NMR Spectra of Organogermanium Compounds tuted 1‐Trichlorogermylethanes 2‐13c NMR spectra of 2‐substituted 1‐Trichlorogermylethanes

Takeuchi, Yoshito; Tomoda, Shuji; Kakimoto, Norihiro

doi:10.1002/mrc.1260230221

Cited by 3 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Takeuchi et al published a series of thirteen papers in the 1980s that focused on the 73 Ge NMR of numerous germanes and correlated their spectral data with those of the analogous silicon and tin compounds [48][49][50][60][61][62][63][64][65][66][67][68][69]. Molecular mechanics calculations were also used to further explain the experimental data.…”

Section: Isrn Spectroscopymentioning

confidence: 99%

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

Weinert

2012

ISRN Spectroscopy

View full text Add to dashboard Cite

The field of G73e NMR spectroscopy is reviewed in this paper, from early developments in the 1950s to present day research. Specific attention is paid to recent investigations, including the observation of fluxional behavior of hypervalent germanium species having five or six attached ligands by 73Ge NMR spectroscopy, the spectral properties of linear and branched oligogermanes that contain single germanium-germanium bonds, and the relatively new field of solid-state germanium-73 NMR.

show abstract

Section: Isrn Spectroscopymentioning

confidence: 99%

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

Weinert

2012

ISRN Spectroscopy

View full text Add to dashboard Cite

show abstract

“…(including 73Ge n.m.r.) spectroscopy ' 9 ' y 6 and molecular mechanics calculations. Germacyclohexane (1G) is a key compound in organogermanium chemistry and its role is exactly the same as that of Crucial features of the chemistry of (IC) are associated with the stereochemistry of the ring, e.g., ring reversal and its barrier, 1,3diaxial interactions or relative stabilities of equatorial and axial conformers of monosubstituted species.…”

mentioning

confidence: 99%

Nuclear magnetic resonance spectra of organogermanium compounds. Part 4. Nuclear magnetic resonance spectra and molecular mechanics calculations of germacyclohexane, methylgermacyclohexanes, and dimethylgermacyclohexanes

Takeuchi¹,

Shimoda²,

Tanaka³

et al. 1988

J. Chem. Soc., Perkin Trans. 2

Self Cite

View full text Add to dashboard Cite

Molecular mechanics calculations in germacyclohexane and methyl-substituted germacyclohexanes reveals that (i) the ring is flattened around the germanium and that (ii) a methyl group on germanium has a slight preference for the axial conformation rather than the equatorial, which is in line with the results for the corresponding silacyclohexanes. The 13C and 73Ge chemical shifts of these germacyclohexanes are consistent with the calculations. Thus, both 13C and 73Ge data indicate that I -m e t h y l -Igermacyclohexane is a ca. 60: 40 mixture of axial and equatorial isomers. Attempts to observe directly the two conformers b y freezing the inversion on the n.m.r. time scale failed because of the very lower barrier t o inversion.Though the chemistry of organogermanium compounds with tetravalent germanium has been described,24 the structural details of these compounds are much less investigated. We have initiated a study to cast light upon this unexplored field chiefly by n.m.r. (including 73Ge n.m.r.) spectroscopy ' 9 ' y 6 and molecular mechanics calculations. Germacyclohexane (1G) is a key compound in organogermanium chemistry and its role is exactly the same as that of R pJ\R 1 1 4 6 M e X = C c y c l o h e x a n e s ( C ) X = Si s i l a c y c l o h e x a n e s ( S ) X = Ge germacyclohexanes (GI cyclohexane (1C) in the chemistry of carbocyclic compounds.Crucial features of the chemistry of (IC) are associated with the stereochemistry of the ring, e.g., ring reversal and its barrier, 1,3-diaxial interactions or relative stabilities of equatorial and axial conformers of monosubstituted species. Although these are fully documented for (lC),' the equivalent has not been reported for (W.The situation is slightly better for silacyclohexane (1s) and derivatives. Thus, Ouellette 13 reported molecular mechanics calculations of (lS), 1-methyl-(2S), 4-methyl-(4S), and 1,ldimethyl-1-silacyclohexane (5S), and found that the axial isomer of (2s) is slightly more favourable than the equatorial (by 0.20 kcal mol-l), while Jensen and Bushweller attempted to determine the barrier height of ring reversal of (5S), which was found in the range of 5.25-5.75 kcal mol-'.Carleer and Anteunis l o reported that the conformational energy, i.e., the free energy difference between the axial and equatorial conformers, as determined from the spin-spin coupling constant for the methyl group of (2S), is 0.34 kcal mol-' in favour of the axial position, in agreement with the prediction of molecular mechanics calculations.*The purpose of this study is to obtain stereochemical information on the hitherto unexplored (1G) and its methyl derivatives by means of n.m.r. spectroscopy and molecular mechanics calculations. Combined with the corresponding information for (1s) and (lC), it is expected to open a new field of chemistry of the heteracyclohexanes of Group IVB elements.For this purpose (IG), 1-, 3-, and 4-methyl-1-germacyclohexane (2G)--(4G), and 1,l-, 1,3-, and 1,4-dimethyl-l-germacyclohexane (5G)-(7G)were prepared, and their I3C and 73Ge n.m.r. s...

show abstract

⁷³Ge and ¹³C NMR spectra of some methylgermacyclohexanes

Takeuchi¹,

Shimoda²,

Tomoda³

1985

Magnetic Reson in Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

NMR Spectra of Organogermanium Compounds tuted 1‐Trichlorogermylethanes 2‐13c NMR spectra of 2‐substituted 1‐Trichlorogermylethanes

Abstract: 13C NMR spectra of a variety of 2‐substituted 1‐trichlorogerrnylethanes of the type Cl3GeC1(R1R3)C2H(R2)X, where R1, R2 and R3 are H, methyl or phenyl and X is Me, CH2Cl, CO2H, CO2Me, CO2Et, COCl, CONH2, CHO, COMe and CN, are reported.

Cited by 3 publications

References 7 publications

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

Nuclear magnetic resonance spectra of organogermanium compounds. Part 4. Nuclear magnetic resonance spectra and molecular mechanics calculations of germacyclohexane, methylgermacyclohexanes, and dimethylgermacyclohexanes

⁷³Ge and ¹³C NMR spectra of some methylgermacyclohexanes

Contact Info

Product

Resources

About

NMR Spectra of Organogermanium Compounds tuted 1‐Trichlorogermylethanes 2‐13c NMR spectra of 2‐substituted 1‐Trichlorogermylethanes

Abstract: 13C NMR spectra of a variety of 2‐substituted 1‐trichlorogerrnylethanes of the type Cl3GeC1(R1R3)C2H(R2)X, where R1, R2 and R3 are H, methyl or phenyl and X is Me, CH2Cl, CO2H, CO2Me, CO2Et, COCl, CONH2, CHO, COMe and CN, are reported.

Cited by 3 publications

References 7 publications

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

G73e Nuclear Magnetic Resonance Spectroscopy of Germanium Compounds

Nuclear magnetic resonance spectra of organogermanium compounds. Part 4. Nuclear magnetic resonance spectra and molecular mechanics calculations of germacyclohexane, methylgermacyclohexanes, and dimethylgermacyclohexanes

73Ge and 13C NMR spectra of some methylgermacyclohexanes

Contact Info

Product

Resources

About

⁷³Ge and ¹³C NMR spectra of some methylgermacyclohexanes