Oligothiophenes properties

Polythiophenes (including oligothiophenes) are one of the most studied and important classes of linear conjugated polymers [444,445], Versatile synthetic approaches to PTs (chemical [446] and electrochemical [447]), easy functionalization and unique, widely tunable electronic properties have been the source of tremendous interest in this class of polymers. 

G. Barbarella, L. Favaretto, G. Sotgiu, M. Zambianchi, L. Antolini, O. Pudova, and A. Bongini, Oligothiophene 5,5-dioxides. Synthesis and electronic properties in relation to the parent oli-gothiophenes, J. Org. Chem., 63 5497-5506, 1998. 

The heteroaromatic stannanes undergo the normal electrophilic substitution reactions of their protic precursors, and often to an enhanced degree. They are often prepared with the aim of a subsequent Stille cross-coupling reaction, and oligothiophenes with potentially useful optical and electron properties have been prepared by coupling between stannyl- and bromo-thiophenes, for example, Equation (63).204... 

Other polyunsaturated substances such as oligothiophenes [8.95a] or dyes [8.95b] as well as organometallic or coordination compounds [8.85, 8.95c] may also present pronounced NLO properties. 

Radical cations and dications of oligothiophenes have been investigated by many research groups to understand the nature of polarons and bipolarons in polythiophenes which are responsible for the electrical and optical properties of these re-conjugated polymers. 

Some dendrimers (389-391) have been reported. The thiophene-containing dendrimers are promising materials, due to the unique properties of oligothiophenes and their derivatives, such as high charge carrier mobility, efficient fluorescence, excellent stability in ambient conditions (even at elevated temperatures), and easy functionalization. 

Poly- and oligothiophenes are generally p-type (hole-transporting) semiconductors. In thiophene-S,S-dioxide (98AM551 98JOC5497), this modification results in de-aromatization of the thiophene unit and increases the electron affinity and electron-transport properties of the... 

The lowest excited triplet state in anthryl-oligothiophenes (634) were studied (96CPL(260)125). Also, binaphthyl oligothiophenes have been studied (09MM1710). The triplet state properties are studied with respect to coupling effects between the molecular subunits for a different chain length n and also for additional pyridine substitution (635). 

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