Synthesis and Crystal Structure of a One-dimensional Azido-bridged Manganese (II) Compound [Mn(N_3)_2(H_2O)_3·C_6H_(12)N_4]_n

1 INTRODUCTION The azide anion is a good bridging ligand for di- valent metal ions to form discrete, one-dimensional, two-dimensional or three-dimensional complexes. In recent years, these complexes have drawn consider- able attentions for their interesting magnetic charace- ristics which attribute to the efficient magnetic coup- ling ability of the azido bridges[1]. When the azide anion acts as a bridging ligand, two typical modes are adopted: end-to-end (EE, μ1, 3) or end-on (EO, μ1…     

Synthesis and Crystal Structure of a One-dimensional Azido-bridged Manganese (II) Compound [Mn(N3)2(H2O)3·C6H12N4]n

A new one-dimensional azido-bridged manganese compound has been prepared and structurally characterized by X-ray diffraction. The complex [Mn(N3)2(H2O)3·C6H12N4]n crystallizes in space group Pnma with a = 6.5252 (5), b = 9.3226(7), c = 22.2070(15)(A), V = 1350.89(17)(A)3, Z = 4, Mr = 333.24, Dc = 1.639 g/cm3, μ= 1.005 mm-1 and F(000) = 692. The final refinement gave R = 0.0328 and wR = 0.0777 for 1085 observed reflections with I > 2σ(I). The structure contains [Mn- (N3)2(H2O)3]n polymeric chains and uncoordinated hexamethylenetetramine (HMTA) molecules with Mn/HMTA molar ratio of 1:1. The Mn atoms are bridged by end-to-end azido ligands to construct one-dimensional zig-zag infinite chains. Each Mn atom is six-coordinated by three N atoms of three azido ligands and three water O atoms, resulting in an octahedral geometry. Extending hydrogen- bonding interactions involving water O atoms, azido and HMTA N atoms link the chains and HMTA molecules into a three-dimensional network.     

A POLYMERIC COMPLEX OF MANGANESE(II) AZIDE CONTAINING ALTERNATE END-ON AND END-TO-END BRIDGING AZIDO LIGANDS Synthesis,Structural, Spectroscopic and Thermal Study of [Mn(N3)2 (Ethyl Nicotinate)2]n

Abstract

A mixed ligand 1:2 manganese(II) azido complex of ethyl nicotinate has been synthesized and characterized by spectroscopic and crystallographic methods. The structure consists of a two-dimensional manganese-azido compound with each manganese atom in a trans octahedral environment, bonded to four azido ligands [Mn?N = from 2.199(4) Å to 2.231(3) Å] and two axial ethyl nicotinate ligands [Mn-N = 2.285(3) and 2.308(3) Å]. Two azido ligands are coordinated end-on between the manganese atoms giving planar and centrosymmetric Mn₂N₂ units. Each Mn₂N₂ unit is linked to four neighboring Mn₂N₂ units by means of four end-to-end azido bridges. The IR and Raman spectra correlate with the structure of the complex. The vibrational bands are compared with those of the free ligand. The EPR spectra of polycrystalline powder and solutions of the complex are measured at room temperature and discussed. The thermal decomposition of the complex was investigated derivatographically under nitrogen.     

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 Novel 3D Inorganic-organic Hybrid Metallic Coordination Polymer, [Na2Cd（2,6-pyda）（N3）2（H2O）6]n

A novel coordination polymer [Na2Cd（2,6-pyda）（N3）2（H2O）6]n （2,6-H2pyda = 2,6- pyridinedicarboxylic acid） has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c, with a = 24.416（4）, b = 10.7638（17）, c = 6.9224（11） A^°, β= 106.124（2）A^°, V = 1747.7（5） A^°3, Mr = 515.64, De= 1.960 g/cm^3,μ = 1.365 mm^-1, F（000） = 1024, Z = 4, the final R = 0.0426 and wR = 0.1320. In the title complex, there exist two kinds of metal centers in the structure, cadmium ions and sodium ions. The Cd（Ⅱ） atom shows a distorted pentagonal-dipyramidal geometry defined by two O and one N atoms from one deprotonated pyda ligand and four N atoms from four μ-1,1,3 azido groups. The adjacent cadmium atoms are bridged via two μ-1,1,3 azido groups, along the c axis to afford an extended chain. There is also a 2D network which is comprised of binuclear subunits [NaE（H2O）6] connected by O atoms from coordinated water between the adjacent Cdn（pyda）n（Na）2n infinite chains. Furthermore, each cadmium atom is connected with four adjacent sodium atoms through the bridging N3- ligand in μ-1,3 patterns. Thus, the title complex exhibits a novel three-dimensional network structure.     

