Related Experiment Video
Updated: Aug 4, 2025
Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Optimizing the structure of acene clusters
1Institute of Physics, University of Freiburg, 79104 Freiburg (Breisgau), Germany.
Abstract:
We present a study of the potential energy surface of anthracene, tetracene, and pentacene clusters with up to 30 molecules. We have applied the basin-hopping Monte Carlo algorithm to clusters of acene molecules in order to find their lowest energy states. The acene molecules are described by the polymer-consistent force field-interface force field. We present the structures with the lowest observed energy, and we discuss the relative stability and accessibility of structures corresponding to local energy minima.
More Related Videos
06:35Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
05:57Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function
Published on: April 26, 2024
Related Concept Videos
01:28Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the...
02:39Nomenclature of Alkynes
02:27Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
02:42Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
02:37Structure and Physical Properties of Alkynes
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The...
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...