CH255 Home Page

CH255J Homepage

NMR Spectroscopy

¹H Chemical Shift Prediction Substituent Constant Approach for Proton Chemical Shifts.

JMM: 1st Order Multiplet Maker for spin-spin splitting multiplets (or, JMM: alternate version without frames or J estimation)

JD: Spin-Spin Splitting Simulation for up to five spins.

Exchange(Netscape) Exchange Lineshape Simulation for 2 site exchange. Exchange(IE) is also available for Internet Explorer.

Mass Spectrometry

Fragment Finder finds the possible formulas that match a given molar mass. Then the M+1 and M+2 ratios and the exact masses of each of the possible fragments is calculated.
Formula Finder finds the possible formulas that match a given molar mass and several fragments. Then the M+1 and M+2 ratios and the exact masses of each of the possible fragments is calculated.
Molar Mass Finder guesses possible molecular ion masses if your spectrum might not have a molecular ion peak. If you have the tabulated peak list as a text file from an HP ChemStation on a disk, you can download the peak list into the MolarMass applet. Currently, this applet does not work with Netscape on a Windows system. Other combinations are OK.
Isotope Cluster calculates the isotope pattern for a given molecular formula. It includes 3rd and 4th period representative and transition metal elements.
Tripeptide Mass Finder searchs for di- or tripeptide ions that match a given mass.
Peptide Mass Finder calculates the masses of ions for a given peptide sequence. You can also plot the isotope cluster for the ion. This applet allows for stable isotope substitution for an amino acid with variable composition for the normal and substituted form.
Solvent Cluster Ion Finder finds the formula for solvent cluster ions for the background in electrospray ionization MS.

Metal Complex Finder finds the formula for an inorganic complex.

Infra-Red Spectroscopy

IR Helper is a step-by-step tutorial on the interpretation of Infra-Red spectra. IR Helper is available in two versions:
IR Helper, Internet Explorer version
IR Helper, Netscape 4.03 version

Units Conversions

Here is an energy conversion application that you will find helpful, especially for converting Hartrees and eV to kJ/mol and Boltzman population ratios.

Distance Geometry

Distance geometry is a useful computational technique for building molecular structures when a few distance constraints are known, for example from NMR nOe measurements. Distance geometry is also a powerful way to convert atom connection tables to 3-dimensional form. Distance Geometry is a Web application that does distance geometry calculations for small molecules. This Web page can also be used to set-up complete input files for MOPAC and Gaussian94/98. You can also use distance geometry to build and molecular mechanics minimize a structure with Distance Geometry and MM2. These Web pages now also support Netscape 4.07 as well as Internet Explorer.

HPLC Simulator

The HPLC Simulator uses a purely equilibrium model for chromatography to simulate the separation of two compounds. Equilibrium Constants and Partition coefficients can be set up for all complexes that form including dimers. The mobile phase can have an additive, M, that might be a cyclodextrin, an ion pairing reagent, etc. Detection can be direct or indirect, using the mobile phase additive. Caution: this JavaScript takes a long time to run. A 100 plate column requires 20 sec. on a very fast PC. This script is new and under development, so expect changes. This script runs using Netscape and Internet Explorer on Macs and PCs. The Programmed HPLC Simulator is even newer and allows the mobile phase additive to be programmed, i.e. pulsed, so that you can do some interesting equilibrium constant determinations. Comments and suggestions will be very helpful (11/26/99).

WWW Links

NMR Specific

Proton NMR Spectral Data Viewer
SDBS Integrated Spectral Data Base System for Organic Compounds
Educational NMR Software List
Sweet J A Mac application to calculate J-coupling constants using the Karplus and Altona Equations. This is a local bin-hexed Mac version, for faster downloading than directly from the Web.

NMR Home Page at the University of Potsdam has on-line applications for NMR Spectral Interpretation and Mass Spec interpretation, including:

¹H Wizard: Interactive ¹H Chemical Shift Correlation Chart
IR Wizard: Interactive IR Correlation Chart
MS Wizard: Interactive MS Fragment Chart
¹³C Database Chemical Shift Database search
AROSIM Calculation of ¹³C chemical shifts of aromatic compounds
DynamicNMR Simulation of dynamic lineshape (2 nuclei without coupling)
NMR-PTE Periodic Table of the Elements with NMR- related information
Chemical Shift Tables
Coupling Constants Ranges of ⁿJ(H,H)- coupling constants
NMR- Solvents Overview of common solvents in NMR- spectroscopy

NMR Tutorials

NMR Spectroscopy: Principles and Application (Prof. H. S. Rzepa)
Introduction to NMR UWI-Mona
Applications of ¹H NMR spectroscopy (P. Hallpap, H. Händel)
Introduction to Mass Spectrometry B. M. Tissue, U. Vermont
Introduction to Mass Spectrometry L. Breci, U. Arizone
Mass Spectrometry R. Caprioli and M. Sutter, M. Stoeckli, Vanderbilt

General Spectroscopy

The National Institutes of Standards and Technology Chemical Web Book includes thermochemical and gas phase IR and mass spectral data.
IR Wizard Interactive IR Correlation Chart
MS Wizard Interactive MS Fragment Chart

Molecular Mechanics and Graphics

The RasMol Home page is a source for RasMol/RasMac applications and information.

Molecular Structure

The Klotho Biochemical Compounds Declarative Database includes 3D-Chime structures of over 400 biochemical compounds.
The Protein Data Bank at Brookhaven National Labs is a repository of X-ray and NMR 3D-structures of proteins and nucleic acids.

General Reference

ChemInfo at the Univ. of Indiana will help you find and learn how to use chemistry information resources on the Internet and elsewhere.

For more information or corrections contact Tom Shattuck at twshattu@Colby.edu.

Colby Chemistry Home Page

Last modified: 1/28/2000