A new end-on azido-bridged dicopper(II) complex; syntheses,structure, solvatochromism,magnetic properties,and DFT study

Abstract

A new asymmetric azido-bridged dinuclear copper(II) complex with formula [L(N₃)Cu(μ_N,N-N₃)]₂, L = N,N-dimethyl-N′-benzyl-ethylenediamine, has been synthesized and characterized structurally and magnetically. Single-crystal structural analysis reveals the Cu(II) ions are linked by two end-on azido nitrogen atoms. The copper(II) ions adopt s penta-coordinated geometry that is intermediate between square pyramidal and trigonal bipyramidal (τ = 0.528). Variable temperature magnetic susceptibility data were collected and fitted to the appropriate equations derived from the Hamiltonian H = ?JS₁S₂ that show antiferromagnetic intradimer interactions with J = ?1.0 cm^?1 through the end-on azido bridges between the metal centers. To rationalize the magnetic behavior, a DFT calculation has been performed within the broken symmetry framework. The analyses of the magnetic orbital interaction and spin distribution indicate the nature of the magnetic properties of the complex. The complex is solvatochromic and its solvatochromism was investigated by visible spectroscopy. To explore the mechanism of interaction between the solvent molecules and the complex, different solvent parameters were utilized and analyzed by a statistical method using the multiple linear regression (MLR) method. It was found that the hydrogen bond donation (β) and polarity/polarizability (π*) parameters of the solvents lead to the solvatochromism property.     

Two new copper azido polymorphs: structures, magnetic properties, and effects of "noninnocent" reagents in hydrothermal methods

Two new 3D copper(II) azido isomers, [Cu(N3)(nic)]infinity (1 and 2) (nic = nicotinate), have been synthesized and characterized. To the best of our knowledge, 1 is the first metal azido complex showing rutile-type topology, while 2 is a chiral compound obtained by spontaneous resolution upon crystallization.     

Ferromagnetic interaction in an asymmetric end-to-end azido double-bridged copper(II) dinuclear complex: a combined structure, magnetic, polarized neutron diffraction and theoretical study

A new end-to-end azido double-bridged copper(II) complex [Cu(2)L(2)(N(3))2] (1) was synthesized and characterized (L=1,1,1-trifluoro-7-(dimethylamino)-4-methyl-5-aza-3-hepten-2-onato). Despite the rather long Cu-Cu distance (5.105(1) A), the magnetic interaction is ferromagnetic with J= +16 cm(-1) (H=-JS(1)S(2)), a value that has been confirmed by DFT and high-level correlated ab initio calculations. The spin distribution was studied by using the results from polarized neutron diffraction. This is the first such study on an end-to-end system. The experimental spin density was found to be localized mainly on the copper(II) ions, with a small degree of delocalization on the ligand (L) and terminal azido nitrogens. There was zero delocalization on the central nitrogen, in agreement with DFT calculations. Such a picture corresponds to an important contribution of the d(x2-y2) orbital and a small population of the d(z2) orbital, in agreement with our calculations. Based on a correlated wavefunction analysis, the ferromagnetic behavior results from a dominant double spin polarization contribution and vanishingly small ionic forms.     

Double End‐On Azido Copper(II) Dinuclear Complex with Oxazoline Ligand: Synthesis,Structure, Magnetic Properties and Theoretical Study

A double azido‐bridged Cu^II dinuclear complex with the chelating chiral ligand, [Cu₂(L)₂(N₃)₄] ( 1 ) [L = (+)‐2, 2′‐isopropylidene‐bis((4R)‐4‐benzyl‐2‐oxazoline)] was synthesized and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, magnetic measurements, and theoretical studies. The asymmetric double end‐on azido bridges in complex 1 lead to a weak antiferromagnetic behavior with J = –7.4 cm^–1. The exchange interactions in complex 1 were investigated by DFT calculations, and the calculated exchange interaction (J = –8.0 cm^–1) is in good agreement with the experimental value.     

