Organic Chemistry: Properties and Nomenclature of Hydrocarbons - Prof. Gunnar Schade, Study notes of Meteorology

Download Organic Chemistry: Properties and Nomenclature of Hydrocarbons - Prof. Gunnar Schade and more Study notes Meteorology in PDF only on Docsity! Organic chemistry • Chemistry of carbon – Simplest molecule: CH4 (methane) – valence: 4 (aka C always makes four bonds) • Hydrocarbons (HCs) molecules that contain only carbon and hydrogen, CnHm (n, m ∈ N) • NMHC non-methane HC • hetero atom O, N, S, Halogens • VOC Volatile Organic Compound – volatility (high vapor pressure) is a necessary prerequisite for gas-phase abundance – generally, hetero atoms increase polarity thereby decreasing volatility Organic Chemistry Nomenclature • systematic naming – combination of prefixes and suffixes • each functional group carries its own name whether as prefix or suffix – longest HC-chain takes preference – special rules for ring-structures and hetero atoms – few exceptions – naming gets long and more complicated with molecule size • common/traditional names – based on origin (e.g. country or name-giver) – has advantages for large molecules (shorter name) Alkanes, cont. • 3-D structure due to “hybridization” – non-linear chain(s) – symmetry (“looks the same” after turning) – free rotation around single bonds – only bond-structure is drawn omitting all C-H bonds (in org. chemistry textbooks) • different “flavors” of C-H bonds: – primary (C of C-H has max. 1 C-C-bond) – secondary (C of C-H has 2 C-C bonds) – tertiary (C of C-H has 3 C-C bonds) – C-H bond strength decreases with #C-C bonds Hybridization • “mixing” s- and p-orbitals before entering MOs – energy equilibration – symmetry Ø minimizing potential energy of resultant molecule • 3 hybrid forms Ø sp3 tetrahedron (109.5°) Ø sp2 triangle (120°) Ø sp linear molecule (180°) • Non-organic examples: • NH3 • H2O