Figure 3 shows electrostatic interactions in a cross section of a NaCl crystal. Each sodium cation experiences strong electrostatic interactions with adjacent chloride anions. Electrostatic interactions are between and among cations and anions, species with charge of …-2,-1,+1,+2…

Tryptophan is the most frequent π system in protein cation-Π pairs while arginine is the most frequent cation. Tryptophan and arginine can form extended coplaner assemblies. A cation can interact favorably with this partial negative charge when the cation is near the face of the Π-system. In the most stable arrangment, the cation is centered directly over the Π-system and is in direct van der Waals contact with it.

The general formula for alkenes with one double bond is CnH2n. Alkenes can be straight chain, branched chain, or cyclic. Simple alkenes often have common names, but all alkenes can be named by the system of the International Union of Pure and Applied Chemistry. Substances containing the benzene ring are common in both animals and plants, although they are more abundant in the latter.

Consider the series in Figure 1.3 “Members of a Homologous Series”. The sequence starts with C3H8, and a CH2 unit is added in each step moving up the series. The members of such a series, called homologs, have properties that vary in a regular and predictable manner. The principle of homology gives organization to organic chemistry in much the same way that the periodic table gives organization to inorganic chemistry. Instead of a bewildering array of individual carbon compounds, we can study a few members of a homologous series and from them deduce some of the properties of other compounds in the series. Organic compounds, like inorganic compounds, obey all the natural laws.

The “rotations” also include the free rotation around the single bonds. The table below shows whether the examples in the previous sections are polar or nonpolar. Lone pairs on some outer atoms have been kendall college job omitted for clarity. The name“meso” has been adopted more generally. A “meso compound” is a molecule that has chiral centers, but is achiral overall due the presence of an internal mirror plane.

Hydrocarbons are the simplest organic compounds, but they have interesting physiological effects. These effects depend on the size of the hydrocarbon molecules and where on or in the body they are applied. Alkanes of low molar mass—those with from 1 to approximately 10 or so carbon atoms—are gases or light liquids that act as anesthetics. The two structures have the same molecular formula and the same connectivity, therefore they must be stereoisomers. They each have four chiral centers, and the configuration is different at two of these centers (at carbons #3 and #4).

One liter of oil can create a slick 2.5 hectares (6.3 acres) in size. This and similar spills provide a reminder that hydrocarbons and water don’t mix. The alkyl groups we will use most frequently are listed in Table 1.4 “Common Alkyl Groups”.

Alkenes and cyclic compounds can exhibit cis-trans isomerism. All four structures have a double bond and thus meet rule 1 for cis-trans isomerism. The IUPAC System of Nomenclature provides rules for naming organic compounds. An alkyl group is a unit formed by removing one hydrogen atom from an alkane. Chlorofluorocarbons contribute to the greenhouse effect in the lower atmosphere.