The first example of half-sandwich cobalt(III) complex with hydrotris(pyrazolyl)borate ligand

This paper presents the synthesis, crystal structure and spectroscopic properties of a novel half-sandwich mononuclear cobalt(III) complex with hydrotris(3,5-dimethylpyrazolyl)borate ligand and thiocyanate [Tp^*Co(Hpz^*)(NCS)₂]·H₂O·CH₃OH (Tp^*: hydrotris(3,5-dimethyl- pyrazolyl)borate, Hpz^*: 3,5-dimethylpyrazole). The structure was determined by X-ray diffraction. The complex crystallizes in the monoclinic system, space group C_c, a=18.591(6) Å, b=10.536(3) Å, c=17.568(5) Å, β=11.284(5)°, Z=4, R₁=0.0501, wR₂=0.1179. The cobalt(III) ion in the complex is six-coordinated with nitrogen atoms, three from Tp^*, two from pyrazole and two from two thiocyanates, to form octahedral environment. The hydrogen atoms of O(2) of water molecule are connected by hydrogen bonds with S atoms of two adjacent complex molecules to form 1-D chains. The hydrogen atom of N(8) of complex molecule is connected by hydrogen bond with methanol. The spectroscopic results are consistent with the crystallographic study.     

X-ray structure and spectroscopic properties of some lanthanides(III) complexes derived from 2,6-diacetylpyridine-bis(benzoylhydrazone)

A series of trivalent lanthanide complexes of type [Ln(L) NO₃)(S)_n](NO₃)_m(S^′)_n, have been synthesized by the reaction of 2,6-diacetylpyridine-bis-(benzoylhydrazone) (H₂L) with lanthanide(III) nitrates in ethanol. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data revealed the formation of 1:1 (metal:ligand) stoichiometry. Molar conductance in dmf gives 2:1 electrolytes in all the complexes. Magnetic moment values are close proximity of the Van Vleck values. IR study suggests the coordination of the ligand through the azomethine and the oxygen of the hydrazonic moiety. The nitrate ion is also found to be bidentate in all the complexes. The crystal structures were determined. 6, C₂₇H₃₁N₆O₇S₂Gd: a=b=8.6821(4) Å, c=84.363(5) Å, tetragonal P4₁2₁2 and Z=8. bf 7, C₂₅H₂₅N₆O₆SDy: a=11.750(3) Å, b=13.250(3) Å, c=36.000(6) Å, β=98.50(2), monoclinic, C2/c, Z=8. 9, C₂₄H₂₅N₆O₇Yb: a=10.750(2) Å, b=17.750(3) Å, c=14.250(4) Å, β=99.00(2), monoclinic, P2₁/n, Z=4. In these complexes the lanthanide ion assumes a nine coordinated geometry for Gd and an eight coordinated geometry for Dy and Yb.     

A novel two-dimensional chiral coordination polymer: bis(S-(-)-lactate)zinc(II)

The synthesis and X-ray characterization of a novel chiral two-dimensional condensed metal–organic coordination polymer, bis(S-(-)-lactate)zinc(II) (1), are reported. Its crystal structure determination shows that a chiral cavity with approximate dimensions of 5.4×5.4 Ų is present. Crystallographic data for 1, C₆H₁₀O₆Zn, monoclinic P2₁, a=7.4440(15), b=7.4550(15), c=7.4550(15) Å, β=95.73(3)°, V=429.48(15) ų, R₁=0.0272, wR₂=0.0751.     

Hydrothermal synthesis and crystal structure of a new copper(II) molybdenum(VI) arsenate(III), (C5H5NH)2(H3O)2[(CuO6)Mo6O18(As3O3)2]

A new copper(II) molybdenum(VI) arsenate(III), (C₅H₅NH)₂(H₃O)₂[(CuO₆)Mo₆O₁₈(As₃O₃)₂], has been hydrothermally synthesized and characterized by single crystal X-ray diffraction and TG analysis. The compound crystallizes in the monoclinic space group P2₁/n with a=9.303(2), b=20.731(4), c=12.617(3) Å, β=104.17(3)°, V=2359.3(8) ų, Z=2 and R1(wR2)=0.0296(0.0683). The structure is composed of pyridinium cations, proton hydrates and [(CuO₆)Mo₆O₁₈(As₃O₃)₂]⁴⁻ polyanions. The polyanion framework derives from the Anderson type; the central octahedron is filled up by copper(II) and is capped on both sides by a cyclic As₃O₆ group.     

