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Jean Galy - One of the best experts on this subject based on the ideXlab platform.
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Coherent view of crystal chemistry and ab initio analyses of Pb(II) and Bi(III) Lone Pair in square planar coordination
Progress in Solid State Chemistry, 2015Co-Authors: Samir F. Matar, Jean GalyAbstract:Abstract The stereochemistry of 6s 2 (E) lone pair of divalent Pb and trivalent Bi (PbII and BiIII designated by M ∗ ) in structurally related PbO, PbFX (X = Cl, Br, I), BiOX (X = F, Cl, Br, I) and Bi 2 NbO 5 F is rationalized. The lone pair LP presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M ∗ –E directions and distances. Detailed description of structural features of both elements in the above cited compounds characterized by [PbEO] n and [BiEO] n layers allowed to show the evolution of M ∗ –E distance versus the changes with the square pyramidal SP coordination polyhedra. All are different, in red PbO one finds {PbEO 4 E 4 } square Antiprism, a {[Bi.E]O 4 X 4 X apical } monocapped square Antiprism in PbFX and BiOX and {BiEO 4 F 4 }square Antiprism in Bi 2 NbO 5 F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on Pb(II) within {PbEO 4 E 4 } in PbOE, {PbEF 4 X 4 } in PbFXE and Bi(III) within {BiEO 4 X 4 } square Antiprisms, contrary to Bi(III) within {[Bi.E]O 4 F 4 F apical } monocapped square Antiprism. Larger hardness (larger bulk modules B 0 ) and band gap characterize BiOF versus PbO due to the presence of fluorine which brings antibonding Bi–F interactions oppositely to mainly bonding Bi–O. In PbFX and BiOX series there is a systematic decrease of B 0 with the increasing volume following the nature and size of X which is decreasingly electronegative and increasingly large. The electronic densities of states mirror these effects through the relative energy position and relative electronegativities of F/X and O/X leading to decrease the band gap.
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Coherent view of crystal chemistry and ab initio analyses of Pb(II) and Bi(III) Lone Pair in square planar coordination
Progress in Solid State Chemistry, 2015Co-Authors: Samir F. Matar, Jean GalyAbstract:The stereochemistry of 6s2 (E) lone pair of divalent Pb and trivalent Bi (PbII and BiIII designated by M*) in structurally related PbO, PbFX (X= Cl, Br, I), BiOX (X= F, Cl, Br, I) and Bi2NbO5F is rationalized. The lone pair LP presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M*-E directions and distances. Detailed description of structural features of both elements in the title compounds characterized by [PbEO]n and [BiEO]n layers allowed to show the evolution of M*-E distance versus the changes with the square pyramidal SP coordination polyhedra. All are different, in red PbO one finds {PbEO4E4} square Antiprism, a {[Bi.E]O4X4Xapical} monocapped square Antiprism in PbFX and BiOX and {BiEO4F4}square Antiprism in Bi2NbO5F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on PbII within {PbEO4E4} in PbOE, {PbEF4X4} in PbFXE and Bi(III) within {BiEO4X4} square Antiprisms, contrary to Bi(III) within {[Bi.E]O4F4Fapical} monocapped square Antiprism. Larger hardness (larger bulk modules B0) and band gap characterize BiOF versus PbO due to the presence of F which brings antibonding Bi-F interactions oppositely to mainly bonding Bi-O. In PbFX and BiOX series there is a systematic decrease of B0 with the increasing volume following the nature and size of X which is decreasingly electronegative and increasingly large. The electronic densities of states mirror these effects through the relative energy position and relative electronegativities of F/X and O/X leading to decrease the band gap.
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6s2 Lone Pair Effects in related structures PbO, BiOF and Bi2NbO5F: Crystal chemistry and DFT investigations
2014Co-Authors: Samir F. Matar, Jean GalyAbstract:Based on the stereochemistry of 6s 2 (E) lone pair elements Pb II and Bi III , designated by M*, the related PbO, BiOF and Bi2NbO5F crystal structures were revisited. Lone pair presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M*-E directions and distances. Detailed description of structural features of both elements in these three compounds characterized by [PbEO]n and [BiEO]n layers allowed to show the evolution of M*-E versus the coordination polyhedra. All are different, in red PbO one finds {PbEO4E4} square Antiprism, a {[Bi.E]O4F4Fapical} monocapped square Antiprism in BiOF and {BiEO4F4}square Antiprism in Bi2NbO5F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on Pb II within {PbEO4E4} and Bi III within {BiEO4F4} square Antiprisms, contrary to Bi III within {[Bi.E]O4F4Fapical} monocapped square Antiprism. Larger hardness and band gap characterize BiOF versus PbO due to the presence of F which brings antibonding Bi-F interactions oppositely to mainly bonding Bi-O. 2014 Elsevier Ltd. All rights reserved.
