Syntheses and X-ray structures of heteroleptic octahedral Mn(II)-xanthato complexes involving N-donor ligands

A series of octahedral manganese(II) complexes involving xanthates and N-donor ligands, [Mn(S₂COiBu)₂(phen)] (1), [Mn(S₂COiBu)₂(2,2′-bpy)] (2), [Mn(S₂COnPr)₂(phen)] (3), [Mn(S₂COnPr)₂(2,2′-bpy)] (4), [Mn(S₂COMe)₂(2,2′-bpy)] (5), [Mn(S₂COnPr)₂(4,4′-bpy)]_n, and [Mn₂(S₂COnPr)₄(4,4′-bpy)₃] (6) (phen = 1,10-phenanthroline, bpy = bipyridine) was prepared. Complexes were characterized by elemental analysis, FTIR spectroscopy, TG/DSC analysis, and single-crystal X-ray diffraction. The structures are built of monomeric molecules of the complexes, except for 6 with the 4,4′-bipyridine ligand, which contains a binuclear complex and 1D polymeric zigzag chain in one crystal.     

Design,synthesis and magnetic properties of a ladderlike complex constructed by secondary building units

A secondary building unit (SBU), [Ni(2,2′-bipy)(5-npa)(H₂O)] _n [where 2,2′-bipy = 2,2′-bipyridine, 5-npa = 5-nitroisophthalic dianion], was synthesized as starting material of a polystep reaction. A ladderlike complex (LLC) Ni(II) coordination polymer, {[Ni(2,2′-bipy)(5-npa)(4,4′bipy)_0.5]·(H₂O)} _n , was constructed by polystep reaction using this SBU. In LLC, two SBUs were cross-linked by 4,4′-bipy [where 4,4′-bipy = 4,4′-bipyridine] forming a 1-D ladderlike structure. The magnetic properties of the LLC and SBU are discussed.     

Kinetic and mechanistic studies on the complexation and anation of dioxotetracyanomolybdate (IV) with 2,2′-bipyridyl in aqueous solution

Dioxotetracyanomolybdate(IV) has been found to form a 1 : 2 complex with 2,2′-bipyridyl. The kinetics of the reaction has been studied over the pH range 5.3–8.7 by visible spectrophotometry under pseudo conditions. The effect of the 2,2′-bipyridyl and dioxotetracyanomolybdate(IV), temperature, ionic strength, and pH on the reaction rate was determined. The reaction follows first-order kinetics with respect to dioxotetracyanomolybdate(IV) ion and fractional-order kinetics with respect to 2,2′-bipyridyl. Values for the outer-sphere complex formation constant (K_os2) and rate constants (k₂) were also calculated from the kinetic data. It was found that rate of the reaction increases with the decreasing pH. The following rate equation based on the outersphere complexation equilibrium preceding the associative interchange has been derived. On the basis of the observed results probable mechanism has been proposed. © 1996 John Wiley & Sons, Inc.     

Hg(II), Tl(III), Cu(I), and Pd(II) Complexes with 2,2'-Diphenyl-4,4'-Bithiazole (DPBTZ), Syntheses and X-Ray Crystal Structure of [Hg(DPBTZ)(SCN)2]