One-pot template synthesis and crystal structure of two new polyaza copper(II) complexes

A new 14-membered hexazamacrocyclic copper(II) complex [Cu(H₂L¹)](ClO₄)₄(L¹=1,8-bis(2-aminoethyl)-1,3,6,8,10,13-hexaazacyclotetradecane) has been prepared by the one-pot reaction of ethylenediamine and formaldehyde in the presence of the Cu(II) ion. The crystal structure of [Cu(H₂L¹)](ClO₄)₄ was determined by X-ray diffraction. It crystallizes in the triclinic space group P−1 with a=12.118(2) Å, b=12.438(2) Å, c=12.466(2) Å, α=102.26(1)°, β=112.82(1)°, γ=111.51(1)°, and Z=2. The coordination geometry around the copper(II) ions is axially elongated octahedral with four nitrogen atoms of the macrocycle [Cu–N 2.012(7) Å for Cu(1) and 2.013(6) Å for Cu(2), average value] and two oxygen atoms of two ClO₄⁻ anions [Cu–O=2.550 Å for Cu(1) and 2.601(6) Å for Cu(2)]. [CuL²](ClO₄)₂(L²=3,7-bis(2-aminoethyl)-1,3,5,7-tetraazabicyclo[3,3,2]decane) with a novel tetraazabicyclic ligand was obtained from the same reaction system as an additional product. Crystal structure of [CuL²](ClO₄)₂: monoclinic space group Cc, a=16.393(3) Å, b=8.8640(18) Å, c= 13.085(3) Å, β=105.01(3)°, and Z=4.     

Crystal and geometry-optimized structure,Hirshfeld surface analysis and spectroscopic studies of tetrachlorocuprate and nitrate salts of 1-(2-fluorophenyl)piperazine cations, (C10H15FN2)[CuCl4] (I) and (C10H14FN2)[NO3] (II)

Two new organic-inorganic hybrid materials, 1-(2-fluorophenyl)piperazine-1,4-diium tetrachlorocuprate, (C₁₀H₁₅FN₂)[CuCl₄] (I) and 1-(2-fluorophenyl)piperazin-4-ium nitrate, (C₁₀H₁₄FN₂)[NO₃] (II), have been synthesized by an acid/base reaction at room temperature in the presence of 1-(2-fluorophenyl)piperazine as an organic-structure directing agent and their structures were determined by single crystal X-ray diffraction. Compound (I), (C₁₀H₁₅FN₂)[CuCl₄], crystallizes in the monoclinic system and P2₁/c space group with a = 7.5253 (2), b = 20.6070 (7), c = 9.7281 (3) Å, β = 103.6730 (17)°, V = 1465.82 (8) Å³ with Z = 4. Full-matrix least-squares refinement converged at R = 0.037 and wR(F²) = 0.088. Compound (II), (C₁₀H₁₄FN₂)[NO₃], belongs to the monoclinic system, space group P2₁/c with the following parameters: a = 10.8034 (2), b = 7.5775 (1), c = 14.4670 (3) Å, β = 111.761 (2)°, V = 1099.91 (4) ų and Z = 4. The structure was refined to R = 0.044, wR(F²) = 0.136.In the structures of (I) and (II), the anionic and cationic entities are interconnected by means of set of hydrogen bonding contacts forming three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces and the contacts of the four different chloride atoms were notably compared. The results of the optimized molecular structure are presented and compared with the experimental one. The Molecular Electrostatic Potential (MEP) maps and the HOMO and LUMO energy gap of both compounds were computed. The vibrational absorption bands were identified by infrared spectroscopy. Theory (DFT) calculations of normal mode frequencies are compared with experimental ones.     

Eu5(μ4-OH)(μ3-OH)4(μ-DBM)4(DBM)6 (DBM=dibenzoylmethide): a novel Eu5 square-pyramid polynuclear complex with a rare μ4-OH bridging mode

The reaction of EuOCl (EuCl₃) with dibenzoylmethane (HDBM) in the presence of N-methylmorpholine yields a novel Eu₅ square-pyramid polynuclear complex with a rare μ₄-OH bridging mode, Eu₅(μ₄-OH)(μ₃-OH)₄(μ-DBM)₄(DBM)₆ (1). The compound was characterized by elemental analysis, IR, fluorescence and Mössbauer spectra as well as by an X-ray single crystal structure determination. Crystallographic data for 1, C₁₅₀H₁₁₅Eu₅O₂₅, monoclinic, P2₁/c, a=22.223(5), b=17.427(1), c=35.708(5) Å, β=100.11(2)°, V=13614(4) ų, Z=4, R₁=0.0979, wR₂=0.1695.     

