101 results on '"Hanqin Liu"'
Search Results
2. Formation of a bridging sulfide in (Co4(mu3-S)(SCH2CH2S)3(PPh3)3Cl) via disruption of the C-S bond from dithiolate
- Author
-
Feilong Jiang, Zhiying Huang, Daxu Wu, Beisheng Kang, Maochun Hong, and Hanqin Liu
- Subjects
Sulfides -- Analysis ,Copper compounds -- Research ,Transition metal compounds -- Observations ,Chemical bonds -- Observations ,Thiols -- Analysis ,Chemistry - Abstract
Investigations were conducted to synthesize and structurally characterize CO4(mu3-S)(SCH2CH2S)3(PPh3)3Cl. This was undertaken to derive a tetranuclear compound having simultaneous ligations of phosphine, dithiolate and sulfide, where dithiolate, besides serving as a ligand, acts as a donor of S2- ion through cleavage of a C-S bond. These efforts were successful owing to the strategy of changing the reaction conditions in the CoX-(PR3)3-dithiolate system.
- Published
- 1993
3. Vanadium(IV) dimer complexes containing [V(o-C6H4OS)3]2− fragment and caged sodium ions
- Author
-
Bei-Sheng Kang, Hanqin Liu, Xinjian Lei, Xuetai Chen, Yonghan Hu, Lin‐Hong Weng, and Maochun Hong
- Subjects
chemistry.chemical_compound ,Crystallography ,Octahedron ,Chemistry ,Dimer ,Sodium ,Infrared spectroscopy ,Vanadium ,chemistry.chemical_element ,General Chemistry ,Triclinic crystal system ,Magnetic susceptibility ,Ion - Abstract
Tris[o-mercaptophenolato]vanadium(IV) dimer complexes (A)2[V(mp)3NaLL']2 (A = Ph4P+, H2mp = o-mercaptophenol, L = MeCN, L'=EtOH, (1); L' = MeOH, (2)) were prepared by the reaction of anhydrous VC13, and Na2mp in the molar ratio 1:3. Complex (3) (A = Et4N+, L=L' = MeOH) was prepared by the reaction of VC13, Na2mp and Li2S in the molar ratio 1:2:1. The complexes were characterized by X-ray diffraction crystallography, infrared spectra, magnetic susceptibility, and cyclic voltammetric measurements. Complex 2 crystallizes in the triclinic space group P1 with a=12.813(6), b = 14.199(4), c = 12.790(5) A, α = 112.72(2), β = 104.24(4). γ = 88.68(4)°, V = 2073.6 A3, and Z=1. The structure was refined to R=0.058. Complex 3 crystallizes in the mono-clinic space group P21/n with a=12.359(3), b=17.452(6), c=14.829(13) A, βequals;96.51(5)°, V=3177.8 A3, and Z=2. The final R factor is 0.067. Both of the anions of 2 and 3 contain two [V(mp)3]2− fragments linked by sodium ions through the μ3-O bridges with a crystallographic center of symmetry. The V(IV) atom is in a coordination environment intermediate between a trigonal prism and an ideal octahedron.
- Published
- 2010
- Full Text
- View/download PDF
4. [Co3(1,2-S2C6H4)3(PPh3)3]+, A basic triangle unit of some polynuclear molecules
- Author
-
Rong Cao, Maochun Hong, Feilong Jiang, Xiao-Ying Huang, Daxu Wu, and Hanqin Liu
- Subjects
Denticity ,Stereochemistry ,Ligand ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,HEXA ,Crystallography ,chemistry.chemical_compound ,chemistry ,Oxidation state ,Molecule ,Cobalt ,Phosphine - Abstract
[Co3(1,2-S2C6H4)3(PPh3)3][CoBr3(DMF)]sol (1, sol=CHCl3·O(C2H5)2·H2O) was obtained from the reaction of CoBr(PPh3)3 with Na2(S2C6H4) in chloroform. The Co3 core in the cation of 1 exhibits a metal-metal bonded isosceles triangle, in which the two longer Co—Co bonds are both bridged by S2C6H4 ligands on two sides of the triangle plane respectively, while the bottom short Co—Co bond is bridged by the third bidentate S2C6H4 ligand. A series of polynuclear cobalt cluster compounds with phosphine, thiolate and/or sulphur ligands were prepared by low oxidation state Co+ with thiolates in organic solvents. These tri-, tetra-, hexa-, heptanuclear cluster compounds 1–8 with various types of crystal structures can be viewed as the condensed polynuclear cobalt complexes that the cobalt atom frameworks with sulphur bridged were built through the small triangular units of [Co3S3nL3] (n=1,2) with or without [CoL] (L=PR3, Br, Cl,5-C5H5) fragments.
- Published
- 2010
- Full Text
- View/download PDF
5. Synthetic and structural chemistry of nickel(II) complexes containing dithiolato and phosphine ligands I. Preparation and crystal structure of Ni2(PPh3)2(edt)2
- Author
-
Xinjian Lei, Hanqin Liu, Rong Cao, Zhiying Huang, Bei-Sheng Kang, and Maochun Hong
- Subjects
Stereochemistry ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,Triclinic crystal system ,Sulfur ,Spectral line ,chemistry.chemical_compound ,Crystallography ,Nickel ,chemistry ,Atom ,Proton NMR ,Phosphine - Abstract
A nickel(II) complex containing both dithiolato and phosphine ligands, Ni2(PPh3)2(edt)2 (edt = SCH2CH2S2-), has been prepared and characterized by X-ray diffration. The complex crystallizes in the triclinic system, space group P-1, with a = 10.693(3), b = 17.457 (6), c = 10.606 (3) A, α = 102.84(2), β = 96.49 (2), γ = 82.56(3); V = 1906.8 A3; Dc = 1.439 g·cm−3 for Z = 2; the final conventional R was 0.052 based on 3338 observed reflections. Nickel atoms are linked by two sulfur atoms from two edt ligands with the Ni—Ni distance of 2.893 A, and each Ni atom is coordinated by one phosphorus atom and three sulfur atoms with a square-planar geometry, where the average length of Ni—S bond is 2.180 A and Ni—P bond 2.188 A. The UV-Vis and 1H NMR spectra have also been recorded.
- Published
- 2010
- Full Text
- View/download PDF
6. A bi-butterfly W-Cu-S cluster compound: Synthesis and crystal structure of (n-Bu4N)2[W2Cu4S8(S2CNC4H8)2]
- Author
-
Rong Cao, Hanqin Liu, Maochun Hong, Xinjian Lei, and Zhiying Huang
- Subjects
Crystallography ,Chemistry ,Infrared spectroscopy ,General Chemistry ,Crystal structure ,Monoclinic crystal system - Abstract
The compound (n-Bu4N)2[W2Cu4S8(S2CNC4H8)2] was obtained by the reaction of Bu4NBr, (NH4)2WS4, NaS2NCC4H8 and CuCl in CH3CN and CH3OH. It crystallizes in the monoclinic space group P21/c with unit cell parameters: a=21.875(5), b=16.843(4), c=17.745(5)A, β = 101.69(6)°, V=6402(6)A3, Z=4, Dc=1.718 g·cm−3. The final R and Rw values converged to 0.055 and 0.060 respectively. The structure consists of two ‘butterfly’ units [WS4Cu2] linked together by two weak Cu—S bonds and two bridging S2CNC4H8 ligands. Infrared spectra gave characteristic absorptions at 495 cm−1 for W=S and 450, 435, 412 cm−1 for W—μ-S.
- Published
- 2010
- Full Text
- View/download PDF
7. Synthesis and crystal structure of [V2(μ-S2)2(S2CNEt2)4] · 2CH3Cl
- Author
-
Zhiying Huang, Feilong Jiang, Mac‐Chun Hong, Daxu Wu, Hanqin Liu, and Xinjian Lei
- Subjects
chemistry.chemical_classification ,Tetragonal crystal system ,Crystallography ,Denticity ,Coordination sphere ,chemistry ,Atom ,Orthorhombic crystal system ,General Chemistry ,Crystal structure ,Prism ,Dithiocarbamate - Abstract
[V2(μ-S2)2(S2CNEt2)4] 2CH3Cl was synthesized by the reaction of NaS2CNEt2, Li2S and VOCl3 at room temperature. Crystal data: M= 1061.3, space group Pbca, with the orthorhombic parameters: a=20.123(3), b = 20.485(4)1c=10.911(3)A, V=4497.7A3, Z=4, Dc=1.57 g/cm3, Mo Ko radiation (λ=0.71069 A), μ = 13.2 cm−1, F(000)—2168. Final R = 0.041 and Rw=0.047 for 2288 observed reflections with I>3σ(I). The coordination sphere of each V atom in title compound is a distorted tetragonal prism composed of two bidentate dithiocarbamate and two S21− ligands. The V—V distance is 2.890 A while the V—S distances fall in the range of 2.422–2.505 A.
- Published
- 2010
- Full Text
- View/download PDF
8. Synthetic and structural chemistry of hexacobalt cluster compounds II. Preparation and structure of Co6(μ-S)8 (Ph2PCH2P(O)Ph2)6
- Author
-
Maochun Hong, Bei-Sheng Kang, Zhiying Huang, Feilong Jiang, Hanqin Liu, and Xinjian Lei
- Subjects
Crystallography ,Octahedron ,Group (periodic table) ,Chemistry ,Stereochemistry ,Hexagonal crystal system ,Cluster (physics) ,Structure (category theory) ,Molecule ,General Chemistry ,Structural chemistry - Abstract
Co4(μ3-S)8(Ph2PCH2sP(O)Ph2)6, MW = 3012.5, space group R3, has the hexagonal parameters, a = 26.764 (10), c = 16.979 (10) A, V = 10532.8 A3, Z = 3. Mo Ka radiation, λ = 0.71069 A, Dc = 1.425 g/cm3, μ = 9.94 cm−3, F(000) = 4650, R = 0.073 and Rw = 0.077 for 1965 observed unique reflections with I > 3σ (I). The molecular structure consists of a distorted octahedral Co4—core. The Co—Co and Co—S distances fall in the range of 2.805—2.838 and 2.213—2.253 A, respectively.
