title: Encapsulating Subsite Analogues of the [FeFe]-Hydrogenases in Micelles Enables Direct Water Interactions.
abstract: Encapsulation of subsite analogues of the [FeFe]-hydrogenase enzymes in supramolecular structures has been shown to dramatically increase their catalytic ability, but the molecular basis for this enhancement remains unclear. We report the results of experiments employing infrared absorption, ultrafast infrared pump-probe, and 2D-IR spectroscopy to investigate the molecular environment of Fe2(pdt)(CO)6 (pdt: propanedithiolate) [1] encapsulated in the dispersed alkane phase of a heptane-dodecyltrimethylammonium bromide-water microemulsion. It is demonstrated that 1 is partitioned between two molecular environments, one that closely resembles bulk heptane solution and a second that features direct hydrogen-bonding interactions with water molecules that penetrate the surfactant shell. Our results demonstrate that the extent of water access to the normally water-insoluble subsite analogue 1 can be tuned with micelle size, while IR spectroscopy provides a straightforward tool that can be used to measure and fine-tune the chemical environment of catalyst species in self-assembled structures.
authors.affiliation: Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom.
authors.forename: Robby
authors.initials: R
authors.lastname: Fritzsch
authors.affiliation: Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom.
authors.forename: Owen
authors.initials: O
authors.lastname: Brady
authors.affiliation: Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom.
authors.forename: Elaine
authors.initials: E
authors.lastname: Adair
authors.affiliation: Energy Materials Laboratory, School of Chemistry, University of East Anglia , Norwich NR4 7TJ, United Kingdom.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Wright
authors.affiliation: Energy Materials Laboratory, School of Chemistry, University of East Anglia , Norwich NR4 7TJ, United Kingdom.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pickett
authors.affiliation: Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom.
authors.forename: Neil T
authors.initials: NT
authors.lastname: Hunt