1,3-Cyclohexadiene

1,3-Cyclohexadiene is an organic compound with the formula (CH2)2(CH)4. It is a colorless, flammable liquid. Its refractive index is 1.475 (20 °C, D). A naturally occurring derivative of 1,3-cyclohexadiene is terpinene, a component of pine oil. 1,3-Cyclohexadiene is an organic compound with the formula (CH2)2(CH)4. It is a colorless, flammable liquid. Its refractive index is 1.475 (20 °C, D). A naturally occurring derivative of 1,3-cyclohexadiene is terpinene, a component of pine oil. Cyclohexadiene is prepared by the dehydrobromination of 1,2-dibromocyclohexane: 1,3-Cyclohexadiene can also be prepared by the electrocyclic reaction from 1,3,5-hexatriene either photochemically or at temperatures above 110 °C. Useful reactions of this diene are cycloadditions, such as the Diels-Alder reaction. Conversion of 1,3-cyclohexadiene to benzene + hydrogen is exothermic by about 25 kJ/mol (gas phase). Compared with its isomer 1,4-cyclohexadiene, 1,3-cyclohexadiene is about 1.6 kJ/mol more stable. Cyclohexadiene and its derivatives form metal-alkene complexes. Illustrative is , an orange liquid. This complex reacts with hydride-abstracting reagents to give the cyclohexadienyl derivative +. Cyclohexadienes react with ruthenium trichloride to give (benzene)ruthenium dichloride dimer.