- Published
- 2010
- Full Text
- View/download PDF
9. Directionally dendritic growth of metal chalcogenide crystals via mild template-free solvothermal method
- Author
-
Cheng-Yong Su, Hanqin Liu, Wenxia Zhao, Ai-Miao Qin, and Yueping Fang
- Subjects
Materials science ,Chalcogenide ,Solvothermal synthesis ,Crystal growth ,Condensed Matter Physics ,Inorganic Chemistry ,Crystal ,Dendrite (crystal) ,chemistry.chemical_compound ,Crystallography ,chemistry ,Transmission electron microscopy ,Materials Chemistry ,Selected area diffraction ,High-resolution transmission electron microscopy - Abstract
Dendritic metal chalcogenide (HgS, CdS and PbS) single crystals have been prepared via facile and mild solvothermal process in water or ethanol/water systems. SEM and TEM observations show that HgS and CdS dendrites exhibit whole or part of the two-dimensional (2D) hexagonal snowflake spatial pattern while PbS exhibits whole or part of the three-dimensional (3D) octahedral star-like morphology. Selected area electron diffusion (SAED) and HRTEM show that all of these dendrites are single crystals whose shape evolution is closely related to their intrinsic crystal symmetries. The factors influencing the evolution of the crystal morphology, i.e. reactant molar ratio, solvent, sulfur source, reaction time and temperature have been investigated. Two dimensional six-fold symmetrical HgS and CdS dentrites and 3D four-fold symmetrical PbS dentrite have been fabricated by a facile solvothermal method. The crystal evolution process has been investigated.
- Published
- 2005
- Full Text
- View/download PDF
10. Formation of Various Morphologies of Covellite Copper Sulfide Submicron Crystals by a Hydrothermal Method without Surfactant
- Author
-
Hanqin Liu, Yueping Fang, Huang-Dong Ou, Cheng-Yong Su, and Ai-Miao Qin
- Subjects
Absorption spectroscopy ,Chemistry ,Stereochemistry ,Energy-dispersive X-ray spectroscopy ,Crystal growth ,General Chemistry ,Covellite ,Condensed Matter Physics ,Hydrothermal circulation ,Copper sulfide ,chemistry.chemical_compound ,Thiourea ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Hydrothermal synthesis ,General Materials Science - Abstract
Covellite copper sulfide submicron crystals in the shapes of ball-like, rodlike, and chrysanthemum-like architectures congregated from nanoslices with thickness of 20 to 100 nm have been prepared by a hydrothermal method without using any surfactant and characterized by X-ray diffraction, energy-dispersive X-ray spectrometer (EDX), UV−vis optical absorption spectra, and electron-microscopy techniques. A systematic investigation has been carried out to understand the factors influencing the evolution of the crystal morphology which was found to be predominant by the reactant molar ratio (Tu:Cu(NO3)2, Tu = thiourea), the hydrothermal reaction time, and the temperature. Possible crystal growth processes are also discussed.
- Published
- 2005
- Full Text
- View/download PDF
11. Hydrothermal Synthesis of Rare Earth (Tb, Y) Hydroxide and Oxide Nanotubes
- Author
-
Rui-Qi Song, Jimmy C. Yu, Yueping Fang, Liping You, Hua-Xin Zhang, Hanqin Liu, Quan Li, and An-Wu Xu
- Subjects
Nanotube ,Materials science ,Scanning electron microscope ,Oxide ,Nanotechnology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,Thermogravimetry ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,chemistry ,Electron diffraction ,Chemical engineering ,law ,Electrochemistry ,Hydroxide ,Hydrothermal synthesis ,Calcination - Abstract
In this paper, Tb(OH)3 and Y(OH)3 single-crystalline nanotubes with outer diameters of 30–260 nm, inner diameters of 15–120 nm, and lengths of up to several micrometers were synthesized on a large scale by hydrothermal treatment of the corresponding oxides in the presence of alkali. In addition, Tb4O7 and Y2O3 nanotubes can be obtained by calcination of Tb(OH)3 and Y(OH)3 nanotubes at 450 °C. X-ray diffraction (XRD), field-emission scanning electron microscopy, transmission electron microscopy (TEM), electron diffraction (ED), energy-dispersive X-ray spectroscopy (EDS), thermogravimetry, and differential scanning calorimetry (DSC) have been employed to characterize these nanotube materials. The growth mechanism of rare earth hydroxide nanotubes can be explained well by the highly anisotropic crystal structure of rare earth hydroxides. These new types of rare earth compound nanotubes with open ends have uses in a variety of promising applications such as luminescent devices, magnets, catalysts, and other functional materials. Advantages of this method for easily realizing large-scale production include that it is a simple and unique one-pot synthetic process without the need for a catalysts or template, is low cost, has high yield, and the raw materials are readily available. The present study has enlarged the family of nanotubes available, and offers a possible new, general route to one-dimensional single-crystalline nanotubes of other materials.
- Published
- 2003
- Full Text
- View/download PDF
12. Syntheses, Crystal Structures, and Luminescent Properties of Lanthanide Complexes with Tripodal Ligands Bearing Benzimidazole and Pyridine Groups
- Author
-
Xiao-Ping Yang, Hanqin Liu, Bei-Sheng Kang, Wai-Kwok Wong, and Cheng-Yong Su
- Subjects
Lanthanide ,Benzimidazole ,Ligand ,Stereochemistry ,Chemistry ,Coordination number ,Metal ions in aqueous solution ,Crystal structure ,Medicinal chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Pyridine ,Amine gas treating ,Physical and Theoretical Chemistry - Abstract
Two tripodal ligands, bis(2-benzimidazolylmethyl)(2-pyridylmethyl)amine (L(1)) and bis(2-pyridylmethyl)(2-benzimidazolylmethyl)amine (L(2)), were synthesized. With the third chromophoric ligand antipyrine (Antipy), three series of lanthanide(III) complexes were prepared: [LnL(1)(Antipy)(3)](ClO(4))(3) (series A), [LnL(1)(Antipy)Cl(H(2)O)(2)]Cl(2)(H(2)O)(2) (series B), and [LnL(2)(NO(3))(3)] (series C). The nitrate salt of the free ligand H(2)L(1).(NO(3))(2) and six complexes were structurally characterized: Pr(3+)A, Y(3+)A, Eu(3+)B, Eu(3+)C, Gd(3+)C and Tb(3+)C, in which the two A and three C complexes are isomorphous. Crystallographic studies showed that tripodal ligands L(1) and L(2) exhibited a tripodal coordination mode and formed 1:1 complexes with all lanthanide metal ions. The coordination numbers of the lanthanide metal ions for the A, B, and C complexes were 7, 8, and 10, respectively. Conductivity studies on the B and C complexes in methanol showed that, in the former, the coordinated Cl(-) dissociated to give 3:1 electrolytes and, in the latter, two coordinated NO(3)(-) ions dissociated to give 2:1 electrolytes. Detailed photophysical studies have been performed on the free ligands and their Gd(III), Eu(III), and Tb(III) complexes in several solvents. The results show a wide range in the emission properties of the complexes, which could be rationalized in terms of the coordination situation, the (3)LC level of the complexes, and the subtle variations in the steric properties of the ligands. In particular the Eu(3+)A and Tb(3+)A complexes, in which the central metal ions were wholly coordinated by chromophoric ligands of one L(1) and three antipyrine molecules, had relatively higher emission quantum yields than their corresponding B and C complexes.
- Published
- 2002
- Full Text
- View/download PDF
13. Chair- andBoat-Configurations of Silver(I) Complexes of Ditopic Ligand Involving Benzimidazolyl Substituents
- Author
-
Zhongyuan Zhou, Bei-Sheng Kang, Cheng-Yong Su, Albert S. C. Chan, Li-Xin Zhu, Hanqin Liu, Hua-Xin Zhang, and Yue-Peng Cai
- Subjects
Inorganic Chemistry ,Silver salts ,Hydrogen bond ,Chemistry ,Ligand ,Polymer chemistry ,Proton NMR ,Molecule ,Network structure ,Trigonal crystal system ,Crystal structure ,Medicinal chemistry - Abstract
The ditopic ligand 1, 2-bis(benzimidazol-1-ylmethyl)benzene (L1) as well as its silver(I) complexes [Ag2L12(CF3CO2)2] (1) and [Ag2L12](CF3SO3)2 · (L1) · 2H2O · 0.5C2H5OH (2) were prepared and structures characterized by X-ray crystallography. The AgI atoms in 1 are trigonally coordinated by two NBIm atoms from the arms of L1 and by one O atom of the anion CF3CO2—, while those in 2 are only linearly ligated by NBIm. Different silver salts of CF3CO2— and CF3SO3— lead to different configurations of the dimeric unit [Ag2L12]2+: chair-form in (1) but boat-form in (2). The discrete molecules in both 1 and 2 are assembled into network structures through face-to-face π · · · π stacking and edge-to-face C—H · · · π interactions in the crystalline state, as well as N—H · · · O and C—H · · · O hydrogen bonds. Solution 1H NMR studies showed the formation of one sole species in solution or a rapid equilibrium was established on the NMR time scale at room temperature. Sessel- und Boot-Konfigurationen von Silber(I)-Komplexen des ditopen Liganden mit Benzimidazolylsubstituenten Der ditope Ligand 1, 2-Bis(benzimidazol-1-ylmethyl)benzen (L1) und seine Silber(I)-Komplexe [Ag2L12(CF3CO2)2] (1) und [Ag2L12](CF3SO3)2 · (L1) · 2H2O · 0.5C2H5OH (2) wurden dargestellt und durch Rontgenstrukturanalysen charakterisiert. Die Silber(I)-Atome in 1 sind trigonal von zwei NBim-Atomen der Arme von L1 und von einem O-Atom des CF3CO2—-Anions koordiniert, wahrend sie in 2 nur linear von NBim koordiniert werden. Die verschiedenen Silbersalze von CF3COO2— bzw. CF3SO3— fuhren zu unterschiedlichen Koonfigurationen der dimeren [Ag2L12]2+-Einheit: Sessel-Form in 1 und Boot-Form in 2. Im kristallinen Zustand sind die isolierten Molekule sowohl von 1 wie von 2 in Netzwerkstrukturen angeordnet mit Flache-zu-Flache-π · · · π-Stapelung und Kante-zu-Flache-C—H · · · π-Wechselwirkung sowie N—H · · · O und C—H · · · O-Wasserstoff-Bruckenbindungen. 1H-NMR-Untersuchungen in Losung zeigen die Bildung von nur einer Spezies oder einer schnellen Gleichgewichtseinstellung in Losung bei Raumtemperatur.
