Synthesis,Structure,and Magnetic Property of One Novel Entangled Cobalt~Ⅱ-organic Compound

One novel entangled cobalt compound, {[Co3（nbta）2（4,4＇-bpy）2（H2O）2]（H2O）2}n （1, H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, 4,4＇-bpy = 4,4＇-bipyridyl）, was prepared and characterized by X-my diffraction, magnetism, elemental analysis, XPS, TGA and IR spectroscopy. The crystal of 1 crystallizes in monoclinic, space group Pc with a = 13.0717（16）, b = 11.4167（14）, c = 15.9342（19） A, β = 90.5190（10）°, V= 2377.9（5） A3, Z= 2, C48H36Co3N8O20, Mr = 1221.64, Dc = 1.706 g/cm3, F（000） = 1242 and μ（MoKa） = 1.128 mm^-1. The final R = 0.0497 and wR = 0.1461 for 4185 observed reflections with I 〉 20（0 and R = 0.0721 and wR = 0.1619 for all data. X-ray diffraction analyses revealed that Co（l） is linked by the nbta3- ligands to form the ladder shape along the c axis, which is further extended into two-dimensional networks via the joint of Co（2） along the a axis. Moreover, these two dimensional motifs are interconnected by the 4,4＇-bpy bridges to form a complicated 3-D polymeric framework. Magnetic measurements revealed that compound 1 shows strong antiferromagnetic property.

Ionothermal Syntheses and Crystal Structures of Two Cobalt(Ⅱ) Compounds:Co(2,2'-bpy)_2Br_2 and Co(1,10-phen)_2Br_2

Two cobalt（Ⅱ） compounds,Co（2,2-bpy） 2 Br 2 （1,2,2-bpy=2,2-bipyridyl） and Co（1,10-phen） 2 Br 2 （2,1,10-phen=1,10-phenanthroline）,have been prepared under ionothermal reactions using the 1-propyl-3-methylimidazolium bromide ionic liquid solvent.Single-crystal X-ray analyses reveal that 1 crystallizes in a monoclinic space group P2 1 /c,with a=8.5509（13）,b=14.804（2）,c=15.650（2）,β=97.119（2） o,V=1965.8（5） 3,Z=4,C 20 H 16 Br 2 N 4 Co,M r=531.12,D c=1.795 g/cm 3,μ=4.950 mm-1,F（000）=1044,the final R=0.0467 and wR=0.0736 for 2291 observed reflections with I 2σ（Ⅰ）.Complex 2 crystallizes in a monoclinic space group P2 1 /n,with a=10.4237（8）,b=16.8657（12）,c=12.4945（9）b,β=102.110（1） o,V=2147.7（3） 3,Z=4,C 24 H 16 Br 2 N 4 Co,M r=579.16,D c=1.791 g/cm 3,μ=4.540 mm-1,F（000）=1140,the final R=0.0431 and wR=0.1042 for 3470 observed reflections with I 2σ（Ⅰ）.The mononuclear molecules of 1 are linked by the C-H···Br hydrogen bonds and π-π interactions to form a three-dimensional supramolecular framework structure.The C-H···Br hydrogen bonds and π-π interactions link the mononuclear molecules of 2 to give a two-dimensional layer structure.

Novel cobalt(Ⅱ) complexes of amino acids-Schiff bases catalyzed aerobic oxidation of various alcohols to ketones and aldehyde

Two cobalt（Ⅱ） complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH,solvent,temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes.Under obtained optimum conditions,various alcohols were oxidized to corresponding aldehydes and ketones.

Simple, Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel(Ⅱ), Copper (Ⅱ), Cobalt (Ⅱ), and Iron (Ⅲ) with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.

Hydrothermal Syntheses and Crystal Structures of Cobalt(Ⅱ) Complexes Constructed by Dipyrido[3,2-a:2',3'-c]phenazine and Different Carboxylate Ligands

Two new metal-organic complexes,{[Co2（bptc）（DPPZ）2（H2O）2]·H2O}n 1 and {[Co2（ccm）2（DPPZ）2]·2H2O}n 2,were obtained by the hydrothermal reactions of Co（NO3）2·6H2O with chelating ligand dipyrido[3,2-a：2＇,3＇-c]phenazine（DPPZ） and the corresponding carboxylic acid,namely,3,3＇,4,4＇-benzophenonetetracarboxylic acid（H4bptc） or 2-carboxycinnamic acid（H2ccm）,respectively.The complexes were structurally characterized by single-crystal X-ray diffraction,elemental analyses,IR spectra,and thermal gravimetry.1 presents unique chiral chain structures,which are further consolidated into three-dimensional supramolecular frameworks via noncovalent bonds,such as hydrogen bonding and π-π interactions.2 features infinite double-chain structures,which are connected by strong π-π interactions to result in three-dimensional supramolecular architectures.

