Tt conjugation

Polymers. The Tt-conjugated polymers used in semiconducting appHcations are usually insulating, with semiconducting or metallic properties induced by doping (see Flectrically conductive polymers). Most of the polymers of this type can be prepared by standard methods. The increasing use of polymers in devices in the last decade has led to a great deal of study to improve the processabiUty of thin films of commonly used polymers. 

Other polymers ia this category iaclude CJ-conjugated polygermylenes (20) and TT-conjugated poly acetylene, polythiophene, and poly(p-phenylenevinylene). The photoconductivity of many TT-conjugated polymers can be enhanced by dopiag with fuUerenes (21). 

TT-conjugated. Only classes / and 2 have been used in copiers and printers. 

TT-Conjugating groups tend to favor attack at C, but the ratio of Ca. C attack depends strongly on a balance of steric and electronic factors arising from both substituent and nucleophile (Table 4). The results can be rationalized, to a first approximation, by assuming that with good vr-donors stabilization of the incipient carbocation in (50) offsets steric hindrance. 

Linear monodisperse tt-conjugated oligopyrroles and oligothiophenes as model compounds for polymers 99AG(E)1350. 

Synthetic principles for bandgap control in tt-conjugated systems of poly-(thiophene) and related systems with fused thiophene rings 97CRV173. 

The classification into Kekule and non-Kekule diradicals is mainly based on the difference in their resonance structures. From the proceeding discussions, however, such a classification does not closely relate to the relative stabilities and spin preference of TT-conjugated diradicals. For example, some non-Kekule diradicals, such as 1 and 8, prefer a triplet ground state, but some others (like 7) have a singlet ground... 

Scheme 13 tt conjugations and numer of it electrons in inorganic molecules... 

The Rise of Organophosphorus Derivatives in tt-Conjugated Materials Chemistry 141... 

Porphyrin is a multi-detectable molecule, that is, a number of its properties are detectable by many physical methods. Not only the most popular nuclear magnetic resonance and light absorption and emission spectroscopic methods, but also the electron spin resonance method for paramagnetic metallopor-phyrins and Mossbauer spectroscopy for iron and tin porphyrins are frequently used to estimate the electronic structure of porphyrins. By using these multi-detectable properties of the porphyrins of CPOs, a novel physical phenomenon is expected to be found. In particular, the topology of the cyclic shape is an ideal one-dimensional state of the materials used in quantum physics [ 16]. The concept of aromaticity found in fuUerenes, spherical aromaticity, will be revised using TT-conjugated CPOs [17]. 

Rabinovitz, M. Polycyclic Anions From Doubly to Highly Charged tt-Conjugated Systems. 146, 99-170(1988). 

Brief Historical Account of Two-Photon Absorption and TT-Conjugated Systems... 

Imidazo[2,l-/][[l,3,4]thiadiazoles 161 (Figure 33), containing practically planar and rigid heteroaromatic systems with two condensed heterocycles, which have different Tt-conjugation, have been identified as useful fragments for liquid crystal molecules <2002MI6>. 

M Wohlgenannt, K Tandon, S Mazumdar, S Ramasesha, and ZV Vardeny, Formation cross-sections of singlet and triplet excitons in TT-conjugated polymers, Nature, 409 494-497, 2001. 

AP Monkman, HD Burrows, LJ Hartwell, LE Horsburgh, I Hamblett, and S Navaratnam, Triplet energies of TT-conjugated polymers, Phys. Rev. Lett., 86 1358-1361, 2001. 

T. Yamamoto, Electrically conducting and thermally stable TT-conjugated poly(arylene)s prepared by organometallic processes, Prog. Polym. Sci., 17 1153-1205, 1992. 

S. Beaupre and M. Leclerc, Optical and electrical properties of TT-conjugated polymers based on electron-rich 3,6-dimethoxyfluorene unit, Macromolecules, 36 8986-8991, 2003. 

M. Chen, E. Perzon, M.R. Andersson, S.K.M. Jonsson, M. Fahlman, and M. Berggren, 1 Micron wavelength photo- and electroluminescence from TT-conjugated polymer, Appl. Phys. Lett., 84 3570-3572, 2004. 

T. Yamamoto, A. Morita, Y. Miyazaki, T. Marayama, H. Wakayama, Z.H. Zhou, Y. Nakamura, T. Kanbara, S. Sasaki, and K. Kubota, Preparation of ir-conjugated poly(thiophene-2,5-diyl), poly(p-phenylene), and related polymers using zerovalent nickel complexes. Linear structure and properties of the TT-conjugated polymers, Macromolecules, 25 1214—1223, 1992. 

JS Wilson, AS Dhoot, AJAB Seeley, MS Khan, A Kohler, and RH Friend, Spin-dependent exciton, formation in TT-conjugated compounds, Nature, 413 828-831, 2001. 

W Wohlgenannt, XM Jiang, C Yang, OJ Korovyanko, and ZV Vardeny, Spin-dependent polaron pair recombination in TT-conjugated polymers enhanced singlet exciton densities, Synth. Met., 139 921-924, 2003. 

JM Lupton, A Pogantsch, T Piok, EJW List, S Patil, and U Scherf, Intrinsic room-temperature electrophosphorescence from a TT-conjugated polymer, Phys. Rev. Lett., 89 167401, 2002. 

YV Romanovskii, A Gerhard, B Schweitzer, U Scherf, RI Personov, and H Bassler, Phosphorescence of TT-conjugated oligomers and polymers, Phys. Rev. Lett., 84 1027-1030, 2000. 

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