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107 results on '"Xia, Bao-Hui"'

15. Metallophilic attractions between d8–d10 heterometallic compounds trans-[Pt(PH3)2(CN)2] and M(PH3)2+ (M=Ag or Cu): Ab initio study.

Author

Xia, Bao-Hui, Zhang, Hong-Xing, Jiao, Yu-Qiu, Pan, Qing-Jiang, Li, Ze-Sheng, and Sun, Chia-Chung

Subjects
*METALLIC composites, *HYDROGEN-ion concentration, *HYDROGEN bonding, *EQUILIBRIUM, *PHYSICS, *PLATINUM
Abstract

The weak metal–metal interactions of Pt(II)–Ag(I)/Cu(I) have been investigated by ab initio method at MP2 level through the model complexes [trans-Pt(PH3)2(CN)2-M(PH3)2+] (M=Ag,Cu). The calculated interaction energy of 12.9 and 11.5 kcal mol-1 for [trans-Pt(PH3)2(CN)2-Ag(PH3)2+] and [trans-Pt(PH3)2(CN)2–Cu(PH3)2+] respectively, are in the middle of the van der Waals force and the strong hydrogen bond. The estimated equilibrium separations between Pt and M, req(Pt–M) (3.32 Å for M=Ag and 3.23 Å for M=Cu), lie within the region expected for weak metal–metal interaction. The electronic dispersive contributions dominate the weak interaction. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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16. Metal-metal interactions in heterobimetallic D8-D10 complexes. structures and spectroscopic investigation of [M'M'(mu-dcpm)2(CN)2](super +) (M' = Pt, Pd; M'= Cu, Ag, Au) and related complexes by UV-vis absorption and resonance Raman spectroscopy and ab initio calculations

Author

Xia, Bao-Hui, Zhang, Hong-Xing, Che, Cjhi-Ming, Leung, King-Hung, Phillips, David Lee, Zhou, Zhang-Yuan, and Zhu, Nianyong

Subjects
Nonferrous metals -- Research, Nonferrous metals -- Atomic properties, Raman spectroscopy -- Usage, Coordination compounds -- Research, Chemistry
Abstract

The structural and spectroscopic properties of heterodinuclear d8-d10 metal complexes [M'M'(mu-dcpm)2(CN)2](super +) (M' = Pt, Pd; M'= Cu, Ag, Au) are investigated by UV-vis absorption and resonance Raman spectroscopy and ab initio calculations. It is found that the metal...metal distances in these complexes are shorter than the sum of van der Waals radii of the M' and M' atoms.

Published
2003

40. Metal−Metal Interactions in Heterobimetallic d8−d10Complexes. Structures and Spectroscopic Investigation of [M‘M‘ ‘(μ-dcpm)2(CN)2]+(M‘ = Pt, Pd; M‘ ‘ = Cu, Ag, Au) and Related Complexes by UV−vis Absorption and Resonance Raman Spectroscopy and ab Initio Calculations

Author

Xia, Bao-Hui, primary, Zhang, Hong-Xing, additional, Che, Chi-Ming, additional, Leung, King-Hung, additional, Phillips, David Lee, additional, Zhu, Nianyong, additional, and Zhou, Zhong-Yuan, additional

Published
2003
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44. Theoretical investigation on the spectroscopic properties of cyclometallated iridium (III) complexes and the deprotonation influence on them in solution.

Author

Wang, Jian, Xia, Bao‐Hui, Bai, Fu‐Quan, Sun, Lei, and Zhang, Hong‐Xing

Subjects
*IRIDIUM, *METAL complexes, *PROTON transfer reactions, *SOLUTION (Chemistry), *ELECTRONIC structure, *BIPYRIDINE, *EXCITED state chemistry, *DENSITY functionals
Abstract

Electronic structures and spectroscopic properties of mixed-ligand cyclometallated iridium complexes with general formula [Ir(NˆC)2(NˆN)]+ (NˆC = 2-phenylpyridine, NˆN = Hcmbpy = 4-carboxyl-4′-methyl-2,2′-bipyridine, 1; H2dcbpy = 4,4′-dicarboxyl-2,2′-bipyridine, 2) were studied theoretically. The geometries of the complexes in ground and excited state were optimized at B3LYP and CIS levels, respectively. The absorption and emission of the complexes in CH3CN solutions were calculated by time-dependent density functional theory (TD-DFT) with the PCM solvent model. The calculated absorptions and emissions of the complexes are in good agreement with the measured results. The deprotonation influence on the electronic structure and the optical properties of 2 was also investigated. The results indicate that the deprotonation which occurs on the COOH groups influences the geometries of the complexes in ground and excited state slightly but leads to significant blue-shifts in low energy absorption and emission maximum. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [ABSTRACT FROM AUTHOR]

