Ultrafast 2D IR vibrational echo experiments and IR heterodyne detected transient grating (HDTG) experiments are used to study the dynamics of molecular monolayers on functionalized SiO2 surfaces. The experiments are conducted on functionalized planar surfaces and on functionalized porous SiO2 particles. The photocatalytic moiety, tricarbonyl (1,10-phenanthroline) rhenium chloride (RePhen(CO)3Cl), is attached to the surface with different alkyl chain lengths and exposed to different solvents. The experiments are conducted on the symmetric CO stretching mode of RePhen(CO)3Cl. The experiments show that it is possible to make high quality 2D IR and HDTG measurements on surface monolayers as well as in systems of particles that produce extreme amounts of scattered light. These experiments demonstrate that surface monolayers undergo picosecond time scale structural fluctuations that are influenced by chain length, solvent, and nanoconfinement in the pores. A new theoretical and experimental approach is presented for using HDTG measurements to extract orientational structure and dynamics from monolayers or any uniaxial system.

Investigations of functionalized surface monolayer molecular dynamics with ultrafast 2D IR experiments

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.