A novel transition-metal-linked hexaniobate cluster with photocatalytic H2 evolution activity

A novel transition-metal (TM) complex based on Lindqvist polyoxoniobate K₁₀[(Nb₆O₁₉)Cr^III(H₂O)₂]₂·28H₂O (1) has been synthesized by a new two-pot synthesis strategy and structurally characterized by single crystal X-ray diffraction analysis, IR spectrum, UV–vis spectroscopy, XRPD and TG analysis. Compound 1 crystallizes in the C2/m space group with a = 32.143(19) Å, b = 10.030(6) Å, c = 12.878(8) Å, β = 110.611(9)°, and V = 3886(4) ų. X-ray structure analysis reveals that polyanion [(Nb₆O₁₉)Cr^III(H₂O)₂]₂^10 − (1a) represents the first example of two nuclear dimeric polyoxoniobate, in which two Lindqvist anions [Nb₆O₁₉]⁸ are sandwiched by two {Cr^III(H₂O)₂} groups. Further, 1 exhibits photocatalytic H₂ evolution activity.     

Metal–Organic Framework Based on Pyridine-2,3-Dicarboxylate and a Flexible Bis-imidazole Ligand: Synthesis, Structure, and Photoluminescence

A novel metal–organic framework {[Zn(2,3-pydc)(bbi)]·0.5CH₃CN·2H₂O} _n (2,3-pydc = pyridine-2,3-dicarboxylate, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (1), was prepared under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction. Crystal data for 1 are monoclinic, space group C2/c, a = 19.685(2) Å, b = 14.332(1) Å, c = 16.930(2) Å, β = 121.205(2)°, U = 4085.3(6) Å³, Z = 4. The results reveal that the Zn(II)-atom is five-coordinated with two O-atoms and three N-atoms forming a distorted trigonal bipyramidal geometry. The Zn(II) atoms are bridged by 2,3-pydc and bbi ligands, leading to a three-dimensional network. The Zn···Zn separations are 8.277 Å [through the 2,3-pydc bridge] and 12.638 Å [through the bbi bridge]. Additionally, 1 shows strong fluorescence in the solid state at room temperature.     

A novel lead borate of NaPb4(H2O)(B5O9)2·BO3 with nonlinear optical property

A new mixed metal borate, NaPb₄(H₂O)(B₅O₉)₂·BO₃, with an acentric structure has been successfully made under hydrothermal conditions and structurally characterized by IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction, respectively. The structural analysis shows that 1 crystallizes in the orthorhombic space group Pnn2 (No. 34) with a = 11.3724(5) Å, b = 11.4455(4) Å, c = 6.5578(2) Å and Z = 2. In the structure 1, the structural building unit, B₅O₁₂ cluster, connects adjacent six same ones to form a 3-D oxoboron framework with 8-membered ring (MR) and 10-MR channels along the c-axis. The Pb atoms and coordinated water molecules are located in the 8-MR channels, while the 10-MR channels were occupied by the chains built by Na atoms and the BO₃ groups. Second-harmonic generation (SHG) measurements on the powder samples reveal that 1 exhibits SHG efficiency approximately 2 times that of KH₂PO₄ (KDP). Also it has a UV cutoff edge below 220 nm.     

A novel paradodecatungstate-B compound decorated by transition metal copper,Na2Cu5(H2O)24(OH)2[H2W12O42]·10H2O: Synthesis,structure and antitumor activities

A new paradodecatungstate-B compound decorated by transition metal copper, Na₂Cu₅(H₂O)₂₄(OH)₂[H₂W₁₂O₄₂]·10H₂O (1), has been synthesized by convenient aqueous solution method and structurally characterized by single-crystal X-ray diffraction, IR spectrum, elemental analysis and TGA. The compound crystallizes in the triclinic P-1 space group with a = 10.7140(8) Å, b = 12.9476(9) Å, c = 13.6696(10) Å, α = 73.56°, β = 75.73°, γ = 67.69°, V = 1661.8(2) ų and Z = 1. In compound 1, polyanion of [H₂W₁₂O₄₂]^10 − acts as a dodecadentate ligand that links copper and sodium cations, forming a remarkable three-dimensional framework. The experiment of antitumor activities in vitro shows that the title compound exhibits remarkable inhibitory actions on human cervical carcinoma HeLa cells, ovarian carcinoma SKOV-3 cells, hepatoma HepG2 cells and neuroblastoma SHY5Y cells.     