Published
2011
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46. The Quest for PdII–PdIIInteractions: Structural and Spectroscopic Studies and Ab Initio Calculations on Dinuclear [Pd2(CN)4(μ‐diphosphane)2] Complexes

Author

Xia, Bao‐Hui, Che, Chi‐Ming, and Zhou, Zhong‐Yuan

Abstract

Structural and spectroscopic properties of and theoretical investigations on dinuclear [Pd2(CN)4(P–P)2] (P–P=bis(dicyclohexylphosphanyl)methane (1), bis(dimethylphosphanyl)methane (2)) and mononuclear trans‐[Pd(CN)2(PCy3)2] (3) complexes are described. Xray structural analyses reveal Pd⋅⋅⋅Pd distances of 3.0432(7) and 3.307(4) Å in 1and 2, respectively. The absorption bands at λ>270 nm in 1and 2have 4d${_{\sigma }^{{\ast}}}$→5pσelectronic‐transition character. Calculations at the CIS level indicate that the two low‐lying dipole‐allowed electronic transition bands in model complex [Pd2(CN)4(μ‐H2PCH2PH2)2] at 303 and 289 nm are due to combinations of many orbital transitions. The calculated interaction‐energy curve for the skewed dimer [{trans‐[Pd(CN)2(PH3)2]}2] is attractive at the MP2 level and implies the existence of a weak PdII–PdIIinteraction.

Published
2003
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47. The Quest for Pd<SUP>II</SUP>–Pd<SUP>II</SUP> Interactions: Structural and Spectroscopic Studies and Ab Initio Calculations on Dinuclear [Pd<INF>2</INF>(CN)<INF>4</INF>(μ-diphosphane)<INF>2</INF>] Complexes

Author

Xia, Bao-Hui, Che, Chi-Ming, and Zhou, Zhong-Yuan

Abstract

Structural and spectroscopic properties of and theoretical investigations on dinuclear [Pd2(CN)4(P–P)2] (P–P=bis(dicyclohexylphosphanyl)methane (1), bis(dimethylphosphanyl)methane (2)) and mononuclear trans-[Pd(CN)2(PCy3)2] (3) complexes are described. Xray structural analyses reveal Pd···Pd distances of 3.0432(7) and 3.307(4) Å in 1 and 2, respectively. The absorption bands at λ>270 nm in 1 and 2 have 4d${_{\sigma }^{{\ast}}}$→5pσ electronic-transition character. Calculations at the CIS level indicate that the two low-lying dipole-allowed electronic transition bands in model complex [Pd2(CN)4(μ-H2PCH2PH2)2] at 303 and 289 nm are due to combinations of many orbital transitions. The calculated interaction-energy curve for the skewed dimer [{trans-[Pd(CN)2(PH3)2]}2] is attractive at the MP2 level and implies the existence of a weak PdII–PdII interaction.

Published
2003
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48. Photoluminescent Metal–Sulfur Clusters Derived from Tetrathiometalates: Metal-to-Metal Charge-Transfer Excited States of d<SUP>0</SUP>–d<SUP>10</SUP> Heterobimetallic Sulfido Clusters with Bulky Phosphine Ligands

Author

Che, Chi-Ming, Xia, Bao-Hui, Huang, Jie-Sheng, Chan, Chi-Keung, Zhou, Zhong-Yuan, and Cheung, Kung-Kai

Abstract

Reactions of MS42− (M=Mo, W) with M'(PCy3)X (M'=Ag/Au, X=ClO4/Cl) and [Cu2(dcpm)2(MeCN)2](ClO4)2 (dcpm=bis(dicyclohexylphosphino)methane) afforded heterometallic sulfido clusters [M'2(PCy3)2(MS4)] (M=Mo, M'=Au: 2; M=W, M'=Ag: 3, Au: 4) and [Cu4(dcpm)4(MS4)](ClO4)2 (M=Mo: 5·(ClO4)2, W: 6·(ClO4)2), all of which, except 4, have been characterized by X-ray structure determination. Clusters 5·(ClO4)2 and 6·(ClO4)2 feature unusual 16-membered {Cu4P8C4} metallamacrocycles formed on the respective tetrathiometalate anion templates and have unusually long Cu−S bonds and Cu···M distances for metal–sulfur clusters that contain a saddle-shaped {Cu4MS4} core. Low-energy absorption bands are observed in their electronic spectra at ~562 and 467 nm, respectively, assignable to MMCT transitions; quasireversible reduction waves are observed with E1/2=−1.43 (52+) and −1.78 V (62+) versus FeCp20/+; and they are emissive either in the solid state or in solution. The emission of 62+ can be quenched by both electron acceptors, such as methylviologen, or electron donors, such as aromatic amines, with the excited state reduction potential E(62+*/6+) estimated to be ~1.13 V versus a normal hydrogen electrode.

