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Polyhydroxyalkanoates (PHAs) are green and sustainable bioplastics that could replace petrochemical synthetic plastics without posing environmental threats to living organisms. In addition, sustainable PHA production could be achieved using marine photosynthetic purple nonsulfur bacteria (PNSBs) that utilize natural seawater, sunlight, carbon dioxide gas, and nitrogen gas for growth. However, PHA production using marine photosynthetic PNSBs has not been economically feasible yet due to its high cost and low productivity. In this work, strain improvement, using genome-wide mutagenesis coupled with high-throughput screening via fluorescence-activated cell sorting, we were able to create Rhodovulum sulfidophilum mutants with enhanced volumetric PHA productivity, with an up to 1.7-fold increase. The best selected mutants (E6 and E6M4) reached the stationary growth phase 1 day faster and accumulated the maximum PHA content 2 days faster than the wild type. Maximizing volumetric PHA productivity before the stationary growth phase is indeed an additional advantage for R. sulfidophilum as a growth-associated PHA producer.

The low-cycle fatigue (LCF) deformation mechanism and fatigue life of an Al-12Si alloy were investigated at different temperatures and strain rates. With increasing temperature, the fatigue life increases at first and then reduces, which is derived from the deformation mechanism. At the lower temperatures, the primary Si cracking induced by piling-up of dislocations dominates fatigue damage behaviors. Both of increasing temperature and reducing the strain-rate can restrain the phase cracking, thus increase fatigue life. However, with further increasing temperature, the micro-scale void caused by dislocation annihilation dominates the phase debonding behavior, leading to the decrease of fatigue life.

The cyclic deformation and damage behaviors of Al-Si piston alloys are comprehensively studied. It is found that the fatigue cracks mainly initiate from broken primary Si at low temperature and phase/matrix interface debonding at higher temperature. The transgranular crack propagation can be found for all the temperatures and the grain is obviously reduced after low-cycle fatigue at higher temperature. Furthermore, a hysteresis energy-based life prediction model was developed and utilized. Based on the model, the optimum fatigue life was found at intermediate temperature. A strategy for fatigue property optimization was proposed: increasing W0 at low temperature and increasing β at high temperature, to enhance the fatigue life during entire service temperatures with the ultrasonic melt treatment. In this way, the remarkable improvement of the fatigue properties may be achieved. Keywords: Al-Si alloys, Low cycle fatigue, Fatigue crack initiation, Temperature, Property optimization

Significance Imaging flow cytometry is a powerful tool for analyzing every single cell in a large heterogeneous population but relies on fluorescent labeling, which comes with cytotoxicity, nonspecific binding, and interference with natural cellular functions. This paper presents label-free multicolor chemical imaging flow cytometry based on stimulated Raman scattering (SRS), a highly sensitive method of molecular vibrational spectroscopy. With the help of deep learning, it demonstrates high-precision characterization and classification of microalgal cells and cancer cells without the need for fluorescent labeling., Combining the strength of flow cytometry with fluorescence imaging and digital image analysis, imaging flow cytometry is a powerful tool in diverse fields including cancer biology, immunology, drug discovery, microbiology, and metabolic engineering. It enables measurements and statistical analyses of chemical, structural, and morphological phenotypes of numerous living cells to provide systematic insights into biological processes. However, its utility is constrained by its requirement of fluorescent labeling for phenotyping. Here we present label-free chemical imaging flow cytometry to overcome the issue. It builds on a pulse pair-resolved wavelength-switchable Stokes laser for the fastest-to-date multicolor stimulated Raman scattering (SRS) microscopy of fast-flowing cells on a 3D acoustic focusing microfluidic chip, enabling an unprecedented throughput of up to ∼140 cells/s. To show its broad utility, we use the SRS imaging flow cytometry with the aid of deep learning to study the metabolic heterogeneity of microalgal cells and perform marker-free cancer detection in blood.

The high-performance Al12Si4Cu3NiMg alloy with massive transition elements has been developed recently for piston of diesel engines. The influences of microstructures on the tensile and low-cycle fatigue (LCF) behaviors were investigated with conventional and in situ testing technologies in this study. Upon the tensile loading, the microcracks initiate from the primary Si near the surface when the tensile stress reaches approximately 280 MPa (close to the tensile strength); then, the microcracks grow rapidly through eutectic Si and intermetallics (Al3CuNi) for the gravity casting (GC) alloy. With regard to the LCF, the microcracks initiate from the shrinkage pores regularly because of the localization of fatigue damage in the GC alloy. The shrinkage pores, usually accompanied by the brittle intermetallics (Al3CuNi), typically exhibit more complex geometry. The lamellar Al3CuNi provides a preferred path for the crack propagation after fatigue crack initiation. The ultrasonic melt treatment (UT) was used to optimize the microstructures and reduce casting defects (shrinkage pores), thereby resulting in improvement in tensile and LCF properties. For the UT alloy (pore-free), the microcrack initiates from some coarser primary Si rather than from the shrinkage pores because of the accumulation of micro-scale plastic deformation. Furthermore, higher resistance of crack propagation can also be realized with refinement of microstructures in the UT alloy. Increase in crack initiation and propagation resistances is the main reason for improvement in the LCF life of the UT alloy.

A metamaterial analogy of tunable electromagnetically induced transparency (EIT) is theoretically investigated in terahertz regime. The proposed metamaterial consists of vertical gold strips and horizontal graphene wires, which perform as bright elements and dark elements, respectively. The EIT-like phenomenon can be induced by bright–dark mode coupling on condition of structural lateral displacement. Numerical result reveals that the EIT-like effect remains noticeable with a wide range of incidence polarization angles. Most importantly, by manipulating gate voltages, the EIT window can be dynamically controlled without refabricating the structure. The amplitude modulation depth can reach 81%, 79%, and 68% respectively at three characteristic frequencies as Fermi energy changes in the scope of 0.8–1.0 eV. Furthermore, a sensitivity of 0.95 THz per refractive index unit (RIU) is realized varying the refractive index in the surrounding medium. This structure provides potential applications for detectors, sensors, and modulators.

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.

[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.

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.

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.

[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.

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.

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.

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.

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.

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.

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.

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.

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.

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...

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 OMo 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.

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.

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...

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.

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.

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...

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.

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)CuS 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 WCu 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 WCu and WS distances are 2.726(8) and 2.247(7) A and the average angles of SWS, SCuS and SCuBr are 109.5(3), 104.1(4) and 112.6(3)°, respectively.

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.

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 AgAg 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.

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.

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...

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.