Samir F. Matar - One of the best experts on this subject based on the ideXlab platform.
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Coherent view of crystal chemistry and ab initio analyses of Pb(II) and Bi(III) Lone Pair in square planar coordination
Progress in Solid State Chemistry, 2015Co-Authors: Samir F. Matar, Jean GalyAbstract:Abstract The stereochemistry of 6s 2 (E) lone pair of divalent Pb and trivalent Bi (PbII and BiIII designated by M ∗ ) in structurally related PbO, PbFX (X = Cl, Br, I), BiOX (X = F, Cl, Br, I) and Bi 2 NbO 5 F is rationalized. The lone pair LP presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M ∗ –E directions and distances. Detailed description of structural features of both elements in the above cited compounds characterized by [PbEO] n and [BiEO] n layers allowed to show the evolution of M ∗ –E distance versus the changes with the square pyramidal SP coordination polyhedra. All are different, in red PbO one finds {PbEO 4 E 4 } square Antiprism, a {[Bi.E]O 4 X 4 X apical } monocapped square Antiprism in PbFX and BiOX and {BiEO 4 F 4 }square Antiprism in Bi 2 NbO 5 F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on Pb(II) within {PbEO 4 E 4 } in PbOE, {PbEF 4 X 4 } in PbFXE and Bi(III) within {BiEO 4 X 4 } square Antiprisms, contrary to Bi(III) within {[Bi.E]O 4 F 4 F apical } monocapped square Antiprism. Larger hardness (larger bulk modules B 0 ) and band gap characterize BiOF versus PbO due to the presence of fluorine which brings antibonding Bi–F interactions oppositely to mainly bonding Bi–O. In PbFX and BiOX series there is a systematic decrease of B 0 with the increasing volume following the nature and size of X which is decreasingly electronegative and increasingly large. The electronic densities of states mirror these effects through the relative energy position and relative electronegativities of F/X and O/X leading to decrease the band gap.
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Coherent view of crystal chemistry and ab initio analyses of Pb(II) and Bi(III) Lone Pair in square planar coordination
Progress in Solid State Chemistry, 2015Co-Authors: Samir F. Matar, Jean GalyAbstract:The stereochemistry of 6s2 (E) lone pair of divalent Pb and trivalent Bi (PbII and BiIII designated by M*) in structurally related PbO, PbFX (X= Cl, Br, I), BiOX (X= F, Cl, Br, I) and Bi2NbO5F is rationalized. The lone pair LP presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M*-E directions and distances. Detailed description of structural features of both elements in the title compounds characterized by [PbEO]n and [BiEO]n layers allowed to show the evolution of M*-E distance versus the changes with the square pyramidal SP coordination polyhedra. All are different, in red PbO one finds {PbEO4E4} square Antiprism, a {[Bi.E]O4X4Xapical} monocapped square Antiprism in PbFX and BiOX and {BiEO4F4}square Antiprism in Bi2NbO5F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on PbII within {PbEO4E4} in PbOE, {PbEF4X4} in PbFXE and Bi(III) within {BiEO4X4} square Antiprisms, contrary to Bi(III) within {[Bi.E]O4F4Fapical} monocapped square Antiprism. Larger hardness (larger bulk modules B0) and band gap characterize BiOF versus PbO due to the presence of F which brings antibonding Bi-F interactions oppositely to mainly bonding Bi-O. In PbFX and BiOX series there is a systematic decrease of B0 with the increasing volume following the nature and size of X which is decreasingly electronegative and increasingly large. The electronic densities of states mirror these effects through the relative energy position and relative electronegativities of F/X and O/X leading to decrease the band gap.