Published
2001
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49. Photoluminescent Metal–Sulfur Clusters Derived from Tetrathiometalates: Metal‐to‐Metal Charge‐Transfer Excited States of d0–d10Heterobimetallic Sulfido Clusters with Bulky Phosphine Ligands

Author

Che, Chi‐Ming, Xia, Bao‐Hui, Huang, Jie‐Sheng, Chan, Chi‐Keung, Zhou, Zhong‐Yuan, and Cheung, Kung‐Kai

Abstract

Reactions of MS42−(M=Mo, W) with M′(PCy3)X (M′=Ag/Au, X=ClO4/Cl) and [Cu2(dcpm)2(MeCN)2](ClO4)2(dcpm=bis(dicyclohexylphosphino)methane) afforded heterometallic sulfido clusters [M′2(PCy3)2(MS4)] (M=Mo, M′=Au: 2; M=W, M′=Ag: 3, Au: 4) and [Cu4(dcpm)4(MS4)](ClO4)2(M=Mo: 5⋅(ClO4)2, W: 6⋅(ClO4)2), all of which, except 4, have been characterized by X‐ray structure determination. Clusters 5⋅(ClO4)2and 6⋅(ClO4)2feature unusual 16‐membered {Cu4P8C4} metallamacrocycles formed on the respective tetrathiometalate anion templates and have unusually long Cu−S bonds and Cu⋅⋅⋅M distances for metal–sulfur clusters that contain a saddle‐shaped {Cu4MS4} core. Low‐energy absorption bands are observed in their electronic spectra at ∼562 and 467 nm, respectively, assignable to MMCT transitions; quasireversible reduction waves are observed with E1/2=−1.43 (52+) and −1.78 V (62+) versus FeCp20/+; and they are emissive either in the solid state or in solution. The emission of 62+can be quenched by both electron acceptors, such as methylviologen, or electron donors, such as aromatic amines, with the excited state reduction potential E(62+*/6+) estimated to be ∼1.13 V versus a normal hydrogen electrode.

Published
2001
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50. A density functional theory investigation of the stability, aromaticity, and photophysical behavior for the highly conjugated macrocycles containing 4 pyrroles.

Author

Wei, Wei, Bai, Fu ‐ Quan, Xia, Bao ‐ Hui, Wang, Jian, and Zhang, Hong ‐ Xing

Subjects
AROMATICITY, PORPHYRINS, PORPHYCENES, PYRROLES, ELECTRONS
Abstract

Porphyrin ( Pr), porphycene ( Pc), and [22]porphyrin(2.2.2.2) ( P[22]) have been theoretically investigated. We design 2 highly conjugated macrocycles containing 4 pyrroles with different linkage bridges, which are named for 4 pyrrole ( Pf) and methylene-dipyrrolidine ( Pm), as the theoretical model so as to investigate the stability, aromaticity, and photophysical behavior of these porphyrin derivatives, and the influence of getting or losing electron to the neutral molecule. The geometric structures of the molecules are optimized by density functional theory method. The absorptions are calculated by the time-dependent density functional theory method. Based on the optimized structures, the nucleus-independent chemical shifts (NICS) are calculated. The molecule with negative NICS value possesses larger highest occupied molecular orbital (HOMO)-lowest occupied molecular orbital (LUMO) gap than that with positive NICS value, the molecule with bigger positive NICS value possesses smaller HOMO-LUMO gap, and the molecule with bigger negative NICS value (in absolute value) possesses bigger HOMO-LUMO gap. The current density indicates that the π-electron delocalization is more effective in Pr and Pc than in Pf, Pm, and P[22] and corresponds to the stability of molecules. The absorptions of the molecules are all in the UV-visible and infrared regions. The major transitions for most of the molecules are all from HOMO to LUMO. Compared with Pf 2−, Pr 2−, Pc 2−, and P[22] 2−, Pm 2− shows distinctive photophysical properties, which is due to the reduced HOMO-LUMO gap, structural distortion, and strong antiaromaticity. [ABSTRACT FROM AUTHOR]

Published
2017
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