Syntheses,Crystal Structures,and Magnetic Properties of Cobalt(Ⅱ) Complexes with 1,1-Cyclohexanediacetic Acid

Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane and bpe = 1,2-bis（4-pyridinyl）ethylene）,were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square（4,4） grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.

Synthesis and Crystal Structure of a Cobalt(Ⅱ) Complex with 2-(4'-Chlorine-benzoyl)-benzoic Acid and 1,10-Phenanthroline

A new metal-organic complex Co2（cbba）4（phen）2（μ2-OH2）（H2cbba=2-（4＇-chlorine-benzoyl）benzoic acid,phen=1,10-phenanthroline） 1 has been hydrothermally synthesized and struc-turally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in triclinic,space group P1 with a=10.7659（7）,b=17.1856（11）,c=19.2022（13）,α=83.8120（10）,β=84.9930（10）,γ=87.2070（10）°,V=3515.8（4）3,C80H50Cl4Co2N4O13,Mr=1534.90,Dc=1.450 g/cm3,μ（MoKα）=0.693 mm-1,F（000）=1568,Z=2,the final R=0.0490 and wR=0.1092 for 8216 observed reflections（Ⅰ 〉2σ（Ⅰ））.In the crystal structure,the cobalt atom is six-coordinated with three carboxylate oxygen atoms from three different cbba ligands,one oxygen atom from coordinated water molecule and two nitrogen atoms from phen ligand,showing a distorted octahedral geometry.Furthermore,it exhibits a 3D supramolecular network through π-π and hydrogen bonding interactions.

Hydrothermal Synthesis and Crystal Structure of a New One-dimensional Cobalt(Ⅱ) Complex with 2-Pyridinecarboxyic Acid and 4,4′-Bipyridine Ligands

A new metal-organic coordination polymer [Co（2-pya）2（4,4＇-bipy）]2n-[（4,4＇- bipy）0.5· H2O]2n （2-pya = 2-pyridinecarboxylic acid, 4,4＇-bipy = 4,4＇-bipyridine） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in tetragonal, space group I41/a with a = b = 22.719（2）, c = 10.710（2）/k, V = 5527.8（14） A3, C54H46N10Co2O10, Mr= 1112.87, Dc = 1.337 g/cm3,μ（MoKa） = 0.665 mm-1, F（000） = 2296, Z = 4, the final R = 0.0633 and wR = 0.1096 for 1261 observed reflections （I 〉 2σ（I））. It exhibits a one-dimensional chain-like structure constructed by mixed ligands of 2-pyridinedicarboxylic acid and 4,4＇-bipyridine.

Crystal Structure and Luminescent Properties of a 3D Cd(Ⅱ) Compound Constructed from Succinate and 3,6-Di(4-pyridyl)pyridazine

A three-dimensional（3D） coordination polymer,[Cd（SC）（DPPD）]_n（1,H_2SC = succinic acid and DPPD = 3,6-di（4-pyridyl）pyridazine）,has been synthesized by the solvothermal reaction of Cd（NO_3）_2·4H_2O with H_2 SC and DPPD at 120 ℃ in DMF solvent. Compound 1 crystallizes in the monoclinic system,space group P2_1/c,with a = 10.7993（4）,b = 11.7705（3）,c = 13.5336（6） A,V = 1678.89（11） A^3,Z = 4,C18H14N4O_4 Cd,M_r = 462.73,D_c = 1.831 g/cm^3,μ = 1.335 mm^（-1）,F（000） = 920.0,the final R = 0.0500 and wR = 0.1567 for 3714 observed reflections with I 〉 2s（I）. In compound 1,the Cd（Ⅱ） ions are linked by the SC^2– ligands to give a two-dimensional（2D） undulating sheet based on the centrosymmetric dinuclear Cd_2（COO）_2 units. The 2D sheets are further connected by the DPPD ligands to produce a 3D structure,which is a 6-connected（4^4·6·^10·8） topological network based on the dinuclear Cd_2（COO）_2 node. Compound 1 exhibits a photoluminescent emission with a maximum at 540 nm upon excitation at 460 nm.