Reaction of the ligand 2,2′-diphenyl-4,4′-bithiazole (DPBTZ) with Hg(SCN)₂, Tl(NO₃)₃, CuCl, and PdCl₂ gives complexes with stoichiometry [Hg(DPBTZ)(SCN)₂], [Tl(DPBTZ)(NO₃)₃], [Cu(DPBTZ)(H₂O)Cl]_, and [Pd(DPBTZ)Cl₂]. The new complexes were characterized by elemental analyses and infrared spectroscopy. The crystal structure of [Hg(DPBTZ)(SCN)₂] determined by X-ray crystallography. The Hg atom in the title monomeric complex, (2,2′-diphenyl-4,4′-bithiazole)mercury(II)bisthiocyanate, [Hg(C₁₈H₁₂N₂S₂)(SCN)₂], is four-coordinate having an irregular tetrahedral geometry composed of two S atoms of thiocyanate ions [Hg-S 2.4025(15) and 2.4073(15) Å] and two N atoms of 2,2′-diphenyl-4,4′-bithiazole ligand [Hg-N 2.411(4) and 2.459(4) Å]. The bond angle S(3)-Hg(1)-S(4) of 147.46(5)° has the greatest derivation from ideal tetrahedral geometry. Intermolecular interaction between Hg(1) and two S atoms of two neighboring molecules, 3.9318(15) and 3.9640(18) Å, make the Hg(1) distort from a tetrahedron to a disordered octahedron. The attempts for preparation complexes of Tl(I), Pb(II), Bi(III), Cd(II) ions with 2,2′-diphenyl-4,4′-bithiazole ligand were not successful and also the attempts for preparation complexes of 4,4′,5,5′-tetraphenyl-2,2′-bithizole ligand with Cu(II), Ni(II), Co(II), Co(III), Mn(II), Mn(III), Fe(II), Fe(III), Cr(III), Zn(II), Tl(III), Pb(II), Hg(II), Cu(I), Pd(II) were not successful. This point can be regarded as the initial electron withdrawing of phenyl rings and also their spatial steric effects.     

Synthesis,structure and properties of a binuclear complex {[Mn(bpy)2(CuL)(H2O)2](ClO4)2} and its CuL precursor (H2L = 2,3-dioxo-5,6 : 14,15-dichlorobenzo-7,13-diphenyl-1,4,8,12-tetraazacyclo-pentadeca-7,12-diene)

A binuclear complex {[Mn(bpy)₂(CuL)(H₂O)₂](ClO₄)₂} (2) and its CuL (1) precursor (H₂L?=?2,3-dioxo-5,6?:?14,15-dichlorobenzo-7,13-diphenyl-1,4,8,12-tetraazacyclo-pentadeca-7,12-diene; bpy?=?2,2′-dipyridyl) have been synthesized and characterized structurally. Complex 1 consists of the neutral [CuL] fragments and methanol molecules. In complex 2, [Mn(bpy)₂(CuL)]²⁺ cation, two water molecules and two perchloric anions make up of the crystal. Mn(II) is coordinated by four nitrogen atoms from two 2,2′-dipyridyl and two oxygen atoms from the Cu(II) precursor. Magnetic characterization of 2 exhibits an antiferromagnetic interaction between Cu(II) and Mn(II) ions, with J?=??74.1?cm^?1.     

Schwingungsspektren von Komplexen des Gold(III)-chlorids mit 2,2′- und 4,4′-Dipyridin

Vibrational Spectra of Complexes of Gold Trichloride with 2,2′-Dipyridne and 4,4′-Dipyridine, Dipyridine and 4,4′-Dipyridine By reaction of Au₂Cl₆ with 2,2′-Dipyridine and 4,4′-Dipyridine, respectively, the complexes [AuCl₂(2,2′-Dipy)][AuCl₄] (I) and [AuCl₂(4,4′-Dipy)]Cl (II) are obtained. IR and Raman spectra show that (I) has a complex chelate structure, whereas (II) is polymeric with cis-configuration of the ligands.     

Influence of Steric Hindrance of N‐Heterocyclic Ancillary Ligands on the Structure and Magnetic Properties of Manganese(II) Coordination Polymers