1D Coordination Polymer from Tetraaza Macrocyclic Nickel(II) Complex and 1,2,3,4-Cyclobutanetetracarboxylic Acid

The self assembly of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) and 1,2,3,4-cyclobutanetetracarboxylic acid (H₄cbtc) acid generates a 1D coordination and 2D hydrogen-bonded polymer [Ni(L)(H₂cbtc)₂·3H₂O] _n (1). Complex 1 is characterized by X-ray crystallography, spectroscopy and magnetic susceptibility. Each nickel(II) ion has a distorted octahedral coordination environment with the four secondary amines of the macrocycle in which two carboxylate anions of the H₂cbtc^2? ligand have assembled around each nickel center. The compound crystallizes in the triclinic system P-1 with a = 9.715(3) Å, b = 12.891(5) Å, c = 13.903(6) Å, α = 72.64(2)°, β = 75.70(3)°, γ = 73.27(3)°, V = 1566.6(10) ų, Z = 2. The electronic spectrum of 1 indicates a high-spin octahedral environment. The magnetic behavior of 1 reveals a weak intramolecular antiferromagnetic interaction with J = ?1.23(1) cm^?1.     

Synthesis and characterization of the zinc(II) complex of a bleomycin analogue: a unique polymeric 2-[((2-(4-imidazoyl)ethyl)amino)carbony]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine zinc(II) nitrate complex

The reaction of 2-[((2-(4-imidazoyl)ethyl)amino)carbonyl]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine (L) with Zn^II(NO₃)₂·6H₂O has afforded a novel one-dimensional polymeric Zn^II complex, (Zn^II(L)(NO₃)₂)_n (2). Complex 2 crystallizes in the space group P2₁/n with a=8.955(3), b=13.216(3), c=18.941(3) Å, β=103.39(2)°, V=2180.6(10) ų, and Z=4. The geometry of each Zn^II is approximately a trigonal bipyramid: three nitrogens and one oxygen of the amide group are coordinated to the zinc while the fifth site is occupied by the imidazole nitrogen of a neighboring unit.     

Synthesis,structure and characterization of a new nonlinear optical calcium borate [Ca2B5O9]·[H(OH)2]

A new nonlinear optical crystal [Ca₂B₅O₉]·[H(OH)₂] (1) has been synthesized under hydrothermal condition. Compound 1 crystallizes in the monoclinic space group C2 with lattice constants a = 10.111(2) Å, b = 7.754(11) Å, c = 6.198(14) Å, β = 127.04(3)° and Z = 2. The fundamental building block (FBB) of 1 is a [B₅O₁₂] unit with two BO₃ triangles and three BO₄ tetrahedra. 1 was characterized by single-crystal X-ray diffraction, IR and UV–Vis spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) respectively. Also, powder second harmonic generation (SHG) measurements indicate that 1 is phase matchable and displays a SHG response of about 3.5 times that of KDP (KH₂PO₄).     

Nitrosyl cis-dichlorodiammine ruthenium complex with bridging H3O2− ligand

The ruthenium complex with bridging H₃O₂⁻ ligand was obtained and the crystal structure was determined. The compound cis-[{RuNO(NH₃)₂Cl₂}₂(μ₂-H₃O₂)]Cl crystallizes in the monoclinic space group P2₁/n with cell parameters a = 15.0651(5), b = 6.3624(2), c = 15.3813(6) Å, β = 94.9690(10)°, Z = 4 and R = 0.0185. The hydroxide hydrate anion is coordinated to the ruthenium atoms of the identical cis-{RuNO(NH₃)₂Cl₂} fragments. The protonation of the starting cis-[RuNO(NH₃)₂(NO₂)₂OH] complex leads to the required coordinated aqua/hydroxide ratio if the specific amount of hydrochloric acid is used. The DFT calculations confirm the formation of the dimer structure in the gas phase. However, the presence of water molecules dramatically reduces the dimerization efficiency.     

