μ-Oxo-Bis(Tetraphenylantimony): Synthesis,Structure, and Reactions

Heating of a solution of pentaphenylantimony in toluene in atmospheric oxygen affords -oxo-bis(tetraphenylantimony) (I) in a 63% yield. The latter compound can be converted to bis(tetraphenylantimony) carbonate or phthalate by the action of carbon dioxide or phthalic anhydride, respectively. According to X-ray diffraction data, the antimony atoms in compound Ihave a distorted trigonal-bipyramidal coordination (Sb–O 2.0050(4) Å, the SbOSb angle 151.71(9)°). The molecule of bis(tetraphenylantimony) phthalate is composed of two equal fragments, and its Sb atoms also have trigonal-bipyramidal coordination (Sb–O 2.2421(8) Å; Sb–C 2.176(1), 2.115(1), 2.130(1), and 2.137(1) Å).     

Syntheses,crystal structures,and luminescence of coordination polymers [Cu(μ-Br)(μ-phpzm)] n , [{Cu(μ-SCN)}2(μ-phpzm)] n,and [(phpzm)Cu(μ-CN)] n (phpzm = bis(4-phenylpyrazol-1-yl)methane)

Solvothermal reactions of CuX (X?=?Br, SCN, CN) with bis(4-phenyl-pyrazol-1-yl)methane (phpzm) gave two 2-D coordination polymers, [Cu(μ-Br)(μ-phpzm)] _n (1) and [{Cu(μ-SCN)}₂(μ-phpzm)] _n (2), and a 1-D coordination polymer, [(phpzm)Cu(μ-CN)] _n (3). Compounds 1–3 were characterized by elemental analysis, IR spectra, and X-ray crystallography. Compounds 1 and 2 have 2-D networks in which split-stair [Cu(μ-Br)] _n chains (1) or staircase-like [Cu(μ-SCN)] _n double chains (2) are linked by μ-phpzm bridges. Compound 3 consists of a zigzag chain formed by linking [Cu(phpzm)] fragments via cyanide bridges. Luminescence properties of 1–3 along with phpzm in the solid state at ambient temperature were also investigated.     

Microfluidic Paper-Based Analytical Devices (μPADs) and Micro Total Analysis Systems (μTAS): Development, Applications and Future Trends

Microfluidic paper-based analytical devices and micro total analysis systems are relatively new group of analytical tools, capable of analyzing complex biochemical samples containing macromolecules, proteins, nucleic acids, toxins, cells or pathogens. Within one analytical run, fluidic manipulations like transportation, sorting, mixing or separation are available. Recently, microfluidic devices are a subject of extensive research, mostly for fast and non-expensive biochemical analysis but also for screening of medical samples and forensic diagnostics. They are used for neurotransmitter detection, cancer diagnosis and treatment, cell and tissue culture growth and amplification, drug discovery and determination, detection and identification of microorganisms. This review summarizes development history, basic fabrication methods, applications and also future development trends for production of such devices.     

Thiolate-bridged heterometallic complexes of manganese and platinum: Synthesis and molecular structures of (CO)4Mn(μ-SPh)Pt(PPh3)2, (CO)3(PPh3)Mn(μ-SPh)Pt(PPh3)(CO), and (CO)3Mn(μ-SPh)Pt(PPh3)(Dppm)

A reaction of the dimer [Mn(CO)₄(SPh)]₂ with (PPh₃)₂Pt(C₂Ph₂) gave the heterometallic complex (CO)₄Mn(μ-SPh)Pt(PPh₃)₂ (I) and its isomer (CO)₃(PPh₃)Mn(μ-SPh)Pt(PPh₃)(CO) (II). A reaction of complex I with a diphosphine ligand (Dppm) yielded the heterometallic complex (CO)₃Mn(μ-SPh)Pt(PPh₃)(Dppm) (III). Complexes I–III were characterized by X-ray diffraction. In complex I, the single Mn-Pt bond (2.6946(3) ?) is supplemented with a thiolate bridge with the shortened Pt-S and Mn-S bonds (2.3129(5) and 2.2900(6) ?, respectively). Unlike complex I, in complex II, one phosphine group at the Pt atom is exchanged for one CO group at the Mn atom. The Mn-Pt bond (2.633(1) ?) and the thiolate bridge (Pt-S, 2.332(2) ?; Mn-S, 2.291(2) ?) are retained. In complex III, the Mn-Pt bond (2.623(1) ?) is supplemented with thiolate (Pt-S, 2.341(2) ?; Mn-S, 2.292(2) 0?) and Dppm bridges (Pt-P, 2.240(1)?; Mn-P, 2.245(2) ?). Apparently, the Pt atom in complexes I–III is attached to the formally double bond , as in Pt complexes with olefins.     