Three biphenyl‐3,5‐dicarboxylic acid (H₂ L ) based coordination polymers, namely, [Mn₃( L )₃(2,2′‐bpy)₂]_n ( 1 ), {[Mn( L )(phen)] · (MeOH)}_n ( 2 ), and [Mn( L )(dipt)]_n ( 3 ), (2,2′‐bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline, and dipt = 2,9‐dimethyl‐1,10‐phenanthroline) were synthesized and characterized by single‐crystal X‐ray diffraction and analyses of their magnetic properties. 1 is a trinuclear manganese structure with a 2D motifs, which can join by hydrogen bond bridges to give 3D supramolecular architectures. 2 has a dinuclear center forming a 1D supramolecular ladder chain. The mononuclear complex 3 displays 1D metal‐organic chains driven by μ₂‐ L linkers. Their structural differences were investigated, revealing that the influence of steric hindrance on the structures of acid‐based coordination polymers is realized through changing the N‐heterocyclic ancillaries of diverse steric hindrance. Obviously, with decreasing of the steric hindrance of the N‐donor ligand, complexes 1 – 3 show structures from 1D to 2D and mononuclear to multinuclear. Magnetic susceptibility measurements indicate that 1 and 2 have dominating antiferromagnetic couplings between metal ions, whereas compound 3 is paramagnetic.     

Mononuclear tungsten(VI) complexes with bis(phenolato) ligands: syntheses,characterisations and activity in ROMP reaction

The reaction of bulky ligand precursor 2,2′-methylenebis(4-methyl-6-tert-butylphenol) (H₂mbp) or 2,2′-ethylidenebis(4,6-di-tert-butylphenol) (H₂ebp) with trisdiolatotungsten(VI) complex [W(eg)₃] 1 (eg=ethanediolate dianion) provides heteroleptic complexes [W(mbp)(eg)₂] 2 or [W(ebp)(eg)₂] 3, respectively. Sterically less hindered 2,2′-dihydroxy-1,1′-dinaphtylmethane (H₂dinap) forms heteroleptic disubstituted complex [W(dinap)₂(eg)] 4. The X-ray crystal structure determinations confirmed that the isolated compounds are made of monomeric tris(diolato)tungsten(VI) molecules in which the central tungsten atom is bonded to six oxygen atoms forming a distorted octahedral coordination sphere around the metal ion. Complexes 2 and 3 catalyse the ring opening metathesis reaction of norbornene when activated by Et₂AlCl.     

Metal complex with terpyrindine derivative ligand as highly selective colorimetric sensor for iron(Ⅲ)

A new metal complex[MnL₂]（NO₃）₂·CH₃CN（1） was synthesized by reaction of 4’-4-（l,2,4-triazol-l-yl）phenyl -2,2’:6’,2"-terpyridine（L） with manganese nitrate.The structure of the complex was determined by X-ray crystallography.The results of UV-vis studies showed that the complex exhibits colorimetric sensing ability for Fe³⁺,which can be observed by naked eye.     

Tungstoarsenate(III) polyoxoanions as inorganic ligands for polynuclear copper complexes

A trinuclear copper(II) complex and a tetranuclear copper(II) complex that each incorporate a 9-tungstoarsenate(III) polyoxoanion ligand and several 2,2′-bipyridine (2,2′-bpy) ligands co-crystallize as the acid form: H₄[{Cu(2,2′-bpy)}₃(α-AsW₉O₃₃)] · [{Cu(2,2′-bpy)₂}{Cu(2,2′-bpy)}₃(α-AsW₉O₃₃)] · 38H₂O (1). Compound 1 was obtained from a hydrothermal reaction employing the trivacant lacunary polyoxometalate [α-AsW₉O₃₃]^9? as a precursor. The α-isomeric form of the parent ion is retained in both product anions. Four different coordination modes are observed for the seven copper centers, with unusual structural distortions imposed by the steric bulk of the polyanion. Intra- and intermolecular π-stacking of the 2,2′-bpy ligands are both evident. Variable temperature magnetic susceptibility, magnetization and EPR data are consistent with very weak antiferromagnetic interactions between the copper centers that are likely mediated by the π-stacking of the 2,2′-bpy ligands.     