Synthesis, Crystal Structure, and Fluorescent and Thermal Stability Properties of Two New Cobalt(Ⅱ) Complexes with 2,2’-Bipy as Ligand

Two new cobalt(Ⅱ)complexes[Co2(2,2?-bipy)2(dpa)2(H2O)5]·4H2O(1)and Co(2,2?-bipy)3(SO4)]·7.5H2O(2)have been synthesized with diaphonic acid(H2dpa)and 2,2?-bipyridine(2,2?-bipy)as ligands.In 1,two neighboring cobalt(Ⅱ)ions are linked together by one bridging diaphonic acid group,forming an asymmetric dinuclear structure.1 crystallizes in triclinic,space group P1 with a=9.825(6),b=13.007(8),c=19.586(1)A,α=80.773(1)o,β=77.065(1)o,γ=85.902(1)o,Mr=431.4,V=2406.5(3)A^3,Dc=1.48 g/cm^3,Z=2,μ(Mo Kα)=0.767 mm-1,F(000)=1112,the final R=0.0379 and wR=0.0862.The central cobalt(Ⅱ)ions in 1 and 2 are coordinated with six atoms,forming distorted octahedral coordination geometry.The fluorescence and thermal stability properties of 1 and 2 are also reported.

Synthesis and Crystal Structure of Trans-diaquabis(hexamethylenetetramine-N)bis(isothiocyanato)cobalt(Ⅱ) trans-tetraaquabis(isothiocyanato)cobalt(Ⅱ) dihydrate

The synthesis and crystal structure of [Co(NCS)2(hmt)2(H2- O)2]穂Co(NCS)2(H2O)4]?H2O (hmt = hexamethylenetetramine) are reported. The crystal belongs to triclinic, space group P with unit cell parameters: a = 7.917(1), b = 9.023(1), c = 12.877(1) ? ?= 94.21(1), = 96.68(1), ?= 115.42(1)? C16H40Co2N12O8S4, Mr = 774.7, V = 817.33 3, Z = 1, Dc = 1.574 g/cm3, F(000) = 402 and (MoK? = 1.328mm-1. The final values of R and wR are 0.0251 and 0.0598, respectively, for 2545 observed reflections with I > 2(I). Each Co atom is in an octahedral coordination environment, and the independent uncharged components [Co(NCS)2(hmt)2(H2O)2], [Co(NCS)2(H2O)4] and H2O are linked together by three kinds of hydrogen bonds (O(2)H贩種(3) and O(3)H贩種(2), O(1)H贩稯(4) and O(3)H贩稯(4), O(2)H贩稴(2) and O(4)H贩稴(1)) to form a three-dimensional supramolecular architecture.

Dioxygen affinities and catalytic oxidation performance of cobalt(Ⅱ) hydroxamates with benzo-15-crown-5 pendants

The oxygenation constants （Ko2） of cobalt（Ⅱ） hydroxamates （CoL^1 2-CoL^3 2） with benzo-15-crown-5 （B15C5） pendants were measured over the range of -5 to ＋20 ℃, and the values of thermodynamic parameters （ΔH^0 and ΔS^0） were calculated based on these （Ko2） values, Meanwhile, these crowned complexes were employed to the oxidation for p-xylene to p-toluic acid with air at 110Δ under normal atmospheric pressure. The effects of B15C5 pendant and the length of chain bonded to B15C5 in these complexes on the O2-binding capabilities and oxidation for p-xylene were investigated with the comparison of crown-free analogues CoL^4 2.

The Interaction of Cobalt (Ⅲ) Mixed-Ligand Coordination Compound Containing Dipyrido[3,2-a:2′,3′-c] phenazine With Calf Thymus DNA -

The binding of Co (phen)2dppz3+ to calf thymus DNA,as investigated using absorption spectroscopy. viscosity and electrophoresis measurements,here dppz is dipyrido[3, 2-a: 2'3'-c]phenazine. The compound shows absorption hypochromicity and the specific viscosity increased upon binding to calf thymus DNA The complex is also shown to be more efficient photosensitisers for single strand breaks in plasmid DNA

Infrared Spectroscopic and Theoretical Studies on Cobalt(Ⅱ) Complex of Maleinitriledithiolate and 4, 4′-Dimethyl-2, 2′-bipyridine

The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.

