dimethyln.

/dʌɪˈmɛθɪl/

Etymology: See di- comb. form 2 and methyl n.

Chemistry.

1. as n. A name of Ethane (C₂H₆), regarded as two molecules of the radical methyl (CH₃).

ΚΠ

1868 H. B. Jones & H. Watts Fownes's Man. Elem. Chem. (ed. 10) 596 A colourless gaseous mixture containing ethane, or dimethyl.

1877 H. Watts Fownes's Man. Elem. Chem. II. 47 Ethane. This compound..may also be regarded as dimethyl, or as ethyl hydride.

2. attributive and in other combinations denoting an organic compound in which two equivalents of methyl take the place of two of hydrogen, as dimethyl ketone = Acetone CO(CH₃)₂; dimethylaniline, H₅N(CH₃)₂, one of the aniline bases; dimethyl-benzeneC₆H₄(CH₃)₂; dimethyl-ethyl carbinol = tertiary pentyl alcohol, C·OH·(CH₃)₂·(C₂H₅); dimethylamine, a colourless gas, (CH₃)₂NH, which liquefies at 7° C. and has an ammoniacal odour; dimethyl phthalate, a colourless liquid ester, C₆H₄(COOCH₃)₂, used esp. in insect repellents and as a plasticizer.

ΚΠ

1852 H. Watts tr. L. Gmelin Hand-bk. Chem. VII. 319 Dimethylamine..is formed as a hydriodate..by the action of ammonia on iodide of methyl.

1868 H. B. Jones & H. Watts Fownes's Man. Elem. Chem. (ed. 10) 576 Xylene..or Dimethyl-benzene.

1869 H. E. Roscoe Lessons Elem. Chem. (new ed.) xxx. 307 The secondary propyl alcohol or dimethyl carbinol..boils at 84°.

1880 Friswell in Jrnl. Soc. Arts 444 The dimethyl compound resulting from the use of two molecules of the alcoholic compound.

1910 Jrnl. Soc. Chem. Industry 29 1398/2 Perfectly clear solutions of rosin are obtained by warming it with 30 per cent. of its weight of dimethyl or diethyl phthalate.

1944 Knipling & Dove in Jrnl. Econ. Entomol. 37 479/2 Dimethyl phthalate had been found by the Orlando workers to be a good flea repellent.

1946 Lancet 13 Apr. 559/2 Dimethyl-phthalate (D.M.P.), a repellant used against the mosquito during the war.

1947 Thorpe's Dict. Appl. Chem. (ed. 4) VIII. 7/2 Dimethylamine has been employed as an accelerator in vulcanising rubber, and in the manufacture of detergent soaps.

1947 R. L. Wakeman Chem. Commercial Plastics xxii. 665 The number of plasticizers which can be used successfully with cellulose acetate is also restricted. Dimethyl and diethyl phthalates..are often used.

This entry has not yet been fully updated (first published 1896; most recently modified version published online March 2021).

单词	dimethyl
释义	dimethyln. /dʌɪˈmɛθɪl/ Etymology: See di- comb. form 2 and methyl n. Chemistry. 1. as n. A name of Ethane (C₂H₆), regarded as two molecules of the radical methyl (CH₃). ΚΠ 1868 H. B. Jones & H. Watts Fownes's Man. Elem. Chem. (ed. 10) 596 A colourless gaseous mixture containing ethane, or dimethyl. 1877 H. Watts Fownes's Man. Elem. Chem. II. 47 Ethane. This compound..may also be regarded as dimethyl, or as ethyl hydride. 2. attributive and in other combinations denoting an organic compound in which two equivalents of methyl take the place of two of hydrogen, as dimethyl ketone = Acetone CO(CH₃)₂; dimethylaniline, H₅N(CH₃)₂, one of the aniline bases; dimethyl-benzeneC₆H₄(CH₃)₂; dimethyl-ethyl carbinol = tertiary pentyl alcohol, C·OH·(CH₃)₂·(C₂H₅); dimethylamine, a colourless gas, (CH₃)₂NH, which liquefies at 7° C. and has an ammoniacal odour; dimethyl phthalate, a colourless liquid ester, C₆H₄(COOCH₃)₂, used esp. in insect repellents and as a plasticizer. ΚΠ 1852 H. Watts tr. L. Gmelin Hand-bk. Chem. VII. 319 Dimethylamine..is formed as a hydriodate..by the action of ammonia on iodide of methyl. 1868 H. B. Jones & H. Watts Fownes's Man. Elem. Chem. (ed. 10) 576 Xylene..or Dimethyl-benzene. 1869 H. E. Roscoe Lessons Elem. Chem. (new ed.) xxx. 307 The secondary propyl alcohol or dimethyl carbinol..boils at 84°. 1880 Friswell in Jrnl. Soc. Arts 444 The dimethyl compound resulting from the use of two molecules of the alcoholic compound. 1910 Jrnl. Soc. Chem. Industry 29 1398/2 Perfectly clear solutions of rosin are obtained by warming it with 30 per cent. of its weight of dimethyl or diethyl phthalate. 1944 Knipling & Dove in Jrnl. Econ. Entomol. 37 479/2 Dimethyl phthalate had been found by the Orlando workers to be a good flea repellent. 1946 Lancet 13 Apr. 559/2 Dimethyl-phthalate (D.M.P.), a repellant used against the mosquito during the war. 1947 Thorpe's Dict. Appl. Chem. (ed. 4) VIII. 7/2 Dimethylamine has been employed as an accelerator in vulcanising rubber, and in the manufacture of detergent soaps. 1947 R. L. Wakeman Chem. Commercial Plastics xxii. 665 The number of plasticizers which can be used successfully with cellulose acetate is also restricted. Dimethyl and diethyl phthalates..are often used. This entry has not yet been fully updated (first published 1896; most recently modified version published online March 2021). < n.1852
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