| 释义 |
quinhydrone Chem.|kwɪnˈhaɪdrəʊn|
[f. quin-a + hydrone.]
1. A brown crystalline substance with a green lustre formed by direct union of quinol and quinone. Also, any analogous molecular compound formed by a quinone and another aromatic compound.
1857H. Watts tr. Gmelin's Hand-bk. Chem. XI. 164 Quinhydrone. [Ibid., When kinhydrone is heated, it sublimes partly undecomposed, partly converted into yellow kinone.] 1865–72[see hydroquinone]. 1893T. E. Thorpe Dict. Applied Chem. III. 340 Quinhydrones..the composition of which has not been established with certainty. 1908Chem. Abstr. II. 104 In the reaction of α-hydronaphthoquinone with quinone, the former is oxidized to α-naphthoquinone and the latter reduced to hydroquinone, and these react to give the mixed quinhydrone. 1963I. L. Finar Org. Chem. (ed. 4) I. xxvii. 670 Quinhydrones are a group of coloured substances formed from quinones and other aromatic compounds. Some are believed to be charge-transfer complexes. Ibid. 671 Another type of quinhydrone is the one formed between one molecule of benzoquinone and one molecule of quinol... It is believed that the rings of the two molecules are parallel and held together by hydrogen bonds at both ends.
2. attrib. quinhydrone electrode, an electrode (usu. of platinum) immersed in a test solution to which quinhydrone has been added, which has a potential dependent upon the pH of the solution and can thus be used to measure the pH potentiometrically.
1921E. Biilmann in Jrnl. Soc. Leather Trades' Chemists V. 27 In the quinhydrone electrode two hydrions disappear, and at the same time a mol. of quinone is hydrogenated to one of hydroquinone. 1930G. D. Elsdon in C. A. Mitchell Recent Advances in Analytical Chem. I. vii. 250 Certain difficulties are encountered in the determination of the pH value of milk. These have been overcome to a considerable extent..by the use of the quinhydrone electrode. 1969H. Rossotti Chem. Applications Potentiometry viii. 92 The quinhydrone electrode can..be used as a probe for hydrogen ions in the acidity range 1{slle}pH{slle}8. |