Synthesis,X-ray crystal structure,and electrochemistry of polynuclear azido-bridged manganese(III) and copper(II) Schiff base complexes

New azido-bridged [Mn^III(salabza)(μ-1,3-N₃)]_n (1), and [Cu^II₄(salabza)₂(μ-1,1-N₃)₂(N₃)₂(HOCH₃)₂],(2) complexes with an unsymmetrical Schiff base ligand, {H₂salabza = N,N’-bis(salicylidene)-2-aminobenzylamine}, have been synthesized, characterized by spectroscopic and electrochemical methods, and their crystal structures have been determined by X-ray diffraction. In complex 1, each manganese(III) atom is coordinated with N₂O₂ donor atoms from salabza and two adjacent Mn(III) centers are linked by an end-to-end (EE) azide bridge to form a helical polymeric chain with octahedral geometry around the Mn(III) centers. Complex 2 is a centrosymmetric tetranuclear compound containing two types of Cu(II) centers with square pyramidal geometry. Each terminal copper atom is surrounded by N₂O₂ atoms of a salabza ligand, and the oxygen atom of the methanol molecule. Each central copper(II) ion is coordinated with two phenoxo oxygen atoms from one salabza, one terminal azido, and two end-on (EO) bridging azido ligands. The central copper(II) ions are linked to each other by the two end-on (EO) azido groups.     

Fourier transform infrared characterization of the azido complex of methane monooxygenase hydroxylase from Methylococcus capsulatus (Bath)

The azido complex formed in oxidized methane monooxygenase from Methylococcus capsulatus (Bath) was investigated with resonance Raman and FTIR techniques. These experiments show the presence of a nuas(NNN) at approximately 2077 cm-1 which splits to two components at 2059 and 2073 cm-1 with 15N14N2. The vibrational data are assigned to an azido complex bound terminally to one iron(III) at the diiron center. When the azido complex is illuminated at 15 K, a new nuas(NNN) is observed at 2136 cm-1 which is assigned to a photodissociated HN3 within the substrate pocket. We propose a model where an aqua ligand engages a hydrogen bond interaction with the 1N atom of the azido group and acts as at a proton donor during the photolysis process.     

席夫碱大环双核锌配合物的合成与表征

本文用丙酮和乙二胺在高氯酸催化下合成了四氮杂十四环席夫碱(1),并用此化合物(1)与氧化锌和叠氮化钠反应,生成锌的双核大环配合物。通过X-射线单晶衍射和红外光谱对其进行了结构表征。该配合物属单斜晶系,C2/c空间群,晶胞参数为a=2.4914(2)nm,b=1.4 9748(13)nm,c=1.26800(11)nm;β=102.1900(10)°;v=4.6240(7)nm3,Z=4,Dc=1.482Mg/m3,Mr=1032.03,F(000)=2160,最终R=0.0506,wR=0.1434。该配合物中锌原子是五配位,它们分别和大环配体上的4个氮原子及叠氮根负离子两端的氮原子配位形成畸变的三角双锥构型。     

Silver Salt and Derivatives of 5‐Azido‐1H‐1, 2, 4‐triazole‐3‐­carbonitrile

This study features the preparation of three new energetic C‐azido‐1, 2, 4‐triazoles, with the anion of one being a new binary C–N compound. 5‐Azido‐1H‐1, 2, 4‐triazole‐3‐carbonitrile ( 1 ) was prepared from 5‐amino‐1H‐1, 2, 4‐triazole‐3‐carbonitrile and further derivatized to 5‐azido‐1H‐1, 2, 4‐triazole‐3‐carbohydroximoyl chloride ( 5 ) with 3‐azido‐1H‐1, 2, 4‐triazole‐5‐carboxamidoxime ( 3 ) as an intermediate. The ability of 1 and 3 for salt formation was shown with the respective silver salts 2 and 4 . All compounds were well characterized by various means, including IR and multinuclear NMR spectroscopy, mass spectrometry, and DSC. The molecular structures of 1 , 3 , and 5 in the solid state were determined by single‐crystal X‐ray diffraction. The sensitivities towards various outer stimuli (impact, friction, electrostatic discharge) were determined according to BAM standards. The silver salts were additionally tested for their potential as primary explosives.     

