Conjugated molecular rods

A.-A. Dhirani, R.W. Zehner, R.P. Hsung, P. Guyot-Sionnest, L.R. Sita, "Self-assembly of conjugated molecular rods a high-resolution STM study", J. Am. Chem. Soc., 1996,118(13), 3319-3320. 

Lortscher E, Elbing M, Tschudy M, von Hanisch C, Weber HB, Mayor M, Riel H (1997) Charge transport through molecular rods with reduced 7i-conjugation. ChemPhysChem 9 2252-2258... 

A rapid and versatile covalent assembly technique starting from DEE oligomers has provided the 11.9 nm long hexadecameric poly(triacetylene) rod 20.1481 With its linearly conjugated 16 double and 32 triple bonds spanning in-between the terminal silicon atoms, compound 20 is currently the longest linear, fully Jt-conjugated molecular wire without aromatic repeat units in the backbone. 

Synthesis and Properties of Conjugated Poly(aryleneethynylene)s Linear Monodisperse jr-Conjugated Oligomers Model Compounds for Polymers and More Molecular Rods. 1. Simple Axial Rods... 

Samori, P., et al. 1999. Self-assembly of a conjugated polymer From molecular rods to a nanoribbon architecture with molecular dimensions. Chem Eur ] 5 2312. 

The preparation of (alk-l-ynyl)thiophenes 154 is possible via palladium-catalyzed Sonogashira cross-coupling reactions between iodo- or bromothiophenes 152 and terminal alkynes 153 (Scheme 60, Table 38) [309, 360, 363, 364], Alkynylated thiophenes represent an important structural motif found in many ir-electronic systems such as molecular rods or conjugated macrocycles [163, 362, 365, 366], In the case of bromoiodo-substituted thiophenes, the more reactive iodine atom is replaced selectively [367]. Some coupling methods require stoichiometric amotmts of paUadium(0) [360, 368], whereas other methods proceed successfully tmder photochemical conditions without the need of a catalyst [369]. Recent... 

Polyquinolines represent another class of photocon-ductive 7r-conjugated rigid-rod polymers. High molecular weight polyquinolines (M 5 x 10 ) are prepared by an acid catalyzed reaction of aromatic o-amino ketones with keto methylene compounds [468,469]. Stolka and co-workers [470] recently reported on steady state photoconductivity measurements in poly(2,2 -(biphenylene)-6,6 -bis(4-phenyl quinoline)) (73b). In both polymers like in other conjugated polymers the low energy threshold of... 

As far as the criterion for sectioiung this review article is concerned, it is not straightforward. For conveiuence, we will review 1-D assemblies of molecular rods in terms of molecular architecture. We classify rod assemblers into six molecular categories (1) rod-coil molecifles, (2) macrocyclic molecules, (3) dendron-rod-coil molecules, (4) dumbbell-shaped molecules, (5) wedge-typed molecules, and (6) conjugate rods with lateral chains. We will describe biomimetic or bioconjugate amphiphiUc rods in the last section. 

R. E. Martin, T. Mader, F. Diederich, Monodisperse Poly(triacetylene) Rods Synthesis of a 11.9 nm Long Molecular Wire and Direct Determination of the Effective Conjugation Length by UV/Vis and Raman Spectroscopies , Angew. Chem Int. Ed. Engl. 1999,38, 817-821. 

The concept of a molecular wire is a remarkable case in this a conjugated rod-like molecule bridges the gap between nanoelectrodes with molecular dips as crudal components.161... 

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