ˌheteroˈcyclic, a. and n.
[f. hetero- + cyclic a.]
1. Bot. = heteromerous a. 2 b.
| 1895 S. H. Vines Text-bk. Bot. 500 When the whorls are heteromerous the flowers are said to be heterocyclic. 1924 Holman & Robbins Textbk. Gen. Bot. vii. 228 The flowers of the great majority of plants are heterocyclic. |
2. Chem. Pertaining to or containing a ring of atoms of more than one kind. Opp. to homocyclic, isocyclic. Also as n., a heterocyclic compound.
| 1899 E. F. Smith tr. V. von Richter's Org. Chem. (ed. 3) I. 78 In the case of many heterocyclic compounds..the substances with open chains from which they may be theoretically deduced do not really exist. 1900 Proc. Chem. Soc. 6 Feb. 11 The action of bases on ethyl phenyl⁓propiolate gives rise to heterocyclic compounds. 1936 L. J. Desha Org. Chem. xxiv. 479 In the most typical heterocyclic compounds, the ring systems are extremely stable. 1956 Nature 16 June 1116/2 The oxygenated heterocyclics were discussed with emphasis on the biochemical aspects. 1966 McGraw-Hill Encycl. Sci. & Technol. VI. 427/2 Heterocyclic systems are encountered in many groups of organic compounds, both synthetic and natural. 1968 New Scientist 31 Oct. 268/3 Classification of heterocyclics into suitable groups is somewhat of a problem. |
Hence ˈheterocycle, a heterocyclic ring or compound.
| 1909 Webster, Heterocycle, a heterocyclic compound. 1931 Jrnl. Amer. Chem. Soc. LIII. 806 Ethylene oxide, the simplest oxygen heterocycle. 1957 E. H. Rodd Chem. Carbon Compounds IVa Introd. 1 Compounds containing these heterogeneous rings (heterocycles) are classed as heterocyclic. |