- Published
- 2002
- Full Text
- View/download PDF
14. Preparation of inorganic salts (CaCO3, BaCO3, CaSO4) nanowires in the Triton X-100/cyclohexane/water reverse micelles
- Author
-
Hanqin Liu, Yueping Fang, An-Wu Xu, Dai-Bin Kuang, and Huang-Dong Ou
- Subjects
Nanostructure ,Morphology (linguistics) ,Cyclohexane ,Chemistry ,Inorganic chemistry ,Nanowire ,Condensed Matter Physics ,Micelle ,Inorganic Chemistry ,chemistry.chemical_compound ,Calcium carbonate ,Chemical engineering ,Transmission electron microscopy ,Triton X-100 ,Materials Chemistry - Abstract
Nanowires of inorganic salts (CaCO 3 , BaCO 3 , CaSO 4 ) were prepared in the nonionic surfactant reverse micelles (Triton X-100/cyclohexane/water) system. The growth process of CaCO 3 nanowire was monitored by the transmission electron microscopy (TEM) technique as a function of time. TEM images reveal that the CaCO 3 nanowires were formed in the reverse micelles by the directional aggregation process. The nanowires of CaCO 3 were 5–30 nm in diameter and had a length more than 10 μm.
- Published
- 2002
- Full Text
- View/download PDF
15. Helical complexes from the self-assembly of silver salts and the polydentate thioether α,α′-bis(8-thioquinoline)-m-xylene
- Author
-
Cheng-Yong Su, Jun-Ling Shi, Zhongyuan Zhou, Albert S. C. Chan, Sen Liao, Hua-Xin Zhang, Hanqin Liu, and Bei-Sheng Kang
- Subjects
Denticity ,Ligand ,Cationic polymerization ,Crystal structure ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Thioether ,chemistry ,Intramolecular force ,Helix ,Materials Chemistry ,Physical and Theoretical Chemistry ,Xylylene - Abstract
The self assembly of AgX with the sulfur-containing multidentate ligand α,α′-bis(8-thioquinoline)-m-xylene (m-XYTQ) affords two isomorphous complexes [Ag(m-XYTQ)]nXn (X=ClO4 1; X=BF4 2). Single crystal X-ray analyses revealed the complexes to contain linear cationic chains of [Ag(m-XYTQ)]nn+ in helical arrangement and the anions are discrete. Intramolecular π⋯π stackings pack the asymmetric units [Ag(m-XYTQ)] in shelves-like arrays while interchain π⋯π interactions between racemic chains constructed the 2D network. The key to helix formation is the folding at the sulfur sites of the spacer xylylene in the ligand. The complexes were also characterized by 1H NMR and IR.
- Published
- 2002
- Full Text
- View/download PDF
16. Supramolecular Architectures Based on trans -Oxamidato-Bridged Copper(II) Synthons and Intramolecular Synergism
- Author
-
Hua-Xin Zhang, Hanqin Liu, An-Wu Xu, Bei-Sheng Kang, and Zhong-Ning Chen
- Subjects
Inorganic Chemistry ,Crystallography ,Covalent bond ,Chemistry ,Hydrogen bond ,Intramolecular force ,Synthon ,Intermolecular force ,technology, industry, and agriculture ,Supramolecular chemistry ,Molecule ,Bridging ligand - Abstract
The trans-oxamidato dicopper(II) "synthons", [Cu 2 (trans-L)] 2+ (L= oxen, oxpn, oxap, and oxpy) have been used as construction units when further connected by a second bridging ligand L′ (spacer) to fabricate supramolecular architectures via covalent and hydrogen bonding interactions. The structural topologies of the polymeric networks contained by these compounds depend mainly on the coordination modes of the spacers. When the spacers are 2-connectors bridging two synthons, the resulting compounds usually contain 1-D infinite chains, while 3- or 4-connector provides compounds containing 2-D extended coordination networks. The hydrogen bonds, in which the oxamidate, the spacer, and the water molecules are involved, are prevalent and the predominant intermolecular interactions. Compared with the polymeric networks constructed via covalent bonding interactions between synthons and spacers, the structural topologies of the 3-D supramolecular architectures fabricated via hydrogen bonding interactions are mor...
- Published
- 2002
- Full Text
- View/download PDF
17. Syntheses and characterization of copper(II) complexes of bis(acetylacetone)trimethylenediimine
- Author
-
Sun Jie, Bei-Sheng Kang, Yue-Peng Cai, Hanqin Liu, An-Wu Xu, Cheng-Yong Su, and Yexiang Tong
- Subjects
Schiff base ,Dimer ,Acetylacetone ,Inorganic chemistry ,chemistry.chemical_element ,Crystal structure ,Electrochemistry ,Copper ,Adduct ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Materials Chemistry ,Moiety ,Physical and Theoretical Chemistry - Abstract
Copper(II) complexes [Cu(acactn)H2O]2 (1) and [Cu2(acactn)2KClO4]2 (2), where H2acactn is a tetradentate Schiff base bis(acetylacetone)trimethylenediimine, have been prepared and characterized by IR, CV and X-ray single crystal structure analyses. The ligand H2acactn is strongly metallophilic to stabilize Cu(II) ion with a square planar N2O2 coordination environment. Complex 1 can be seen as a hydrogen-bonded dimer of building block Cu(acactn) via bridging water molecules, while complex 2 is a tetrametric adduct of [Cu(acactn)] moiety and KClO4, in which K+ and ClO4− are the bridging-groups. Electrochemical studies displayed that Cu(II)/Cu(I) is an irreversible one-electron reduction process.
- Published
- 2001
- Full Text
- View/download PDF
18. Self-assembly of silver(I) polymers with single strand double-helical structures containing the ligand O,O′-bis(8-quinolyl)-1,8-dioxaoctane
- Author
-
Bei-Sheng Kang, Li Zhang, Cheng-Yong Su, Hua-Xin Zhang, An-Wu Xu, Yue-Peng Cai, Chun-Long Chen, and Hanqin Liu
- Subjects
chemistry.chemical_classification ,Crystallography ,Denticity ,chemistry ,Ligand ,Hydrogen bond ,Molecule ,General Chemistry ,Polymer ,Self-assembly ,Single crystal ,Coordination geometry - Abstract
The flexible multidentate ligand O,O′-bis(8-quinolyl)-1,8-dioxaoctane (ODOQ) reacted with AgX (X = ClO4−, BF4−, CF3SO3−, or CF3CO2−) to give four new complexes [Ag(ODOQ)]nXn: X = ClO4−1; X = BF4−2; X = CF3SO3−3, and [Ag(ODOQ)(CF3CO2)]n4. All four complexes have been characterized by elemental analyses, IR and 1H NMR spectroscopy. Single crystal X-ray analyses showed that they have similar 1-D extended architectures with each ligand in “∼” shape, while the chains are alternately and parallelly arranged with the silver(I) atoms as the backbone to form double helical mesomeric strands. The structures are controlled more by the spacer (CH2)6 than by the anions: the versatile coordination geometry of the silver(I) atom is trigonally bonded but changes to distorted tetrahedral or trigonal bipyrimidal via weak Ag⋯O interactions. In addition, face-to-face π⋯π (in 1–4) and edge-to-face C–H⋯π (in 3) interactions as well as hydrogen bonds C–H⋯O and C–H⋯F between adjacent strands assemble the cations in 1–3 or neutral molecules in 4 into an extended network.
- Published
- 2001
- Full Text
- View/download PDF
19. Bivalent transition metal complexes of 4,5-diazafluorene-9-one benzoylhydrazone (HL) and the characterization of weak interaction in CoL 2 (H 2 O) 2
- Author
-
Zhong-Lin Lu, Liang-Rong Deng, Cheng-Yong Su, Kai-Bei Yu, Wen Xiao, Hanqin Liu, and Bei-Sheng Kang
- Subjects
Denticity ,Chemistry ,Hydrogen bond ,Ligand ,Stereochemistry ,Organic Chemistry ,Molar conductivity ,Analytical Chemistry ,Inorganic Chemistry ,Metal ,Crystallography ,Transition metal ,visual_art ,Octahedral molecular geometry ,visual_art.visual_art_medium ,Molecule ,Spectroscopy - Abstract
A new ligand 4,5-diazafluorene-9-one benzoylhydrazone (HL) and six of its transition metal complexes ML2·nH2O [ M(II) = Mn, n=2, 1; Co, 2, 2; Ni, 2, 3; Cu, 3, 4; Zn, 1.5, 5; Pb, 4, 6] have been prepared and characterized. Elemental analyses, IR, UV–Vis, 1H NMR, molar conductivity and thermal analyses measurements showed that the ligand coordinates to the metal ion with the enolic O and azomethine N atoms of the acylhydrazone group while the 4,5-diazafluorene moiety is free. Single crystal X-ray diffraction studies showed that CoL2(H2O)2, 2, has a centrosymmetric octahedral geometry of N2O4 with the two bidentate ligands in the basal plane and the two water molecules in the axial sites. The molecules of 2 are linked together by intermolecular hydrogen bonds Ndiazafluorene⋯HOH⋯N′diazafluorene and π–π stacking interactions between the diazafluorene rings to form 2D sheets.
