Dipyrrolyl-functionalized bipyridine-based anion receptors for emission-based selective detection of dihydrogen phosphate.
New cationic anion receptors, based on the use of pyrrole-substituted bipyridine and coordinated to transition metals, are described. Specifically, polypyridine-ruthenium and -rhodium cores have been functionalized to generate an anion binding site. The design was chosen to probe the influence of the pyrrole-to-pyrrole separation on anion-binding affinities and selectivities; this distance is greater in the new systems of this report (receptors 1 and 2) relative to that present in related dipyrrolyl quinoxaline based receptors 3 and 4. Solution-phase anion-binding studies, carried out by means of (1)H NMR spectroscopic titrations in [D(6)]DMSO and isothermal titration calorimetry (ITC) in DMSO, reveal that 1 and 2 bind most simple anions with substantially higher affinity than either 3 or 4. In the case of chloride anion, structural studies, carried out by means of single-crystal X-ray diffraction analyses, are consistent with the solution-phase results and reveal that receptors 1 and 2 are both able to stabilize complexes with this halide anion in the solid state.
Plitt
Patrick
P
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712, USA.
Gross
Dustin E
DE
Lynch
Vincent M
VM
Sessler
Jonathan L
JL
D015082:2,2'-Dipyridyl / Q000737:chemistry*; D000838:Anions / Q000737:chemistry*; D001665:Binding Sites; D002712:Chlorides / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D015394:Molecular Structure; D010710:Phosphates / Q000032:analysis* / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry; D013057:Spectrum Analysis; D017186:Titrimetry; D028561:Transition Elements / Q000737:chemistry*; D014961:X-Ray Diffraction
D000838:Anions; D002712:Chlorides; D010710:Phosphates; D011758:Pyrroles; D028561:Transition Elements; D015082:2,2'-Dipyridyl; D012428:Ruthenium; D012238:Rhodium; D004121:Dimethyl Sulfoxide