Understanding 125Te NMR chemical shifts in disymmetric organo-telluride compounds from natural chemical shift analysis

摘要: Organotellurium compounds of general formula X–Te–R display a broad range chemical shifts that are very sensitive to the X and R substituents. In order link 125Te shift series perfluoroalkyl aryl tellurides their electronic structure, shielding tensors nuclei were calculated by density functional theory (DFT) further analyzed decomposition into contributions natural localized molecular orbitals (NLMOs). The analysis indicated variation in molecules 1–13 is mainly due magnetic coupling tellurium p-character lone pair with antibonding perpendicular it {σ*(Te–X) σ*(Te–C(Ar))} upon action an external field. strength affected properties X-substituents, polarization presence secondary interactions perturbing energy these orbitals. lower more polarized towards are, stronger deshielded nucleus.