Poly naphthalene

The formation ofC—C bonds between aromatic rings is an important step in many organic syntheses and can be accomplished by chemical, photochemical, or electrochemical means. As was noted earlier, fundamental considerations of the parameters for a dielectric which must be dealt with in designing a thermally stable, low-dielectric-constant polymer naturally lead one to consider rigid-rod, nonconjugated aromatic polymers containing no lossy functional groups. A structure such as poly(naphthalene) is a likely candidate. 

Poly(naphthalene) is chemically similar to poly(p-phenylene), which is an insoluble, infusible, low-molecular-weight polymer, all attributes that preclude application in thin-film form in microelectronics. Although these materials possess several very desirable properties, such as high glass transition tempera-... 

Scheme 6 outlines the stepwise synthesis of poly(naphthalene) and poly-(tetrafluoronaphthalene). 

Poly(naphthalene) and poly(tetrafluoronaphthalene) were synthesized by vaporizing the appropriate precursor in vacuo and transporting the vapor into a hot chamber maintained at 150-400°C. In the high-temperature zone, the... 

The diethynylbenzene analogues, depending on their individual properties, can be evaporated or sublimed into the reaction zone. The lower limit of the deposition temperature for poly(naphthalene) (PNT-N) was explored, and it was observed that deposition began at a substrate temperature somewhere in range of 150-200°C. A summary of the poly(naphthalene) and poly(tetrafluoronaphtha-lene) deposition conditions described here is given in Table 18.6. 

Table 18.6. Deposition Conditions for Poly(Naphthalene) and Poly(Tetrafluoronaphthalene)...

There are a few reports of poly(naphthalene) thin films. Yoshino and co-workers. used electrochemical polymerization to obtain poly(2,6-naphthalene) film from a solution of naphthalene and nitrobenzene with a composite electrolyte of copper(II) chloride and lithium hexafluoroarsenate. Zotti and co-workers prepared poly( 1,4-naphthalene) film by anionic coupling of naphthalene on. platinum or glassy carbon electrodes with tetrabutylammonium tetrafluoroborate as an electrolyte in anhydrous acetonitrile and 1,2-dichloroethane. Recently, Hara and Toshima prepared a purple-colored poly( 1,4-naphthalene) film by electrochemical polymerization of naphthalene using a mixed electrolyte of aluminum chloride and cuprous chloride. Although the film was contaminated with the electrolyte, the polymer had very high thermal stability (decomposition temperature of 546°C). The only catalyst-free poly(naphthalene) which utilized a unique chemistry, Bergman s cycloaromatization, was obtained by Tour and co-workers recently (vide infra). 

Physical and optical properties of selected poly naphthalenes are provided in Table 1. TABLE 1. Physical and Optical Properties of Selected Polynaphthalenes"... 

Ring-opening metathesis polymerization (ROMP) has been used to make precursor polymers to PAVs as shown in Scheme 6.10 for the synthesis of poly (naphthalene vinylene)s 43 by Grubbs and coworkers [55, 56], ROMP has also... 

Dispersants are polyanionic polymers, mostly poly(naphthalene sulfonate) (PNS) and poly melamine sulfonate, which adsorb on the positively charged zones of the particle surfaces and suppress the interactions required to build the gel structure. Thus, the slurry is dispersed (Figure 17). With large quantities of dispersant, it is possible to obtain a New-... 

K. Nakabayashi, H. Mori, All-Polymer Solar Cells Based on Fully Conjugated Block Copolymers Composed of Poly(3-Hexylthiophene) and Poly(Naphthalene Bisimide) Segments. Macromolecules 2012, 45, 9618-9625. 

Synthesis oxidative electropolymerization from 5-amino-l-naphthol in acid media. In basic media, the polymerization proceeds through the oxidation of the —OH group and yields the poly(naphthalene oxide) structure [714],... 

---