- Published
- 2000
- Full Text
- View/download PDF
20. Chemistry of aroylhydrazones II
- Author
-
Wen Xiao, Bei-Sheng Kang, Xiu-Jian Wang, Kai-Bei Yu, Cheng-Yong Su, Hanqin Liu, and Zhong-Lin Lu
- Subjects
Chemistry ,Ligand ,Inorganic chemistry ,Crystal structure ,Inorganic Chemistry ,Metal ,Crystallography ,Transition metal ,visual_art ,Octahedral molecular geometry ,Materials Chemistry ,visual_art.visual_art_medium ,Moiety ,Molecule ,Chelation ,Physical and Theoretical Chemistry - Abstract
Transition metal complexes M(HL)2·nH2O (M(II)=Mn, n=2 (1); Co, n=3 (2); Ni, n=4 (3); Cu, n=3 (4); Zn, n=2 (5); Pb, n=0 (6)) of 4,5-diazafluorene-9-one salicyloylhydrazone (H2L), have been prepared by the reaction of H2L with the metal(II) acetates in EtOH–DMF. X-ray diffraction studies showed that the ligand in the solid state has a pseudo-helical structure in the keto-form. In complexes Mn(HL)2(H2O)2 (1) and Co(HL)2(DMF)2 (2a), the ligand coordinates to the metal ion as a mononegative ion in the enol-form with the enolic oxygen and azomethine nitrogen atoms of the aroylhydrazone group forming a five-membered chelate ring, while the phenolic hydroxyl group and pyridyl-N atoms of the diazafluorene moiety are free. The metal atoms are in octahedral geometry with N2O4 from two ligands HL in the equatorial plane and the axial sites occupied by solvent molecules. The structures were also characterized by IR and 1H NMR spectroscopy.
- Published
- 2000
- Full Text
- View/download PDF
21. [Untitled]
- Author
-
Weimin Liu, Cheng-Yong Su, Bei-Sheng Kang, Sen Liao, Hanqin Liu, Yue-Peng Cai, Zefu Zhang, and Cheng Zhang
- Subjects
Ligand ,Stereochemistry ,Quinoline ,Metals and Alloys ,chemistry.chemical_element ,Magnetic susceptibility ,Catalysis ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Nickel ,chemistry ,Materials Chemistry ,Molecule ,Cobalt ,Organometallic chemistry - Abstract
New nickel(II) and cobalt(II) complexes of a symmetric acyclic mixed O,N,S-donor ligand, S,S′-bis(8-quinolyl)-4-oxo-1,7-dithiaheptane (OESQ), with quinoline as the terminal group, [M(OESQ)(H2O)](NO3)2 [M = NiII (1) and CoII (2)], have been prepared and characterized by elemental analyses, u.v.–vis. and i.r. spectra, and by magnetic susceptibility measurement. Single X-ray diffraction analyses show that (1) and (2) are isomorphous. The nickel (or cobalt) ion in (1) [or (2)] is hexa-coordinated and the complex cation exhibits a slightly distorted-octahedral geometry defined by all five donor atoms of the ON2S2 of OESQ and a water, molecule with N2S2 in equatorial and two oxygens in axial position.
- Published
- 2000
- Full Text
- View/download PDF
22. Silver(I) complexes with quinoline based linear multidentate ligands: self-assembly of sulfur-bridged tetrametallotricyclic boxes †
- Author
-
Sen Liao, Bei-Sheng Kang, Hai-Liang Zhu, Hanqin Liu, Xiao-Ming Chen, and Cheng-Yong Su
- Subjects
Denticity ,Inorganic chemistry ,Quinoline ,chemistry.chemical_element ,General Chemistry ,Sulfur ,Ion ,Perchlorate ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Molecule ,Self-assembly ,Single crystal - Abstract
The flexible linear multidentate ligands 1,5-bis(8-quinolylsulfanyl)-3-oxapentane (OESQ) and 1,8-bis(8-quinolylsulfanyl)-3,6-dioxaoctane (ODSQ) reacted with silver(I) perchlorate affording the simple mononuclear complexes [Ag(OESQ)]ClO41 and [Ag(ODSQ)]ClO42, respectively. However, with silver(I) nitrate, novel metallosupramolecular complexes [Ag4(ODSQ)2(η1-NO3)2(η2-NO3)2] 3 and [Ag4(OESQ)(ODSQ)(η1-NO3)2(η2-NO3)2]·H2O 4 were obtained, in which the co-ordination motifs [Ag(OESQ)]+ and [Ag(ODSQ)]+ are spontaneously self-assembled by sulfur-bridged silver(I) ions into tetrametallotricyclic molecules containing the same or mixed building blocks. All four complexes have been characterized by elemental analyses, IR and 1H NMR spectroscopy, and single crystal X-ray diffraction methods. The possible self-assembly process has been discussed with the aid of electrospray mass spectrometry.
- Published
- 2000
- Full Text
- View/download PDF
23. ThegValues of Some Halomolybdenyl, -vanadyl, and -chromyl Complexes
- Author
-
Wenjie Li, Maochun Hong, Bei-Sheng Kang, Rong Cao, and Hanqin Liu
- Subjects
Ions ,Models, Molecular ,Molybdenum ,Nuclear and High Energy Physics ,Series (mathematics) ,Chemistry ,Inorganic chemistry ,Molecular Conformation ,Biophysics ,Condensed Matter Physics ,Biochemistry ,Molecular conformation ,Ion ,Structure-Activity Relationship ,Chromates ,Humans ,Physical chemistry ,Vanadates - Abstract
The principal g values of a series of [MOXn]m- (M = VIV, CrV, MoV; X = F-, Cl-, Br-; n = 4, 5; m = 1, 2, 3) complexes are calculated by the INDO-CI-Stone method. The results agree well with the experimental data and reveal that the traditional models have some limitations in calculating g values for some complexes of this type.
- Published
- 1999
- Full Text
- View/download PDF
24. Chemistry of tripodal ligands. Part III
- Author
-
Hanqin Liu, Yexiang Tong, Xiao-Ping Yang, Bei-Sheng Kang, Ting-Bin Wen, Cheng Zhang, Cheng-Yong Su, and Jie Sun
- Subjects
Stereochemistry ,Copper protein ,chemistry.chemical_element ,Medicinal chemistry ,Copper ,Redox ,Square pyramidal molecular geometry ,Inorganic Chemistry ,Active center ,chemistry.chemical_compound ,Trigonal bipyramidal molecular geometry ,chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Phosphine ,Derivative (chemistry) - Abstract
The reactions of copper (I or II) salts with ligands Rntb (tris( N -alkylbenzimidazol-2-ylmethyl)amine) gave complexes [Cu(II)(ntb)Cl]Cl·3H 2 O ( 1 ), [Cu(I)(ntb)(PPh 3 )](NO 3 )·1.5H 2 O ( 2 ), [Cu(II)(Prntb)I]Cl ( 3 ) and [Cu(I)(Prntb)I] ( 4 ), depending on the reaction conditions. X-ray single crystal diffraction analyses showed the copper atom to be tetrahedrally coordinated in 2 and 4 , but square pyramidal in 1 and trigonal bipyramidal in 3 . Structural characteristics were revealed for the complexes and compared, and complex 3 was shown to be the best model compound among the four for the active center of blue copper proteins. CV studies showed the electrochemical behaviors of the complexes: 1 has two redox couples, phosphine ligation stabilizes 2 towards redox reactions, while 3 and 4 , with the same cationic formula [Cu(Prntb)I] 1+,0 have very similar complicated redox patterns, indicating the reversibility of the two species. IR and UV–Vis spectroscopic studies were also reported.
- Published
- 1999
- Full Text
- View/download PDF
25. REACTIONS OF TRANSITION METAL THIOLATO UNITS IV. FORMATION OF PHOSPHINE-CONTAINING COBALT OR NICKEL COMPLEXES WITH iso-MALEONITRILE-DITHIOLATE
- Author
-
Zhang Lin, Bei-Sheng Kang, Zhong-Ning Chen, Hanqin Liu, Xiao-Ying Huang, and Hua-Xin Zhang
- Subjects
chemistry.chemical_classification ,Denticity ,Stereochemistry ,chemistry.chemical_element ,Crystal structure ,Coordination complex ,Crystallography ,Nickel ,chemistry.chemical_compound ,Transition metal ,Octahedron ,chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Phosphine ,Monoclinic crystal system - Abstract
The reaction of M2+ (M=Co or Ni) with K2(i-mnt) and phosphine forms chelated ternary coordination compounds (1)-(4). The crystal structures of Ni(i-mnt)(dppmSe) (1) (in the presence of Se) and (“Bu4N”)[Co(i-mnt)2(PBu n 2] (2) were determined by single-crystal X-ray diffraction analyses; (1) crystallizes in the monoclinic space group P21/n with a = 12.002(3), b = 19.568(11), c = 12.456(5) A, β = 92.22(3)°, V = 2923.4 A3, Z=2, R(Rw ) = 0.051 (0.062). The distorted, square planar Ni atom forms two individual chelate rings with the two bidentate ligands. Complex (2) crystallizes in space group P 1 with a = 10.682(2), b = 28.496(6), c = 9.959(2) A, α = 91.31(2), β = 97.71(2), γ = 83.68(2)°, V=2986(1)A3, Z=2, R (Rw ) = 0.060 (0.072). The octahedral Co(III) ion in (2) has an elongated structure with two monodentatc phosphines in axial positions and i-mnt groups chelating in the equatorial plane. Spectroscopic characterization was performed where appropriate.
- Published
- 1999
- Full Text
- View/download PDF
26. [Untitled]
- Author
-
Ting-Bin Wen, Qiutian Liu, Bei-Sheng Kang, Xiu-Jian Wang, Cheng-Yong Su, and Hanqin Liu
- Subjects
Synthon ,Metals and Alloys ,Vanadium ,chemistry.chemical_element ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Trigonal prism ,chemistry ,Octahedron ,Materials Chemistry ,Organometallic chemistry ,Coordination geometry - Abstract
The mononuclear complex (BzMe3N)2[V(mp)3] · MeCN · 1/2 MeOH (1) (mp = o-SC6H4O2−) obtained by reacting VCl3 with Na2mp in the presence of BzMe3NBr contains the synthon [V(mp)3]2−. Further reaction with Co2(CO)8 gave [V(mp)3Co(Py)2(MeCN)] · 2MeCN (2) and [V(mp)3Co(DMF)3] (3), depending on the recrystallization conditions. The coordination geometry of the V atoms in all these complexes lies between an octahedron and a trigonal prism. Upon formation of (2) and (3), the terminal oxo atoms of mp become μ2-O bridges between V and Co, while the latter atom is also octahedral.
