Abstract and Keywords

Aromatic hydrocarbons (AHs) play an important role in the atmospheric chemistry and are related especially to anthropogenic activities. The complexity of AHs oxidation mechanisms consists of a diversity of reaction pathways leading to a multitude of ring retaining and ring opening products. Particular interest is represented by oxygenated AHs gas phase chemistry.

The primary reaction steps and a few of the major end products of the atmospheric oxidation of aromatic hydrocarbons have been satisfactorily established. The carbon balance in product investigations is highly unsatisfactory and the further reaction mechanisms of the first generation products, which lead to multifunctional oxidised products, are presently ambiguous and need elucidation. A major problem to achieving this goal is the lack of suitable analytical techniques for the detection of reaction intermediates and also end products. A broad range of techniques and methods will be used to intensively explore the degradation mechanisms of cresols and methylated catechols in their reaction with OH and NO3 radicals, respectively. The study of gas phase and secondary organic aerosol phase in the simulation chamber will lead to a very complex and detailed investigation on the chemistry of the cresols and methylated catechol isomers.

Key words: aromatic hydrocarbon, gas phase mechanism, catechol, cresol, OH and NO3 radicals

Hidrocarburile aromatice (HA) joaca un rol important in chimia atmosferei si sunt legate in special de activitatile antropogenice. Complexitatea mecanismelor de oxidare a HA consta intr-o diversitate de cai de reactie care conduc la o multitudine de produsi de reactie obtinuti atat prin mentinerea inelului aromatic cat si ca urmare a deschiderii acestuia.

Un interes particular este reprezentat de chimia in faza gazoasa a HA oxigenate. Primele trepte de reactie si cativa dintre produsii finali de oxidare atmosferica a HA au fost stabiliti la un nivel satisfacator. Balanta de carbon a produsilor investigati este mult mai neconcludenta, astfel incat mecanismele de reactie ale primei generatii de produsi, ce conduc la produsi de oxidare multifunctionali, sunt in prezent ambigue si necesita elucidare. O problema majora in atingerea acestui scop este lipsa unor tehnici instrumentale analitice pentru detectarea intermediarilor de reactie si a produsilor finali. O larga paleta de tehnici si metode vor fi utilizate pentru a studia intensiv mecanismele de degradare a crezolilor si cateholilor metilati in urma reactiilor lor cu radicalii OH si respectiv NO3. Studiul fazei gazoase si a fazei de aerosoli organici secundari in camere de simulare va conduce la un studiu foarte complex si detaliat asupra chimiei crezolilor si a izomerilor metilati ai cateholului.

Cuvinte cheie: hidrocarburi aromatice, mecanisme in faza gazoasa, catehol, cresol, radicali OH si NO3