Naphthalene transition density

The product distribution in the zeolite-catalysed alkylation of polynuclear aromatics depends on the structure of zeolite pores. High regioselectivities were observed in the HM catalysed isopropylation of polynuclear aromatics, such as biphenyl, naphthalene, p-terphenyl, and dibenzofuran, to yield predominantly the least bulky products e.g., 4,4 -DIPB for biphenyl, and 2,6-DIPN for naphthalene. These reactions are controlled by steric restriction at the transition state inside the pores and by the entrance of intermediate products molecules into the pores. On the other hand, the catalysts with large-pore HY and HL zeolite are controlled at low temperature by the electron density of the reactant molecule and at higher temperature by the stability of the product molecules because their pores have enough space for a transition state, which allow the formation of all corresponding isomers. 

A simulation of such a superposition, using the fine-structure constants of the naphthalene molecule (D/hc = 0.100 cm , E/hc = -0.015 cm , and g = ge), and with a linewidth of AB = 1.2 mT for each component is shown in Fig. 7.13a. The discontinuities in the broad Am = 1 ESR spectrum correspond to the principal-axis orientations Bo u u = x,y,z). They occur because of the high density of resonance-field values in the neighbourhood of the principal-axis directions (compare Fig. 7.4). For B = 0, two of these discontinuities occur at the same place. The Am = 2 spectrum is narrow because the anisotropy of the Am = 2 transitions is to first approximation zero. The ESR signal (Fig. 7.13b) is - as usual in ESR due to the method of measurement - the first derivative of the spectrum (absorption vs. frequency or field strength. Fig. 7.13a). Even with a powder or a glass sample. 

Malhotra et al. [147] prepared the pyrrole/a-naphthalene oxide by copolymerizing pyrrole with a-naphthol in a procedure similar to that reported for the pyrrole/ phenol system. The polymerization chamber consists of a beaker holding a three-electrode system and containing both monomers and tetrabutylammonium tetrafluoroborate dissolved in acetonitrile. The conductivity of the copolymer composed of 2 a-naphtha-lene oxide units for every pyrrole unit with 18.5 mole% dopant is 2 S cm. Films are stable up to 200°C and show no degradation after exposure to air for 6 months. Their glass transition temperature is ISrC and the density is 1.31 g cm . 

Table 6 Performance of Density Functional and Correlated Wave Function Methods for Oscillator Strengths of First Three Dipole-Allowed Transitions of Naphthalene...

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