Synthesis and Molecular Structure of Tris(pentamethylphenyl)aluminum, (C6Me5)3Al, and the Magnesium Cluster [Mg6(μ3-OH)2(μ3-Br)2(μ2-Br)8(OEt2)8]

The synthesis and molecular structures of tris(pentamethylphenyl)aluminum, (C₆Me₅)₃Al, (I), and the magnesium cluster [Mg₆( ₃-OH)₂( ₃-Br)₂( ₂-Br)₈(OEt₂)₈] (II), are reported. Both compounds were isolated from the same system. The aluminum atom in (I) resides in an almost idealized trigonal planar environment. The dihedral angles of the pentamethylphenyl rings relative to the AlC₃plane in (I) are 67.2, 62.4, and 61.2°. The neutral magnesium cluster, (II), is interesting in that contains six magnesium atoms each of which resides in octahedral environments.     

Syntheses,crystal structures,and electrochemical studies of Fe2(CO)6(μ-PPh2)(μ-L) (L = OH,OPPh2, PPh2)

Reaction of Fe₃(CO)₁₂ and Ph₂PH in the presence of Et₃N in THF at 0?°C immediately forms Fe₂(CO)₆(μ-PPh₂)(μ-OH) (1), Fe₂(CO)₆(μ-PPh₂)(μ-k²O,P-OPPh₂) (2), and Fe₂(CO)₆(μ-PPh₂)₂ (3) in yields of 25, 14, and 19%, respectively. Experiments confirm that Et₃N shortens the reaction time. The absence of O₂ hinders the formation of 2. The presence of H₂O can increase the yield of 1. Their structures have been determined by X-ray crystallography and the complexes have been completely characterized by EA, IR, and ¹H, ¹³C, ³¹P NMR. Electrochemical studies reveal that they exhibit catalytic H₂-producing activities.     

Synthesis,Crystal Structure and Catalytic Activity of a Hexa-μ-chloro-tetrakis-(1-triphenylmethyltriazole)-μ4-oxo-tetracopper(Ⅱ)

A new Cu(Ⅱ) complex,[Cu_4Cl_6O(1-TrTz)_4]where 1-Tr Tz is 1-trityl-1H-[1,2,4]triazole,was synthesized by the reaction of 1-trityl-1H-[1,2,4]triazole with two hydrated cupric chlorides,and its structure was characterized by X-ray single-crystal diffraction.[Cu_4Cl_6O(1-TrTz)_4]is of monoclinic system,space group P21/c,a=12.5024(13),b=26.400(3),c=28.588(3)?,β=112.807(4)°,V=8698.1(16)?~3,Z=4,ρ_(calc)=1.411 g/cm~3,μ=1.265 mm~(–1),F(000)=3772,the final R=0.1293 and w R=0.3644 for 55774 observed reflections (I2s(I)),R(all data)=0.1972,w R(all data)=0.3989,completeness to theta of 25.242 is 99.9%and GOF=1.103.In the structure of[Cu_4Cl_6O(1-TrTz)_4],the central O atom is tetrahedral and is coordinated with four Cu atoms.The distance between copper and oxygen bond is 1.909(6)?.In addition,the catalytic property of this complex was investigated and it could effectively catalyze the Ullmann coupling reaction of various (hetero)aryl chlorides with azoles.     