- Published
- 1999
- Full Text
- View/download PDF
27. Chemistry of 2-mercaptophenol (H2mp) . Part iii. One dimensional arrays of binuclear anions of Mo (VI) linked by bis (2-hydroxyphenyl) disulfide via hydrogen bondings
- Author
-
Hong Liang, Zhong-Ning Chen, Bei-Sheng Kang, Hanqin Liu, Zhen-Feng Chen, Cheng-Yong Su, Xiu-Jian Wang, and Kai-Bei Yu
- Subjects
Hydrogen ,Chemistry ,Hydrogen bond ,Inorganic chemistry ,Disulfide bond ,chemistry.chemical_element ,Medicinal chemistry ,Spectral line ,Ion ,Inorganic Chemistry ,Part iii ,Molybdenum ,Materials Chemistry ,Proton NMR ,Physical and Theoretical Chemistry - Abstract
The reaction of (Bu4N) 4 [Mo8O26] with a suitable amount of 2-mercaptophenol (H2mp) in MeOH in the presence of equimolar Et3N gave the complex (Bu4N) 2 [{MoO2 (2-SC6H4O) }2 (μ-O) ] (2 2′-HOC6H4SSC6H4OH) 2H2O (1) with a one-dimensional chain network formed via hydrogen bondings (average OH OMo distance 2655 A) of the hydroxyl groups in the spacer 2 2′-HOC6H4SSC6H4OH with the terminal oxo groups of the dimolybdenum anions 2 2′-HOC6H4SSC6H4OH was obtained by oxidation of H2mp in the presence of molybdenum when the reaction was run in air The characteristic cis-MoO22 absorptions appear at 913 and 864 cm−1 1 H NMR and 1 H–1 H COSY spectra characterized the phenyl protons of the mercaptophenol groups in the anion and in 22′-HOC6H4SSC6H4OH in the ranges of 6700–6270 and 7368–6799 ppmrespectivelywith 3J and 4J coupling constants of 8 and 1 Hz respectively.
- Published
- 1999
- Full Text
- View/download PDF
28. [Untitled]
- Author
-
Y. X. Tong, X. Y. Yu, Cheng-Yong Su, Zhong-Ning Chen, H. X. Zhang, Ting-Bin Wen, Bei-Sheng Kang, and Hanqin Liu
- Subjects
chemistry.chemical_compound ,Crystallography ,chemistry ,Stereochemistry ,Cluster (physics) ,General Materials Science ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,Biochemistry ,Phosphine - Abstract
Two new members of the hexanuclear series [Co6S8(PR3)6] n+, complexes [Co6S8(PMe2Ph)6](ClO4) (1) and [Co6S8P(OMe)3 6] (2), have been synthesizes and characterized by X-ray diffraction analyses. Their formation process was postulated to go through trinuclear μ3--S bridged moieties. The structural characteristics of the M6E8P6 skeleton of a whole series of [M6E8(PR3)6] n+ (M=Co, Cr, Fe, Mo; E=S, Se, Te) complexes are presented in terms of atomic distances and core volumes.
- Published
- 1999
- Full Text
- View/download PDF
29. Chemistry ofo-Mercaptophenolate: Syntheses, Structures, and Characterization of Titanium(IV) Complexes
- Author
-
Bei-Sheng Kang, Hanqin Liu, Daxu Wu, Cheng-Yong Su, Li-Ge Wang, Sen Liao, and Ting-Bin Wen
- Subjects
chemistry.chemical_classification ,Crystallography ,Base (chemistry) ,chemistry ,Octahedron ,Synthon ,Proton NMR ,Crystallographic data ,chemistry.chemical_element ,General Chemistry ,Titanium - Abstract
The reaction of Cp2TiCl2 with o-mercaptophenolate in the presence of a base (Et3N or NaOMe) afforded the complex (BnMe3N)2[Ti(o-SC6H4O)3] or (Et4N)2[Ti2(o-SC6H4O)4(OMe)2]·2H2O under slightly varied conditions. Single-crystal X-ray diffraction studies showed that the Ti(IV) geometry in both complexes is a severely distorted octahedron with average trans-angles of 162.2° and 159.1(2)°, respectively. Crystallographic data for (BnMe3N)2[Ti(o-SC6H4O)3]: a = 9.884(3), b = 16.501(7), c = 23.028(7) A; β = 99.89(3)°, V = 3700.2(22) A3, Z = 4, final R = 0.050 for 3134 observed reflections; for (Et4N)2[Ti2(o-SC6H4O)4(OMe)2]·2H2O: a = 8.953(4), b = 10.148(3), c = 14.527(3) A; α = 73.16(2)°, β = 73.00(3)°, γ = 83.56(4)°, V = 1207.4(9) A3, Z = 1, final R = 0.082 for 2233 observed reflections. The isolation of (BnMe3N)2[Ti(o-SC6H4O)3] provides strong evidence for the synthon character of [Ti(mp)3]2−, which was previously predicted to be present in the complex (Et4N)2[Ti(mp)3Na(MeOH)2]2. Both electronic and 1H NMR spectr...
- Published
- 1998
- Full Text
- View/download PDF
30. Synthesis, Structure and Magnetic Properties of a Cyclic Heterotetranuclear Co3Fe Complex of 2-Mercaptophenol (H2mp) with tri-n-Butylphosphine Participation
- Author
-
Wenjie Li, Hua-Xin Zhang, Yuan-Ba Cai, Thomas C. W. Mak, Bei-Sheng Rang, Zhong-Ning Chen, Zhongyuan Zhou, Hanqin Liu, and Maochun Hong
- Subjects
Crystallography ,Trigonal bipyramidal molecular geometry ,Stereochemistry ,Chemistry ,Mass spectrum ,Molecule ,Chelation ,General Chemistry ,Triclinic crystal system ,Magnetic susceptibility ,Dissociation (chemistry) ,Ion - Abstract
Neutral heterotetranuclear complex Co3Fe(mp)4(Hmp)(PBun3)3 2 (PBun3 = tri-n-butylphosphine) of 2-mercaptophenol (H2mp) was synthesized in a molar ratio of CoCl2:FeCl3:H2mp:NaOMe:PBun3 = 0.75:0.25:1:2:1 under anaerobic conditions. It represents partially FeIII-substituted form of the asymmetric mixed-valence tetracobalt complex Co4(mp)4(Hmp)(PBun3)3 (1). 2 crystallizes in the triclinic space group Pl, with a = 12.373(2) A, b = 15.677(3) A, c = 20.571(4) A, α = 93.59(3)° β = 93.45(3)° γ = 112.30(3)°, V = 3669 A3, and Z = 2. The molecule exhibits a cyclic skeleton of Co3FeS4O3 with two doubly μ2-S bridges, one doubly μ2-O bridge, and one singly μ2-O bridge. The four mp2− ligands display two different modes, ObSb-T and OtSb, while the monoanion Hmp− is only terminally chelated to Fe3+ ion in HOtSt fashion (b stands for bridge, t for terminal, and T for trinuclear). The three Co centers are located in approximately square-based pyramidal environments, and the Fe atom in distorted trigonal bipyramidal geometry. Three types of main fragment ions were observed in the FAB mass spectrum of 2. The dissociation of the fragments follows the order: PBun3 first, then Hmp and mp ligands. Moreover, the dissociation of Fe(Hmp) is first, followed by Co(mp) and Co(mp)2, according with the fact that Fe(Hmp) is only loosely bonded. Variable-temperature magnetic susceptibility measurements showed that 2 exhibits weak magnetic exchange interactions.
- Published
- 1998
- Full Text
- View/download PDF
31. Syntheses and spectroscopic characterizations of the compounds containing univalent coinage metal and tetraselenomolybdate. Crystal structure of [MoSe4(AuPPh3)2]
- Author
-
Rong Cao, Maochun Hong, Daxu Wu, Qianfeng Zhang, Wenjian Zhang, Yu Zhen, and Hanqin Liu
- Subjects
Chemistry ,Chemical shift ,Crystal structure ,Triclinic crystal system ,Inorganic Chemistry ,Metal ,symbols.namesake ,Crystallography ,visual_art ,Atom ,Materials Chemistry ,visual_art.visual_art_medium ,symbols ,Molecule ,Physical and Theoretical Chemistry ,Raman spectroscopy - Abstract
From the reactions of [Et 4 N] 2 MoSe 4 and M(PPh 3 ) n L(M = Cu, Ag, Au: L = Cl, NO 3 : n = 1−2)in univalent comage metal and an MoSe 4 2 unit, [MoSe 4 (CuPPh 3 )PPh 3 ) 2 ] ( 1 ), [MoSe 4 (AgPPh 3 ) Ag(PPh 3 ) 2 ] ( 2 ), [MoSe 4 (Ag-PPh 3 ) 2 ] ( 3 ), [MoSe 4 (AuPPh 3 ) 2 ] ( 4 ), [MoSe 3 )Set(CuPPh 3 ) 3 Cl] ( 6 ), have been isolated and characterized by 93 Mo NMR, IR and Raman spctra. The 93 Mo chemical shifts are mainly dependent upon the shielding effects from the number of the coinage metal atoms around the Mo atom and the geometric structure of the molecule. The shielding order is Au > Cu > Ag. The crystal structure of 4 has been determined by X-ray single-crystal diffraction analysis. It crystallizes in the triclinic space group P -1 with cell constants a = 9.570(2), b = 10.755(2), c = 19.837(4) A : α = 89.59(3), β = 80.37(3), γ = 68.33(3)° and Z = 2 . The molecule has a linear structure with an average Mo distance of 2.846(2) A.