Syntheses,Structures and Characterization of Cobalt(II) and Cobalt(III) Complexes with N-Benzylated Polyamines and a Terminal Azido Ligand

Mononuclear cobalt(II) and cobalt(III) complexes, [Co(trenb)(N₃)]Cl (1) and [Co(dienb)(N₃)₂(OAc)] (2) (trenb = tris[2-(benzylamino)ethyl]amine, dienb = 1,9-diphenyl-2,5,8-triazanonane) were synthesized and characterized by elemental analyses, IR and electronic spectra. Their crystal structures were also determined by X-ray diffraction analyses. In Complex 1, cobalt(II) is five-coordinate trigonal bipyramidal with one azido nitrogen atom and four nitrogen donors of the tripodal ligand; the chloride interacts weakly with one of the secondary amino groups of trenb via a hydrogen bond. In Complex 2, cobalt(III) is in a distorted octahedral coordination environment, consisting of three nitrogen atoms of the amine ligand, two azide nitrogen atoms and an oxygen atom of the acetate ion; a six-membered ring involving the hydrogen bond may stabilize the complex, which maintains its solid geometry in DMF as indicated by the electronic spectrum.     

Synthesis, crystal structures, and urease inhibitory activities of two azido-bridged polynuclear copper(II) complexes with Schiff bases

Two azido-bridged polynuclear Cu(II) complexes with the formulae [Cu(L1)(μ_1,3-N₃)] _n and [Cu(L2)(μ_1,3-N₃)] _n (HL1 = 2-[(2-morpholin-4-ylethylimino)methyl]phenol, HL2 = 2-methoxy-6-[(2-piperidin-1-ylethylimino)methyl]phenol), have been synthesized and characterized by physico-chemical and spectroscopic methods. The Cu atom in each of the complexes is five-coordinate in a square pyramidal geometry, with one O and two N atoms of a Schiff base ligand and one terminal N atom of a bridging azido ligand defining the base-plane, and with another terminal N atom of a symmetry-related azido ligand occupying the apical position. The molecules are linked through end-to-end azido bridges, forming one-dimensional polymeric chains. Both of the complexes show moderate inhibitory activities against jack bean urease.     

Template synthesis of tungsten complexes with saturated N-heterocyclic carbene ligands

Tungsten complex with a coordinated 2-azidoethyl isocyanide ligand reacts with PMe3 at the azido function to give a complex with a coordinated iminophosphorane which upon hydrolysis of the P=N bond yields a complex with an NH,NH-stabilized N-heterocyclic carbene ligand, 7; alkylation of the carbene ring nitrogen atoms gives a complex with an N,N'-dialkylated imidazolidin-2-ylidene ligand, 8 .     

Synthesis and characterization of a new Tiara Pd(II) thiolate complex, [Pd(SC12H25)2]6, and its solution-phase thermolysis to prepare nearly monodisperse palladium sulfide nanoparticles

A new tiara Pd(II) thiolate complex, [Pd(SC12H25)2]6, has been synthesized and fully characterized by X-ray single crystal analysis, elemental analysis, MALDI, 1H NMR, powder XRD, IR, Raman, and UV/vis. It was found that, in each complex cluster, the six palladium atoms form a nearly planar hexagonal ring and the adjacent palladium atoms are bridged by sulfur atoms from both sides. Then the complex was further used as a single-source precursor to prepare nearly monodisperse palladium sulfide (PdS) nanoparticles through the high-temperature-induced decomposition in diphenyl ether. The obtained nanoparticles are 2.87 +/- 0.51 nm in diameter and protected by a layer of thiolate species on the surface.     

