Synthesis and Crystal Structure of a Novel Complex [Cu(Phen)3](ClO4)2(btio)(H2O)

1 INTRODUCTION There has been increasing interest of Cu(II) and phenanthroline complexes in the field of coor- dination chemistry[1～4]. At the same time, nitronyl nitroxide radicals have played a prominent role in the design and construction of molecula…     

Synthesis and Crystal Structure of an Imino Nitroxide Complex [Cd（IM2py）2Cl2]

1 INTRODUCTION Nitroxide radicals including nitronyl nitroxide (NITR) and imino nitroxide (IMR) have been widely used as units in the synthesis of molecule-based magnetic materials, especially as ligands in their complexes with paramagnetic metals[1～11]…     

Synthesis, crystal structure and magnetic properties of a novel manganese(II)-nitronyl nitroxide-azido(μ_(1,1) and μ_(1,3)) one-dimensional complex

A novel one-dimensional manganese(Ⅱ) complex containing nitronyl nitroxide radical [Mn2(IM2-py)2(Ac)2((μ1.1-N3)(μ1,3-N3) . EtOH]n was synthesized and characterized structurally and magnetically. It crystallizes in the monoclinic space group p21/n. Each Mn(Ⅱ) ion is six-coordinated in a distorted octahedral environment. The two N atoms of the nitronyl nitroxide radical and the two O atoms of acetate ligands are in the equatorial plane, whereas the two different azido bridging ligands are in trans axial position. Mn(Ⅱ) ions are linked by nitrogen atom of μ1,1-azido and oxygen atoms of two carboxy groups to form a Mn-Mn unit. Mn-Mn units are linked by azido ligands through u1,3 bridging style to form a one-dimensional chain. The compound is connected by the coordination bonds,π-π interactions and hydrogen bonds as a three-dimensional structure. Magnetic susceptibility data support that there are stronger antiferromagnetic interactions between the radical and Mn(Ⅱ) ion, weak antiferromagnetic inter     

Synthesis and Crystal Structure of a 1-D Coordination Polymer {[Cu(NIT4py)_2(ip)]·6H_2O}_n

1 INTRODUCTION Pyridyl-substituted nitroxide radicals have at- tracted considerable attention in recent years due to the ability to coordinate with metal ions and act as magnetic couplers, giving rise to new functional ma- terials with particular magnetic and optical prope- rties as well as a variety of structural topologies[1~3]. Considerable efforts have been made in designing and preparing multi-dimensional materials with app- ropriate bridges, such as pseudohalide, dicyanide, dicyanoa…     

Magnetic Properties in Mononuclear Gadolinium(Ⅲ) and Terbium(Ⅲ) Complexes Based on Ethoxylphenylsubstituted Nitronyl Nitroxide Radical and Hexafluoroacetylacetonate Ligand

Two new lanthanide complexes with ethoxybenzene-substituted nitronyl nitroxide radical(NIT-C_8H_9O) and hexafluoroacetylacetonate(hfac) ligand,[Gd(NIT-C_8H_9O)_2(hfac)_3]·C_7H_(16)(1) and [Tb(NIT-C_8H_9O)_2(hfac)_3]·C_7H_(16)(2),have been successfully synthesized and characterized by IR spectroscopy,elemental analyses,thermogravimetry analyses,and single-crystal X-ray diffraction.Both 1 and 2 exhibit a mononuclear structure in which the nitronyl nitroxide radical and hfac ligand act as monodentate and bidentate chelating modes,respectively.Magnetic studies show that ferromagnetic interactions(between intramolecular Gd and radical) and antiferromagnetic interactions(between the intramolecular radicals) coexist in complex 1.No obvious frequency dependent out-of-phase signals were observed in complex 2.     

Synthesis, Crystal Structure and Magnetic Properties of Cobalt(II) Complex Involving Imino Nitroxide Radicals

1 INTRODUCTION The synthesis and study of transition metal com-plexes incorporating organic free radicals have arou-sed great interest in the field of molecular magne-tism[1]. Nitronyl nitroxide radicals (NITR), stable or-ganic radicals, have been widely used as molecularunits in the design and construction of magnetic ma-terials[2～5]. These radicals are especially attractivedue to that their donor atoms can assemble an exten-ded coordination geometry with changing magneticcoupling. A…     

Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(II) Complex Including the Reduced Derivative of Nitronyl Nitroxide,[Zn(Him2Py)(N3)2]2

1 INTRODUCTION The design and synthesis of transition metal complexes with organic free radicals is one of the major challenges in the field of molecular magnetic materials[1,2]. Nitronyl nitroxide radicals are normal- ly used as spin carriers due to th…     

