Benzene intermolecular interactions

The diazonio group of one zwitterion is stabilized by intermolecular interactions with the carboxylato oxygens of two neighbouring zwitterions. The same type of coordination is observed in crystals of benzene diazonium chloride, tribromide, and tetrafluoroborate (Andresen and Romming, 1962 Romming, 1963 Cygler et al., 1982). 

Meijer, E. J., Spriek, M., 1996, A Density Functional Study of the Intermolecular Interactions of Benzene , J. Chem. Phys., 105, 8684. 

In contrast to the dihalogens, there are only a few spectral studies of complex formation of halocarbon acceptors in solution. Indeed, the appearance of new absorption bands is observed in the tetrabromomethane solutions with diazabicyclooctene [49,50] and with halide anions [5]. The formation of tetrachloromethane complexes with aromatic donors has been suggested without definitive spectral characterization [51,52]. Moreover, recent spectral measurements of the intermolecular interactions of CBr4 or CHBr3 with alkyl-, amino- and methoxy-substituted benzenes and polycyclic aromatic donors reveal the appearance of new absorption bands only in the case of the strongest donors, viz. Act = 380 nm with tetramethyl-p-phenylendiamine (TMPD) and Act = 300 nm with 9,10-dimethoxy-l,4 5,8-... 

The first type applies in solutions of hydrogen halide in benzene and methylbenzenes, where thermodynamic measurements force one to the conclusion of an intermolecular interaction between the solvent molecules and the dissolved hydrogen halide molecules (Brown and Brady, 1952). 

Next, we shall describe why the magnitudes of the E and C numbers are not just quantitative manifestations of the HSAB concept, but give insight into intermolecular interactions which are absent in the qualitative soft-soft and hard-hard labeling of interactions. As can be seen from the data in Tables 3 and 4, each acid and base has both a C and an E number which could be thought to correspond to possessing properties of softness and hardness. If this were the case, ammonia, which Pearson labels hard, has a larger Cb value than benzene, which is labeled soft. 

Lacking a meta constituent, it is clear that 19 alone cannot satisfy an analogous ring of continuous intermolecular interactions aroimd anthracene. Hence, no cocrystalhsation occurred by sohd-state grinding, and the incorporation of a benzene solvent molecule upon solution evaporation was necessary to permit cocrystalhsation (Fig. 4c). The authors thus attributed the lack of cocrystal formation by solid-state grinding to an inabihty of reactants to satisfy the desired intermolecular interactions, rather than the relative stabihty of reactants. 

If a mechanical degradation of a solution of two polymers is carried out by high speed stirring, the formation of a block copolymer is not probable as the scission of polymer molecules at low concentration is not caused mainly by intermolecular interaction, such as by collision of molecules and through entanglements, but by displacements due to hydrodynamic forces in velocity gradients. Nakamo and Minoura (98) did obtain reaction by stirring a benzene solution of polyethylene oxide and poly(methyl methacrylate). 

But let us now inspect the Yu values for the various chemicals given in Table 3.2. As we would probably have expected intuitively from our discussions in Section 3.2, Yu values close to 1 are found in those cases in which molecular interactions in the solution are nearly the same as in the pure liquid compound. For example, when the intermolecular interactions in a pure liquid are dominated by vdW interactions, and when solutions also exhibit only vdW interactions between the solute and solvent and between the solvent molecules themselves, we have Yu values close to 1. Examples include solutions of nonpolar and monopolar compounds in an apolar solvent (e.g., n-hexane, benzene, and diethylether in hexadecane), as well as solutions of nonpolar solutes in monopolar solvents (e.g., n-hexane in chloroform). In contrast, if we consider situations in which strong polar interactions are involved between the solute... 

Ideal solution behavior is observed only when the solute and solvent molecules have similar sizes and intermolecular interactions, as in benzene/toluene or hexane/octane solutions. 

One of us has used molecular polarization potentials (MPP) to study the interaction of aromatic molecules, including furan, thiophene, and pyridine with a positive unitary charge, these maps being powerful tools for the study of intermolecular interactions and chemical reactivity [129,130], This kind of study leads us to examine theoretically the problem of the interaction between cations and anions with aromatic rings. We were pioneers in proposing that, in parallel with cation-7i-systems (for instance, benzene), there should exists anion-perfhiorinated-7i-systems (for instance, hexafluorobenzene) [131]. These studies include tetrafluorofuran and tetrafluorothiophene (128, 129). Simultaneously, Mascal et al. [132] described the same phenomenon but with 1,3,5-triazine (130) and 2,4,6-trifluoro-l,3,5-triazine (131) as acid 7i-systems. The group of the University of Palma de Mallorca has published a large number of papers on this topic [133] that are well summarized in a two recent reviews [134,135],... 

Abstract. A comparative investigation of C6o fiillerene solubility and donor force of alkyl derivatives of benzene has been performed. Based on the found correlation, which was determined by current methods, between C6o solubility and donor force of solvents, it has been concluded that the process of Cgo dissolution in aromatic hydrocarbons is a process of intermolecular interaction combined with charge-transfer and formation of complexes of the donor-acceptor type. The agreement between a series of physical and chemical phenomena (factors, properties) observed in studies of C60 solubility and a number of existing criteria which allow the phenomena to be interpreted as a manifestation of the charge-transfer interaction substantiates our conclusion. 

Let us look at the benzene-cyclohexane separation more closely as we summarize how GC works. The boiling points of benzene and cyclohexane are nearly the same, 80.1 and 81.4°C respectively. Any GC separation will have to depend on differences in the intermolecular interactions between the stationary phase and these two analytes, both of which are nonpolar hydrocarbons. What differences could be exploited with GC Benzene has a -n-electron cloud, which should make it more susceptible to induction effects and perhaps dispersion attractions (Chapter 3). Therefore we should choose a stationary liquid phase that would accentuate this difference—a polar one also, using the like-dissolves-like rule we might choose an aromatic compound that would interact more with benzene than with cyclohexane. One possible liquid phase that meets these criteria is dinonylphthalate, and it has been used to separate benzene and cyclohexane. The relative retention has been found to be 1.6, which represents a very good separation.1... 

Meijer EJ, Sprik M (1996) A density-functional study of the intermolecular interactions of benzene, J Chem Phys, 105 8684-8689... 

Because dispersion is an important component of the intermolecular interaction— in fact the most important for the relative stability of benzene dimers [140]—the value of the (molecular) polarizability is most likely very important for the stability... 

In the present work, we performed MC simulations at different operation conditions, constant fluid density and constant pressure, for calculating K2 to investigate the distribution behavior in the supercritical region. We selected C02, benzene, and graphitic slitpore as a model system by adopting the Lennard - Jones (LJ) potential function for intermolecular interactions. 

CD spectra can be used for an exploration of intermolecular interactions. For example, flavanpentol, a dmg for different protein related diseases, has a benzene moiety and three chiral centers. Capelli et al. [293] studied the conformers that this molecule adopts when in close proximity to a proline-rich peptide in aqueous solution. The authors compared ECD spectra of conformers in gas phase and methanol computed with TDDFT at the B3LYP/6-31+G(d) level of theory. Solvent effects were modeled by an integral equation formalism of PCM. The authors noted... 

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