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6s2 Lone Pair Effects in related structures PbO, BiOF and Bi2NbO5F: Crystal chemistry and DFT investigations
2014Co-Authors: Samir F. Matar, Jean GalyAbstract:Based on the stereochemistry of 6s 2 (E) lone pair elements Pb II and Bi III , designated by M*, the related PbO, BiOF and Bi2NbO5F crystal structures were revisited. Lone pair presence determined by its sphere of influence E, equal to those of oxygen or fluorine anions, was settled by its center then giving M*-E directions and distances. Detailed description of structural features of both elements in these three compounds characterized by [PbEO]n and [BiEO]n layers allowed to show the evolution of M*-E versus the coordination polyhedra. All are different, in red PbO one finds {PbEO4E4} square Antiprism, a {[Bi.E]O4F4Fapical} monocapped square Antiprism in BiOF and {BiEO4F4}square Antiprism in Bi2NbO5F. To analyze the crystal chemistry results, the electronic structures of these compounds were calculated within density functional theory DFT. Real space analyses of electron localization illustrate a full volume development of the lone pair on Pb II within {PbEO4E4} and Bi III within {BiEO4F4} square Antiprisms, contrary to Bi III within {[Bi.E]O4F4Fapical} monocapped square Antiprism. Larger hardness and band gap characterize BiOF versus PbO due to the presence of F which brings antibonding Bi-F interactions oppositely to mainly bonding Bi-O. 2014 Elsevier Ltd. All rights reserved.
Yuyun Mintarsih - One of the best experts on this subject based on the ideXlab platform.
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On the strong metric dimension of Antiprism graph, king graph, and Km ? Kn graph
2018Co-Authors: Yuyun MintarsihAbstract:Abstract. Let G be a connected graph with a set of vertices V (G) and a set of edges E(G).The interval I[u; v] between u and v to be the collection of all vertices that belong to someshortest u-v path. A vertex s ∈ V (G) is said to be strongly resolved for vertices u, v ∈ V (G)if v ∈ I[u; s] or u ∈ I[v; s]. A vertex set S ⊆ V (G) is a strong resolving set for G if every twodistinct vertices of G are strongly resolved by some vertices of S. The strong metric dimensionof G, denoted by sdim(G), is de ned as the smallest cardinality of a strong resolving set. Inthis paper, we determine the strong metric dimension of an Antiprism An graph, a king Km;ngraph, and a Km ? Kn graph. We obtain the strong metric dimension of an antiprim graphAn are n for n odd and n + 1 for n even. The strong metric dimension of King graph Km;n ism+n−1. The strong metric dimension of Km ?Kn graph are n for m = 1, n ≥ 1 and mn−1for m ≥ 2, n ≥ 1.
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on the strong metric dimension of Antiprism graph king graph and km kn graph
2018Co-Authors: Yuyun MintarsihAbstract:Abstract. Let G be a connected graph with a set of vertices V (G) and a set of edges E(G).The interval I[u; v] between u and v to be the collection of all vertices that belong to someshortest u-v path. A vertex s ∈ V (G) is said to be strongly resolved for vertices u, v ∈ V (G)if v ∈ I[u; s] or u ∈ I[v; s]. A vertex set S ⊆ V (G) is a strong resolving set for G if every twodistinct vertices of G are strongly resolved by some vertices of S. The strong metric dimensionof G, denoted by sdim(G), is de ned as the smallest cardinality of a strong resolving set. Inthis paper, we determine the strong metric dimension of an Antiprism An graph, a king Km;ngraph, and a Km ? Kn graph. We obtain the strong metric dimension of an antiprim graphAn are n for n odd and n + 1 for n even. The strong metric dimension of King graph Km;n ism+n−1. The strong metric dimension of Km ?Kn graph are n for m = 1, n ≥ 1 and mn−1for m ≥ 2, n ≥ 1.
Shuping Wang - One of the best experts on this subject based on the ideXlab platform.
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crystal structures thermal properties and biological activities of a series of lanthanide compounds with 2 4 dichlorobenzoic acid and 1 10 phenanthroline
Industrial & Engineering Chemistry Research, 2013Co-Authors: Jianjun Zhang, Shumei He, Shuping WangAbstract:A new family of binuclear lanthanide compounds of general formula [Ln(2,4-DClBA)3phen]2 (Ln(III) = Nd (1), Sm (2), Dy (3), Yb (4); 2,4-DClBA = 2,4-dichlorobenzoate; phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, molar conductance, infrared spectroscopy, ultraviolet spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. On the basis of X-ray crystallography, compounds 2–4 belong to the triclinic crystal system, PI space group. In compound 2, the Sm3+ ion adopted a distorted monocapped square-Antiprism coordination geometry. Compounds 3 and 4 are isomorphous whose central ions (Dy3+ and Yb3+) formed a distorted square-Antiprism geometry. The heat capacities of compounds 1–4 are measured using DSC technology and fitted to a polynomial equation by the least-squares method. The smoothed molar heat capacities and thermodynamic function data of compounds 1–4 relative to the reference temperature 298.15 K are then calculated. Meanwhile, these compou...
