单词 | methene |
释义 | methenen. Chemistry. 1. A divalent —CH2— group; = methylene n. disused. ΘΚΠ the world > matter > chemistry > organic chemistry > hydrocarbons > [noun] > hydrocarbon radicals > named, by number of carbon atoms > one methylene1835 methyl1840 methene1867 1867 A. W. Hofmann in Proc. Royal Soc. 1866–7 15 58 According to this principle the following names are formed:..Methane, (C H4)0. Methyl, (C H3)′. Methene, (C H2)″. Methenyl, (C H)‴. 1881 H. E. Roscoe & C. Schorlemmer Treat. Chem. III. i. 266 The dyad radical methene. 1911 Science 1 Sept. 286/1 Yttrium methene disulphonate Y2[CH2(SO2O)2]3 + 2½H2O? 1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) i. 50 Methylene (methene), CH2, does not exist [independently]. 2. The trivalent =CH— group; = methine n. Now chiefly Biochemistry.In quot. 1923, also a compound containing this radical. ΚΠ 1923 Chem. Abstr. 17 3186 [The copper salt of] bis-[2,4-dimethylpyrryl]methene, C26H30N4Cu (0.2g from 0.5g. of the methene), green needles.., shows..an absorption band at λ490–515. 1947 Adv. Enzymol. 7 320 The porphins are 16-membered-ring compounds containing four pyrrole rings bound together at their α-positions by ≡CH, methene, bridges. 1988 L. Stryer Biochem. (ed. 3) vii. 144 The four pyrroles are linked by methene bridges to form a tetrapyrrole ring. 2000 Jrnl. Biol. Chem. 275 6857/1 Large differences in spin lattice relaxation of the stearoyl and arachidonoyl methene and methyl groups were demonstrated. This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022). < |
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