Treatment and nursing values of a new mixed-ligand In(III)-based complex on acute ischemic stroke

In the current research, through employing the dual ligand method, a novel coordination polymer has been produced in success via the reaction between H₂glu and In(NO₃)₃·6H₂O in the existence of the nitrogen-donor chelating 2,2′-bpy ligand in CH₃CN In(III) and DMF mixed solvent, and its chemical formula is In(glu)(Hglu)(2,2′-bpy) (1, 2,2′-bpy is 2,2′-bipyridine and H₂glu is glutaric acid). Its application values on the acute stroke were assessed and the corresponding mechanism was investigated simultaneously. Firstly, the levels of inflammatory response in the astrocytes were evaluated by ELISA by measuring the content of inflammatory cytokines released into cerebrospinal fluid. Additionally, the miRNA199a relative expression levels in astrocytes were measured via exploiting real time RT-PCR. Molecular docking simulation demonstrated that synthesized In ion complex exhibited excellent biological activities, multiple binding interactions were formed by the carboxyl groups on the In ion complex.     

Synthesis and characterization of a novel coordination polymer {[Mn(L)(Phen)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O}<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript><Superscript>1</Superscript>

A novel coordination polymer {[Mn(L)(Phen)₂] · 2H₂O} _n (I) has been synthesized by the reaction of Mn(CH₃COO)₂, 2,2′-bipyridine-5,5′-dicarboxylic acid (HL) and 1,10-phenanthroline (Phen). The structure of the complex was charactered by single-crystal X-ray diffractometry. The unit cell parameters for complex I: a = 11.796(3), b = 17.837(5), c = 15.081(4) Å; β = 101.804(5)°; V = 3106.0(15) ų; Z = 4; space group C2/c. The Mn(II) atom is coordinated by four nitrogen atoms from two Phen molecules and two oxygen atoms from two molecules L with a distorted octahedral geometry. Complex was dibridged by the L ligand forming a 1D infinite chain. Intramolecular weak interactions, such as hydrogen bonds and π...π-stacking, were found in the title complex, and 3D supramolecular framework was constructed by intermolecular weak interactions mentioned above.     

Optimized spectrophotometric determination of trace cobalt and manganese by their catalysis of the tiron—hydrogen peroxide reaction

A kinetic—spectrophotometric method for the detemination of traces of cobalt(II) and manganese(II) based on their catalytic effect on the tiron—hydrogen peroxide indicator reaction is proposed. Optimal conditions for determination of Co(II) are deduced from response surface studies, considering the sensitivity and the blank absorbance as responses. The detection limit is 0.05 ng Co ml^?1. The Mn(II)-catalyzed reaction was optimized for 1,10-phenanthroline as the activator by the simplex method and for 2,2′-bipyridine as the activator by response surface methodology on the basis of a previously described mechanistic model of the catalytic reaction. In the presence of 2,2′-bipyridine, the detection limit is 0.2 ng Mn ml^?1. The influence of foreign metal ions on both determinations is discussed and is related in the case of the 2,2′-bipyridine—activated Mn(II)-catalyzed reaction with model generated effects of these metal ions.     

Crystal structures and electrochemical properties of two Mn(II) 2-sulfoterephthalate complexes with N-donor ligands

Two Mn(II) sulfoterephthalate complexes, [Mn(HStp)(o-Phen)₂] (I) and [Mn(HStp)(2,2′-Bipy)₂] (II) (H₃Stp = 2-sulfoterephthalic acid, o-Phen = 1,10-phenanthroline, 2,2′-Bipy = 2,2′-bipyridine), were synthesized under hydrothermal condition. Single crystal X-ray diffraction analyses reveal that complexes I and II possess similar structure, in which the center Mn²⁺ ions are hexa-coordinated with one Hstpanion and two N-donor ligands. For both of them, the formation of 3D supramolecular structures are based on both H-bonds and π...π/C-H...π stacking interactions. Electrochemical properties of complexes I and II have been investigated by means of cyclic voltmetry, which shows that electron transfer between Mn(III) and Mn(II) in electrolysis is quasi-reversible process.     

