Water dynamics in deuterated gypsum, CaSO⋅2DO, investigated by solid state deuterium NMR.

NMR relaxation theory and NMR lineshape calculations were used to characterize the rates of C symmetry jumps of deuterium nuclei in partly deuterated gypsum powder. The experimental data consisted of variable temperature deuterium NMR powder line shapes and deuterium T relaxation times. All of the Mathematica© notebooks used to simulate the spectra and match the experimental T values are included as supplementary material, and are suitable templates for similar calculations on other systems.

Solute diffusion in ionic liquids, NMR measurements and comparisons to conventional solvents.

Diffusion coefficients of a variety of dilute solutes in the series of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imides ([Prn1][Tf2N], n = 3, 4, 6, 8, and 10), trihexyltetracedecylphosphonium bis(trifluoromethanesulfonyl)imide [P14,666][Tf2N], and assorted imidazolium ionic liquids are measured using pulsed field gradient (1)H NMR. These data, combined with available literature data, are used to try to uncover the solute and solvent characteristics most important in determining tracer diffusion rates. Discussion is framed in terms of departures from simple hydrodynamic predictions for translational friction using the ratio ζobs/ζSE, where ζobs is the observed friction, determined from the measured diffusion coefficient D via ζobs = kBT/D, and ζSE = 6πηR is the Stokes friction on a sphere of radius R (determined from the solute van der Waals volume) in a solvent with viscosity η.

Identification and characterization of a cellulose binding heptapeptide revealed by phage display.

Cellulose nanowhiskers (CNWs) were used in conjunction with phage display technology to identify polypeptides which bind the crystalline region of cellulose. A consensus peptide WHWTYYW was identified to efficiently bind the CNWs. The binding affinities of specific phage particles were assessed using biopanning assays and enzyme-linked immunosorbent assay (ELISA).

A catalytically driven organometallic molecular motor.

We have observed by NMR spectroscopy that the diffusive movement of a ruthenium-based Grubbs' catalyst increases during ring-closing metathesis as a function of the substrate concentration. This is one of the smallest single molecule motors to exhibit catalytically driven motion.