Structures and Properties of Two Pb^Ⅱ Compounds and Theoretical Study of 2,4-Oxybis（benzoic acid）

Two Pb^Ⅱ coordination polymers [Pb（oba）（2,2′-bipy）]·1.5H2O（1） and [Pb（oba）（phen）]（2）（H2oba = 2,4-oxybis（benzoic acid）, 2,2′-bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline） were synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, IR spectroscopy and elemental analysis. Structures of compounds 1 and 2 are similar. Compounds 1 and 2 show 1D wavy chains, which are further connected through aromatic π-π stacking interactions to expand into 2D wavelike networks. The crystal structure of 2,4-oxybis（benzoic acid） ligand（3） was obtained, and its full geometry optimization was carried out by using DFT methods at the B3LYP/6-31G（d） level. The calculated data show that the bond distances and bond angles were very close to the experimental data. The values of the frontier orbital energies indicate that this configuration is stable. Moreover, the solid-state fluorescence properties of 1-3 have also been investigated.

A New Manganese(Ⅱ) Coordination Compound Constructed by 1,10-Phenanthroline Derivative and Chlorine Anions: Synthesis, Crystal Structure and Theoretical Calculation

The new manganese(Ⅱ) coordination compound,[Mn(Cl)2(L)2](1, L = 11-fluorodipyrido[3,2-a:2?,3?-c]phenazine), has been achieved under hydrothermal conditions. The structure of compound 1 was determined by single-crystal X-ray diffraction. 1 crystallizes in monoclinic system, space group C2/c with a = 8.419(2), b = 12.286(2), c = 28.451(6)A,β= 95.889(3)°, V =2927.5(10)A3, Z = 4, C36 H16 MnF2 Cl2 N8, Mr = 724.41, Dc = 1.644 g/cm3, F(000)= 1460,μ(Mo Ka)= 0.691 mm-1, R = 0.0445 and wR = 0.0982. Adjacent compounds are stacked by one type of π-πinteraction among L ligands to generate a 1D supramolecular chain. Further, the 1D supramolecular chains are stacked by another type of π-π interaction among L ligands to give a 2D supramolecular layer. Moreover, the C-F···π interactions between the carbon atom of the L ligand and the pyrazine ring of the adjacent L ligand further stabilize the supramolecular layer of 1. In addition, natural bond orbital(NBO) analysis has been calculated by the B3LYP/LANL2DZ method, which shows obvious covalent interaction between the coordinated atoms and Mn(Ⅱ) ion.

Hydrothermal Synthesis, Crystal Structure and Luminescent Property of a Cd(Ⅱ) Compound with(4,6)-Connected Topology

A new Cd（Ⅱ） coordination polymer, namely {Cd_2（L）（biimpy）（H_2O）}_n（1, H4 L = 3-（3？,5？-dicarboxylphenoxy）phthalic acid, biimpy = 2,6-bis（1-imdazoly）pyridine）, has been successfully synthesized via the hydrothermal reactions of Cd（Ⅱ） ions, H_4L and biimpy. The crystal structure is of triclinic, space group P1 with a = 7.7874（5）, b = 9.9716（5）, c = 18.5278（6） ？, α = 91.327（4）, β = 96.689（4）, γ = 111.896（5）o, V = 1322.39（12） ？~3, C_（27）H_（17）Cd_2N_5O_（10）, M_r = 796.26, Z = 2,D_c = 2.000 g/cm^3, F（000） = 780, μ = 1.679 mm^（-1）, R = 0.0345 and wR = 0.0767 for 3890 observed reflections（I 〉 2s（I））. Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional（3D） framework based on two different dinuclear [Cd_2（COO）_2] building subunits, and topological analysis shows that it can be simplified into a binodal（4,6）-connected topological network with the point symbol of {3.4~2.5~2.6}{3~2.4~2.5~2.6~4.7~4.8}. Moreover, the thermal stability and luminescent property of compound 1 were also studied.