Syntheses,Structures and Properties of Four New Transitional Metal Complexes Based on Benzotriazole‐5‐carboxylic Acid

Four new complexes, [Zn(btca)(2,2′‐bpy)] ( 1 ), [Mn(btca)(2,2′‐bpy)] ( 2 ), [Co(btca)(phen)] ( 3 ), and [Cu(btca)(phen)] ( 4 ), (H₂btca=benzotriazole‐5‐carboxylic acid, 2,2′‐bpy=2,2′‐bipyridine, phen=1,10‐phenanthroline), were successfully synthesized and characterized by elemental analysis, single crystal X‐ray diffraction, and IR spectroscopy. Complexes 1 – 4 crystallize in the orthorhombic system with space group of Pbca and show similar 2D layers, which are interlinked to supramolecular networks by π‐π stacking interactions. Furthermore, TGA curves show that complexes 1 – 4 have good thermal stability. Solid‐state fluorescent property of complex 1 was also investigated at room temperature.     

Photoinduced Oxygen Atom Transfer to α-Pinene and R-Carvone using a Dioxo-Molybdenum (VI) Complex Incorporated within a Modified UiO-67 (Zr/Ti) MOF

We report a highly selective (100 %) epoxidation of α-pinene and R-carvone using an oxygen atom transfer (OAT) reaction facilitated by a dioxo-Mo complex (Mo^(VI)O₂Cl₂Ln) incorporated into the ligand 5,5’-dicarboxylate-2,2’-bipyridine (bpydc) within a Metal-Organic Framework (MOF) type UiO-67. Photo-stimulated (350 nm) OAT reaction was carried out with oxygen molecular used as the oxidant for 10 h. UiO-67 was synthesized with a mixture of the ligands 2,2′-biphenyl-5,5′-dicarboxylate (bpdc) and 2,2-bipyridine-5,5-dicarboxylate (bpydc) in different molar ratios (67 : 33, 50 : 50, 70 : 30, 0 : 100 bpdc : bpydc) to promote a higher presence of catalytic sites, i. e., the dioxo-Mo complex units. Furthermore, a post-synthetic exchange of Zr for Ti, between 64 : 36 to 78 : 22 Ti : Zr molar ratio, was performed to improve the optical properties of the MOF and promote the photoinduced OAT reaction. The Catalytic system was characterized by FTIR, XRD, ¹H NMR, XPS, TGA, N₂ adsorption/desorption and UV-Vis-DR. The amount of the epoxide monoterpene is proportional to the number of the dioxomolybdenum^(VI) units (MoO₂) incorporated in the UiO-67 (Zr/Ti), and the OAT reaction selectivity is due to the absence of the oxygen radicals in the medium of reaction. Besides, The Mo complex exhibited excellent stability after five cycles of use.     

含联吡啶，Eu(III)或Gd(III)的手性高分子配合物的合成及荧光性质研究

手性高分子P–1由(R)-5,5′-二溴-6,6′-二(4-三氟甲基苯基)-2,2′-二正辛氧基-1,1′-联萘(R–M–1)和5,5′-二乙烯基-2,2′-联吡啶(M–2)通过Pd催化的Heck偶合反应合成得到,高分子配合物P-2和P-3由高分子P-1与Eu(TTA)3·2H2O和Gd(TTA)3·2H2O (TTA– = 2-噻吩甲酰三氟丙酮)反应生成。手性高分子P-1能发射强的蓝色荧光,这是由于手性重复单元(R)-6,6′-二(4-三氟甲基苯基)-2,2′-二正辛氧基-1,1′-联萘和单元2,2′-联吡啶通过亚乙烯基桥连形成共轭高分子结构造成的。在不同的激发波长激发下,含Eu(III)的高分子配合物P–2不仅显示高分子荧光,还可显示Eu(III) (5D0→7F2)特征荧光。含Gd(III)的高分子配合物P–3仅发射高分子荧光。基于高分子及含RE(III)的高分子配合物的荧光性质研究发现,共轭高分子并没有把能量转移到Eu(III)或Gd(III) 配合物部分,只发射它自身的荧光,含Eu(III)的高分子配合物P–2发射Eu(III) (5D0→7F2)特征荧光能量主要来源于配阴离子TTA–。     

