Carbocyclic Compounds

isocyclic organic compounds in which the molecules contain rings of carbon atoms.

Carbocyclic compounds differ from heterocyclic compounds, in which the rings contain in addition to carbon, atoms of other elements, such as (usually) oxygen, nitrogen, or sulfur; they differ also from acyclic compounds, which have no rings at all. Carbocyclic compounds form one of the basic classes of organic compounds; they are subdivided into the alicyclic compounds and the aromatic compounds (benzenoid and nonbenzenoid). Carbocyclic compounds are extremely widespread, and many of them are of great practical importance. For example, most petroleum hydrocarbons and terpenes, a number of antibiotics, and many dyes, pharmaceuticals, and insecticides are included

Table 3. Mechanical properties of carbides
	Hardness H			Tensile strenglh (MN/m²)			Compressive strength (MN/m²)			Elastic modulus (GN/m²)
	20°C	1230°C	1730°C	20°C	1230°C	1730°C	20°C	1230°C	1730°C	20°C	730°C	1230°C
TIC……	31.O	1.6	0.3	560	200	90	1,350	470	260	460	420	400
ZC……	29.0	2.0	1 3	300	100	—	1,700	300	—	550	520	500
NbC……	20.5	0.75	0.28	—	—	—	1,400	400	200	540	500	470
WC……	18.0	0.9	0.45	—	—	—	2.700	600	100	722	690	600
Sic……	33.4	2.2	0.9	180	230	—	800	400	160	386	373	350

among the carbocyclic compounds. Carbocyclic compounds are also used in the preparation of synthetic resins and plastics.