| 释义 |
semidine Chem.|ˈsɛmɪdiːn|
[ad. G. semidin (P. Jacobson 1893, in Ber. d. Deut. Chem. Ges. XXVI. 700), f. semi- semi- + benzi-din benzidine (s.v. benzo-).]
Any compound which is either (a) an ortho- anilino-derivative, or (b) an N-para-aminophenyl derivative, of a para-substituted aniline (distinguished as ortho- and para-semidines respectively); also semidine base; semidine reaction, semidine transformation, etc., the rearrangement of para-substituted hydrazobenzenes in the presence of acid to yield ortho- and para-semidines (in proportions governed by the nature of the substituents).
1893Jrnl. Chem. Soc. LXIV. i. 330 The hydrazo⁓compound..undergoes molecular change yielding two compounds, derivatives of ortho- and of para-amido⁓diphenylamine. It is proposed to call this reaction the semidine reaction, and to designate the orthamido⁓diphenylamine bases thus obtained by the name orthosemidines; the paramidodiphenylamine bases by the name parasemidines. 1898Ibid. LXXIV. i. 441 Only 50 per cent. of the total semidines obtained. 1938A. J. Mee tr. P. Karrer's Org. Chem. xxxiv. 498 If a para-position in hydrazobenzene is already occupied by a substituent, there are still further possibilities of isomerization. In addition to a diphenyline base and benzidine compounds.., two diphenylamine derivatives are formed in which only one of the benzene nuclei has rotated, the so-called p-semidine and o-semidine bases. The transformation is known as the semidine transformation. 1959E. S. Gould Mech. & Structure in Org. Chem. xv. 658 The rearrangements of hydrazobenzenes to benzidines, to diphenylenes, and to o-semidines are third-order reactions, first order in substrate and second order in hydrogen ion. 1975R. F. Brown Org. Chem. xxii. 772 A small amount of o shift occurs anyway, as well as a halfway shift to give semidines. |