Structural characterization of copper (II) tetradecanoate with 2,2′-bipyridine and 4,4′-bipyridine to study magnetic properties

This paper presents synthesis, structural characterization and spintronic applications of copper (II) tetradecanoate derived magnetic complexes. The complexes were prepared by a chemical reaction between [Cu₂(CH₃(CH₂)₁₂COO)₄](EtOH)₂ and 2,2′-bipyridine-4,4′-bipyridine ligands respectively. The complexes were further reacted between the product of the first reaction and 4,4′-bipyridine-2,2′-bipyridine respectively. The structural characterization techniques included elemental analysis, Fourier transformed infrared spectroscopy (FTIR), Ultra-violet–Visible (UV–Vis) spectroscopy, polarized optical microscopy, magnetic moment and thermogravimetric analysis. The structural and characterization results suggested that the synthesized complexes were binuclear and mononuclear covalent complexes of copper(II) with structural formulas [Cu₂(η²-(OOCR)₄](4,4′-bpy)2H₂O] and [Cu(η¹-(OOCR)₂(2,2′-bpy) (4,4′-bpy)] respectively.     

Synthesis,characterization, and crystal structure determination of Cu(II) coordination compounds with 2,2′-dimethyl-4,4′-bithiazole

[{CuCl(dm4bt)}₂ μ-Cl)₂] (1) (dm4bt = 2,2′-dimethyl-4,4′-bithiazole) was prepared from the reaction of CuCl₂ · 2H₂O with 2,2′-dimethyl-4,4′-bithiazole in methanol; [Cu(dm4bt)₂NO₃](NO₃) (2) was prepared from the reaction of Cu(NO₃)₂ · 3H₂O with 2,2′-dimethyl-4,4′-bithiazole in methanol. Both complexes were characterized by IR, UV–Vis spectroscopy, and single-crystal structure. The structure of 1 consists of centrosymmetric dimeric [{CuCl(dm4bt)}(μ-Cl)], in which two chloro ligands bridge the coppers forming a four-membered ring; a terminal chloride and a bidentate chelating bithiazole complete five coordination at each Cu(II) in a highly distorted trigonal-bipyramidal geometry. The mononuclear structure 2 consists of a Cu(II), two 2,2′-dimethyl-4,4′-bithiazoles, one monodentate nitrate and one uncoordinated nitrate in a highly distorted square pyramid.     

Modification of the structure and magnetic properties of fumarato-bridged Mn coordination polymers through different dimethyl-2,2′-bipyridine co-ligands

Manganese coordination polymers {Mn(fum)(5dmb)(H₂O)₂} _n (1) and {[Mn₂(fum)₂(4dmb)₂]·H₂O} _n (2) (fum = fumarato; 5dmb = 5,5′-dimethyl-2,2′-bipyridine; 4dmb = 4,4′-dimethyl-2,2′-bipyridine) were obtained from one-pot, solution reactions under ambient conditions. The fum ligand acquires different coordination modes in the presence of the different dmb ancillary ligands, promoting distinctive crystal structures, including divergent dimensionalities. Thus, X-ray single-crystal data reveal that complex 1 crystallizes in a monoclinic system with C2/c space group and forms an infinite one-dimensional polymer. The Mn(II) center is six-coordinated and displays a distorted octahedral configuration. In addition, the solid-state self-assembly of the polymeric structure of 1 gives rise to a two-dimensional (2D) supramolecular framework, mainly through hydrogen bonding. In contrast, complex 2 crystallizes in a monoclinic system with a Cc space group and forms an infinite 2D coordination polymer having dinuclear units. The Mn(II) center has a distorted octahedral configuration. The thermal stabilities of both coordination polymers were investigated. Variable-temperature magnetic measurements show that complex 1 is paramagnetic, while complex 2 exhibits weak antiferromagnetic coupling between adjacent Mn(II) centers.