRBA). The following relationship had been found: ΔE =ΔEo ‐F d0e2/εd2; here ΔE is the observed excitation energy, e the charge on the electron, ε the dielectric constant, d0 a constant and d the distance between centers of opposite charge as estimated from crystallographic radii. Resonance theory implies that ΔEo should be of the same numerical value as the corresponding carbonium ion which can be generated readily from the corresponding alcohol. The C22SB analog of NRBA was prepared and then converted to the halide salts. The Δmax of these salts was determined in several halohydrocar‐bon solvents, and ΔEo was determined by least squares for each solvent. The average value of ΔEo was found to be 653 nm, while the Λmax, for the carbonium ion was previously found to be 644 nm. The results are supportive of previous work.