Toward Planar Tetracoordinate Carbon in the Puckered Ladder Structures of Chelated Cyclopropenyllithium Aggregates

Sorger, Klas; Schleyer, Paul von Ragué; Fleischer, and Roland; Stalke, Dietmar

doi:10.1021/ja9603362

Cited by 44 publications

(27 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact in the amide derivative the twist angle between the LiCLi and cyclopropenyl ring plane is measured at 17.4° in one monomeric unit and 29.7° in the second, thanks to the coordination of the amide moiety to the Li centers (scheme 10). 27 Scheme 10: Attempts and successes in the synthesis of geminal dianions with planar environment at C.…”

Section: Scheme 9: Double Deprotonation Of 8hmentioning

confidence: 99%

Geminal Dianions Stabilized by Main Group Elements

2019

View full text Add to dashboard Cite

This review is dedicated to the chemistry of stable and isolable species that bear two lone pairs at the same C center, i.e. geminal dianions, stabilized by main group elements. Three cases can thus be considered: the gem dilithio derivative, for which the two substituents at C are neutral, the ylidiide derivatives, for which one substituent is neutral while the other is charged, and finally the geminal bisylides, for which the two substituents are positively charged. In this review the syntheses and electronic structures of the geminal dianions are presented, followed by the studies dedicated to their reactivity toward organic substrates and finally to their coordination chemistry and applications. Reactivity of doubleylides towards organic compounds. 4.4. Coordination chemistry of double ylides to metallic species. 4.4.1. Coordination to Group 2 Metals. 4.4.2. Coordination to Actinides: Uranium Complexes 4.4.3. Coordination to Group 4 Metals: Zirconium Complexes 4.4.4. Coordination to Group 6 Metals: Tungsten Complexes 4.4.5. Coordination to Group 7 Metals: Manganese and Rhenium Complexes 4.4.6. Coordination to Group 8 Metals: Iron Complexes 4.4.7. Coordination to Group 9 Metals: Rhodium and Iridium Complexes 4.4.8. Coordination to Group 10 Metals 4.4.9. Coordination to Group 11 (Coinage) Metals 4.4.10. Coordination to Group 12 Metals 4.5. Reactivity of double ylides towards main group elements. 4.5.1. Group 13 4.5.2. Group 14 4.5.3. Group 15 4.5.4. Group 16 4.5.5. Group 17 4.6. Carbodicarbenes 4.6.1. Synthesis 4.6.2. Reactivity 4.6.3. Coordination chemistry 4.6.4. Reactivity with main group elements 5. Conclusion 6. Acknowledgements 7. References lengths in complexes [(7)Mg(THF)] 2 and [(14)Mg(THF) 3 ] at 2.156(5)Å and 2.113(4)Å resp. are as expectedly significantly shorter than the ones measured in the dimers [(6a)Mg] 2 and [(10)Mg] 2 at 2.225(2)Å (av.) and 2.267(3)Å (av.). Electronic structureThe question of the nature of the bond between the AE metal and C was addressed. Harder et al.performed a DFT study first on models of [(6a)Ca] 2 and [(6f)Ca] where H atoms were considered in place of the real phenyl groups at P and groups (SiMe 3 and Ar resp.) at N. 49 In the case of the monomeric complex [(6f)Ca], the solvent molecules were not taken into account. Not surprising in light of the difference of electronegativity of the elements, the charge at C varied between -1.623 (monomer) and -1.847 (dimer) whereas charge at Ca varied between +1.760 (monomer) and +1.821 (dimer). The Ca-C bond was thus described as highly ionic. The calculations with the full dimeric system were carried out, and a slightly reduced charge was calculated at C (-1.778). The NPA charges were also compared to the ones in neutral 6aH 2 and the [Ca(6aH) 2 ] complex. Expectedly the charge at C goes from -1.079 to -1.409 to -1.778 (in 6aH2, [Ca(6aH) 2 ], [Ca(6a)] 2 resp.). The charge at N also increases (-1.474 to -1.580 to -1.665 resp.) upon deprotonation at C. Conversely, the charge at P varies but to a small extent (+1.747 to +1.727 to +1.7...

