Oxygen, heterocyclic compounds 1,4-dioxane

The heterocyclic compounds of oxygen that are largely used as solvents, tetrahydro-furan and 1,4-dioxane, are an irritant to the eyes and respiratory tract, a depressant to the central nervous system, and exhibit a low order of toxicity. Exposure to high concentrations, however, may cause injury to the kidney and liver in humans. 

Radicals from heterocyclic compounds containing oxygen (tetrahydropyran, carbohydrates, morpholine, dioxane, etc.) ... 

Thermochemical data, and in particular the enthalpies of formation of oxygen-and sulfur-containing six-membered heterocycles, provide essential information on the factors responsible for the contrasting behaviour (structural, conformational and reactivity) between these types of compounds. Understanding of the experimental thermochemical observations has required theoretical modeling to confirm the relative importance of the steric, electronic, electrostatic and stereo-electronic interactions that are responsible for the enthalpies of formation for 1,3- and 1,4- dioxanes, 1,3,5-trioxane and their... 

---