Bidentate Nitrato Groups Research Articles

Selective Solvent Extraction of Silver(I) by Tris-Pyridyl Tripodal Ligands and X-Ray Structure of a Silver(I) Coordination Polymer Incorporating One Such Ligand

Two tripodal ligands, each derived from 1,1,1-tris(hydroxymethyl)ethane and terminated respectively by 4-pyridyl (L1) and 2-pyridyl groups (L2), have been synthesised. Competitive seven-metal extraction studies (H2O/CHCl3) incorporating equal concentrations of cobalt(ii), nickel(ii), copper(ii), zinc(ii), silver(i), cadmium(ii), and lead(ii) in the aqueous phase and L1 or L2 in the organic phase showed selective extraction of silver(i) in each case. A parallel solvent extraction experiment involving a related tripodal tris-pyridyl ligand (L3) based on a 1,3,5-substituted aryl ring scaffold and incorporating thioether sulfurs in each tripod arm also showed extraction selectivity for silver(i); extraction efficiencies towards this metal ion fall in the order L3 > L1 > L2. Physical data are in accord with L1 forming a capsule-like complex of type [Ag3L12]3+ in which silver ions link pairs of pyridyl groups from different ligands. In contrast, L2 yields a complex of type [Ag2L2(NO)3]n whose X-ray structure showed it to be a two-dimensional coordination polymer in which the three pyridyl donors of each L2 coordinate to three silver(i) centres, two of which are crystallographically distinct, with the centres also bonded to bidentate and/or bridging bidentate nitrato groups.

Silver(I) Coordination Polymers Incorporating Neutral γ-Carbon Bound N,N′-Bis(acetylacetone)alkanediimine Units

Five new silver(I) coordination polymers of types [Ag2L1(NO3)2]n (1), [Ag2L2(NO3)2]n (2), [Ag2L3(NO3)2]n (3), [Ag2L4(NO3)2]n (4), and [AgL5(NO3)]n (5) have been synthesized, where L1–L5 are the Schiff base ligands formed from 2:1 condensation of acetylacetone with the symmetrical diamines H2N(CH2)nNH2, with n = 2 and 6 to give L1 and L2, 1,2-bis(2-aminophenoxy)ethane to give L3, 1,4-bis(2-aminophenoxy)butane to give L4, and 1,6-bis(4-aminophenoxy)butane to give L5. The single crystal X-ray structures of the Ag(I) complexes 1–5 have been determined. Both 1 and 2 adopt three-dimensional polymeric network structures, while 3–5 adopt two-dimensional-layered framework structures. In 1 and 2, the terminal O and γ-C atoms of two acacH-imine domains of the same ligand bind to different silver ions, while in each of 3–5 a γ-C from one or both acacH-imine domains binds to a silver ion, with the remaining coordination sites occupied by bridging monodentate or bidentate nitrato groups and/or a Schiff base ligand oxyg...

Reactivity of benzil bis(4-methyl-3-thiosemicarbazone) with cadmium nitrate. Crystal structure of [Cd(LMe 2H 4)(NO 3) 2][Cd(LMe 2H 4)(NO 3)(H 2O)]NO 3 · H 2O

The reaction between cadmium nitrate dihydrate and benzil bis(4-methyl-3-thiosemicarbazone), LMe 2H 4, depends on the working conditions. In methanol the reaction gives the novel complex [Cd(LMe 2H 4)(NO 3) 2][Cd(LMe 2H 4)(NO 3)(H 2O)]NO 3 · H 2O ( 1). Its crystal structure shows the presence of two cadmium atoms with different coordination numbers, seven and eight, and the ligands acting as N 2S 2 neutral molecules. One cadmium has the coordination sphere completed by a bidentate nitrato group and a water molecule, whereas the other one is bonded to two bidentate nitrato groups. Both molecules are joined to one nitrate ion and to an additional water molecule by hydrogen bonds. In the presence of lithium hydroxide, the reaction leads to a binuclear complex with the ligand doubly deprotonated [Cd(LMe 2H 2)] 2 ( 2). The complexes were characterized by elemental analysis, mass spectrometry, 13C and 113Cd CP/MAS NMR and, in the case of complex 1, by X-ray diffraction.