- Published
- 1998
- Full Text
- View/download PDF
32. Chemistry of the Tetraselenomolybdate Anion: Syntheses, Spectroscopic Results, and Structural Characterizations of Polynuclear Mo−Cu−Se Compounds Containing Thiolate Ligands
- Author
-
Daxu Wu, Rong Cao, Hanqin Liu, Jiaxi Lu, Qianfeng Zhang, Maochun Hong, Wenjian Zhang, and Jiutong Chen
- Subjects
Inorganic Chemistry ,Crystallography ,Chemistry ,Stereochemistry ,Cluster (physics) ,Moiety ,Reactivity (chemistry) ,Orthorhombic crystal system ,Physical and Theoretical Chemistry ,Ion - Abstract
In the study on the reactivity of tetraselenomolybdate, a DMF solution of [Et4N]2[MoSe4] was found to react with 3 equiv of CuCl in the presence of NaS2CNR2 [R2 = Et2, C5H10, (PhCH2)2, Me2] to give a series of Mo−Cu−Se compounds, [Et4N]2[MoCu3Se4(R2NCS2)3] (R2 = Et2 (1a), C5H10 (1b), (PhCH2)2 (1c)) and [Et4N]2[MoCu4Se4(Me2NCS2)4] (2). Furthermore, the reaction of 2 or [Et4N]2[MoSe4(CuCN)2] with [Et4N]2[Cu(SPh)3] in DMF/MeCN afforded a polynuclear Mo−Cu−Se cluster compound, [Et4N]4[MoCu10Se4(PhS)12] (3). [Et4N]2[MoCu3Se4(Et2NCS2)3] (1a) crystallizes in the orthorhombic space group P212121 with cell dimensions a = 12.949(3) A, b = 13.339(3) A, c = 29.744(6) A, V = 5137.6 A3, and Z = 4. Full anisotropic refinements of the structure led to convergence with a value of R = 0.052 (Rw = 0.055) for 453 variables and 6854 reflections (F > 4.0σ(F)). The [MoCu3Se4(Et2NCS2)3]2- anion in 1a comprises three Et2NCS2Cu fragments linked by a slightly distorted tetrahedral MoSe4 moiety. Compound 2 crystallizes in the orthor...
- Published
- 1997
- Full Text
- View/download PDF
33. Synthesis and characterization of (Ph4P)2[MoCu3OSe3Cl3(Py)]·CH3CN (Py=pyridine): a novel tetranuclear Mo–Cu–Se cluster containing an incomplete cubane-like core
- Author
-
Hanqin Liu, Rong Cao, Jiaxi Lu, Feilong Jiang, Minghui Wu, Xiaoyin Huang, and Maochun Hong
- Subjects
Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Chemistry ,Cubane ,Pyridine ,Materials Chemistry ,Cluster (physics) ,Crystal structure ,Physical and Theoretical Chemistry ,Single Crystal Diffraction ,Ion - Abstract
A novel tetranuclear Mo–Cu–Se cluster compound (Ph 4 P) 2 [MoCu 3 OSe 3 Cl 3 (Py)] (Py=pyridine) has been synthesized by the reaction of (Ph 4 P) 2 [MoSe 4 ], CuCl and pyridine in CH 3 CN. X-ray single crystal diffraction analysis reveals that the anion structure consists of an incomplete cubane-like MoCu 3 Se 3 core. The average Mo–Cu and Mo–Se distances are 2.704(7) and 2.394(2) A and the average angles of Se–Mo–Se, Se–Cu–Se, and Se–Cu–Cl are 109.4(2), 104.5(3), and 112.3(3)°, respectively.
- Published
- 1997
- Full Text
- View/download PDF
34. Syntheses, reactions and spectroscopic properties of Mo(W)CuS cluster compounds, and crystal structure of (Et4N)4[WS4Cu10Br12]
- Author
-
Rong Cao, Xinjian Lei, Daxu Wu, Jiaxi Lu, Hanqin Liu, and Maochun Hong
- Subjects
Diphenylphosphine ,chemistry.chemical_element ,Crystal structure ,Inorganic Chemistry ,NMR spectra database ,Crystallography ,chemistry.chemical_compound ,chemistry ,Octahedron ,Molybdenum ,Materials Chemistry ,Cluster (physics) ,Moiety ,Physical and Theoretical Chemistry ,Single crystal - Abstract
The synthetic reactions and spectroscopic studies of molybdenum(tungsten)-copper-sulfur cluster compounds, which can be prepared by the stepwise or unit construction reactions through the successive addition of CuL (L = Cl, Br, R2dtc) across six edges or four faces of MS4 (M = Mo, W) tetrahedra, are described. A series of Mo(W)CuS cluster compounds, (Et4N)2[MoCu2S4(S2CNEt2)2] (1) (Et4N)2- [MoCu2S3O(S2CNC4H8)2 (2), [MoCu2S4(dppe)2] (3) (dppe = bis(diphenylphosphine ethane, (Et4N)2[MoCu3S4(S2CNEt2)3] (4), (Et4N)2[Mo2Cu4S8(S2CNEt2)2] (5), (Et4N)2[Mo2Cu4S6O2(S2CNC4H8)2] (6), [Mo2Cu4S8(dppm)2] (7), [Mo2Cu4S6O2(dppm)2] (8) (dppm = bis(diphenylphosphine)methane), (Et4N)4[MoS4Cu10Br12] (9), (Et4N)4[WS4Cu10Br12] (10), have been prepared and characterized by IR and 95Mo NMR spectra. The polynuclear WCu cluster compound (Et4N)4[WS4Cu10Br12] (10) is characterized by single crystal X-ray diffraction analysis. The anion structure consists of a central WS4 moiety, an octahedral Cu6 and a tetrahedral Cu4 array. The average WCu and WS distances are 2.726(8) and 2.247(7) A and the average angles of SWS, SCuS and SCuBr are 109.5(3), 104.1(4) and 112.6(3)°, respectively.
- Published
- 1997
- Full Text
- View/download PDF
35. A novel phenoxy-bridged polynuclear cobalt complex. Synthesis and structural characterization of [Co7Na2(1,2-OSC6H4)8(DMF)12]·2DMF·H2O
- Author
-
Rong Cao, Weiping Su, Xiao-Ying Huang, Maochun Hong, Feilong Jiang, Wenjie Li, and Hanqin Liu
- Subjects
Inorganic Chemistry ,Crystallography ,Oxygen atom ,Chemistry ,Sodium ,Materials Chemistry ,chemistry.chemical_element ,Molecule ,Crystal structure ,Physical and Theoretical Chemistry ,Cobalt ,Single crystal - Abstract
A novel polynuclear cobalt complex [Co 7 Na 2 (1,2-OSC 6 H 4 ) 8 (DMF) 12 ] was obtained from the reaction of CoBr(PPh 3 ) 3 with Na 2 (1,2-OSC 6 H 4 ) (H 2 mp= o -mercaptophenol) in DMF and its crystal structure has been determined by single crystal X-ray diffraction analysis. The molecular structure contains nine layers. The cobalt and sodium atoms are arranged in nearly linear chain configuration and bridged by 1,2-OSC 6 H 4 2− and DMF ligands via their oxygen atoms.
- Published
- 1997
- Full Text
- View/download PDF
36. Syntheses, structures and spectroscopic properties of [Ag(dppm)(O2CCH2Ph)]2 and [Ag2(dppm)3](NO3)2·3H2O
- Author
-
De-Dong Wu, Daxu Wu, Zhong-Yong Zhou, Hanqin Liu, Maochun Hong, Songling Li, and Thomas C. W. Mak
- Subjects
Inorganic Chemistry ,NMR spectra database ,Crystallography ,symbols.namesake ,Chemistry ,Sodium phenylacetate ,Materials Chemistry ,symbols ,Crystal structure ,Physical and Theoretical Chemistry ,Raman spectroscopy ,Single crystal - Abstract
The reaction of [Ag(dppm)(NO 3 ] 2 with sodium phenylacetate and dppm in THF at room temperature gave rise to the silver complexes [Ag(dppm)(O 2 CCH 2 Ph)] 2 ( 1 ) and [Ag 2 (dppm) 3 ](NO 3 ) 2 ( 2 ), respectively. Their crystal structures have been determined by single crystal X-ray diffraction analysis. Complex 1 is binuclear with a silver-silver separation of 3.080 A and bridged by two dppm ligands. The cation in complex 2 possesses a Ag 2 P 6 core with AgAg distance of 2.987 A and the silver atoms are each coordinated by three phosphorus atoms in an ideal trigonal-planar environment. Their IR, Raman, 1 H and 31 P NMR spectroscopic properties are also reported.
- Published
- 1997
- Full Text
- View/download PDF
37. Syntheses and X-ray structural characterization of phosphine cobalt(II) complexes with 2-mercaptobenzothiazole
- Author
-
Bo-Mu Wu, Zhong-Ning Chen, Thomas C. W. Mak, Bei-Sheng Kang, Hanqin Liu, Han-Rong Gao, and Yexiang Tong
- Subjects
Denticity ,Spin states ,chemistry.chemical_element ,Magnetic susceptibility ,law.invention ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Octahedron ,law ,Materials Chemistry ,Chelation ,Physical and Theoretical Chemistry ,Electron paramagnetic resonance ,Cobalt ,Phosphine - Abstract
Mononuclear cobalt(II) complexes Co(mbt-N)2(PBu3n)2 (1) (Hmbt = 2-mercaptobenzothiazole; PBu3n = tri-n-butyphosphine) and Co(mbt-S, N)2(dppe)·MeCN (2) [dppe = 1, 2-bis(diphenylphosphino) ethane] were synthesized and characterized by X-ray crystallography, IR and EPR spectra, cyclic voltammetric data and magnetic susceptibility measurements. The Co atom in (1) exhibits an approximate square-planar geometry with the heterocyclic N-donors from mbt bonding to the cobalt atom in a monodentate mode. Complex (2) has a distorted octahedral environment of Co with both the exocyclic-S and the hetero-N donors of mbt bound to the cobalt atom in a bidentate chelating mode. The Co atom in both complexes shows spin state of S =3/2 with μeff of 4.25 and 4.40μB for 1 and 2, respectively.