Synthesis,reactivity, and X-ray structural characterization of a vanadium(III) oxidation pre-catalyst, (CpPOEtCo)VCl2(DMF)

Vanadium complexes are extensively used in the chemical industry as oxidation catalysts. During the course of our investigations into vanadium oxidation catalysis, the rich reactivity of a vanadium(III) scorpionate analogue complex, (CpP^OEtCo)VCl₂(DMF) (1), was investigated. The octahedrally coordinated 1 was prepared by mixing vanadium(III) chloride with Na(CpP^OEtCo) in DMF. The crystal structure of 1 has been determined through X-ray diffraction. Complex 1, C₂₀H₄₂Cl₂CoNO₁₀P₃V, crystallizes in the monoclinic space group P2₁/c with a = 38.566(9) Å, b = 9.499(2) Å, c = 18.149(4) Å, and β = 100.485(4)° with Z = 8. Complex 1 was found to be an effective pre-catalyst for the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone. The reactivity studies, oxidative catalytic ability, as well as X-ray structural characterization of (CpP^OEtCo)VCl₂(DMF) will be discussed. ((CpP^OEtCo) = [η⁵-cyclopentadienyltris(diethylphosphito-κ¹P) cobaltate(III)⁻; DMF = N,N-dimethylformamide).     

Synthesis,structure and fluorescence properties of a uranyl-2,5-pyridinedicarboxylic acid coordination polymer: The missing member of the UO22+-2,n-pyridinedicarboxylic series

A 3D uranium-pyridinedicarboxylate, compound (1) [UO₂(C₇H₃NO₄)], represents the final member of a series of materials incorporating a series of 2,n-pyridinedicarboxylic (pydc) acids (n = 3,4,5,6). The resulting crystal structure [FW = 419.13, monoclinic, P2₁/n, a = 9.0096(3) Å, b = 8.1371(2) Å, c = 11.6954(4) Å, V = 852.45 ų, Z = 4] was determined by single crystal X-ray diffraction and fluorescent properties were investigated. Additionally, the complete series of uranium-2,n-pydc materials was examined on a basis of fluorescent behaviors and architectural similarities.     

The First Two Examples of (R)-2-Chloromandelato Coordination Polymers: Synthesis,Structure, Magnetic and Ferroelectric Properties

Both (R)-2-Chloromandelato coordination polymers, [Cu(Clma)₂] _n 1 and [Mn(H₂O)(Clma)₂] _n 2, crystallizing in the polar chiral monoclinic space group P2₁ represent the first two examples of metal complexes with (R)-2-Chloromandelic acid (HClma) ligand. Through the (R)-2-Chloromandelate Clma^? ions, the penta- and hexa-coordinated metal atoms in 1 and 2 are linked into chains, _∞ ¹ {[Cu(Clma)](Clma)_2/2} _n and _∞ ¹ {[Mn(H₂O)(Clma)](Clma)_2/2} _n , respectively, and further assembled into 3D supramolecular architectures via hydrogen bonding and close packing interactions. They exhibit ferroelectricity (Pr = 0.03 and 0.01 μC cm^?2, Ec = 5.09 and 0.52 kV cm^?1, Ps = 0.10 and 0.17 μC cm^?2, respectively). The magnetic behaviors of 1 and 2 can be interpreted by means of a 1D chain model, where the magnetic exchanges are transmitted via carboxylate groups between metal atoms, and the best fit results in J = 2.97, ?0.15 cm^?1 for 1 and 2, suggesting ferromagnetic and antiferromagnetic interactions, respectively.     

Room temperature assembly of a uranyl carboxyphosphonate: Synthesis,characterization and UO22+ hydrolysis

A novel 1-dimensional U(VI) phosphonoacetate, UO₂(O₃PCH₂CO₂H)(H₂O)·2H₂O (1), has been synthesized from the room temperature reaction of uranium nitrate and phosphonoacetic acid (H₃PPA) in water. The compound crystallizes in a monoclinic space group (P2₁, a = 8.3517(5) Å, b = 7.0013(4) Å, c = 8.3728(5) Å, β = 107.310(1)°, Z = 2) and exhibits bonding to the UO₂²⁺ through both phosphonate and carboxylate oxygen atoms of the acid unit. The crystal structure, thermal and fluorescent behaviors, and role of UO₂²⁺ hydrolysis in the context of ambient versus hydrothermal syntheses are discussed.