Syntheses,Crystal Structures and Fluorescence Properties of Two Mononuclear Copper(Ⅱ) Compounds

Two new compounds,1（[Cu（IDB_）2]Cl_2·2CH_3CH_2OH·2H_2O（IDB = N,N-di（2-benzimidazolylmethyl）imine]） and 2（[Cu（EDTB）]·2[C_6H_4（OH）COO]·6H_2O（EDTB = N,N,N＇,N＇-tetrakis-[（2-benzimidazolyl）methyl]-1,2-ethanediamine]）,have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system,space group P1 with a = 9.565（2）,b = 9.863（2）,c = 10.252（3） ？,α = 81.915,β = 88.330,γ = 87.347°,V = 956.28（40） ？3,Z = 1,F（000） = 427,D_c = 1.419 g/cm3,Mr = 817.27 and μ（MoKα） = 0.764 mm^（-1）. The final R indices（I 〉 2σ（I））： R = 0.0505,wR = 0.1417; R indices（all data）： R = 0.0591,wR = 0.1525. Crystal 2 is of triclinic system,space group P1 with a = 11.487（3）,b = 13.396（4）,c = 17.977（5） ？,α = 73.899（5）,β = 86.629（5）,γ = 65.018（4）°,V = 2403.8（12） ？3,Z = 2,F（000） = 1072,D3c = 1.417 g/cm,Mr = 1025.54,μ（MoKα） = 0.528 mm^（-1）. The final R indices（I 〉 2σ（I））： R = 0.0769,w R = 0.163 2; R indices（all data）： R = 0.0769,wR = 0.1632. The two compounds exhibit mononuclear structures. The copper（Ⅱ） atom of crystal 1 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand IDB to adopt a distorted octahedral coordination geometry. The copper（Ⅱ） atom of crystal 2 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand EDTB to show a distorted octahedral coordination geometry. Particularly,the two compounds exhibit fluorescent properties at room temperature in ethanol.

Solvothermal Synthesis,Crystal Structure and Luminescent Property of a Two-dimensional Lead(Ⅱ) Compound：[Pb(bmzbc)2]n

A two-dimensional coordination polymer, [Pb（bmzbc）2]n（1）（Hbmzbc =4-benzimidazole-1-yl-benzoic acid）, has been synthesized by the solvothermal reaction of Pb（NO3）2 with Hbmzbc at 120 ℃ in ethanol solvent. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the orthorhombic system, space group Pccn, with a = 12.5801（7）, b = 20.0795（11）, c = 9.1830（6） ？, V = 2319.6（2） A^3, Z = 4, C（28）H（18）N4O4Pb, Mr = 681.65, Dc = 1.952 g/cm^3, μ = 7.319 mm^-1, F（000） = 1312, the final R = 0.0336 and wR = 0.0965 for 1699 observed reflection with I 〉 2σ（I）. In 1, the bmzbc^– ligands bridge the Pb（Ⅱ） ions to generate a 2-D sheet with（4, 4） topology. The complex exhibits turquoise photoluminescent emission with a maximum at 480 nm upon excitation at 300 nm.

Synthesis, Crystal Structure and Magnetic Properties of a Cobalt(Ⅱ) Complex with Quinoxaline-substituted Nitronyl Nitroxide Radicals

A new complex with the formula [Co（acac）_2（NITQ）_2]×2CH_2Cl_2 1（acac = acetylacetone, NITQ = 2-（2′-quinoxalinyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide）, was synthesized and elucidated structurally as well as magnetically in detail. The crystal belongs to the monoclinic system, space group P2_1/c with a = 9.6896（1）, b = 20.539（4）, c = 12.147（2） ？, β = 93.84（3）°, M_r = 997.65, V = 2412.1（8） ？~3, Z = 2, Dc = 1.374 g/cm, F（000） = 1038, m = 0.635 mm^（-1）, the final R = 0.0539 and w R = 0.1289 for 5998 observed reflections（I 〉 2σ（I））. The Co（Ⅱ） ion is coordinated by two nitrogen atoms of quinoxaline rings from two NITQs and four oxygen atoms from two acac ions to complete a distorted octahedral coordination environment. Compound 1 is further linked into a three-dimensional（3D） supramolecular network by hydrogen-bonding, Cl×××O weak contact and π···π stacking interactions. The magnetic measurements show compound 1 exhibits weak ferromagnetic interactions.