Chromophores polymer synthesis

The preparation of soluble polymers containing species 1-4 was accomplished by the use of the polar trifluoroethoxy group as co-substituent. The partially substituted trifluoroethoxy polymer, prepared in the first step of the polymer synthesis (see Scheme II), provided a polar environment for the incorporation of the chromophoric side chains. However, the maximum loading of the polymers by the chromophores 1-4 was limited by the solubility of the polymeric products. Hence, the side group ratios for polymers 6-9 represent a maximum incorporation range of the chromophore side group by the use of this synthetic scheme. 

This account has summarized several of our approaches to the preparation of electric-field-aligned chromophoric polymers for second order NLO applications. Molecular design has been employed wherever possible to arrive at structures that probe particular aspects of the polar orientation issue. The rich variety of accessible organic structures has enabled us to consider the orientation problem from a variety of points of view, and to indicate by example the manner in which multifunctional organic synthesis may play a role in the fabrication of oriented materials. 

This application of DEC chromophores requires synthesis of asymmetrically functionalized chromophores as illustrated in Fig. 1. In this example, the hydroxyl terminated end of the chromophore is capable of condensation polymerization reactions while the acrylate functionality is capable of undergoing free radical polymerization. In Fig. 2, we illustrate schematically the stepwise synthesis of a highly crosslinked polymer matrix where both ends of the chromophore are coupled to polymer main chains. The first step in the scheme shown is accomplished by free radical polymerization yielding a soluble and processible polymer with flexible pendant chromophore groups. This polymer is spin cast into an optical quality film (0.5-1.5 micron thickness) and is heated near the glass transition temperature, poled and subsequently crosslinked by a thermal crosslinking reaction involving... 

TPD acrylate can be polymerized with ethyl-2-bromo-2-methylpropionate as an initiator [152]. The polymer serves as a charge transport homopolymer. 2-(4-Azepan- l-yl-benzylidene)-malononitrile (7-DCST) is prepared and serves as a chromophore. The synthesis of 7-DCST is shown in Figure 1.16. 

Conjugated polymers can be prepared in which fluorescent moieties are pendant to the polymer chain either by polymerisation of monomers containing the chromophore or hy attaching chromophore units to an existing polymer chain. This approach has the advantage of producing polymers where the chromophore is well defined and also enables the utilisation of the considerable body of expertise developed in classical polymer synthesis to control the physical properties of the polymer. " ... 

Xie J, Deng X, Cao Z, Shen Q, Zhang W, Shi W (2007) Synthesis and second-order nonlinear optical properties of hyperbranched polymers containing pendant azobenzene chromophores. Polymer 48 5988-5993... 

An important challenge in the design of novel conjugated polymers is the synthesis of materials with tailor-made solid-state electronic properties. This section outlines the synthesis of the most significant classes of poly(para-phenylenevinylene)s (PPVs), poly(para-phenylene)s (PPPs), and related structures. Furthermore, this review demonstrates that the chromophoric and electronic properties of conjugated rr-systems are sensitive to their molecular and supra-molecular architecture. 

The optical and electrochemical properties of porphyrins make these chromophores useful building blocks for the synthesis of electro- and photoactive polymers. Two types of linear polymers have been constructed using the self-assembly approach homo-polymeric assemblies and hetero- or shish kebab polymers. 

These results illustrate the diversity of synthetic and processing approaches that can be taken in the synthesis of thin-film frequency doubling materials. Specifically, we have demonstrated that it is possible to assemble chromophore-functionalized polymers with greater than one chromophore substitutent per monomer subunit, with d33 values as high as 65 x 10 esu, with Tg values as high as 173°C, with improved temporal stability, and with good transparency characteristics at A 0.633 fim. We have also shown that known chromophore-functionalized polymers can be simultaneously poled and cross-linked... 

SCLC Polymers. There has been a series of papers on the synthesis and photochemistry of SCLC polymers containing the 4-alkoxyphenyl-4 -alkoxy-cinnamate chromophore, the same chromophore as that of the MCLC polymer, 1. Ritter and co-workers [37] were the first to examine the photochemistry of any SCLC cinnamate polymer. The DSC data reported for polymer 10 indicated the... 

Angeloni, Chiellini, and their co-workers [116-118] reported the synthesis and characterization of both MCLC and SCLC polymers containing the 4,4 -bisalkoxyazobenzene chromophore. These interesting materials photoisomerized in solution but their photochemistry in an LC mesophase was not reported. 

---