Theoretical Aspects of Compounds Containing Si, Ge, Sn and Pb

Karni, Miriam; Apeloig, Yitzhak; Kapp, Jürgen; Schleyer, Paul von Ragué

doi:10.1002/0470857269.ch1

Cited by 76 publications

(46 citation statements)

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“…The atomic properties of silicon differ significantly from those of carbon, leading to distinct changes in the chemistry of these elements, as exemplified by multiple bonded systems . An illustrative example concerns the chemistry of μ 2 -tetrelido complexes of the general formula L n MEM′L n ′ (E = C–Pb; M, M′ = transition metal, L n , L n ′ = ligand sphere) in which a single tetrel atom is bridging two metal centers.…”

Section: Introductionmentioning

confidence: 99%

Linearly Two-Coordinated Silicon: Transition Metal Complexes with the Functional Groups M≡Si—M and M═Si═M

et al. 2018

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A detailed experimental and theoretical analysis is presented of unprecedented molybdenum complexes featuring a linearly coordinated, multiply bonded silicon atom. Reaction of SiBr(SIdipp) (SIdipp = C[N(CH-2,6- iPr)CH]) with Na[Tp'Mo(CO)(PMe)] (Na-1) in the ratio 1:2 afforded the reddish-brown metallasilylidyne complex [Tp'(CO)Mo≡Si-Mo(CO)(PMe)Tp'] (Tp' = κ- N, N', N″-hydridotris(3,5-dimethylpyrazolyl)borate) (2), in which an almost linearly coordinated silicon atom (∠(Mo1-Si-Mo2) = 162.93(7)°) is bridging the 15VE metal fragment Tp'Mo(CO) with the 17VE metal fragment Tp'Mo(CO)(PMe) via a short Mo1-Si bond (2.287(2) Å) and a considerably longer Mo2-Si bond (2.438(2) Å), respectively. The reddish-orange silylidyne complex [Tp'(CO)Mo≡Si-Tbb] (3) was also prepared from Na-1 and the 1,2-dibromodisilene ( E)-Tbb(Br)Si═Si(Br)Tbb (Tbb = CH-2,6-[CH(SiMe)]-4- tBu) and contains as 2 a short Mo-Si bond (2.2614(9) Å) to an almost linearly coordinated Si atom (∠(Mo-Si-C) = 160.8(1)°). Cyclic voltammetric studies of 2 in diglyme revealed an irreversible reduction of 2 at -1.907 V vs the [Fe(η-CMe)] redox couple. Two-electron reduction of 2 with potassium graphite yielded selectively the 1,3-dimetalla-2-silaallene dianion [Tp'(CO)Mo═Si═Mo(CO)Tp'] (4), which was isolated as the bright yellow dipotassium salt [K(diglyme)]-4. Single crystal X-ray diffraction analysis revealed a centrosymmetric structure of 4. The Mo-Si bond length of 4 (2.3494(2) Å) compares well with those of Mo-Si double bonds and lies in-between the Mo1-Si triple bond and Mo2-Si single bond length of 2. Compounds 2, 3 and [K(diglyme)]-4 were characterized by elemental analyses, IR and multinuclear NMR spectroscopy. Comparative ELF (electron localization function), NBO (natural bond orbital) and NRT (natural resonance theory) analyses of 2, 3 and 4 shed light into the electronic structures of these compounds.

