Mr. Samandram,

You need new standard?

@Bojidarka B. Ivanova ..mem you mean standard means Tms to check the shift, i just want to know why it is shifting higher,

I have some new derivatives of compounds which I have synthesis, in this derivative such as furan, followed by Ph, and P-MeO substituents appears higher chemical shift in proton NMR (in a particular C4-H singlet peak which i have consider) as compare to PNO2, P-Cl,3-Cl,3-Br,4-Br substituents, as I have studied so far substituents which have electron withdrawing group has higher chemical shift but instead of this furan substituents proton peak shift higher, is it furan are considered to be EWG but what about PH, P-MeO which is EDG? any idea Yahia Z Hamada

Sir, in general aromatic systems are electron sinks, the magnetic anisotropic effects due to aromatic pi electron currents alone can play arole in the position of the NMR signal. there may be solvent effects also