Pulsed fourier transform NMR of substituted aryltrimethyltin derivatives : IV. Proton and carbon-13 NMR data for ortho-, 2,6-, and poly-substituted aryltrimethyltins

摘要: Abstract Proton and carbon-13 NMR data recorded in the Fourier transform mode are reported for ten ortho -substituted, six 2,6-disubstituted, miscellaneous polysubstituted aryltrimethyltin compounds. Although ¦ 1 J ( 13 C  H)¦ 2 119 SnC coupling constants rather insensitive to substituent variation, tin methyl proton chemical shifts reflect increasing inductive effects as methyl-, chloro-, fluoro-, trifluoromethyl-groups brought into juxtaposition with trimethyltin moiety. Resonances natural-abundance spectra derivatives assigned on basis of additivity relationships, undecoupled spectra, relative magnitudes Sn C)¦ 19 F)¦ constants. Mutually deshielding γ-, δ-, ϵ-effects carbons rationalized terms steric crowding between group neighboring substituents. Deshieldings ring formally para - conjugating substituents discussed inhibition resonance model. Previous conclusions concerning lack significant higher coordination at aryltin bearing lone pair electrons corroborated this work.