Tetraaryl-methane analogues in group 14-4. Ph4−nM(p-Tol)n (n = 0–4, M = Si, Ge, Sn, Pb). Synthesis, structural and spectroscopic data, and semi empirical calculations: Mutual interaction of tetrahedral σ-orbitals (symmetry and electronegativity) and delocalized σ-lumos (π-Lewis acidity)

Charissé, Michael; Mathiasch, B.; Dräger, Martin; Russo, Umberto

doi:10.1016/0277-5387(95)00069-5

Cited by 12 publications

(5 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Halogen containing groups retain the same order as found for the halogens themselves with XF 3 always being the most electronegative group, followed by XCl 3 . These results correlate with the earlier suggestions in NMR studies of compounds with a MR 4 backbone (with R = aryl and M = Si, Ge, Sn, and Pb) . It also confirms the electronegativity effects on the stabilization of Pb compounds .…”

Section: Resultssupporting

confidence: 91%

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Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)

2005

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All electron nonrelativistic and relativistic density functional theory calculations at the BP86/QZ4P (Slater type) level are reported for a set of fundamentally useful DFT based reactivity descriptors for group 14 elements (C, Si, Ge, Sn, Pb, Element 114 (abbreviated as Uuq)) and functional groups, -XY3 (X = C, Si, Ge, Sn, Pb, Element 114 (Uuq); Y = CH3, H, F, Cl, Br, I, At); these include electronegativity (chi), chemical hardness (eta), global softness (S), and electrophilicity index (omega). This approach permits an evaluation of the discrepancies in electronegativity scales and associated properties at uniform levels affording a nonempirical analysis for the first time. The vital importance of the spin-orbit interaction, in addition to the scalar relativistic terms, is demonstrated in reproducing the experimental trends on going from top to bottom of the group. The order for isolated atoms is altered when passing to -XY3 groups for all of the properties studied. For example, the calculated atomic electronegativities show a uniform decrease from C to Pb increasing again to Uuq as verified in the experimental data for C-Pb but at variance with several other scales. The sequence for functional groups is different and in accordance with experimental NMR data where available. The experimental hardness sequence for the isolated atoms (C > Pb > Si > Ge > Sn) is opposed to the trends of decreasing hardness on going down the periodic table as is found, e.g., in the halogen group and confirmed by this study. The -XY3 functional groups however follow the C > Si > Ge > Sn > Pb sequence. The recently developed electrophilicity index (omega) has been shown to be highly correlated with the electron affinity rather than the electronegativity. Finally, regression analyses that discriminate between the properties are carried out to investigate the nature of additivity of atomic contributions in functional group properties.

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Section: Resultssupporting

confidence: 91%

“…A similar order is also found for Y = Me. Information available based on experimental NMR studies is clearly in favor of the present investigation …”

Section: Resultsmentioning

confidence: 90%

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)

2005

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“…Our calculated bond lengths of C−H on the phenyl rings are generally about 0.1 Å longer than the crystallographic results (which are usually estimations). Our DFT calculation results provided the concrete quantitative evidences for the qualitative analysis results obtained by Charissé et al That is, the C 2 v local symmetry of the phenyl groups lowers the symmetry at the central atoms from T d to S 4 , which causes the six tetrahedral C−X-C angles to split into two groups. Though the tetrahedron in compounds with a bond length X−C smaller than 2.0 Å (X = C, Si, Ge) is always elongated (two angles less and four angles greater than the tetrahedral value 109.5°), the tetrahedron in compounds with d (X−C) > 2.0 Å (X = Sn, Pb) is always contracted (two angles greater and four angles less than the tetrahedral value) along its S 4 axis.…”

Section: Resultssupporting

confidence: 77%

“…The superimposition of four 2-fold rotors (in this case, phenyl groups) onto a skeleton of T d symmetry brings about the removal of all four 3-fold symmetry axes and the Ar 4 X system can therefore never adopt T d symmetry, but must belong to one of the seven subgroups of D 2 d ( D 2 d , D 2 , S 4 , C 2 v , C 2 , C s , C 1 ). Semiempirical calculations and NMR spectroscopic studies were carried out for Ph 4 - n X( p -Tol) n ( n = 0−4, X = Si, Ge, Sn, Pb) by Charissé et al They found that a change of the symmetry of the formally tetrahedral XC 4 backbone arises if X = Si and Ge (elongation along one S 4 or C 3 axis) are altered to X = Sn and Pb (contraction along S 4 axis). Recently, as the computer capacity increases, accurate ab initio computations are affordable for these medium-sized molecules.…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Investigation of the Structural and Electronic Properties of the Molecules and Crystals of Tetraphenyl Derivatives of Group IVA Elements

