| 释义 |
steric, a. Chem.|ˈstɛrɪk|
[irreg. f. Gr. στερεός solid + -ic: cf. stereochemistry.]
Pertaining or relating to the arrangement in space of the atoms in a molecule.
steric hindrance, hindrance of a reaction, held to be due to the spatial arrangement of the atoms in the molecules of one of the reacting compounds.
1898H. N. Stokes in Smithsonian Rep. 301 Stereochemical formulas are..more than reaction formulas, and the steric conception of the so-called double and triple union asserts that these actually exist. 1905A. W. Stewart in Jrnl. Chem. Soc., Trans. LXXXVII. 185 Angeli..suggested that steric hindrance played a part in the reactions involving the addition of metallic hydrogen sulphites [etc.]..to carbonyl groups.
Hence ˈsterically adv., by, or as regards, the three-dimensional arrangement of atoms.
1918Jrnl. Chem. Soc. CXIV. i. 127 If only one group is sterically hindered, then reactions can take place at both tertiary amino-groups. 1959New Scientist 19 Feb. 399/1 Propylene,..using a Natta catalyst, can be turned into straight chains of polypropylene molecules, with all the arms or side groups projecting in the same direction: that is to say, they are sterically oriented. 1974Gill & Willis Pericyclic Reactions v. 130 The face to face interaction of the two π-systems is the only mode that is geometrically and sterically feasible. |