Bis(μ3-barbiturato−O,O,O′)-(μ2-aqua)- aqua-barium(II): crystal structure,spectroscopic and thermal properties

A polymeric coordination compound, [Ba(H₂O) ₂(Hba)₂] (1) (H₂ba – barbituric acid, C₄H₄N₂O₃), was obtained. The structure of 1 was solved using powder X-ray diffraction methods. The Ba²⁺ ion in 1 formed a three-capped trigonal prism. The BaO₉ polyhedra, connected with each other by the edges and faces, formed a chain. Several 4- and 12-membered cycles due to the bridging μ₂-H₂O and bridging μ₃-Hba^– also formed implementing a 3-D polymer structure. The structures of 1 and other thiobarbiturate complexes were compared. The replacement of a S atom by an O atom in the heterocyclic ligand Htba^? (thiobarbiturate ion) of the compound Ba(H₂O)₂(Htba)₂ resulted in changes of the coordination number Ba(II) and supramolecular structure. The intermolecular hydrogen bonds O–H?O and N–H?O formed a 3-D net where pronounced 2-D layers of Hba^– ions could be found. A new topological net in 1 was observed. The IR and thermal stability were investigated.     

Synthesis,crystal structure and magnetic properties of triaquahexakis(μ2-betaine)(μ3-oxo)triiron(III) perchlorate heptahydrate

The synthesis and characterization of the oxo-centered carboxylato-bridged trinuclear iron(III) complex, triaquahexakis(₂-betaine)(₃-oxo)triiron(III) perchlorate heptahydrate are described. X-ray crystallography shows that the Fe^III atom in the complex has a slightly distorted octahedral geometry, coordinated by four oxygen atoms from different betaine ligands [Fe—;O = 2.009(3) 2.034(3) Å], one aqua ligand [Fe—O = 2.028(4) and 2.031(3) Å] and the central ₃-oxo atom [Fe—O = 1.917(2) and 1.917(3) Å]. The central oxygen is ideally coplanar with the plane of the three metal atoms. Magnetic susceptibility data (4–320 K) show the presence of an antiferromagnetic exchange interaction with a coupling constant of J = –20.2 cm^–1.     

Synthesis and structure of sulfur and selenium capped dihydride triruthenium clusters [Ru3(CO)7(μ-H)2(μ-dppm)(μ3-E)] (E = S, Se)

Reaction of [Ru₃(CO)₁₀(μ-dppm)] (1) with H₂S at 66 °C affords high yields of the sulfur-capped dihydride [Ru₃(CO)₇(μ-H)₂(μ-dppm)(μ₃-S)] (2), formed by oxidative-addition of both hydrogen-sulfur bonds. Hydrogenation of [Ru₃(CO)₇(μ-dppm)(μ₃-CO)(μ₃-S)] (3) at 110 °C also gives 2 in similar yields, while hydrogenation of [Ru₃(CO)₇(μ-dppm)(μ₃-CO)(μ₃-Se)] (4) affords [Ru₃(CO)₇(μ-H)₂(μ-dppm)(μ₃-Se)] (5) in 85% yield. The molecular structures of 2 and 5 reveal that the diphosphine and one hydride simultaneously bridge the same ruthenium-ruthenium edge with the second hydride spanning one of the non-bridged edges. Both 2 and 5 are fluxional at room temperature being attributed to hydride migration between the non-bridged edges. Addition of HBF₄ to 2 affords the cationic trihydride [Ru₃(CO)₇(μ-H)₃(μ-dppm)(μ₃-S)][BF₄] (6) in which the hydrides are non-fluxional due to the blocking of the free ruthenium-ruthenium edge.     

Synthesis and characterization of dinuclear p-, m- and o-xylyl bridged complexes of molybdenum and tungsten. The crystal structures of μ-p-xylyl- bis(η-pentamethyl-cyclopentadienyltri- carbonylmolybdenum) and μ-m-xylyl-bis(η- pentamethylcyclopentadienyltricarbonyltungsten)

The reactions of (M = Mo, W) with α,α′-p-, m- and o-dichloro-xylenes yielded p-, m- and o-xylyl bridged dinuclear complexes of in high yields. All of such new complexes are stable to air and water, even stable in dilute acids and bases.     