- Published
- 1997
- Full Text
- View/download PDF
38. Heterooctanuclear Cluster Complex Formation with Phosphine Participation: Synthesis, Structure, and Magnetic Properties of Co6Ru2(mp)10(PBun3)6 (H2mp = 2-Mercaptophenol, PBun3 = Tri-n-butylphosphine)
- Author
-
Wenjie Li, Zhong-Ning Chen, † and Xiao-Ming Chen, Maochun Hong, Zhongyuan Zhou, Zhang Lin, Thomas C. W. Mak, Hanqin Liu, and Bei-Sheng Kang
- Subjects
Denticity ,Chemistry ,Ligand ,Stereochemistry ,chemistry.chemical_element ,Ruthenium ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Octahedron ,Moiety ,Chelation ,Physical and Theoretical Chemistry ,Cobalt ,Phosphine - Abstract
The reaction of CoCl2, RuCl3, Na2(mp), and PBun3 (H2mp = 2-mercaptophenol, PBun3 = tri-n-butylphosphine) in ethanol in the molar ratio of 0.75:0.25:1:1 gave the complex Co6Ru2(mp)10(PBun3)6. The heterooctanuclear complex consists of six cobalt and two ruthenium ions chelated to as well as bridged by the 2-mercaptophenol ligands in a near-dimeric fashion with two μ2-OR groups bridging the two Co3Ru(mp)5(PBun3)3 fragments without a crystallographic center of symmetry. Each fragment is formed by binding two of the Co(mp)2(PBun3) structural units and one Co(mp) species to a central Ru(III) ion through the S donors of the five mp ligands, while the sixth coordination site of the octahedral Ru environment is completed by a phosphine ligand in the axial position. The Co6Ru2 moiety exhibits a zigzag assembly constructed by the μ2-O and μ2-S bridges of the bidentate 2-mercaptophenol ligands in a highly asymmetric fashion. The Co atoms are square pyramidally coordinated with apices that are occupied by the phosphin...
- Published
- 1997
- Full Text
- View/download PDF
39. Syntheses and spectroscopic properties of palladium(II) complexes with bidentate phosphine and thiolate ligands. X-ray crystal structure of [Pd(SCH2Ph)2{Ph2P(CH2)3PPh2}]
- Author
-
Rong Cao, Zhongyong Zhou, Thomas C. W. Mak, Hanqin Liu, Maochun Hong, Weiping Su, and Feng Xie
- Subjects
Denticity ,Stereochemistry ,chemistry.chemical_element ,Infrared spectroscopy ,Crystal structure ,Medicinal chemistry ,Inorganic Chemistry ,NMR spectra database ,chemistry.chemical_compound ,chemistry ,Propane ,Materials Chemistry ,Proton NMR ,Physical and Theoretical Chemistry ,Phosphine ,Palladium - Abstract
By the reactions of Pd 2+ , thiolate (PhCH 2 S − or pdt) and dppe or dppp [pdt = SCH 2 CH 2 CH 2 S 2− , dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane] in MeOH, the following complexes, [Pd(SCH 2 Ph) 2 (dppe)] ( 1 ), [Pd(SCH 2 Ph) 2 (dppp)] ( 2 ) and [Pd(pdt)(dppp)] ( 3 ), were prepared. The crystal structure of 2 was analysed by single-crystal X-ray diffraction. The palladium atom is tetra-coordinated with a distorted square-planar geometry of two phosphorus and two sulfur atoms. Their IR, 31 P and 1 H NMR spectra are reported.
- Published
- 1997
- Full Text
- View/download PDF
40. Cobalt (iron) thiolato complexes containing the Co-ligand phosphine and reaction products of the structural fragment ML 2 L? (L = 1,2-bidentate thiolate,L?= tertiary phosphine)
- Author
-
Yong-Jin Xu, Zhi-Tao Xu, Hanqin Liu, Zhong-Ning Chen, Han-Rong Gao, Zhongyuan Zhou, Bei-Sheng Kang, Yuan-Ba Cai, Bo-Mu Wu, and Thomas C. W. Mak
- Subjects
Denticity ,Ligand ,Stereochemistry ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Biochemistry ,Medicinal chemistry ,Catalysis ,chemistry.chemical_compound ,Fragmentation (mass spectrometry) ,chemistry ,Cluster (physics) ,General Materials Science ,Transition metal thiolate complex ,Cobalt ,Phosphine - Abstract
Mono-, di-, tri-, and tetra-nuclear cobalt (iron) complexes containing co-ligands phosphine and thiolate are presented according to the classification by combination of different dentates of the two ligands. Emphasis is being put on the triand tetranuclear cluster complexes of monodentate phosphines and 1,2-bidentate thiolates. These complexes are considered to be constructed based on the general structural fragment (or building block) ML 2L′ (L=1,2-bidentate thiolate,L′=tertiary phosphine). Structural regularities are presented in Tables I, III, IV, and V and discussed. FAB mass spectroscopic data showed the possible fragmentation patterns. Synergism of the cluster skeletons is proposed to explain the occurrence of the distinct structural modes.
- Published
- 1996
- Full Text
- View/download PDF
41. A cleavage of the S-C bond in 2-aminothiophenal
- Author
-
Hanqin Liu, De-Dong Wu, Zhongyun Zhou, Weipin Su, Maochun Hong, Thomas C. W. Mak, and Feilong Jiang
- Subjects
Inorganic Chemistry ,Crystallography ,Chemistry ,Materials Chemistry ,chemistry.chemical_element ,Cleavage (crystal) ,Crystal structure ,Physical and Theoretical Chemistry ,Silver cluster ,Sulfur - Abstract
The reaction of AgNO 3 , NaS 2 CNEt 2 and H 2 NPhSH in the presence of (Ph 3 P) 3 CuCl in MeOH gave a polynuclear silver cluster compound, [Ag 11 (μ 5 -S)(μ 4 -S 2 CNEt 2 ) 6 (μ 3 -S 2 CNEt 2 ) 3 ]. A cleavage of the S-C bond and release of S 2 from 2-aminothiophenal occurred in the reaction. The core of Ag 11 S consists of five layers: Ag, 3Ag, 3AgS, 3Ag and Ag. The average Ag-Ag and Ag-S c (S c for core sulfur atom) distances are 3.046 and 2.513 , respectively. Copyright © 1996 Elsevier Science Ltd
- Published
- 1996
- Full Text
- View/download PDF
42. Syntheses of palladium(II) complexes with thiolate and phosphine ligands. X-ray crystal structures of [Pd(tdt)(PPh3)2] · C2H4Cl2 and [Pd2(Hmp)2(PPh3)Cl2]
- Author
-
Rong Cao, Hanqin Liu, Xiulan Xie, Maocuun Hong, Feilong Jiang, and Beisheg Kang
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Reaction mechanism ,chemistry ,Materials Chemistry ,X-ray ,chemistry.chemical_element ,Crystal structure ,Physical and Theoretical Chemistry ,Phosphine ,Palladium - Abstract
By the reactions of Pd 2+ , 1,1-dithiolate [SC 6 H 3 (CH 3 )S 2− , SCH 2 CH 2 S 2− or SCH 2 CH (CH 3 )S 2− ] or thiolate (HOC 6 H 4 S − ) and PR 3 (R = Ph, Et) in MeOH, the complexes [Pd(tdt)(PPh 3 ) 2 ] ( 1 ), [Pd 2 (edt) 2 (PPh 3 ) 2 ] ( 2 ), [Pd 2 (pdt) 2 (PPh 3 ) 2 ] ( 3 ), [Pd 2 (edt) 2 (PEt 3 ) 2 ] ( 4 ), [Pd 2 (pdt) 2 (PEt 3 ) 2 ] ( 5 ), [Pd 2 (Hmp) 2 (PPh 3 ) 2 Cl 2 ] ( 6 ) and [Pd 2 (tdt) 2 (PEt 3 ) 2 ] ( 7 ) (tdt = 1,2-toluenedithiolateedt = 1,2-ethanedithiol, pdt = 1,2-propanedithiol and mp = mercaptophenol) were prepared and analysed by X-ray diffraction. All palladium atoms are tetra-coordinated with distorted square-planar geometry of phosphorus and/or sulfur atoms. The reaction mechanism of Pd 2+ , 1,2-dithiolate and PR 3 (R = Et, Ph) is discussed.
- Published
- 1996
- Full Text
- View/download PDF
43. Structure of a binuclear silver(I) complex [Ph3PAg(O2CCH2Ph)]2
- Author
-
Zhong-Yong Zhou, Thomas C. W. Mak, Yu Zhen, Hanqin Liu, Mao-Chun Hong, De-Dong Wu, and Feng Xue
- Subjects
NMR spectra database ,Crystallography ,chemistry.chemical_compound ,Phenylacetate ,chemistry ,Molecule ,General Chemistry ,Carboxylate ,Crystal structure ,Triphenylphosphine ,Condensed Matter Physics ,Single crystal ,Organometallic chemistry - Abstract
The reaction of [Ph3PAgI]4 with sodium phenylacetate in MeOH and CH2Cl2 at room temperature gave rise to a binuclear silver complex with triphenylphosphine and phenylacetate mixed ligands, [Ph3PAg(O2CCH2Ph)]2. The crystal and molecular structure of the complex has been determined by single crystal X-ray diffraction analysis. The space group is $$P\bar 1$$ witha=9.198(2),b=9.516(2),c=13.842(3) A, α=102.00(3), β=108.34(3), γ=93.58(3)°,Z=1, andDc=1.506 g cm−3. The silver atoms are each coordinated by one phosphorus atom from triphenylphosphine and two oxygen atoms from the carboxylate groups in a T-shape. The complex is further characterized by its IR,1H, and31P NMR spectra.
- Published
- 1996
- Full Text
- View/download PDF
44. Transition metal 1,2-bidentate thiolates as building blocks and their construction into cluster complexes
- Author
-
Ting-Bin Wen, Jun Lu, Maochun Hong, Hanqin Liu, and Bei-Sheng Kang
- Subjects
Denticity ,Chemistry ,Nanochemistry ,General Chemistry ,Condensed Matter Physics ,Biochemistry ,Catalysis ,Crystallography ,chemistry.chemical_compound ,Transition metal ,Cluster (physics) ,General Materials Science ,Structural regularity ,Phosphine - Abstract
Simple fragments of transition metal 1,2-bidentate thiolates, the so-called building blocks of the general compositions ML3, ML2, ML, M(O)L2, ML2L′, MLL′, etc. have been proposed to constitute the di-, tri- and tetranuclear complexes concerned in this review. Structureal regularities and characteristics have been discussed and summarized according to the thiolato ligands edt and pdt, bdt and tdt, mp, and mpo, and mpp, respectively.
