title: Hydrogen bonding in redox-modulated molecular recognition. An experimental and theoretical investigation.
abstract: Two receptors, a diaminotriazine derivative (DAT) and diamidopyridine (DAP), are complementary to the electroactive naphthalimide (N) through three-point hydrogen bonding. The association constants of the two receptors were evaluated for both the fully oxidized and the radical anion forms of N. In the oxidized state, the two receptors displayed identical binding constants. Diamidopyridine, however, lowers the reduction potential of naphthalimide to a far greater extent than does diaminotriazine, indicating a greater affinity for diamidopyridine by naphthalimide in the radical anion form. This behavior was mirrored by EPR experiments that showed small deviations from the hyperfine coupling pattern of N(red) in the presence of DAT, with greater effects seen for the N(red).DAP complex. Computational simulations using the UB3LYP/6-311+G(d,p)//UHF/6-31G(d) hybrid gave theoretical hyperfine constants in good quantitative agreement with the experimental results. Using this correlation, we determined that electrostatics and hydrogen bond polarizability play key roles in controlling redox-modulated molecular recognition.
authors.affiliation: Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Gray
authors.forename: Alejandro O
authors.initials: AO
authors.lastname: Cuello
authors.forename: Graeme
authors.initials: G
authors.lastname: Cooke
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Rotello
mesh_terms: D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D009281:Naphthalenes / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D055672:Static Electricity; D014227:Triazines / Q000737:chemistry*
chemical_list: D009281:Naphthalenes; D011725:Pyridines; D014227:Triazines