Lanthanide nitrate complexes of diphenylmethylphosphine oxide: synthesis and spectroscopic studies. Crystal structures of [La(Ph 2MePO) 3(NO 3) 3], [La(Ph 2MePO) 4(NO 3) 3]· xMe 2CO and [Yb(Ph 2MePO) 4(NO 3) 2]PF 6

The reaction of Ln(NO 3) 3·6H 2O (Ln=lanthanide except Pm) with Ph 2MePO in a 1:3 or 1:4 ratio in acetone or ethanol produces [Ln(Ph 2MePO) 3(NO 3) 3] which have been characterised by analysis, IR, 1H and 31P{ 1H} NMR spectroscopy and conductance measurements. The [Ln′(Ph 2MePO) 3(NO 3) 3] (Ln′=Pr–Tb) exist only as tris complexes in solution and are unaffected by the presence of excess Ph 2MePO. In contrast the [Ln″(Ph 2MePO) 3(NO 3) 3] (Ln″=Ho–Lu) partially decompose in CH 2Cl 2 solution into [Ln″(Ph 2MePO) 4(NO 3) 2] +, and [Ln″(Ph 2MePO) 4(NO 3) 2]PF 6 are readily isolated from Ln″(NO 3) 3, Ph 2MePO and NH 4PF 6 in acetone. For lanthanum only, a neutral 1:4 complex [La(Ph 2MePO) 4(NO 3) 3] was isolated. X-ray crystal structures show that [La(Ph 2MePO) 3(NO 3) 3] contains nine-coordinate La, whilst [La(Ph 2MePO) 4(NO 3) 3]· xMe 2CO contains a ten-coordinate metal centre. The structure of [Yb(Ph 2MePO) 4(NO 3) 2]PF 6 reveals an eight-coordinate cation and all complexes contain bidentate nitrato-groups.

Crystal structure and physico-chemical properties of hepta-coordinate isomorphic cobalt(II) and nickel(II) complexes of 1-allylimidazole

Nitrato 1-allylimidazole coordination compounds of the general formula [ML3(NO3)2], where M is cobalt(II) or nickel(II) and L is 1-allylimidazole, have been obtained. The compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR, FIR and VIS spectral evidence and by magnetic measurements. Both compounds are isomorphic and crystallize in the monoclinic system, space group C2/c, with Z=4. There are two bidentate nitrato groups and three 1-allylimidazole molecules in the coordination sphere of the metals. One of these 1-allylimdazole molecules is disordered and situated along a twofold axis with half-occupancy (occupation factor, G=0.5).

Crystal structure and physico-chemical characterization of the nitrato complexes of copper(II) with 1-ethoxymethylimidazole

Nitrato complexes of copper(II) with 1-ethoxymethyl- imiazole (L), of general formulae CuL2(NO3)2 (1) and CuL4(NO3)2 (2) have been prepared and characterized by elemental analysis and by i.r., f.i.r., vis-n.i.r. spectral evidence, conductivity, magnetochemical measurements and single crystal X-ray analysis. Compound (1) has two 1-ethoxymethylimidazole molecules and two bidentate nitrato groups in the copper(II) co-ordination sphere. In complex (2) the immediate surroundings of copper(II) is described by a tetragonally elongated octahedron with the difference the horizontal and equatorial bond lengths of 0.462 A.

Interaction between metal ions and zwitterionic species. crystal and molecular structure and spectroscopic characterization of [Cu(mtpa) 2(NO 3) 2l (mtpa[2-(3-METHYL-1,2,3-TRIAZOLO [1,5-a]PYRIDINIO)]ACETATE)

-The crystal and molecular structure of [Cu(mtpa) 2(NO 3) 2] (mtpa[2-(3-methyl-1,2,3-triazolo[1,5-a]pyridinio)]acetate) have been determined by X-ray diffraction methods. The crystal structure is built up of discrete [Cu(mtpa) 2(NO 3) 2] entities. The stereochemistry displayed by the copper atoms, which lie on symmetry centres, can be described as elongated rhombic octahedral (CuO 2O 2′O 2″ chromophore), with bidentate nitrato groups involved in off-the-z-axis coordination. Spectroscopic properties are interpreted on the basis of the above stereochemistry.

Reinvestigation of the Reaction of (NH4)2[Ce(N03)6] with Triphenylphosphine Oxide; the Crystal Structure and Magnetic Properties of mer-Ce(NO3)3(OPPh3)3 • 2 (CH3)2CO

Abstract The reaction of (NH4)2[Ce(NO3)6 ] with two equivalents of OPPh3(Ph = C6H5 ) in acetonitrile yields Ce(NO3 ) 4(OPPh3 )2 (1) in high yield, whereas using acetone as solvent affords mer- Ce(NO3 )3(OPPh3)3 • 2(CH3)2CO (2), the yield of which is dependent on the reaction time. A crystal structure determination of 2 shows that the Ce atom is coordinated with three bidentate nitrato groups and three OPPh3 ligands, thus achieving a coordination number of nine. Eight non-coordinating acetone molecules are present in the unit cell. Crystal data (292 K): space group P21/n (no. 14), 0=12.438(2), b = 25.532(4), c = 20.379 (4) Å, β = 96.33(2)°, V = 6432(1) , Z = 4, dcalc = 1.318 g em 3. Due to poor crystal quality the refinement converges at R = 0.11, Rw = 0.09. 2 is paramagnetic, but it does not follow the Curie-Weiss law at low temperature. Therefore crystal field theory was used in order to explain these findings.

