Delta Software For Nmr Spectra

Posted : admin | On 16-09-2021

Chemical Shifts

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The applied frequency increases from left to right, thus the left side of the plot is the low field, downfield or deshielded side and the right side of the plot is the high field, upfield or shielded side (see the figure below). The concept of shielding will be explained shortly.

SpectralNmr

The position on the plot at which the nuclei absorbs is called the chemical shift. Since this has an arbitrary value a standard reference point must be used. The two most common standards are TMS (tetramethylsilane, (Si(CH3)4) which has been assigned a chemical shift of zero, and CDCl3 (deuterochloroform) which has a chemical shift of 7.26 for 1H NMR and 77 for 13C NMR.

11 Dearborn Road, Peabody, MA 01960. Please direct questions or comments about Delta or JEOL NMR spectrometers to the discussion boards. Integration of 1H NMR resonances The area under an NMR resonance is proportional to the number of nuclei that give rise to that resonance. 2 6 integral d = 3.6 d = 1.2 The relative area under the resonances at d= 3.6 and 1.2 is 1:3 The integral is superimposed over the spectrum as a “stair-step” line.

Delta software for nmr spectral

The scale is commonly expressed as parts per million (ppm) which is independent of the spectrometer frequency. The scale is the delta (δ) scale.

Delta Software For Nmr Spectra Data

The range at which most NMR absorptions occur is quite narrow. Almost all 1H absorptions occur downfield within 10 ppm of TMS. For 13C NMR almost all absorptions occurs within 220 ppm downfield of the C atom in TMS.

Simulating NMR Spectra with WINDNMR-Pro

Delta Software For Nmr Spectra Lab

Delta Software For Nmr Spectra
WINDNMR-Pro (DNMR71.EXE) is a Windows program (Author) for simulating high resolution NMR spectra. It has two main goals:
  • To serve a pedagogic function in teaching and learning NMR spectroscopy,
  • To perform simulations of research NMR spectra:
    • Measurement of rate constants by dynamic NMR line shape simulations
    • Analysis of complex multiplets
    • Line shape integration of overlapping peaks
The 16-bit version of WINDNMR was published by the Journal of Chemical Education - Software. The program will run on all versions of Windows (95, 98, NT, ME, 2000, XP).

WinDNMR will simulate the following NMR patterns:

  • AB, AB2, ABX (screenshot) , ABX3, AA'BB', AA'XX' patterns
  • 3-Spin to 8-Spin coupled spin systems
  • First order multiplets of a nucleus coupled to others (e.g., the 'A' part of A M3X4 or A MXY5 patterns).
  • Up to 15 singlets, or 10 multiplets (s, d, t, q, etc.).
WINDNMR will also simulate full line shape calculations of Dynamic NMR (DNMR) spectra:
  • 2 - 7 exchanging singlets (uncoupled)
  • 2 pairs of 2-spin system
  • 2-spin coupled (AB --> A2)
  • ABX --> A2X, AB part or X part
  • ABX2 --> A2X2, AB part
  • ABX3 --> A2X3, AB part (e.g.: diastereotopic ethyl group)
  • AA'XX' --> A2X2
  • Exchange of two first order multiplets coupled to 4 other nuclei (dddd, dq, dt, etc)
  • Other custom exchanging patterns

Any of the spectral parameters (chemical shifts, couplings, linewidth,vertical and horizontal expansion, etc) can be easily modified in a variety of ways: by typing in a number; by adding or subtracting increments; or by smoothly moving the number up or down with a spin bar. Spectra are automatically recalculated for a 'movie' effect.

'Simulation groups' of up to 15 simulations can be saved and restored for efficient lecture presentation, or for documenting and manipulating a variable temperature DNMR simulation. Simulation data can be copied to and from a spreadsheet program like Excel, allowing sophisticated manipulation of simulation parameters (i.e., creating temperature dependent chemical shifts, nuclei populations or rate constants).

Simulated spectra can be displayed as Lorenzian lines or in stick form (however stick spectra cannot be printed).

Spectra

Spectra produced with the NUTS spectrum workup program, a TECMAG console, or PCNMR for Windows (J. Chem. Ed.: Software, Special Issue 7, 1994) can be loaded, displayed, and printed. The spectra must have been Fourier transformed by NUTS, PCNMR for Windows or the TECMAG software (WinDNMR cannot work with FID's). The program MestrC can load spectra in a number of formats, and save them as NUTS data files.

Line Shape Fitting

Any of the simulations can be performed while a spectrum is displayed on the screen for accurate estimation of NMR parameters or DNMR rate constants.

Difference spectra (Spectrum - Simulation) can be displayed (Screen shot). This is useful for accurate Dynamic NMR line shape fitting. For this example the simulations were done with WINDNMR, the stacked plot graphic was created with WinPLT, and the research was published as Amine-Chelated Aryllithium Reagents - Structure and Dynamics, Reich, Goldenberg, Gudmundsson, Sanders, Kulicke, Simon, Guzei J. Am. Chem. Soc.2001, 123, 8067-8079. PDF

Output

Spectra, simulations and/or difference spectra can be printed on any standard Windows output device. The user can control what appears in the printout.

Spectra, simulation, and/or difference spectra can be copied to the Clipboard as a Windows Metafile (WMF) or Windows bitmap (BMP) for transfer to other programs. The data that appears in the Windows Metafile can be defined by the user in the Print Setup panel. Spectra can also be exported as WMF, EMF, GIF, BMP or EPS files.

Spectra and simulations can be copied to the chemical drawing program PLT Version 7.1 for further processing, labelling with chemical structures and text, producing stacked plots, etc. (AA'BB', DNMR, ABX).

Downloading and installing WINDNMR-Pro on Windows-7 and Windows 10

With Windows 7 Microsoft has made changes that no longer allow the standard Windows installation programs to function, Until this problem is resolved, you can install WINDNMR manually as follows (this, of course, will also work for earlier versions of Windows if you prefer a hands-on installation):
  • Download this zip file: DNMR71-manual-install-2016.zip
  • Create a folder (WinDNMR) on your system and extract the contents of the zip file to this folder. The program might run at this point, but there are some settings that may need to be changed:
  • Open the WinDNMR folder, right-click on the DNMR71.exe file and open the Properties dialog of the executable. Set the 'Run this program in compatibility mode for:' setting to 'Windows XP (Service Pack 3).' It might also be a good idea to set the 'Privilege level' to 'Run this program as administrator'
  • Double click on DNMR71.exe to run the program.
  • To uninstall WinDNMR simply delete the WinDNMR folder.
  • The files Spin32.ocx, COMDLG32.OCX, Grid32.ocx and Threed32.ocx might already be present in your WindowsSysWOW64 or WindowsSystem32 folder. If they are not there, it might be prudent to move them to the WindowsSysWOW64 folder. If they are there, they can be deleted from your WinDNMR folder.
  • This version of WinDNMR does not need to be registered.
In another mean-spirited move Microsoft has decided that it will no longer support the WinHelp files used by WinDNMR. You can install the needed support files by following the directions in this link.

If you have trouble with this, a user of WINDNMR kindly converted the WINHELP files to HTML-HELP. They are primitive but functional, and can be found here: Windows Help Files for WinDNMR

WINDNMR-Pro is Free Shareware.
Hans J. Reich Research Home Page · Bordwell pKa Table · Info for Chemists · WINPLT - Chemical Drawing

Delta Software For Nmr Spectra Software

Delta software for nmr spectra lab

Delta Software For Nmr Spectral

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