show abstract

Section: Scheme 9: Double Deprotonation Of 8hmentioning

confidence: 99%

Geminal Dianions Stabilized by Main Group Elements

2019

View full text Add to dashboard Cite

show abstract

“…[3,4] Therefore, to experimentally realize planar four-coordinate carbon, various strategies to impose a planar four-coordinate geometry have been pursued, and of these, organometallic derivatives have delivered the most significant advances. [5] For genuine methanes, von Schleyer showed theoretically [6] and experimentally [7] that the sequential replacement of hydrogen atoms with alkali metals results in an increase in the stabilization of planar four-coordinate methanes. Furthermore, for disubstituted methane derivatives, such as H 2 CLi 2 , the trans-planar form (IV) was found to be destabilized by about 125 kJ mol À1 relative to the cis-planar form (V).…”

mentioning

confidence: 99%

A Monomeric Dilithio Methandiide with a Distorted trans‐Planar Four‐Coordinate Carbon

Cooper¹,

Wooles²,

McMaster³

et al. 2010

Angew Chem Int Ed

View full text Add to dashboard Cite

show abstract

“…Computations by Schleyer and co‐workers in 1976 showed that a ptC can be stabilized by electropositive substitutes, [5] and this prediction was experimentally verified by others and notably by the Liddle group in 2010 [6] . Different strategies to stabilize the ptC have been envisioned theoretically, but experimentally the ptC cores in all known compounds so far are generally stabilized by metallic [3h, 4a] or organometallic ligands [4b] . In contrast to ptC, the study of planar tetracoordinate silicon (ptSi) remains limited, [7] although the ptSi formation from the stereo‐mutation of a tetrahedral configuration (ttSi) generally demands less energy input, compared with ptC [8] …”

Section: Introductionmentioning

confidence: 99%

Planar Tetracoordinate Silicon in Organic Molecules As Carbenoid‐Type Amphoteric Centers: A Computational Study

Zhang

et al. 2020

Chemistry A European J

View full text Add to dashboard Cite

Designing and synthesizing as table compound with ap lanar tetracoordinate silicon (ptSi)c enteri sachallenginggoal for chemists. Here, as eries of potentiala romatic ptSi compounds composed of four conjugated rings shared by acentrally embedded Si atom are theoretically designed and computationally verified.B oth Born-Oppenheimer molecular dynamics (BOMD) simulations and potential energy surface scannings verify the high stability and likely existence of these compounds, particularly Si-16-5555 (SiN 4 C 8 H 8)w ith 16 p electrons, under standard ambient temperature and pressure.N otably,t he Hückel aromaticity rule, which works well for single rings, is inconsistent with the high stabilityo fS i-16-5555 where the 16 pe lectrons are spreado verf our five-membered rings fused together.B onding analyses show that the strong electron donation from the peripheral1 2-membered conjugated ring with 16 p electrons to the vacant central atomic orbital Si 3p z leads to the stabilization for both the ptSi coordination and planar aromaticity. The partial occupation of Si 3p z resultsi nt he peculiar carbenoid-type behaviors for the amphoteric center. By modulating the electron density on the ring with substituent groups,w ec an regulate the nucleophilic and electrophilic properties of the central Si.

show abstract

Toward Planar Tetracoordinate Carbon in the Puckered Ladder Structures of Chelated Cyclopropenyllithium Aggregates

Cited by 44 publications

References 63 publications

Geminal Dianions Stabilized by Main Group Elements

Geminal Dianions Stabilized by Main Group Elements

A Monomeric Dilithio Methandiide with a Distorted trans‐Planar Four‐Coordinate Carbon

Planar Tetracoordinate Silicon in Organic Molecules As Carbenoid‐Type Amphoteric Centers: A Computational Study

Contact Info

Product

Resources

About