Effect of fluorine replacement of hydrogen atoms in aromatic compounds on magnetic shielding of nuclei of heavy atoms at a distance from position of substitution

Conclusions From¹³C,¹⁵N,¹⁷O,¹⁹F,²⁹Si,³¹P,⁷³Ge,⁷⁷Se,¹¹⁹Sn, and¹²⁵Te NMR data, it follows that complete replacement of phenyl hydrogen atoms by fluorine in compounds C₆H₅X leads to a systematic increase in shielding of nuclei in the ring carbon atom bonded to the X group and in shielding of the nucleus of the -atom of X, along with deshielding of the nuclei of the - and -atoms of X. The effect evidently has a long-range character and can be described by the extended theory of Dewar and Kelemen.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 829–832, April, 1989.