engleski

The Role of Intramolecular Hydrogen Bonds in Construction of Model Donor-Acceptor Salt Bridged Crystals

Ever since the guanidine-carboxylate salt bridge with various roles in living systems has been discovered, scientists are trying to use the similar concepts in controlling response of their molecular systems to some external input. Thus, Nocera and coworkers constructed several small donor-acceptor (D-A) systems with salt bridge junction between them. They noticed significant dependence of the electron transfer rates on the direction of the dipole of the salt bridge. It was also shown that amidine- carboxylate salt-bridge can be used to construct photoactive triadic supramolecular assemblies.3 Although, inspired by the natural guanidine- carboxylate salt bridge, both groups were using amidinium salts as a simpler model in which only one hydrogen bonding mode between guanidinium and carboxylate ions is relevant. In continuation of our previous work on guanidinium-carboxylate salt bridge formation4, we found significant differences in crystal structures of arylguanidinium dinitrobenzoates caused and controlled by intramolecular hydrogen bonds between guanidinium subunit and aromatic ring attached to it as exemplified by 8- quinolynyl- and 1-naphthylguanidinium dinitrobenzoates.

intramolecular hydrogen bond ; donor-acceptor pair ; salt bridge

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