Water-Soluble, Electroactive, and Photoluminescent Quaterthiophene-Dinucleotide Conjugates

• Published in: Chemistry : a European journal Vol. 14; no. 2; pp. 513 - 521
• Main Authors: Alesi, Silvia, Brancolini, Giorgia, Melucci, Manuela, Capobianco, Massimo Luigi, Venturini, Alessandro, Camaioni, Nadia, Barbarella, Giovanna
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2008; WILEY‐VCH Verlag; Wiley
• Subjects: Adenosine - chemistry; charge mobility; Chemistry; Chemistry, Multidisciplinary; circular dichroism; Electrochemistry; Hydrogen Bonding; Luminescence; Luminescent Measurements - methods; Models, Molecular; Molecular Structure; Nucleotides - chemical synthesis; Nucleotides - chemistry; oligonucleotides; Photochemistry; photoluminescence; Physical Sciences; Science & Technology; Solubility; Spectrophotometry, Ultraviolet - methods; Stereoisomerism; thiophene; Thiophenes - chemistry; Thymidine - chemistry; Water - chemistry; photoluminescence; thiophene; CRYSTAL-STRUCTURE; OLIGOTHIOPHENES; circular dichroism; oligonucleotides; OLIGOMERS; NUCLEIC-ACIDS; ASSEMBLIES; DNA; THIN-FILM TRANSISTORS; MICROWAVE-ASSISTED SYNTHESIS; charge mobility; MOLECULAR MECHANICS
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200700950

Quaterthiophene–dinucleotide conjugates 5′TA3′‐t4‐3′AT5′, 5′AA3′‐t4‐3′AA5′, and 5′TT3′‐t4‐3′TT5′ (TA: thymidine–adenosine, AA: adenosine–adenosine, TT: thymidine–thymidine) were synthesized and analyzed by a combination of spectroscopy and microscopy, electrical characterization, and theoretical calculations. Circular dichroism (CD) experiments demonstrated a transfer of chirality from the dinucleotides to quaterthiophene at high ionic strength and in cast films. The films were photoluminescent and electroactive. CD and photoluminescence spectra and current density/voltage plots (measured under dynamic vacuum) displayed significant variation on changing the dinucleotide scaffold. Molecular mechanics and molecular dynamics calculations indicated that the conformation and packing modes of the conjugates are the result of a balance between intra‐ and intermolecular nucleobase–thiophene stacking interactions and intramolecular hydrogen bonding between the nucleobases. A transfer of chirality from dinucleotides to quaterthiophene is observed for conjugates 5′TA3′‐t4‐3′AT5′, 5′AA3′‐t4‐3′AA5′, and 5′TT3′‐t4‐3′TT5′ at high ionic strength and in cast films (TA: thymidine–adenosine, AA: adenosine–adenosine, TT: thymidine–thymidine). Circular dichroism, photoluminescence, and current density/voltage plots display significant variation on changing the dinucleotide scaffold.