- Published
- 1995
- Full Text
- View/download PDF
45. A Hexacobalt Sulfide Cluster Compound, [Co6(μ-S)8(PPh3)6].2PPh3.2C2H4Cl2.H2O
- Author
-
Rong Cao, Feilong Jiang, Hanqin Liu, Xiao-Ying Huang, and Maochun Hong
- Subjects
chemistry.chemical_classification ,Sulfide ,Chemistry ,Ligand ,Stereochemistry ,General Medicine ,Crystal structure ,General Biochemistry, Genetics and Molecular Biology ,Crystallography ,chemistry.chemical_compound ,Octahedron ,Cluster (physics) ,Molecule ,Triphenylphosphine ,Hydrate - Abstract
The title compound, octa-μ 3 -thio-hexakis(triphenylphosphine)-octahedro-hexacobalt-triphenylphosphine-1,2-dichloroethane-water (1/2/2/1), [Co 6 S 8 (C 18 H 15 P) 6 ].2C 18 H 15 P.2C 2 H 4 Cl 2 .H 2 O, was prepared by the reaction of CoCl(PPh 3 ) 3 with Na(mpo) (mpo = 2-mercaptopyridine N-oxide) or NaS t Bu. The molecular structure consists of discrete cluster units interspersed with molecules of free triphenylphosphine and solvent. The neutral cluster contains a slightly distorted Co 6 octahedron with each triangular face symmetrically capped by a μ 3 -S ligand. The molecular structure possesses a crystallographic inversion centre. The average Co-Co, Co-S and Co-P bond distances are 2.87 (6), 2.24(1) and 2.162(7)A, respectively. The hexacobalt sulfide cluster compound was formed via the capture of S atoms from thiolate reactants.
- Published
- 1995
- Full Text
- View/download PDF
46. Calculation of the chemical shielding constants of 95Mo in the clusters of [MoOmS4 − m(CuX)n]2− (X = CN, Cl; m = 0–2, n = 1–3) by the finite perturbation theory-CNDO/2 method
- Author
-
Hanqin Liu, Xiulan Xie, and Zhiping Liu
- Subjects
Chemistry ,Analytical chemistry ,Molybdate ,Condensed Matter Physics ,Biochemistry ,CNDO/2 ,chemistry.chemical_compound ,Computational chemistry ,Linear regression ,Exponent ,Molecular orbital ,Physical and Theoretical Chemistry ,Perturbation theory ,Scaling ,Chemical shielding - Abstract
By using a semi-empirical molecular orbital method within the framework of the finite perturbation theory (FPT), the FPT-CNDO/2 method, which has been successfully adapted to the study of the 95Mo chemical shielding in molybdate and thiomolybdate [MoOmS 4 − m]2− (m = 0–4) anions, theoretical calculation of the chemical shielding constants of 95Mo in the MoCuS clusters [MoOmS4 − m(CuX)n]2− (X = CN, Cl; m = 0–2, n = 1–3) has been carried out to extend the study of MoCuS clusters. Factors determining the regular change of 95Mo chemical shielding constants in the MoCuS clusters are discussed and the Mo d-orbital exponent is deduced to be the most sensitive one. The deduction is verified in the calculation by varying the Mo d-orbital exponent. The scaling coefficient of the linear regression between the calculated and the experimental results changes from 2.956 to 0.834 as the Mo d-orbital exponent reduces from 3.22 to 3.05, and the value of 3.10 produces the best linear regression. The deviation in the linear regression is attributed to the basic approximation of the CNDO/2 semi-empirical method.
- Published
- 1995
- Full Text
- View/download PDF
47. A tetranuclear cobalt complex with mercaptopyridine N-oxide as ligand. Synthesis and crystal structure of [Na3Co4(μ3-O)2-(mpo)8(DMF)4]Br·2DMF (mpo = 2-mercaptopyridine-N-oxide)
- Author
-
Rong Cao, Bei-Sheng Kang, Xiulan Xie, Daxu Wu, Hanqin Liu, Feilong Jiang, and Maochun Hong
- Subjects
Denticity ,Ligand ,2-mercaptopyridine-N-oxide ,Oxide ,chemistry.chemical_element ,Crystal structure ,Triclinic crystal system ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Atom ,Materials Chemistry ,Physical and Theoretical Chemistry ,Cobalt - Abstract
A new compound [Na3Co4(μ3-O)2(mpo)8(DMF)4]Br·2DMF (1) was prepared by reacting CoBr(PPh3)3 and Nampo (mpo = 2-mercaptopyridine-N-oxide), and structurally characterized by X-ray diffraction methods. The title compound crystallizes in the triclinic space group P1 with a = 13.393(7), b = 14.00(1), c = 13.029(4) A, α = 92.29(4), β = 110.56(3), γ = 115.32(4)°, V = 2015(2) A3, Z = 1 and R (Rw) = 0.047 (0.053) for 1820 reflections (I > 3 σ(I)). The complex contains four cobalt atoms in the form of a square plane with indirect metal-metal bonds. Each Co atom is coordinated by two bidentate mpo ligands with StOb-D and StOb-T coordination modes, respectively. Two Co2(mpo)4O groups each bridged by μ3-O in the Na3Co4 core are linked by Na3 through the oxygen atoms of the mpo ligands and the bridging μ3-O atoms to form a dumbbell-like structure. The structure of the symmetric tetracobalt cation [Na3Co4(μ3-O)2(mpo)8(DMF)4]+ possesses a crystallographic inversion center through the Na(1) atom. The relevance of the spectroscopic and magnetic properties to the structure of 1 is also discussed.
- Published
- 1995
- Full Text
- View/download PDF
48. FPT-CNDO/2 studies of 59Co chemical shielding constants in hexacoordinated diamagnetic Co(III) complexes
- Author
-
Hanqin Liu, Xiulan Xie, and Steve C. F. Au-Yeung
- Subjects
education.field_of_study ,Chemistry ,Chemical shift ,Population ,chemistry.chemical_element ,Condensed Matter Physics ,Biochemistry ,Ion ,CNDO/2 ,Computational chemistry ,Electromagnetic shielding ,Diamagnetism ,Physical chemistry ,Molecular orbital ,Physical and Theoretical Chemistry ,education ,Cobalt - Abstract
The 59 Co nuclear shielding constants of five hexacoordinated diamagnetic cobalt(III) complexes have been calculated using a semiempirical molecular orbital method within the framework of the finite perturbation theory, the FPT-CNDO/ 2 method. Experimental and calculated chemical shifts referenced to the cobalticyanide anion gave good agreement. The difference between the calculated and the experimental chemical shifts is attributed to the underestimation of the radial factor. The origin of the shielding on the cobalt nucleus is discussed in terms of the 3d orbital population. The shielding anisotropy in the compounds with low symmetry is also surveyed.
- Published
- 1995
- Full Text
- View/download PDF
49. Synthesis and molecular structure of the mixed polymeric cobalt compound [Co3(SCH2CH2S)3(PEt3)3]2[Co2Cl4(µ-O2SEt2)2]
- Author
-
Daxu Wu, Feilong Jiang, Bei-Sheng Kang, Rong Cao, Xiulan Xie, Maochun Hong, and Hanqin Liu
- Subjects
Denticity ,Chemistry ,Ligand ,Stereochemistry ,Dimer ,chemistry.chemical_element ,Trimer ,General Chemistry ,Sulfone ,chemistry.chemical_compound ,Crystallography ,Molecule ,Cobalt ,Monoclinic crystal system - Abstract
The mixed polymeric cobalt compound [Co3(SCH2CH2S)3(PEt3)3]2[Co2Cl4(µ-O2SEt2)2]1 containing two trimers and one dimer was isolated from the reaction of [CoCl(PEt3)3] with disodium ethane-1,2-dithiolate in 1,2-dichloroethane. It is monoclinic and crystallizes in space group P21/n, with a= 12.481(7), b= 15.70(2), c= 25.84(2)A, β= 97.85(5)° and Z= 2 from 2436 reflections with I > 3.50σ(I), final R= 0.062. X-Ray diffraction established that the two cobalt atoms in the dimer are linked via the oxygen atoms of the diethyl sulfone forming the eight-membered Co2O4S2 ring with a crystallographic inversion centre through the whole dimer. The observed cleavage of the dithiolate C–S bond together with the formation of the bridging diethyl sulfone are discussed. In the trimer of 1, the Co3 isosceles triangle is capped by two bidentate SCH2CH2S2– ligands on either side of the plane with the sulfur atoms bridging the two long Co–Co bonds, while the short Co–Co bond is bridged by the third SCH2CH2S2– ligand. Considering the framework of the Co3P3(SCH2CH2S)3 unit only, there is a pseudo mirror-image plane passing through the Co3P3 plane which bisects the C(31)–C(32) bond. The 1H NMR spectrum of compound 1 demonstrates the retention of the solid-state structure of the trinuclear species in chloroform solution.
- Published
- 1995
- Full Text
- View/download PDF
50. Fabrication of boehmite AlOOH and γ-Al2O3 nanotubes via a soft solution route
- Author
-
Hanqin Liu, Christoph Frommen, Dieter Fenske, Dai-Bin Kuang, and Yueping Fang
- Subjects
Aluminium oxides ,Nanotube ,Boehmite ,Aqueous solution ,Nanostructure ,Materials science ,Inorganic chemistry ,General Chemistry ,law.invention ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Bromide ,law ,Materials Chemistry ,Calcination ,Self-assembly - Abstract
The tubular form of crystalline boehmite AlOOH was fabricated using AlCl3·6H2O as the alumina precursor in the presence of N-cetyl-N,N,N-trimethylammonium bromide surfactant, and tubular γ-Al2O3 was obtained by calcination of boehmite AlOOH at 520 °C.
- Published
- 2003
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.