homonuclear, a.
(hɒməʊˈnjuːklɪə(r))
[f. homo- + nuclear a.]
a. Physics and Chem. Of a molecule: composed of atoms whose nuclei are alike, i.e. atoms of the same element or (more strictly) the same isotope.
| 1930 Physical Rev. XXXVI. 617 In the case of homonuclear molecules (molecules composed of atoms whose nuclei are identical in charge and mass), any electron state may be either ‘odd’ or ‘even’. 1970 Nature 25 Apr. 354/1 Vibrational levels of N+2, like those of N2, are metastable because both molecules are homonuclear. |
b. Chem. Taking place on the same ring in a molecule.
| 1938 G. H. Richter Textbk. Org. Chem. xxix. 596 In discussing the reactions of naphthalene it is customary to speak of homonuclear substitution if the groups are entering the same ring, and heteronuclear substitution if the radicals are entering different rings. 1951 I. L. Finar Org. Chem. xxix. 586 Substitution products of naphthalene... When OH..or NH·CO·CH3 is in the 2-position, homonuclear substitution usually takes place in the 1-position. |