1204504-40-4Relevant academic research and scientific papers
Double-stranded supramolecular assembly through salt bridge formation between rigid and flexible amidine and carboxylic acid strands
Iida, Hiroki,Shimoyama, Munenori,Furusho, Yoshio,Yashima, Eiji
, p. 417 - 423 (2010)
(Chemical Equation Presented) A series of monomeric strands consisting of m-terphenyl backbones with chiral rigid C-linked (3) and flexible N-linked (5) formamidines and achiral carboxylic acid (4) and flexible carboxymethyl (6) residues were synthesized, and their duplex formations through amidinium-carboxylate salt bridges were investigated by NMR, circular dichroism (CD), and UV-visible spectroscopies. The salt bridge-derived duplex formation was largely dependent on the structures of the formamidine and carboxylic acid strands, and the C-linked formamidine strand 3 formed a more stable duplex with the complementary carboxylic acid strands (4 and 6) than did the flexibleN-linked formamidine strand 5. The single crystal X-ray analysis revealed that the duplex 5·4 has a skewed right-handed double helical structure. A complementary duplex dimer was also synthesized from the dimers of 5 and 4 joined by diacetylene linkers. Variable-temperature CD measurements indicated that the duplex possesses a dynamic double helical structure resulting from the flexible N-linked formamidine units.