The coordination polymer triaquabarium-μ-bis(citrato)germanate trihydrate: Synthesis, properties, and molecular and crystal structure of {[Ge(μ-HCit)2Ba(H2O)3] · 3H2O}n

The polymeric coordination compound {[Ge(μ-HCit)₂Ba(H₂O)₃] · 3H₂O} _n (H₄Cit = citric acid) was obtained for the first time for germanium(IV) citrates. The compound was characterized by elemental analysis, thermogravimetry, IR spectroscopy, and X-ray crystallography. Crystals of the compound are triclinic, a = 7.422(4) ?, b = 10.668(4) ?, c = 14.342(6) ?, α = 91.31(3)°, β = 95.81(4)°, γ = 104.08(4)°, V = 1094.5(8) ?³, Z = 2, space group P $ \bar 1 $ \bar 1 , R1 = 0.0479 for 2284 reflections with I > 2σ(I). Two crystallographically independent octahedral [Ge(HCit)₂]²⁻ anions are linked by Ba²⁺ ions to form a polymeric chain. The coordination number of Ba atoms is equal to 9. The chains are linked to each other and crystal water molecules by hydrogen bonds.     

Synthesis and crystal structure of a new tetradecker complex: Tetra(μ4-N,N′-Ethylen-bis(3-Methoxysalicylideneamine)-bis(μ2-perchlorato-O,O′)-tetranickel(II)-tripotassium perchlorate

The title tetradecker complex C₇₂H₇₂Cl₃K₃N₈Ni₄O₂₈ has been synthesized and structurally characterized. The four NiL (L = N, N-ethylene-bis(3-methoxysalicylideneiminate) segments were linked into a discrete tetradecker structure by three K⁺ cation coordinated to the phenolic oxygen atoms of the neighboring NiL units and the oxygen atom of the ClO₄⁻ anions acting as bridges. The two bicephalous K⁺ cations are nine-coordinated, while the middle one is involved in a distorted bipentagonal pyramid. For the Ni²⁺ ion, it is involved in a square planar coordination sphere formed by a N₂O₂ unit from the Schiff base ligand.     

Synthesis, Structure and Properties of a Copper Complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2

The title complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2 1(C20H24Cu2O10, Mr=structure was determined by X-ray diffraction method. Complex 1 belongs to orthorhombic, space group Pbca with a = 13.083(6), b = 8.078(4), c = 21.566(2)(A), V = 2279(2) (A)3, Z = 4, Dc= 1.607g/cm3, F(000) = 1128,μ(MoKa) = 1.918 mm-1, the final R = 0.0506 and wR = 0.1382. Each Cu(Ⅱ)ion is coordinated by five oxygen atoms from two benzoic acids, two acetic acids and one methanol molecule in a slightly distorted square pyramidal environment. The title molecules construct a 2-D complex 1 displays strong emissions. IR and TG-DTA studies are also presented.     

Synthesis, X-ray crystal structure, and reactivity of Pd2(μ-dotpm)2 (dotpm = bis(di-ortho-tolylphosphino)methane)

Alkylation of PdCl₂(dotpm) (dotpm = bis(di-ortho-tolylphosphino)methane) with n-butyllithium produces the binuclear Pd(0) complex Pd₂(μ-dotpm)₂ and the elimination byproducts 1-butene, cis-2-butene, trans-2-butene, butane, and octane. The dibutyl complex, Pd(dotpm)(n-Bu)₂, is presumed to be the reaction intermediate. The crystal structure of Pd₂(μ-dotpm)₂ reveals that the methylene groups of the bridging dotpm ligands are located on opposite sides of the Pd₂P₄ unit, forming an 8-membered ring that is in an elongated chair conformation. The four phosphorus atoms are not coplanar, and the P1-P2-P3-P4 ring has a torsion angle of 13.8°, which minimizes the spatial interactions among the o-tolyl rings. The Pd-Pd bond distance is 2.8560(6) Å, which indicates that there is a weak “closed-shell” bonding interaction between the d¹⁰-d¹⁰ metal centers. Each palladium atom has a nearly linear geometry, and the eight methyl groups of the dotpm ligands shield the open coordination sites on the metal centers. Four methyl groups shield the metal atoms above and below the Pd₂P₄ ring cavity, and four methyl groups block the open metal sites outside of the Pd₂P₄ ring. The Pd₂(μ-dotpm)₂ complex readily undergoes oxidative addition of dichloromethane to form the rigid A-frame complex Pd₂Cl₂(μ-CH₂)(μ-dotpm)₂.     

