Directly coupled versus spectator linkers on diimine ptii acetylides—change the structure, keep the function

Modification of light‐harvesting units with anchoring groups for surface attachment often compromises light‐harnessing properties. Herein, a series of [donor–acceptor–anchor] platinum(II) diimine (bis‐)acetylides was developed in order to systematically compare the effect of conjugated versus electronically decoupled modes of attachment of protected anchoring groups on the photophysical properties of light‐harvesting units. The first examples of “decoupled” phosphonate diimine PtII complexes are reported, and their properties are compared and contrasted to those of carboxylate analogues studied by a diversity of methods. Ultrafast time‐resolved IR and transient absorption spectroscopy revealed that all complexes have a charge‐transfer (CT) lowest excited state with lifetimes between 2 and 14 ns. Vibrational signatures and dynamics of CT states were identified; the assignment of electronic states and their vibrational origin was aided by TDDFT calculations. Ultrafast energy redistribution accompanied by structural changes was directly captured in the CT states. A significant difference between the structures of the electronic ground and CT excited states, as well as differences in the structural reorganisation in the complexes bearing directly attached or electronically decoupled anchoring groups, was discovered. This work demonstrates that decoupling of the anchoring group from the light‐harvesting core by a saturated spacer is an easy approach to combine surface attachment with high reduction potential and ten times longer lifetime of the CT excited state of the light‐absorbing unit, and retain electron‐transfer photoreactivity essential for light‐harvesting applications.N/

Signal-Amplifying Conjugated Polymer–DNA Hybrid Chips We appreciate financial support from the National Science Foundation (BES 0428010) and the equipment grant from the University of Michigan College of Engineering. J.K. and K.L. also acknowledge the Ilju Foundation for the Ilju scholarship.

No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56086/1/4667_ftp.pd

Synthesis and characterization of a water-soluble carboxylated polyfluorene and its fluorescence quenching by cationic quenchers and proteins

10.1002/asia.200700294Chemistry - An Asian Journal34739-74

Cationic, water-soluble, fluorene-containing poly(arylene ethynylene)s: Effects of water solubility on aggregation, photoluminescence efficiency, and amplified fluorescence quenching in aqueous solutions

10.1002/pola.21628Journal of Polymer Science, Part A: Polymer Chemistry44195778-5794JPAC