1,9-Dichloro paracyclophane

DPXC ndDPXD. The economic pressure to control dimer costs has had an important effect on what is in use today (ca 1997). Attaching substituents to the ring positions of a [2.2]paracyclophane does not proceed with isomeric exclusivity. Indeed, isomeric purity in the dimer is not an essential requirement for the obtaining of isomeric purity, eg, monosubstituted monomer, in the pyrolysis. Any mixture of the four possible heteronucleady disubstituted dichloro[2.2]paracyclophanes, will, after all, if pyrolyzed produce the same monomer molecule, chloro- -xyljIene [10366-09-3] (16) (Fig. 4). 

Fig. 4. Isomeric dichloro[2.2]paracyclophanes produce the same xylylene.

Gorham prepared about 30 kinds of substituted paracyclophanes including dichloro, dibromo, dicyano, dimethyl, diethyl, and tetrachloro derivatives 43). 

The CND0/S3 model has been applied to evaluate the electronic structure of a large number of aromatic hydrocarbons including m-xylene (12), p-xylene (12), l,4-dis(trifluoromethyl) benzene (12), 1,2 di(p-tolyl)ethane (1 ), [2.2]-paracyclophane (1 ), pseudopara-dicyano [2.2]paracyclophane (1 ), pseudo-para-dichloro [2.2]paracyclophane (1 ), 1,1,2,2,9,9,10,10 octaflu-... 

Fig. 18 Reaction scheme for PPV by thermal dehalohydrogenation of (2) film. (2) is formed by the CVP of (1), the dimer (1,9-dichloro-2, 2-paracyclophane). Tp pyrolysis temperature, Tg. sublimation temperature of precursor, T substrate temperature during CVD.

Ethyl[2.2]paracylophane (Parylene E) Amino[2.2]paracyclophane Dicyano[2.2]paracyclophane 4-Carboxyl[2.2]paracyclophane a, a, a a -Tetrafluoro-/7-xylylene Dichloro- [2.2]paracyclophane 3 -(5-Phenylpentyl)-4-methylbenzyl chloride Dichloro tetrafluoro- [2.2]paracyclopane... 

H. Maruyama. Process for the preparation of dichloro-(2,2)-paracyclophane. US Patent 5 679 874, assigned to Daisan Kasei Kabushiki Kaisha (Tokyo, JP), October 21, 1997. 

Dichloro[2.2]-paracyclophane Figure 3.2 Monomers Used for Poly(p-phenylene vinylene)... 

Dichloro[2.2]paracyclophane, 93 Dichloro-p-xylylene, 76 Dicumyl peroxide, 155... 

Figure 3.4 Chemical vapor deposition of 1,9-dichloro[2.2]paracyclophane.

The pseudopara dichloro- and dibromo- [2.2]paracyclophanes are also available in modest yields ( 20 %), and free from other regioisomers, from Winberg 1,6-elimination-dimerization [80, 81], of (2-halo-4-methylbenzyl)lrimethylammonium hydroxides (Fig. 14) [82]. Similarly, reaction of (2,5-dihalo-4-methylbenzyl)trimethyl-ammonium hydroxides affords the cross tetrahalo[2.2]paracyclophane substitution pattern previously reported by de Meijere [79]. Additional value of this route might also lie in the ability to prepare new highly halogenated [2.2]paracyclophanes, including 4,8,12,16-telrabromo[2.2]paracyclophane and 4,5,7,8,12,13,15,16-octabromo[2.2] paracyclophane. 

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