Coordination bonding in dicopper and dichromium tetrakis(μ-acetato)-diaqua complexes: Nature,strength, length,and topology

Geometry optimization, energetics, electronic structure, and topology of electron density of dicopper ( I ) and dichromium ( II ) tetrakis(μ-acetato)-diaqua complexes are studied focusing on the metal–metal interactions. The performance of broken symmetry (BS) single-determinant ab initio (Hartree–Fock, Møller–Plesset perturbation theory to the second and third orders, coupled clusters singles and doubles) and density functional theory (BLYP, B3LYP, B3LYP-D3, B2PLYP, MPW2PLYP) methods is compared to multideterminant ab initio (CASSCF, NEVPT2) methods as well as to the multipole model of charge density from a single-crystal X-ray diffraction experiment (Herich et al., Acta Cryst. 2018, B74, 681–692). In vacuo DFT geometry optimizations (improper axial water ligand orientation) are compared against the periodic ones. The singlet state is found to be energetically preferred. J coupling of ( I ) becomes underestimated for all ab initio methods used, when compared to experiment. It is concluded that the strength of the direct M─M interactions correlates closely with the J coupling magnitude at a given level of theory. The double potential well character of (II) and of the dehydrated form of (II) are considered with respect to the Cr─Cr distance. The physical effective bond order of the metal–metal interaction is small (below 0.1 e) in ( I ) and moderate (0.4 e) in ( II ). The CASSCF results overestimate the electron density of the metal–metal bond critical point by 20% and 50% in ( I ) and ( II ), respectively, when compared to the multipole model. © 2019 Wiley Periodicals, Inc.     

Synthesis,Structure, and Magnetic Properties of Di-μ-Pyrazolatodicopper(II) Complexes of 3,5-Bis(Aminomethyl)Pyrazole

Abstract

3,5-Bis(aminomethyl)pyrazole (Hbampz) forms binuclear copper(II) complexes of the formula [Cu₂(bampz)₂X₂] (X = CI, Br). The crystal structure of [Cu₂(bampz)₂Br₂] has been determined by the X-ray method: formula = CuBrN₄C₅H₉, monoclinic, space group P2₁/n, a = 9.214(1), b = 10.078(1), c = 8.775(1) Å, β = 97.33(1)°, V = 808.1 ų. Two bampz^? molecules combine with two copper(II) ions via the pyrazolate nitrogen and aminonitrogen atoms in the side chains affording an essentially planar N₄ environment for each metal ion. The Cu-Cu separation is 3.947(5)A. The axial site of each copper is weakly coordinated by a bromide ion with a Cu-Br distance of 2.895(4) A. Cryomagnetic investigations over the temperature range 80-300 K revealed a significant antiferromagnetic interaction through the pyrazolate bridges. The exchange integrals (J) based on the Heisenberg model (H =—2J?₁.?₂) was estimated at—200.8 and—192.0 cm^?1 for [Cu₂(bampz)₂Cl₂] and [Cu₂(bampz)₂Br₂], respectively.     

Crystal Structure and Inhibitory Activity against Xanthine Oxidase of Bis(μ2-chloro)-chloro-(μ-N,N'-(2-pyridylmethylene)Furanmethanoamine Copper(Ⅱ)Complex

A chloro-bridged dinuclear copper(Ⅱ) complex with ligand 2-pyridylme-thylene-furfurylamine has been synthesized and characterized by single-crystal X-ray diffraction,and its inhibitory activity on xanthine oxidase(XO)Was also evaluated.It crystallizes in the triclinic system,space group P-1 with a=8.0441(16),b=8.5663(17),c=10.060(2)(A),α=77.52(3),β=72.04(3),γ=70.12(3)°,V=615.3(2)(A)3,Z=1,Dc=1.731 g/cm3,F(000)=322,the final R=0.0401 and wR=0.0934 for 1971 observed reflections with Ⅰ＞2σ(Ⅰ).X-ray analysis reveals that the Cu(Ⅱ)cation is five-coordinated by two N atoms of Schiff base and three C1 anions.The C-H…Cl intermolecular and intramolecular hydrogen bonds connect the molecules to form a three-dimensional network.Tilis copper(Ⅱ) complex shows more potent inhibitory activity against XO with Ⅰ C50=3.48/μM than the standard inhibitor allopurinol.