199Hg chemical shifts of organomercury compounds by fourier transform NMR

Borzo, Marie; Maciel, Gary E.

doi:10.1016/0022-2364(75)90041-4

Cited by 14 publications

(4 citation statements)

References 9 publications

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“…This trend is somewhat counterintuitive, as electron-withdrawing groups might be expected to deshield the nuclei and cause a downfield shift. However, similar findings were reported for a series of para -substituted mercury diaryls (4-R-C 6 H 4 ) 2 Hg (R = OMe, Me, H, F, Cl, CF 3 ), 60 − 62 suggesting that these chemical shifts depend on more than simple σ donor effects. One hypothesis suggests that the bonding in organomercury compounds mainly involves the valence 6s orbital 63 , 64 since the 6p orbital is too high in energy to overlap.…”

Section: Resultssupporting

confidence: 82%

Structural and Electronic Studies of Substituted m-Terphenyl Group 12 Complexes

et al. 2022

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The effects of para -substitution on the structural and electronic properties of four series of two-coordinate m -terphenyl Group 12 complexes (R-Ar # ) 2 M (M = Zn, Cd, Hg; R = t -Bu 1 – 3 , SiMe 3 4 – 6 , Cl 7 – 9 , CF 3 10 – 12 , where R-Ar # = 2,6-{2,6-Xyl} 2 -4-R-C 6 H 2 and 2,6-Xyl = 2,6-Me 2 C 6 H 3 ) have been investigated. X-ray crystallography shows little structural variation across the series, with no significant change in the C–M–C bond distances and angles. However, considerable electronic differences are revealed by heteronuclear nuclear magnetic resonance (NMR) spectroscopy; a linear correlation is observed between the 113 Cd, 199 Hg, and 1 H (2,6-Xyl methyl protons) NMR chemical shifts of the para -substituted complexes and the Hammett constants for the R-substituents. Specifically, an upfield shift in the NMR signal is observed with increasingly electron-withdrawing R-substituents. Density functional theory (DFT) calculations are employed to attempt to rationalize these trends.

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Section: Resultssupporting

confidence: 82%

Structural and Electronic Studies of Substituted m-Terphenyl Group 12 Complexes

et al. 2022

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“…The 199 Hg NMR spectra were obtained on 20 mM samples. Resonances were referenced using the ratio (0.179 108 97) of the TMS resonance frequency [determined from the 1 H NMR of the CD 3 CN solvent peak (1.94 ppm)] to the 0 ppm resonance frequency of 199 Hg [determined using 0.5 M phenyl mercuric acetate in DMSO (−1439.5 ppm vs Hg(CH 3 ) 2 , )] . All data were obtained at −20 °C unless otherwise indicated.…”

Section: Methodsmentioning

confidence: 99%

Solid-State and Solution-State Coordination Chemistry of the Zinc Triad with the Mixed N,S Donor Ligand Bis(2-methylpyridyl) Sulfide

2004

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The binding of group 12 metal ions to bis(2-methylpyridyl) sulfide (1) was investigated by X-ray crystallography and NMR. Seven structures of the chloride and perchlorate salts of Hg(II), Cd(II), and Zn(II) with 1 are reported. Hg(1)(2)(ClO(4))(2), Cd(1)(2)(ClO(4))(2), and Zn(1)(2)(ClO(4))(2).CH(3)CN form mononuclear, six-coordinate species in the solid state with 1 binding in a tridentate coordination mode. Hg(1)(2)(ClO(4))(2) has a distorted trigonal prismatic coordination geometry while Cd(1)(2)(ClO(4))(2) and Zn(1)(2)(ClO(4))(2).CH(3)CN have distorted octahedral geometries. With chloride anions, the 1:1 metal to ligand complexes Hg(1)Cl(2), [Cd(1)Cl(2)](2), and Zn(1)Cl(2) are formed. A bidentate binding mode that lacks thioether coordination is observed for 1 in the four-coordinate, distorted tetrahedral complexes Zn(1)Cl(2) and Hg(1)Cl(2). [Cd(1)Cl(2)](2) is dimeric with a distorted octahedral coordination geometry and a tridentate 1. Hg(1)Cl(2) is comprised of pairs of loosely associated monomers and Zn(1)Cl(2) is monomeric. In addition, Hg(2)(1)Cl(4) is formed with alternating chloride and thioether bridges. The distorted square pyramidal Hg(II) centers result in a supramolecular zigzagging chain in the solid state. The solution (1)H NMR spectra of [Hg(1)(2)](2+) and [Hg(1)(NCCH(3))(x)()](2+) reveal (3)(-)(5)J((199)Hg(1)H) due to slow ligand exchange found in these thioether complexes. Implications for use of Hg(II) as a metallobioprobe are discussed.

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“…Proton chemical shifts were measured relative to internal solvent but are reported relative to tetramethylsilane. Chemical shifts of 199 Hg were measured relative to an external reference of 0.1 M phenylmercuric acetate in acetonitrile-d 3 (Ϫ1439.5 ppm) 19 but are reported relative to dimethylmercury (0 ppm).…”

Section: Nmr Measurementsmentioning

confidence: 99%

Investigation of the mercury(ii) coordination chemistry of tris[(1-methylimidazol-2-yl)methyl]amine by X-ray crystallography and NMR

et al. 2003

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The coordination chemistry of Hg() with tris[(1-methylimidazol-2-yl)methyl]amine (TMIMA) was investigated. The structures of [Hg(TMIMA) 2 ](ClO 4 ) 2 (1), [Hg(TMIMA)(NCCH 3 )](ClO 4 ) 2 (2) and [Hg(TMIMA)Cl] 2 (HgCl 4 ) (3) were characterized by X-ray crystallography. Complex 1 has six strong Hg-N imidazoyl bonds ranging from 2.257(5) to 2.631(6) Å. Ligand geometry suggests the Hg-N (NR 3 ) distances of 2.959(6) Å in 1 reflects weak bonding interactions. This complex has a 199 Hg chemical shift of Ϫ1496 ppm, significantly upfield from nitrogen coordination complexes with lower coordination numbers. The five-coordinate complex 2 has Hg-N (NR 3 ) , Hg-N imidazoyl and Hg-N acetonitrile bond lengths of 2.642(8), 2.198(5) and 2.264(11) Å, respectively. Complex 3 is also five coordinate, with Hg-N (NR 3 ) , Hg-Cl and average Hg-N imidazoyl distances in the cations of 2.758(7), 2.424(2) and 2.29(4) Å, respectively. Conditions for slow exchange on the J(HgH) coupling time-scale were found for both 1 : 1 metal-to-ligand complexes in acetonitrile-d 3 . Observed heteronuclear coupling constants were similar to those associated with Hg() substituted proteins with histidine-metal bonds. Solution and solid-state comparisons to the Hg() coordination chemistry of tetradenate pyridyl ligands are made. Relevance to development of 199 Hg NMR as a metallobioprobe is discussed.

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199Hg chemical shifts of organomercury compounds by fourier transform NMR

Cited by 14 publications

References 9 publications

Structural and Electronic Studies of Substituted m-Terphenyl Group 12 Complexes

Structural and Electronic Studies of Substituted m-Terphenyl Group 12 Complexes

Solid-State and Solution-State Coordination Chemistry of the Zinc Triad with the Mixed N,S Donor Ligand Bis(2-methylpyridyl) Sulfide

Investigation of the mercury(ii) coordination chemistry of tris[(1-methylimidazol-2-yl)methyl]amine by X-ray crystallography and NMR

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