Geminal Delocalization of σ-Electrons and Inverted Tetrahedral Configurations of the Bridgehead Carbons in Bicyclo[1.1.0]butane Frameworks

Inagaki, Satoshi; Kakefu, Takuo; Yamamoto, Tetsushi; Wasada, Hiroaki

doi:10.1021/jp9529432

Cited by 29 publications

(20 citation statements)

References 9 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, this subset includes C−C bonds that have been classified as “exotic” bonds previously, and a large number of studies have been conducted in the last decades to elucidate the detailed nature of these bonds. The members are the naked “formally” triple C−C bond in ortho ‐benzyne ( 73 ), the central single C−C bond in the highly strained bicyclo‐1,1,0‐butane ( 77 ), the strongly deformed central double bond in the strained bicyclo‐2,2,0‐hex‐1,4‐ene ( 81 ), and finally the central inverted C−C bond in 988 . The computed % ρ (%▿ 2 ρ ) are 34, 12, and 35 (72, 121, and 82) for 73 , 77 , and 81 , respectively.…”

Section: Resultsmentioning

confidence: 99%

Tracing the Fingerprint of Chemical Bonds within the Electron Densities of Hydrocarbons: A Comparative Analysis of the Optimized and the Promolecule Densities

2016

View full text Add to dashboard Cite

The equivalence of the molecular graphs emerging from the comparative analysis of the optimized and the promolecule electron densities in two hundred and twenty five unsubstituted hydrocarbons was recently demonstrated [Keyvani et al. Chem. Eur. J. 2016, 22, 5003]. Thus, the molecular graph of an optimized molecular electron density is not shaped by the formation of the C-H and C-C bonds. In the present study, to trace the fingerprint of the C-H and C-C bonds in the electron densities of the same set of hydrocarbons, the amount of electron density and its Laplacian at the (3, -1) critical points associated with these bonds are derived from both optimized and promolecule densities, and compared in a newly proposed comparative analysis. The analysis not only conforms to the qualitative picture of the electron density build up between two atoms upon formation of a bond in between, but also quantifies the resulting accumulation of the electron density at the (3, -1) critical points. The comparative analysis also reveals a unified mode of density accumulation in the case of 2318 studied C-H bonds, but various modes of density accumulation are observed in the case of 1509 studied C-C bonds and they are classified into four groups. The four emerging groups do not always conform to the traditional classification based on the bond orders. Furthermore, four C-C bonds described as exotic bonds in previous studies, for example the inverted C-C bond in 1,1,1-propellane, are naturally distinguished from the analysis.

show abstract

Section: Resultsmentioning

confidence: 99%

Tracing the Fingerprint of Chemical Bonds within the Electron Densities of Hydrocarbons: A Comparative Analysis of the Optimized and the Promolecule Densities

2016

View full text Add to dashboard Cite

show abstract

“…This reflects the unique nature of the bridgehead–bridgehead carbon–carbon bond indicating almost pure p character 55. Because of the low s character of the central carbon–carbon bond, geminal delocalization was suggested to be bonding and thereby responsible for the ring strain relaxation 56…”

Section: Resultsmentioning

confidence: 99%

Continuous‐Flow Synthesis of Adipic Acid from Cyclohexene Using Hydrogen Peroxide in High‐Temperature Explosive Regimes

2013

View full text Add to dashboard Cite

Safe only in a microreactor! The synthesis of adipic acid from cyclohexene by tungstic acid-catalyzed oxidation using hydrogen peroxide following the classical Noyori protocol can be accomplished in good yields with residence times as short as 20 min at 140 °C using a safe and scalable microreactor environment. Under these intensified conditions the use of a phase-transfer catalyst is not required.

show abstract

“…[55] Because of the low s character of the central carboncarbon bond, geminal delocalization was suggested to be bonding and thereby responsible for the ring strain relaxation. [56] In contrast to the butterfly C 2v geometry of bicyclo-A C H T U N G T R E N N U N G [1.1.0]butane, the X-ray structure of [Os 4 (CO) 15 ] (12 in Figure 1) reveals an unexpected planar skeleton ("flat butterfly") with adjacent short (2.775 ) and long (2.998 ) metal-metal bonds. This unusual arrangement is rationalized in terms of three-center, two-electron metal-metal bonds, which suggest the presence of electron delocalization [57] in addition to reduced ring strain.…”

Section: Tetrahedral [M 4 (Co) 14 ]mentioning

confidence: 99%

Aromaticity of Tri‐ and Tetranuclear Metal–Carbonyl Clusters Based on Magnetic Criteria

Corminbœuf¹,

Schleyer²,

King³

2007

Chemistry A European J

View full text Add to dashboard Cite

Recently, the sigma-aromaticity model proposed for cyclopropane by Dewar was employed to account for the stability of Group 8 trinuclear metal-carbonyl compounds [M(3)(CO)(12)] (M=Fe, Ru, Os). This paper further examines this hypothesis and provides the first quantitative evidence for the sigma-aromatic/antiaromatic nature of the [M(3)(CO)(12)]/[M(4)(CO)(16)] species based on structural and nucleus-independent chemical-shift analysis. In addition, the extent of electron delocalization in tetrahedral [M(4)(CO)(14)] and butterfly [M(4)(CO)(15)] is analyzed and compared to prototype cycloalkanes. While remarkable analogies exist between metal-carbonyls and cycloalkanes, transition metals provide additional overlap possibilities that affect both the ring strain and the magnetic properties of metal-carbonyl rings and cages.

show abstract

Geminal Delocalization of σ-Electrons and Inverted Tetrahedral Configurations of the Bridgehead Carbons in Bicyclo[1.1.0]butane Frameworks

Cited by 29 publications

References 9 publications

Tracing the Fingerprint of Chemical Bonds within the Electron Densities of Hydrocarbons: A Comparative Analysis of the Optimized and the Promolecule Densities

Tracing the Fingerprint of Chemical Bonds within the Electron Densities of Hydrocarbons: A Comparative Analysis of the Optimized and the Promolecule Densities

Continuous‐Flow Synthesis of Adipic Acid from Cyclohexene Using Hydrogen Peroxide in High‐Temperature Explosive Regimes

Aromaticity of Tri‐ and Tetranuclear Metal–Carbonyl Clusters Based on Magnetic Criteria

Contact Info

Product

Resources

About