Carbon-13 nuclear magnetic resonance studies of organotellurium compounds. II. Chemical shift trends

Abstract

On rapporte les deplacements chimiques en rmn du 13C de quelques composes aromatiques et aliphatiques du tellure. Pour un groupe organique donne, le deplacement de I'atome C1 varie dans l'ordre RTeCI, RTeCI, 5 R2TeC12 > R2Te R2Te2 que I'on peut prevoir sur la base de considerations d'electronegativite. L'atome C2 subit une tendance inverse alors que les atomes C3 et C4 ne subissent que de faibles changements. Les deplacements chimiques des composes aromatiques du tellure substitues en para ne presentent pas de contributions d'additivite de la part de ces substituants.[Traduit par le journal] Introduction ( Fig. 1) for these compounds show a general linear

Carbon-13 nuclear magnetic resonance study of phenyl derivatives of B, Si, Sn, P, and Te fluorides

“…"C nuclear magnetic resonance data for some phenyl derivatives of B, C, Si, Sn, P, and Te fluorides" A similar result might be expected with donor solvents, although a dynamic equilibrium may give only a weighted average value for SC1, and this effect has been observed by other workers (12) who found a downfield shift in SCl of only 3.7 pprn as acetonitrile was added to PhSnCl,. Any competition between donor solvents and halide ions could mask differences between SC1 of various species in solution, as illustrated by the very similar chemical shifts in p-PhC6H4TeC13 (SC 1 145.5 ppm) and p-PhOC6H,TeC1,-(SC1 146.7 ppm) if both are dissolved in DMSO solution (13).…”

Structure of (p-bromophenyl)dichloro(phenyl)tellurium(IV), (C6H5)(C6H4Br)TeCl2

“…Experimental. Preparation as described by Chadha & Miller (1982) followed by crystallization by slow evaporation of methylene chloride solution, density measured by flotation in CC14/CH3I, 0.46 x 0.38 x 0.29 mm, Syntex P21 diffractometer, highly oriented graphite monochromator, data collected and processed as described earlier (Khan, Steevensz, Tuck, Noltes & Corfield, 1980); intensities of three monitor reflections did not change significantly during data collection; space group PI used, later assumed correct because of successful refinement; 5186 reflections (20max= 50 °, h + k +/), 3428 [I > 3o(1)] unique, Lorentz, polarization, absorption (minimum and maximum 3.73…”

Structural trends in TeI2RR′: Crystal structures and NMR spectra of TeI2(CH2SiMe3)2, TeI2Th(CH2SiMe3), TeI2Ph(CH2SiMe3), and TeI2Th2 (Th = 2‐Thienyl, C4H3S)

“…8, together with those of the corresponding tellanes. The 125 Te chemical shifts of TeMe 2 , TeThMe {218 ppm 33}, TePhMe {329 ppm 34}, TePh 2 {688 ppm 21}, TeI 2 Me 2 {675 ppm 35}, TeI 2 PhMe {698 ppm 36}, and TeI 2 Ph 2 {839 ppm 7} are included for comparison. The electronegativities of the organic groups are estimated based on the approach by Xie et al 37 and that of iodine is taken from the Pauling electronegativity scale 24.…”