0
The molecular geometry and electronic structure of styrene and methyl methacrylate as well as corresponding radicals formed by the addition of a methyl radical to the -carbon of the monomer were determined using the density functional theory at the B3LYP/6-311+G** level. Results were in good agreement with the theoretical and experimental data available in the literature. Full optimized molecular geometry of methyl methacrylate showed the trans form of the molecule. Monomers transformed into corresponding radicals preserved the main structural parameters of substituents whereas bonds between substituents and adjacent radical carbon atoms shortened. It was found that the correlation of the theoretically calculated electronic parameters for monomers and the corresponding radicals with the Q and e parameters from the Alfrey-Price scheme strongly depends on the level of calculations. Application of the higher level of theory including the correlation effect changes the relationship discussed in the literature between energy (EY) of formation of a radical from the monomer, the experimental e parameter, and the Q parameter and monomer/average electronegativity, respectively. The total atomic spin density at the radical carbon atom correlated with the radical parameter P in the Alfrey-Price scheme was computed to be higher for the methoxycarbonyl-1-methyl-ethyl radical when compared with the 1-phenyl-propyl radical. These values are in good agreement with the localization energies and the P values determined from the kinetic measurements for macroradicals ending with styrene and methyl methacrylate monomer units. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3761-3769, 2001
What else can I help you with?
What is the difference between Electron Geometry and Molecular Geometry and explain the circumstances under which they will not be the same?
Electron geometry describes the arrangement of electron pairs around a central atom in a molecule, based on the total number of electron pairs (bonding and nonbonding). Molecular geometry, on the other hand, describes the arrangement of atoms, taking into account only the positions of the atoms. They will not be the same when there are lone pairs of electrons on the central atom. In such cases, the electron geometry is determined by all electron pairs, whereas the molecular geometry considers only the positions of the atoms, leading to a difference.
What is the molecular geometry around the carbon in CF4 is?
The molecular geometry around the carbon in CF4 is tetrahedral. The carbon atom is bonded to four fluorine atoms, with the bond angles between the C-F bonds being approximately 109.5 degrees.
How to tell which is most polar?
To determine which molecule is the most polar, compare the electronegativity difference between the atoms in each molecule. The greater the electronegativity difference, the more polar the molecule. Additionally, look at the molecular geometry and symmetry of the molecule, as asymmetrical molecules tend to be more polar.
What is the molecular geometry on NH3?
The molecular geometry of NH3 (ammonia) is trigonal pyramidal. The nitrogen atom is at the center, with three hydrogen atoms forming a pyramidal shape around it.
Can molecular formula be used to show difference between isomers?
No, molecular formula alone cannot show the difference between isomers. Isomers have the same molecular formula but different structural arrangements of atoms. Additional information, such as structural formula or connectivity of atoms, is needed to differentiate between isomers.
What is the relationship between molecular geometry and O2 bond angles?
The relationship between molecular geometry and O2 bond angles is that the molecular geometry of O2 is linear, meaning that the bond angle between the two oxygen atoms is 180 degrees.
What is the difference between molecular geometry and molecular structure?
Molecular geometry is the distances and angles between the each of the different atoms in the molecule. It is essentially the shape of the molecule.Molecular structure includes the shape of the molecule, but also much more, such as its electronic structure. This includes the nature of the bonding in the molecule (such as where there are single, double or triple bonds), the polarity of the molecule (if the electrons are spread out evenly throughout the molecule or if they are concentrated in particular areas, and if so, what areas), etc.
What is the difference between Electron Geometry and Molecular Geometry and explain the circumstances under which they will not be the same?
Electron geometry describes the arrangement of electron pairs around a central atom in a molecule, based on the total number of electron pairs (bonding and nonbonding). Molecular geometry, on the other hand, describes the arrangement of atoms, taking into account only the positions of the atoms. They will not be the same when there are lone pairs of electrons on the central atom. In such cases, the electron geometry is determined by all electron pairs, whereas the molecular geometry considers only the positions of the atoms, leading to a difference.
How do you determine the molecular geometry of a molecule?
The molecular geometry of a molecule can be determined using the VSEPR theory. VSEPR (Valence Shell Electron Pair Repulsion) Theory: The basic premise of this simple theory is that electron pairs (bonding and nonbonding) repel one another; so the electron pairs will adopt a geometry about an atom that minimizes these repulsions. Use the method below to determine the molecular geometry about an atom. Write the Lewis dot structure for the molecule. Count the number of things (atoms, groups of atoms, and lone pairs of electrons) that are directly attached to the central atom (the atom of interest) to determine the overall (electronic) geometry of the molecule. Now ignore the lone pairs of electrons to get the molecular geometry of the molecule. The molecular geometry describes the arrangement of the atoms only and not the lone pairs of electrons. If there are no lone pairs in the molecule, then the overall geometry and the molecular geometry are the same. If the overall geometry is tetrahedral, then there are three possibilities for the molecular geometry; if it is trigonal planar, there are two possibilities; and if it is linear, the molecular geometry must also be linear. The diagram below illustrates the relationship between overall (electronic) and molecular geometries. To view the geometry in greater detail, simply click on that geometry in the graphic below. Although there are many, many different geometries that molecules adopt, we are only concerned with the five shown below.
What is the difference between a tetrahedral and trigonal planar molecular geometry?
The main difference between tetrahedral and trigonal planar molecular geometries is the number of atoms bonded to the central atom. In a tetrahedral geometry, there are four atoms bonded to the central atom, arranged in a three-dimensional shape resembling a pyramid with a triangular base. In a trigonal planar geometry, there are three atoms bonded to the central atom, arranged in a flat, triangular shape.
What is the difference between geometry and solid geometry?
The difference between regular geometry and solid geometry is that regular geometry deals with angles, measuring angles, and theorem/postulates. Solid geometry deals with shapes and multiple sided figures.
What is the difference between a tetrahedral and a trigonal pyramidal molecular geometry?
In a tetrahedral molecular geometry, there are four atoms or groups of atoms bonded to the central atom, arranged in a symmetrical shape like a pyramid with a triangular base. In a trigonal pyramidal molecular geometry, there are three atoms or groups of atoms bonded to the central atom, with one lone pair of electrons, giving it a pyramid shape with a triangular base.
What is the difference between a plane geometry and a solid geometry?
one is plane and one is solid
What is the difference between electronic and mechanical?
An electronic stopwatch gives a higher accuracy than a mechanical stop watch.
What is the difference between an electronic organ and electronic piano?
The difference between an electronic organ and an electronic piano is in the sounds produced. Sometimes, on the higher end models, the electronic piano will have a piano touch, weighted keyboard.
What is the molecular geometry of C4H8?
The molecular geometry of C4H8 (butene) is trigonal planar. Each carbon atom is sp2 hybridized, with a bond angle of around 120 degrees between each carbon atom.
What is the relationship between HCN molecular geometry and the formation of hybrid orbitals?
The molecular geometry of HCN influences the formation of hybrid orbitals. In HCN, the carbon atom forms sp hybrid orbitals due to the linear molecular geometry, allowing for strong sigma bonds with hydrogen and nitrogen atoms. This arrangement results in a linear shape for the molecule.
