ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Isothiocyanates. V. The effect of the isothiocyanate group on the aromatic ring

K. Antoš, P. Kristián, A. Hulka, R. Rusina, P. Nemec, and Ľ. Drobnica

Slovak Technical University, Bratislava

Abstract: cf. CA 54, 22432e. To det. the effect of the isothiocyanate group on electron density of the aromatic ring, absorption max. of various thiocyanates of various derivs. of dimethylaminoazobenzene in the visible spectral area were studied. The max. showed that the isothiocyanate groups in the o- and p-positions cause a greater movement of the absorption max. towards higher wave lengths than in the m-position, which indicated that there was a possibility of condensing π-electrons in o and p-positions. In the case of Me homologs, the position of the Me group could move the max. to higher or lower wave lengths. From the max., especially of 4-isothiocyanato-4'-dimethylaminoazobenzene, at 432 mμ it could be judged that the isothiocyanate group had a moderate deactivation effect on the aromatic ring and it was very close to the effect of the isocyanate (λ 433 mμ) and CH:CH₂ (λ 435 mμ) groups. The validity of the structure RN+≡CS- was proved.

Full paper in Portable Document Format: 145a365.pdf (in Slovak)

Chemical Papers 14 (5) 365–371 (1960)