Forces, attractive intramolecular

This structure gives stability to the layers. The fourth, non-bonding pair of electrons is delocalized and free to move within the layers. This gives graphite the ability to conduct an electric current. There are no intramolecular forces between the layers. Dispersion forces attract one layer to another, enabling layers to slide by one another. Graphite feels slippery as a result of this characteristic. In fact, many industrial processes use graphite as a lubricant. 

Crystallization is the most important method for the purification of solid organic compounds. A crystalline organic substance is made up of a three-dimensional array of molecules held together primarily by van der Waals forces. These intramolecular attractions are fairly weak most organic solids melt in the range of room temperature to 250°C. 

Intermediate. A species that appears in the mechanism of the reaction (that is, the elementary steps) but not in the overall balanced equation. (13.5) Intermolecular forces. Attractive forces that exist among molecules. (11.2) International System of Units. A system of units based on metric units. (1.7) Intramolecular forces. Forces that hold atoms together in a molecnle. (11.2) Ion. A charged particle formed when a neutral atom or group of atoms gain or lose one or more electrons. (2.5)... 

The 1,2-disubstituted ethanes have two rotational isomers (gauche and tram). Consideration of their relative stabilities provide test data for theories on intramolecular forces (i.e. non-bonded repulsion or attractions, intramolecular hydrogen bonding, etc.). Structural and energetic data on the rotational isomers of XCH2—CH2Y species (where X, Y are F, Cl, Br, OH, NH2, CN, or CH3) in the gas phase are given in Table 23. For the combination... 

The attractive pulling forces of intramolecular bridging polar groups in the deoxy form might become repulsive spreading forces of hydration when... 

Intramolecular forces attractive forces that occur between atoms in a molecule chemical bonds... 

The chemical structure of a polymer can also cause a contraction of the polymer coil compared to the unperturbed dimensions at theta-conditions. In this case the exponent a of the [ ]]-M-relationship shows values of a<0.5. A contraction of the coil occurs if the attractive intramolecular interactions between the polymer segments become larger than the interactions with the solvent molecules. In extreme cases, the solvent is forced out of the polymer coil and the chain segments start to form compact aggregates. The density of the polymer coil is then independent of the molar mass and the intrinsic viscosity is constant. In this case the exponent a is zero. An example is shown in Fig. 6.12 for compact glycogen in aqueous solution. 

Intramolecular force Attractive and repulsive interactions (such as hydrogen-bonding, van der Waal s, and dipole-dipole interactions) that act within a molecular entity to modulate its overall geometry, properties, and reactivity. 

The longest man-made linear alkane is C39oH782> synthesized as a molecular model for polyethene (polyethylene). It crystallizes as an extended chain, but starts folding readily (picture) at its melting point of 132°C, in part due to attractive intramolecular London forces. 

Formation of lateral arrays for which the driving force is intramolecular (chain stiffness) rather than an intermolecular process of attraction. This generally leads to an increase in free energy. 

Intramolecular forces (Section 2 18) Forces either attractive or repulsive between two atoms or groups within the same molecule... 

The small differences in stability between branched and unbranched alkanes result from an interplay between attractive and repulsive forces within a molecule (intramolecular forces). These forces are nucleus-nucleus repulsions, electron-electron repulsions, and nucleus-electron attractions, the sane set of fundamental forces we met when... 

Lipophilicity is the measure of the partitioning of a compound between a lipidic and an aqueous phase [1]. The terms lipophilicity and hydrophobicity are often used inconsistently in the literature. Lipophilicity encodes most of the intramolecular forces that can take place between a solute and a solvent. Hydrophobicity is a consequence of attractive forces between nonpolar groups and thereby is a component of lipophilicity [2]. Lipophilicity is one of the most informative physicochemical properties in medicinal chemistry and since long successfully used in quantitative structure-activity relationship (QSAR) studies. Its... 

The question whether the intramolecularly crosslinked microparticles of non-aqueous polymer dispersions are really microgels is also justified, considering non-aqueous dispersions prepared from acrylic copolymers and melamine/formaldehyde crosslinker with particle sizes of about 300 nm. [45, 343]. In any case, these crosslinked polymeric microparticles are useful constituents of high-solids coatings, imparting a yield stress to those solutions which probably involves attractive forces between the microparticles. 

A number of different molecular mechanisms can underpin the loss of biological activity of any protein. These include both covalent and non-covalent modification of the protein molecule, as summarized in Table 6.5. Protein denaturation, for example, entails a partial or complete alteration of the protein s three-dimensional shape. This is underlined by the disruption of the intramolecular forces that stabilize a protein s native conformation, namely hydrogen bonding, ionic attractions and hydrophobic interactions (Chapter 2). Covalent modifications of protein structure that can adversely affect its biological activity are summarized below. 

In the solid and liquid phases, molecules are very close to each other. This is because forces hold the molecules together in the solid and liquid states. We have already studied intramolecular bonds within molecules in the previous chapter. In this chapter, we will examine the forces of attraction between the particles in liquids and solids. 

Attractive or repulsive forces between molecular entities or groups within the same molecular entity (i.e., both intermolecular and intramolecular) not due to bond formation or to electrostatic interactions of ions or ionic groups with one another or with neutral molecules. The origin of van der Waals forces is in electric polarization of uncharged atoms, groups, or molecules and includes dipole-dipole interactions, dipole-induced dipole interactions, and London forces (induced dipole-induced dipole interactions). 

In organic reactions, ionic interactions may serve as intermolecular or intramolecular forces. In some cases, these may involve metal cations, such as Na% or anions, such as Cl. Cations may include an ammonium ion from an amino group, such as RNH3. The anion may be from a carboxylic acid, such as RCOO. The oppositely charged ions attract each other very strongly. 

While much of the emphasis on inter- and intramolecular interactions, secondary bonding, and forces associated with association and dissociation involve attractive forces, we are finding that phobic effects are also important and for some systems are actually the major factors. Briefly, this can be described by the sayings the enemy of my enemy is my friend, or given the choice between bad and worse, bad wins out. Formation of many self-assemblies is due in large measure to such phobic factors. 

Ionic Bond intramolecular force created when electrons are transferred from one atom to another creating ions that possess electrostatic attraction for one another Ionic Solid a solid composed of anions and cations such as NaCl... 

---