Lin

Liu

2004

J. Phys. Chem. B

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The structural and electronic properties of molecular and crystalline X(C6H5)4 (X = C, Si, Ge, Sn, Pb) have been studied systematically by ab initio/DFT calculations at the level of GGA-PW91 with either a plane wave basis set and ultrasoft pseudopotentials or with a local basis set−double numerical plus polarization (DNP) and all electrons. The optimized geometrical parameters were found to be comparable to the results of X-ray crystallographic, gas-phase electron diffraction, and two reported calculations for CPh4 and SiPh4 molecules. In addition, the electronic and optical properties such as band structures, molecular orbitals, the energy gap between the lowest unoccupied orbital (LUMO) and the highest occupied orbital (HOMO), density of states (DOS), partial density of states (PDOS), refractive indices and absorption spectra etc can be obtained from the calculations at the optimized structures. The calculated LUMO−HOMO gap is 4.1−4.6 eV. The simulated absorption spectra of XPh4 are similar. The effect of the central atom on the HOMO, the LUMO, and other frontier molecular orbitals is increased as the atomic number of the central atom increases. Our studies showed that the present computational methods were good approximations and cost-effective for the medium-sized molecules and could be extended to the large-sized tetrahedral chromophore molecules.

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“…n M(p-Tol) n , semiempirical calculations have been carried out [81], A change of symmetry of the formally tetrahedral MC 4 backbone arises if Μ = Si or Ge (elongatied along one S 4 or C 3 axis) is replaced by Μ = Sn or Pb (contracted along one S 4 axis). n M(p-Tol) n , semiempirical calculations have been carried out [81], A change of symmetry of the formally tetrahedral MC 4 backbone arises if Μ = Si or Ge (elongatied along one S 4 or C 3 axis) is replaced by Μ = Sn or Pb (contracted along one S 4 axis).…”

Section: Lead(iv) Compoundsmentioning

confidence: 99%

Lead Coordination and Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

Holloway¹,

Melnı́k²

1997

Main Group Metal Chemistry

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This review covers over three hundred and sixty coordination and organometallic complexes of lead. About 20% of these contain lead in its +4 oxidation state, of which one fifth are dilead(+6) units, and two are anionic clusters. The Pb(IV) derivatives are predominantly organometallic, many stabilized by sandwich ligation. The majority of the Pb(ll) compounds are typical coordination complexes. Mon-to polynuclear derivatives are found, with coordinations numbers from 2 to 12. The effect of the non bonded pair of valence electrons is observed in lower coordination number Pb(ll) complexes. Examples of distortion, geometric and coordination isomerism are observed. Factors affecting bond lengths and bond angles are discussed, and some ambiguities in coordination polyhedra are outlined.

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Tetraaryl-methane analogues in group 14-4. Ph4−nM(p-Tol)n (n = 0–4, M = Si, Ge, Sn, Pb). Synthesis, structural and spectroscopic data, and semi empirical calculations: Mutual interaction of tetrahedral σ-orbitals (symmetry and electronegativity) and delocalized σ-lumos (π-Lewis acidity)

Cited by 12 publications

References 42 publications

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)

Ab Initio Investigation of the Structural and Electronic Properties of the Molecules and Crystals of Tetraphenyl Derivatives of Group IVA Elements

Lead Coordination and Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

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Tetraaryl-methane analogues in group 14-4. Ph4−nM(p-Tol)n (n = 0–4, M = Si, Ge, Sn, Pb). Synthesis, structural and spectroscopic data, and semi empirical calculations: Mutual interaction of tetrahedral σ-orbitals (symmetry and electronegativity) and delocalized σ-lumos (π-Lewis acidity)

Cited by 12 publications

References 42 publications

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY3 (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH3, H, F, Cl, Br, I, At)

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY3 (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH3, H, F, Cl, Br, I, At)

Ab Initio Investigation of the Structural and Electronic Properties of the Molecules and Crystals of Tetraphenyl Derivatives of Group IVA Elements

Lead Coordination and Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

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Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)

Comprehensive Study of Density Functional Theory Based Properties for Group 14 Atoms and Functional Groups, −XY₃ (X = C, Si, Ge, Sn, Pb, Element 114; Y = CH₃, H, F, Cl, Br, I, At)