Bond distances are not always what they appear to be: discovery and un-discovery of the longest Cr(v)[triple bond, length as m-dash]N triple bond

The coordination chemistry of CrCl3 with three pentadentate ligands having the [1,4,7]-triazacyclononane-1,4-diacetato motif have been investigated. The new resulting six-coordinate Cr(iii)-chloro species react cleanly with sodium azide to form the corresponding azido species, which undergo photolysis under irradiation at 419 nm in acetonitrile-water solution to form Cr(v)-nitrido species that are partially hydrolyzed to their corresponding Cr(III)-hydroxo counterparts. Five of these Cr complexes have been characterized by X-ray crystallography. The hydroxo and nitrido species co-crystallize complicating crystal structural refinement. What at first appeared to be the longest Cr[triple bond, length as m-dash]N triple bond distance yet observed (1.66 A) was found after re-refinement to be an artifact of positional disorder of the Cr atoms of 73% nitrido and 27% hydroxo species. The re-refined Cr[triple bond, length as m-dash]N bond distance is estimated as 1.58 A, which agrees well with the observed Cr[triple bond, length as m-dash]N stretching frequency of 971 cm-1 found by IR spectroscopy. UV-vis data for the "nitrido" complexes suggest that they are all three partially hydrolyzed. These results emphasize the care that must be taken in the characterization of compounds that may co-crystallize with structurally similar analogs.     

Synthesis, structure, and magnetic properties of two new ferromagnetic/antiferromagnetic one-dimensional nickel(II) complexes. Magnetostructural correlations

Two new one-dimensional nickel(II) complexes were synthesized and characterized: [Ni(N,N-dimethylethylenediamine)(N3)2] (1) and [Ni(2-aminoethylpyridine)(N3)2] (2). The crystal structures of 1 and 2 were solved. Complex 1 crystallizes in the monoclinic system, space group P2(1)/n with a = 10.569(2) A, b = 7.331(4) A, c = 12.9072(8) A, beta = 111.324(10) degrees, and Z = 4. Complex 2 crystallizes in the monoclinic system, space group P2(1)/c with a = 12.299(5) A, b = 14.307(2) A, c = 12.604(3), beta = 106.72(2) degrees, and Z = 4. The two complexes are similar and may be described as one-dimensional systems with double-azido-bridged ligands in end-to-end and end-on coordination alternatively. The end-on moiety is almost identical for 1 and 2, but the end-to-end moiety is different in each structure: for 1 this part is almost planar but for 2 is nonplanar. In both cases the Ni atoms are situated in similar distorted octahedral environments. The magnetic properties of the two compounds were studied by susceptibility measurements vs temperature. The chi M vs T plots for 1 and 2 show a global antiferromagnetic behavior with a maximum near room temperature for 1 and at very low temperature for 2. J values for 1 and 2 were deduced from the spin Hamiltonian -sigma(J1SiSi+1 + J2Si+1Si+2). The computational method was based on the numerical solution for finite systems of increasing size. J values for 1 were J1 = -187 cm-1 and J2 = +77 cm-1 and for 2 J1 = -28 cm-1 and J2 = +73 cm-1. The positive values correspond to end-on azido ligands and the negative values to end-to-end azido ligands. Since the geometries of the [Ni(N3)]2 moieties involving the end-on azido ligands are almost the same in the two structures, the ferromagnetic coupling is nearly identical in the two compounds, while the significantly different antiferromagnetic couplings reflect the near planarity of the end-to-end Ni2(N3)2 fragment in 1 and its twisted geometry in 2.     

2D Compound Constructed by Cu3 Units with Mixed Azido and Tetrazole Double Bridges: Synthesis,Structure, and Theoretical Study on Magnetic Properties

The two‐dimensional (2D) layer Cu^II compound [Cu₃(L)₂(N₃)₄] ( 1 ) [L = 2‐amino‐3‐(5‐tetrazole)‐methyate‐N‐pyridine] was synthesized by in‐situ hydrothermal reaction of CuCl₂ · 2H₂O, NaN₃, and 3‐(5‐tetrazole)‐methyate‐N‐pyridine. The central Cu1 and Cu2 atoms are located in five‐coordinate and six‐coordinate arrangements, respectively. Three Cu^II ions are linked by mixed double EO (end‐on)‐azido‐tetrazole bridges to give trinuclear Cu^II clusters, which are further extended by EE (end‐to‐end) azido bridges to form 2D metal‐organic layers. The magnetic exchange interactions in complex 1 were investigated by DFT calculations, and the calculated exchange interaction (J = –849 cm^–1) revealed that the double EO‐azido‐tetrazole bridges transmit antiferromagnetic coupling between Cu^II ions.