HypNMR2006

Equilibrium constants from averaged chemical shifts

HypNMR is a program that may be used to determine equilibrium constants from chemical shifts in NMR spectra. It is assumed that the equilibrium is attained rapidly on the NMR time-scale such that the chemical shift for a given nucleus is a mol fraction-weighted average over all of the chemical species in which the nucleus is present. Data input is comprised of the frequencies (i.e. chemical shifts) of the NMR peaks in relation to the analytical concentrations of reagents in the solution and (optionally) its pH (or pD). The program can handle data in which the chemical shift(s) of one or more nuclei may be assigned in some spectra and not in others.

The refinement process yields the values of both the equilibrium constants and the individual chemical shifts of each nucleus in each chemical compound. For further details concerning the way the program works see C. Frassineti, S. Ghelli, P. Gans, A. Sabatini, M.S. Moruzzi and A. Vacca, "Nuclear Magnetic Resonance as a Tool for Determining Protonation Constants of Natural Polyprotic Bases in Solution", Analytical Biochemistry, 231, 374-382 (1995). (requires Acrobat reader)

See also C. Frassineti, L. Alderighi, P. Gans, A. Sabatini, A.Vacca, S. Ghelli, "Determination of protonation constants of some fluorinated polyamines by means of ¹³C NMR data processed by the new computer program HypNMR2000. Protonation sequence in polyamines", Anal. Bioanal. Chem., 376,: 1041-1052 (2003). (requires Acrobat reader)

The general structure of this program is the same as the structure of Hyperquad.

Data pre-processing modules

• Import wizard for titration curve data
• Edit the model
• Edit the experimental data (multinuclear possibility, e.g. ¹H and ¹³C data)
• Fit the experimental data interactively by adjusting the model. The observed and calculated shifts are plotted for one or more nuclei, with optional speciation. Plots may be tweaked for publication
• Perform Principal Component analysis
• Include known chemical shifts for some species

Stability constant refinement

• The stability constant refinement is performed by means of a compiled FORTRAN program. The program takes its data from files and outputs its results to a file. Once the calculation is finished the results appear in the output viewer.

Analysis of results

• The output viewer allows the results of a stability constant refinement to be viewed section by section.
• The output file includes a table of all calculated concentrations which can be exported to a spreadsheet program
• Stepwise constants can be calculated and the chemical model can be updated.
• Chemical shift for each nucleus in each species are provided.

Ancillary material

The package includes 4 sets of sample data: ligand protonation, metal binding, dimerization, host-guest interaction. There is also a detailed Help file which has descriptions of all the program's functions.

System requirements

HypNMR designed to run on a PC under the Windows95/98/NT/2000/XP operating systems. There are no specific system requirements, but a screen resolution greater than 800*600 pixels is desirable in order to permit interactive preliminary data fitting.

Stability Constants home page