Semiempirical molecular orbital study of mercury-199-proton coupling constants. I. Method and aliphatic systems

Henneike, H. Fred

doi:10.1021/ja00772a002

Cited by 55 publications

(6 citation statements)

References 3 publications

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“…Since the Fermi contact term dominates the two-bond mercury-proton coupling, a decrease in "s" character in the Hg-C bond results in a smaller J value (21) For personal use only.…”

Section: Resultsmentioning

confidence: 99%

Metal ion – biomolecule interactions. X. Synthesis, spectroscopic and magnetic resonance investigations of methylmercury(II) complexes of the sulfur modified nucleosides 6- mercaptopurine riboside and 2-amino-6-mercaptopurine riboside

Buncel¹,

Kumar²,

Norris³

1986

Can. J. Chem.

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. Can. J. Chem. 64, 442 (1986). A number of methylmercurated complexes of 6-mercaptopurine riboside and 2-amino-6-mercaptopurine riboside (6-MNucH2) containing S-bound CH3Hg(II) in neutral and cationic complexes ] and [CH3Hg(6-MNucH2)]N03), S-and N-bound CH3Hg(II) (as in [(CH3Hg)2(6-MNucH)]N03), and S-, N-, C-bound CH3Hg(ll) (as in [(CH3Hg)3(6-MNuc)]N03) have been prepared in aqueous solution at appropriate ptI and mole ratios of the constituents. The complexes were characterized by means of 'H and I3C nmr and ir spectroscopy and elemental analysis. Formation of C-bound methylmercurated species extends our previous results obtained with xanthosine, inosine, and imidazole derivatives, and substantiates our proposal that activation through electrophilic coordination at N(7) is a requirement for C(8)-H abstraction. ' J ( ' H -'~~H~) coupling constants, measured in (CD3)'S0 for a number of CH3Hg(II) complexes of N-, S-, and C-donor heterocyclic ligands, including the 6-mercaptopurine riboside of the present study, correlate well with the ' J ( '~C -'~~H~) coupling constants, according to I J = 8.460'~ -155.6. The significance of this correlation in terms of the strength of the Hg-ligand bond is considered. The results could provide insight into the apparent selectivity of binding of CH3Hg(II) by bio-ligands, as well as in the design of chemotherapeutic agents for the treatment of methylmercury poisoning.

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“…Since the Fermi contact term dominates the two-bond mercury-proton coupling, a decrease in "s" character in the Hg-C bond results in a smaller J value (21) For personal use only.…”

Section: Resultsmentioning

confidence: 99%

Metal ion – biomolecule interactions. X. Synthesis, spectroscopic and magnetic resonance investigations of methylmercury(II) complexes of the sulfur modified nucleosides 6- mercaptopurine riboside and 2-amino-6-mercaptopurine riboside

Buncel¹,

Kumar²,

Norris³

1986

Can. J. Chem.

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“…(5a), measured at various temperatures in each solvent, to the real lines of Eqn. (5). In acetone, acetonitrile and dimethyl sulphoxide, these coupling constants were determined as 85 and 574 Hz, respectively, and the variation among the solvents was within I Hz.…”

Section: Conformational Analysis Of P-methoxyalkylmercuric Chloridesmentioning

confidence: 90%

Conformational analysis of β‐methoxyalkylmercuric chlorides by NMR spectroscopy and extended hückel theory

Ibusuki¹,

Saito²

1974

Org. Magn. Reson.

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Abstract-The energy difference ( A E ) between the two types of rotamers of ,T-methoxyethylmercuric chloride has been satisfactorily determined by only assuming the ratio of vicinal t r a m and gnuche H-H coupling constants. The validity of the result was confirmed by the large temperature dependence of the vicinal Hg-H couplings in various solvents. Moreover, it has become possible to determine small values of AE in nonpolar solvents. Two AE values of Bmethoxypropylmercuric chloride in various solvents were determined on the basis of the substituent electronegativity effect on the H--H couplings and their validity was supported by the large temperature dependence of the vicinal Hg-H couplings. With regard to erythro-and fhreo-(a-methyl-B-methoxy)propylmercuric chlorides, both the H-H and Hg-H couplings were used to estimate the values of A E among the rotamers. Throughout the mercury compounds, it was ascertained that the more polar the solvent, the greater the preference for the conformation with the trans disposed HgCl and OCH, groups. Excellent agreement between the observed facts and the calculations by extended Huckel theory were shown with regard to the relative magnitude of the rotamer polarity and the conformational energy difference of these mercury compounds.

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“…Methylmercury cyanide was obtained by the anion exchange reaction between potassium cyanide and methylmercury acetate and recrystallized from 1:1 benzene/hexane as white granules: mp91-93 °C;NMR (CH2C12) 0.88 (s, 2J = 171. 4 Hz); mass spectrum m/e 243, CH3HgCN+ (31); 228, HgCN+ (12.2); 232, Hg(CH3)2+ (0.8); 217, CH3Hg+ (114); 202, Hg+ (100); 142 (0.8); 101, Hg2+ (7.2); 93 (1.3); 41, CH3CN+ (1.7); 40, CH2CN+ (3.6); 27, HCN+ (18); 26, CN+ (3.7).…”

Section: Methodsmentioning

confidence: 99%

Nuclear magnetic resonance studies on anion-exchange reactions of alkylmercury mercaptides

Bach¹,

Weibel²

1976

J. Am. Chem. Soc.

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The 13C and 3IP NMR data for stabilized and nonstabilized phosphorus-carbon ylides are compared to CNDO/2 and MINDO/3 molecular orbital calculations. Evidence of both an experimental and theoretical nature is presented that indicates that the carbon adjacent to phosphorus exists in a trigonal conformation. The molecular orbital calculations predict substantial ir interactions between the carbanion and phosphonium group. The various theoretical methods are compared to the trends in 13C and 31P chemical shifts developed for the compounds in this study. It is found that the negative charge in stabilized phosphoranes is delocalized over the framework of the molecules to a smaller extent than for analogous carbanions. The conformational preferences of ethylidene, cyclopropylidene, allylidene, and formylmethylenephosphorane are studied by theoretical techniques and the results are in agreement with available experimental data.

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Semiempirical molecular orbital study of mercury-199-proton coupling constants. I. Method and aliphatic systems

Cited by 55 publications

References 3 publications

Metal ion – biomolecule interactions. X. Synthesis, spectroscopic and magnetic resonance investigations of methylmercury(II) complexes of the sulfur modified nucleosides 6- mercaptopurine riboside and 2-amino-6-mercaptopurine riboside

Metal ion – biomolecule interactions. X. Synthesis, spectroscopic and magnetic resonance investigations of methylmercury(II) complexes of the sulfur modified nucleosides 6- mercaptopurine riboside and 2-amino-6-mercaptopurine riboside

Conformational analysis of β‐methoxyalkylmercuric chlorides by NMR spectroscopy and extended hückel theory

Nuclear magnetic resonance studies on anion-exchange reactions of alkylmercury mercaptides

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