Calculation of NMR-Shifts

Why here to calculate NMR-values? Sometimes it is easier to type the frequencies only one time and the rest is automatically calculated. Remember, how often have you typed the frequencies into your calculator, for the coupling constant and the shift value? The goal is to type them only one time, all values are calculated and the output is in the correct style, what means correct number of digits after separation mark, the correct separation mark (comma, point) and so on....

Long text, short picture:

Picture 3: Calculating with DUNM99

First you have to choose the frequence (possible and corresponding values in table 2) and wether the values are typed in Hertz or ppm. These values are recognized for the next calculation. Then you choose the correct multiplicity. According to this selection there appear maximum four text boxes, in which you have to type the values. Field 1 contains the signal with the most downfield signal.

If you type comma, it's automatically converted into point, therefore the calculation works correctly. But for the value in the start-dialogue the correct number-format is used.

For singlets (only the author knows what to calculate here ;-)) and dubletts only the chemical shift and coupling constants are shown in the info-box.

For tripletts the info-box contains the calculated average chemical shift and the value of the middle line, as well as both the coupling constants and the average value.

For multipletts type the area of the signals, a calculation is not implemented, because of no idea what to calculate...

AB-systems are calculated with literature [1]. For spectra of higher order, it is only necessary to indicate both frequencies of the lines, that determine the sum of the coupling constants. This interval is used for the coupling constant.

In addition to the values, also the multiplicity is used in the start dialogue.

If someone has additional comments, contact me, but more than four frequencies for input are bad for the design of the dialogue...

The accuracy of the calculations depends on the input of frequencies or ppm. Note: coupling constants and chemical shifts are calculated over the frequencies, so better type frequencies, the program doesn't need to convert ppm's to Hertz.

^[1]    H. GÜNTHER, NMR-Spektroskopie, 2. Auflage, Georg Thieme Verlag, Stuttgart, 1983.