INQUIRY OF PHOTOSENSITIZATION MECHANISM OF YANGZHOU HEMATOPORPHYRIN DERIVATIVE(YHPD)

By the use of the advanced ESR technique and through comparing with BHPD, the characteristic of YHPD photosensitization is discussed in this paper in the respect of the primary process of photosensitization. The experiment results showed: (ⅰ) not only ~1O_2, but also free radicals(O_2· OH and YHPD)can be formed by the aid of YHPD; and (ⅱ) as to the ability of producing ~1O_2, YHPDBHPD. Two points are indicated: first, the photosensitized damage of YHPD is interrelated to not only ~1O_2, but also free radicals (O_2. OH and YHPD); second, although the photosensitized damage of YHPD is stronger than that of BHPD, yet the photosensitized damage is negatively correlated to the yield of ~1O_2 but positively correlated to those of O_2 and OH. Based on these two points, it is suggested that activated oxygen free radicals(O_2 and. OH) instead of ~1O_2 play the main role as instantaneously activated material in the photosensitized damage of YHPD.     

氮氧自由基-锌配合物[Zn(NIT3Py)2Cl2]的合成、结构和磁行为

A Zn(Ⅱ) complex with nitronyl nitroxide radicals [Zn(NIT3Py)₂Cl₂] (1) (NIT3Py=2-(3′-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized and structurally characterized by X-ray diffraction crystal structure determination method. The complex has a mononuclear-metal structure in which each Zn(Ⅱ) ion adopts a distorted tetrahedral geometry and is coordinated by two Cl^- anions and two pyridyl-N atoms from two NIT3Py radical ligands. The magnetic measurements show the weak antiferromagnetic interaction between the nitroxide radicals through the diamagnetic Zn(Ⅱ) ion. CCDC: 292363.     

Synthesis and Crystal Structure of a New One-dimensional Zn(II) Nitronyl Nitroxide Complex Bridged by Pyridine-2,4-dicarboxylate Anion

1 INTRODUCTION The synthesis and study of transition metal com- pounds incorporating organic free radicals directly bound to their coordination sphere are a major re- search aim in the field of molecular magnetism[1]. Exceptional stability, ease of chemical modification and versatility in their coordination properties have made nitroxide free radicals one of the most attrac- tive spin carriers for the design of molecular magne- tic materials[2, 3]. The structures and magnetic prope- rties …     

One-dimensional lanthanide complexes bridged by nitronyl nitroxide radical ligands with non-chelating nitrogen donors: Structure and magnetic characterization

A series of new lanthanide-radical complexes [{Ln(hfac)3}2(NITPhIM)2] (Ln = Nd (1), Eu (2), Tb (3), Er (4); hfac = hexafluoroacetylacetonate; NITPhIM = 2-[4-(1-imidazole)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln(hfac)3 units bridged by the paramagnetic ligands by the means of coordination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl nitroxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior.     

Effective removal of chlorinated organic pollutants by bimetallic iron-nickel sulfide activation of peroxydisulfate

Chlorinated organic pollutants(COPs) have caused serious contaminants in soil and groundwater,hence developing methods to remove these pollutants is necessary and urgent.By a simple hydrothermal method,we synthesized the bimetallic iron-nickel sulfide(FeNiS) particles which exhibited excellent catalytic property of COPs removal.FeNiS was chosen as the peroxydisulfate(PDS) activator to removal COPs including 4-chlorophenol(4-CP),1,4-dichlorophenol(1,4-DCP) and 2,4,6-trichlorophenol(2,4,6-TCP).The results show that FeNiS can efficiently activate PDS to produce sulfate radical(SO_4~(·-)) which plays major role in the oxidative dechlorination and degradation due to its strong oxidizing property and the ability of producing hydroxyl radicals(~·OH) in the alkaline condition.Meanwhile,the Cl-abscised from COPs during the dechlorination can turn into the chlorine radicals and enhance the degradation and cause further mineralization of intermediate products.This bimetallic FeNiS catalyst is a promising PDS activator for removal of chlorinated organics.     

