Valence and ionic lowest-lying electronic states of small esters studied by high resolution vacuum ultraviolet photoabsorption, photoelectron spectroscopy and ab initio calculations

Esters are an important class of oxygenated volatile organic compounds used in food flavorings, perfumes and other cosmetic products. They are present in fruits and pheromones and are emitted to the atmosphere naturally. Esters are also formed in the atmosphere as a product of the oxidation of ethers. Some of them form poly-molecule chains and are used in plastics. Phosphoesters form DNA backbone, while nitroesters are known for their explosive character. Some small ester molecules were reported to be found in the interstellar space. It was also shown that esters may be a product of hydroxyl radical-initiated oxidation of various ethers in troposphere.