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Section: Introductionmentioning

confidence: 99%

Linearly Two-Coordinated Silicon: Transition Metal Complexes with the Functional Groups M≡Si—M and M═Si═M

et al. 2018

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“…[1][2][3] Also, theoretical aspect of silicon compounds have been already summarized. [4] Dilithioplumbole, a lead-containing five-membered ring, was reported in 2010. [5] Dilithioplumbole is an analog of dilithiocyclopentadiene CH 4 CLi 2 ; a carbon atom is replaced with a lead atom, and therefore, its molecular framework is a planar cyclic form of C 4 H 4 Pb.…”

Section: Introductionmentioning

confidence: 99%

“…[4] Dilithioplumbole, a lead-containing five-membered ring, was reported in 2010. [5] Dilithioplumbole is an analog of dilithiocyclopentadiene CH 4 CLi 2 ; a carbon atom is replaced with a lead atom, and therefore, its molecular framework is a planar cyclic form of C 4 H 4 Pb. Two lithium atoms are solvated in solution and in the crystalline state.…”

Section: Introductionmentioning

confidence: 99%

Quantum‐chemical analyses of aromaticity, UV spectra, and NMR chemical shifts in plumbacyclopentadienylidenes stabilized by Lewis bases

et al. 2014

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We carried out a series of zeroth-order regular approximation (ZORA)-density functional theory (DFT) and ZORA-time-dependent (TD)-DFT calculations for molecular geometries, NMR chemical shifts, nucleus-independent chemical shifts (NICS), and electronic transition energies of plumbacyclopentadienylidenes stabilized by several Lewis bases, (Ph)2 ((t) BuMe2 Si)2 C4 PbL1 L2 (L1, L2 = tetrahydrofuran, Pyridine, N-heterocyclic carbene), and their model molecules. We mainly discussed the Lewis-base effect on the aromaticity of these complexes. The NICS was used to examine the aromaticity. The NICS values showed that the aromaticity of these complexes increases when the donation from the Lewis bases to Pb becomes large. This trend seems to be reasonable when the 4n-Huckel rule is applied to the fractional π-electron number. The calculated (13)C- and (207)Pb-NMR chemical shifts and the calculated UV transition energies reasonably reproduced the experimental trends. We found a specific relationship between the (13)C-NMR chemical shifts and the transition energies. As we expected, the relativistic effect was essential to reproduce a trend not only in the (207)Pb-NMR chemical shifts and J[Pb-C] but also in the (13)C-NMR chemical shifts of carbons adjacent to the lead atom.

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“…The 14th-group-element-containing nucleophiles ,, usually exhibit many favorable qualities, such as air and moisture-stability, shelf-stability, and commercializability. Interestingly, germanium(Ge), as a member of the 14th group that sits between Si and Sn in the periodic table, draws much less attention. , It is presumed that the filling of the fourth-period d electrons into Ge leads to higher electronegativity than both Si and Sn, which makes Ge-containing nucleophiles suffer from low reactivity. However, some particular properties of Ge does give it some benefits.…”

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confidence: 99%

Structure-Modified Germatranes for Pd-Catalyzed Biaryl Synthesis

et al. 2018

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Germanium, a member of 14th group that falls between Si and Sn, has remained considerably ignored as a nucleophile for a long time. Compared with other forms of Ge-containing nucleophiles, germatranes are structure-defined, easily accessible, and stabilized nucleophilic fragments, but they fail to meet the need of high reactivity and facile introducing to organics. Herein, we report a modified structure of germatranes, whose cross-coupling reactivity is greatly improved. The structure can be easily constructed from inexpensive industrial GeO2, and corresponding Ge -Cl and Ge -H can also be obtained after facile transformations. Moreover, Ar- Ge can be effectively synthesized either from Grignard reagents or Pd-catalyzed germylation of aryl halides.

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Theoretical Aspects of Compounds Containing Si, Ge, Sn and Pb

Cited by 76 publications

References 0 publications

Linearly Two-Coordinated Silicon: Transition Metal Complexes with the Functional Groups M≡Si—M and M═Si═M

Linearly Two-Coordinated Silicon: Transition Metal Complexes with the Functional Groups M≡Si—M and M═Si═M

Quantum‐chemical analyses of aromaticity, UV spectra, and NMR chemical shifts in plumbacyclopentadienylidenes stabilized by Lewis bases

Structure-Modified Germatranes for Pd-Catalyzed Biaryl Synthesis

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