Synthesis and Crystal Structure of a 1D Coordination Polymer [Co（nitmpy）2（tp）（H2O）2]n

1 INTRODUCTION The scope of exploring magnetic properties of compounds arising from the combination of tran- sition metal with nitroxide radicals is steadily in- creasing. Considerable efforts have been directed in preparing and characterizing metal-radi…     

A density functional study on magnetic exchange interaction between Mn(II) ion and nitronyl nitroxide radical in trans- and cis-metal-radical complexes

In the recent few years, transition metal complexeswith radical ligands have received much attentionaiming at a so-called metal-radical approach for novelmolecular magnet design[1]. One of the more popularfamilies is concerned in nitronyl nitroxide radica…     

DNA SYNTHESIS INHIBITION OF NITROXIDE RADICALS ON LEUKEMIA CELLS

4-isothiocyanate-2,2,6,6-tetramethyl-piperidine-l-oxyl has the strongest effects on the DNA synthesis and viability of isolated leukemia 7712 cells. This compound is a very potent inhibitor of DNA synthesis with 50% inhibition of cell DNA synthesis occurring at 2.2 μg/ml, while the LD50 for white mice is 277 mg/kg. During the concentration of 50 μg/ml, the inhibition of DNA synthesis is 99.7%, which is unable to damage the DNA replicate templet. The inhibition of this compound, a combination of nitroxide and isothiocyanate, appears to be stronger than that of the sum of the two separate actions. Much more moderate effects are seen for all the other nitroxide radicals. After reducing nitroxide to hydroxyla-mine, there is no inhibition for DNA synthesis. The free radical mechanism of carcinogene-sis and antitumor action has been discussed.     

Theoretical study on the reaction mechanism of (CH_3)_3CO~· radical with NO

Alkoxy radicals RO? form an important class of hydrocarbon oxidation intermediates in combustion processes, interstellar and atmospheric chemistry[1—8]. The number of NO to NO2 conversions can take place during the oxidation of the parent hydrocarbon in the atmosphere and hence affecting tropospheric ozone production. The experimental and theoretical investi-gations of the reactions of alkoxy radicals will be ad-vantageous for safeguarding the environment. Despite the importance of alkoxy r…     

A Corrugated 2D Mn(Ⅱ) Network:[Mn_3(μ-oxalate)_3(μ-4,4'-bpy)_2(4,4'-bpy)_2]_n

1 INTRODUCTION It is well known that the bi-functional 4,4?-bi- pyridine (4,4?-bpy) has the ability to act as a rigid, rod-like organic building block in the self-assembly of coordination frameworks. Many researches have also been done on the metal oxalate compounds. The remarkable coordination abilities of oxalate and 4,4?- bpy ligands are applied to design and synthesize new polymeric coordination complexes[1～4] containing mixed bridging ligands. Manganese is one of the several first-r…     

Structural Determination of Bis-histidinopeptide Zinc Complexes by 15N NMR (HMBC) Spectra

Polynitrogen receptors such as bis-histidine peptides possess strong ability to bind metals, which play much important roles in medicinal, bioinorganic, bioorganic, biomimetic and supramolecular chemistry. In order to investigate the interaction of these hosts with a variety of neutral, cationic and anionic guests, several techniques, for example, NMR,potentiometric tirations and monocrystal X-ray diffraction have been employed. Among them NMR is a powerful technique for unraveling the structure of polynitrogen receptors as long as they are in solution where the rapid tumbling of molecules averages out the anisotropies such as chemical shift and dipole-dipole interactions. General 1H NMR approach has been widely used for the study of host-guest interaction, but it is difficult for the accurate measurement in complexes structures, particularly metal complexes structures in which how the polynitrogen receptors bind metal, and which nitrogen binds metal and so on.     

1-Imino Nitroxide Pyrene, a Burst-type H^＋ Fluorescent Switch

Nitronyl nitroxides and imino nitroxides are paramagnets and stable free radicals, which have been widely used as spin probes as well as for studies related to organic magnets1-4. Among these nitroxides, 1-imino nitroxide pyrene 1 and 1-nitronyl nitroxide pyrene are both representatives4, and evidence accumulated indicating that the nitroxides attached to fluorophores can serve as strong intramolecular quenchers2-3. Based on this property, for example, Zhang et al. found that the fluorescence …     

Synthesis and Crystal Structure of [Ni(bdpm)_2(OAc)]_2(N_3)_2·5H_2O(bdpm=Bis(3,5-dimethylpyrazol-1-yl)methane,OAc=CH_3COO~-)

1 INTRODUCTION Bis(pyrazol-1-yl)methane has been one of the po- pular polydentate nitrogen donor ligands due to its strong chelating coordination to transition metal ions as capping ligand. Coordination behavior of the li- gand is able to yield stable M-N-N-C-N-N six-mem- bered boat conformation[1, 2]. The complexes con- taining bdpm ligand have been widely synthesized and characterized in recent years, and exhibit the striking properties in catalysis, magnetism and so on[3-10]. For exa…