R. B. King - One of the best experts on this subject based on the ideXlab platform.
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Discovery of a silicon-based ferrimagnetic wheel structure in VxSi12− (x = 1–3) clusters: photoelectron spectroscopy and density functional theory investigation
Nanoscale, 2014Co-Authors: Xiaoming Huang, R. B. King, Jijun Zhao, Wei-jun ZhengAbstract:Our studies show that VSi12− adopts a V-centered hexagonal prism with a singlet spin state. The addition of the second V atom leads to a capped hexagonal Antiprism for V2Si12− in a doublet spin state. Most interestingly, V3Si12− exhibits a ferrimagnetic, bicapped hexagonal Antiprism wheel-like structure with a total spin of 4μB.
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The sphericity of the diverse 10-vertex polyhedra found in bare post-transition metal clusters: germanium clusters with interstitial magnesium atoms as model systems
Theoretical Chemistry Accounts, 2012Co-Authors: M. M. Uţă, D. Cioloboc, Ioan Silaghi-dumitrescu, R. B. KingAbstract:The diverse polyhedra found experimentally in bare 10-vertex centered post-transition element clusters characterized structurally by X-ray crystallography include the D 4d bicapped square Antiprism Zn@In 10 8− in the intermetallic K8In10Zn as well as the centered lead clusters M@Pb10 2− in [K(2,2,2-crypt)]2[M@Pb10] (M = Ni, Pd, Pt), the C3v tetracapped trigonal prism M@In 10 10− in the intermetallic K10In10M (M = Ni, Pd, Pt), the D 5d pentagonal Antiprism Pd@Bi10 4+ in Bi14PdBr16, and the D 5h pentagonal prism in the trianions M@Ge 10 3− (M = Fe, Co). The structures of the 10-vertex germanium clusters containing an interstitial magnesium atom (atomic radius 1.30 A), namely Mg@Ge 10 (z = +2, 0, −2, −4), have been optimized as models to analyze the frontier molecular orbitals of the four experimentally known 10-vertex polyhedra noted above. In this connection, the molecular orbital patterns of the most spherical D 4d bicapped square Antiprism cluster Mg@Ge10 as well as that of an approximately spherical C 3v cluster Mg@Ge 10 2+ derived from the tetracapped trigonal prism exhibit the spherical harmonic ordering of the jellium model. In this ordering scheme, the 20-orbital {1s, 1p, 1d, 2s, 1f, 2p} shell is filled before any of the 1g molecular orbitals. However, the molecular orbital patterns of the oblate D 5d pentagonal Antiprism cluster Mg@Ge 10 4− and the D 5h pentagonal prism cluster Mg@Ge10 no longer exhibit the spherical harmonic ordering of the jellium model. In these clusters, the polar 1f(z 3) orbital is raised to antibonding levels and the pair of hexagonal prism g molecular orbitals become bonding orbitals. The sphericities of the four distinct 10-vertex polyhedra found experimentally in centered bare 10-vertex post-transition metal clusters have been evaluated by comparing the relative energies of the cluster bonding molecular orbitals in model Mg@Ge 10 (z = −4 to +2) species with the spherical harmonic ordering predicted by the jellium model. Using this as a criterion, the D 4d bicapped square Antiprismatic and C 3v tetracapped trigonal prismatic structures can be regarded as essentially spherical. However, the molecular orbital patterns of the oblate D 5d pentagonal Antiprismatic and D 5h pentagonal prismatic clusters deviate significantly from spherical harmonic ordering.
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Topological models of the chemical bonding in transition metal-silicon clusters
European Physical Journal D, 1991Co-Authors: R. B. KingAbstract:Models are proposed for the mixed transition metal-silicon bare clusters CuSi10 and MSi16 (M=Cr, Mo, W) in which the transition metals are located in the centers ofD4d silicon polyhedra which are dual polyhedra of the square Antiprism and 4,4-bicapped square Antiprism (gyroelongated square bipyramid), respectively. In CuSi 10 + and MSi16 (M=Cr, Mo, W) the central transition metals have the favored 18-electron rare gas configurations receiving electrons from the silicon atoms through Si2M three-center bonds analogous to the three-center C2M bonds in metal-olefin complexes. Thus in CuSi10 the silicon polyhedron functions as a chelating persila-tetraolefin whereas in MSi16 (M=Cr, Mo, W) the silicon polyhedron functions as a persila-octaolefin in which six of the eight double bonds are complexed to the central metal atom leaving two uncomplexed double bonds.
