Paracyclophanes, table

Paracyclophanes, table, 47 Para formaldehyde (poly oxy methylene), 88... 

Palladium acetate, 61, 82 Paracyclophanes, table, 60, 47 Paraformaldehyde [30525-89-4], 61, 65 Paraformaldehyde (polyoxymethylene), 60, 88 Pentadecanoic acid, 60, 13 PENTAN01C-2-13C ACID, 3-HYDROXY-3-METHYL-5-(PHENYLMETHOXY)-[57830-65-6], 60, 94... 

As shown in Table 6 and Figure 1, the oxidation potentials of 2-substituted norbornadienes (1), 2-substituted bicyclo[2.2.2]octa-2,5-dienes (2) and 4-substituted [2.2]paracyclophanes (3) clearly indicate that the transannular interaction between two double bonds contributes already at the stage of the first electron transfer. Namely, in compounds 1-3, the electron is transferred from the unsaturated bond which is not substituted by the electron-withdrawing group, Figure 1 shows the... 

Starting from empirical valence force potentials, Boyd 8) has calculated the lowest-energy conformation of [2.2]paracyclophane. The geometrical data are in satisfactory agreement with experimentally determined values (see Table 1). 

Table 1. Bond lengths and bond angles in [2.2]paracyclophane...

Table 2. Comparison of the UV absorption of [2.2]paracyclophane with that of the model open-chain compound bis(p-ethylphenyl)butane...

The UV spectrum of [2.2]paracyclophane 19-22>, compared with the spectra of model acyclic (see Table 2) and higher cyclic compounds, is characterized by the absence of fine structure, the occurrence of bathochromic shifts, and reduced extinction coefficients. 

The resonance structures 65 suggest that the pseudo-meta and pseudo-geminal positions are the preferred sites for substitution however, it has been observed (e.g. in the bromination and acetylation of 4-bromo[2.2]paracyclophane (67)) that there is predominant formation of pseudo-ortho and pseudo-para products 8 3b>8 5> (see Table 3) ... 

Table 3. Product distribution in the second electrophilic substitution of mono-substituted [2.2]paracyclophanes...

The naphthalenophanes that have been synthesized to date are listed in Table 6, in order of their discovery. The [m.n] isomers for which m,n > 3 have not yet been synthesized. References for the UV absorbance, fluorescence, and other properties of existing naphthalenophanes are given in Table 6. The UV absorption spectra of all the naphthalenophanes are red-shifted and broadened relative to their respective open-chain analogs, similar to the [2.2] and [3.3] paracyclophanes. Moreover, broad and structureless emissions have been observed for the naphthalenophanes in all references cited in Table 6 except one.107) The structural aspects of naphthalenophane photobehavior will be discussed in detail in the following paragraphs. 

An X-ray crystal structure of 282 was obtained.108 Significant parameters are included in Table VIII. Particularly notable is the large bend-back angle of 58-59°, which is consistent with the presence of the highly strained [2.2]paracyclophane-l -yne moiety.109... 

Table 1.1H—NMR-data and ring deformation of some [m]paracyclophanes...

A number of other unsaturated poiyhydrocarbons have practical applications. These include poiy(phenyl acetylene) and poly((E,E)-[6.2]paracyclophane-1,5-diene), which have been studied as photoconducting polymers. The thermal decomposition of polyacetylenes and of poly((E,E)-[6.2]paracyclophane-1,5-diene) generates fragments summarized in Table 7.1.8 [19]. 

Table 7.1.8. Summary regarding thermal decomposition of polyacetylene and of poly((E,E)-[6.2]paracyclophane-1,5-diene) [19],...

This was concluded by comparison of the TP excitation spectra of the reference compounds 58b and 58c with the paracyclophane containing substances 78a-b (Table 3.7). These chromophores exhibit significant increase of 5 in the case of 78 with increasing length (n) compared to the ID reference compounds (Fig. 3.45). The paracyclophane compounds exhibit an approximately... 

The intra- and intermolecular interaction between cationic center and tt-electron system have attracted many chemists and much knowledge on the interaction has been accumulated (1). In 1975, we intended to apply such a kind of interaction to cyclopolymerization. Thus, it is expected that the transition state leading to a strained cyclic unit in the polymerization could be stabilized by the intramolecular attractive interaction between cationic growing-end and ir-system There had been few examples of cyclopolymerizations giving strained units. A paracyclophane unit was employed as a strained cyclic unit in the polymer main chain. In Table I are summarized some cyclophanes with their strain energies. 

We found that radical, anionic, and coordination polymerization gave benzene-insoluble polymer or soluble polymer as shown in Table V (26). These polymers, however, did not exhibit the characteristic spectra for [3.3]paracyclophane units above mentioned. Therefore they were concluded not to be cyclopolymer. Only cationic initiators could induce cyclopolymerization of St-Cj-St (27, 28). 

The addition polymerization of St-C -St formally gives [3.n]-paracyclophane unit-containing cyclopolymer- As seen in Table I, [3.3]paracyclophane has the strain energy of 12 kcal/mol (50 kJ/ mol), [3.2]paracyclophane of more than 12 kcal/mol but less than... 

Peraza-paracyclophanes, 697, 698 Perazatetracyclohexano-crown-4 macrocycles, table. 651 Phenanthroline, 75, 87... 

Table 5. Crystal structure geometries of [6]paracyclophan Ic, Id, Ig, 74, and 9c (Structures 2 and...

N. are the first, naturally occurring paracyclophanes (see table). They are isolated from the cyanobacterium Nostoc linckia. Four [7.7]paracyclophanes have been identified. They all have cytotoxic activity (IC50 1 -2 pg/mL) and antitumor properties. For isolation, see Lit, for structure elucidation, see Lit., for biosynthesis, see... 

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