Spectral and thermogravimetric studies on thorium(IV) complexes with bidentate heterocyclic SCHIFF bases

Thorium(IV) nitrate and thiocyanate react with the bidentate heterocyclic aldimines (PyAlA) and heterocyclic ketimines (AcPyA) to form yellow., brown- or violet-coloured complexes [Th(SB)X 4] (SB = PyAlA or AcPyA; X = NO 3, NCS). The thiocyanato complexes contain N-bonded isothiocyanato groups and are six-coordinated. The nitrato complexes contain bidentate nitrato groups and are ten-coordinated. All the complexes have been characterised by analytical data, conductivity in non-aqueous media, IR spectra and thermogravimetric studies. From the thermogravimetric measurements of these complexes, it is seen that the thiocyanato complexes are comparatively more stable at higher temperature. Most of the nitrato complexes undergo rapid exothermic decomposition around 200 °C in a single step, whereas the isothiocyanato complexes decompose in a stepwise manner ultimately forming stable ThO 2 as the end product.

Interaction of dioxouranium(VI) acetate and nitrate with pyridoxal

The interaction of dioxouranium(VI) acetate and nitrate with the pyridoxal ligand has been studied. Complexes have been prepared and studied by ir, 1H NMR and conductivity measurements. The data support the formation of UO 2(C 8H 8NO 3)(CH 3COO)2H 2O and UO 2(C 8H 9NO 3) 2(NO 3) 23H 2O compounds, respectively. In the former complex the uranyl group is bound to the phenolic and aldehydic oxygen atoms of pyridoxal and to a bidentate acetato group; the coordination sphere is completed with a molecule of water. In the latter complex the uranyl group is bound to two molecules of neutral ligand through the heterocyclic ring nitrogen and to two bidentate nitrato groups.

The structure of [(C 6H 5) 4As] 2[Eu(NO 3) 5

The structure of the title compound was solved from single crystal X-ray diffractometer data by Patterson and Fourier methods, and refined by least-squares to conventional R F = 0.046 for 2504 independent observed reflections. The crystals are monoclinic with a = 17.920(5), b = 13.594(3), c = 20.992(5) A ̊ , β = 103.60(3)°, and Z = 4, space group I2 1 a (No. 15). The Eu(III) ion lies on a twofold axis; it is 10-coordinated and bound to five bidentate nitrato groups. The mean EuO distance is 2.48(4) Å and the mean OEuO angle is 51.4(5)°. The coordination polyhedron can be described in terms of a distorted bicapped square antiprism of idealized symmetry D 4d( 82m) .

Structural effects of chelate chain length in high-spin nickel(II) complexes of triamines

Bis(3-methylaminopropyl)methylamine (Me 3dpt) forms high-spin five-coordinate [Ni(Me 3dpt)X 2] (X = Cl, Br, NCS, NO 3) and the hydroxo-bridged [Ni(Me 3-dpt)OH] 2(ClO 4) 2. Bis(2-methylaminoethyl)methylamine (Me 3dien), a structurally analogous ligand, yields pseudooctahedral [Ni[Me 3dien) 2]Y 2 (Y = I, ClO 4), [Ni(Me 3dien)(NO 3) 2], containing both mono- and bidentate nitrato groups, and [Ni(Me 3dien)X 2] (X = Cl, Br, NCS) which are X-bridged dimers in the solid state. The [Ni[Me 3dien)(NCS) 2] remains six-coordinate in solution, but the halides yield conducting solutions the electronic spectra of which suggest some five-coordinate species are present. Some dipropylenetriamine analogues are described and the factors influencing the occurrence of five-coordination with triamine ligands are discussed.

Crown ether complexes of actinide elements an X-ray study of the conformational change of the crown ether within the UO 2(NO 3) 2(H 2O) 2(18-crown-6) molecule

Uranyl nitrate dihydrate-18-crown-6 crystallizes in the triclinic system with a = 9.072(3), b = 9.144(3), c = 8.323(3) Å; α = 64.53(10)°, β = 104.23(10)°, γ = 110.72(10)°, space group P 1 . Its structure has been determined from three dimensional X-ray data collected with an automatic diffractometer at room temperature and refined with full matrix methods to the final conventional R value = 0.038. The uranyl group does not enter into the 18-crown-6 cavity, but presents the usual hexacoordination in the equatorial plane where two water molecules and the bidentate nitrato groups are coordinated trans to each other. The whole structure is constituted by neutral UO 2(NO 3) 2(H 2O) 2 units alternated with 18-crown-6 molecules and linked together in infinite chains developping along [001] through a hydrogen bonding system. The cyclic ether assumes two statistically non-equivalent sites in the crystal (occupancy factor 0.7 and 0.3, respectively) related to each other by a 180° rotation about 0(7) …0(7′) axis.

Structural investigation of a nickel(II) complex containing a new type of terdentate ligand with a planar NNN donor set and both uni- and bi-dentate nitrato-groups. X-Ray analysis of 2,6-bis-(phenylliminoethyl)pyridine(dinitrato)nickel(II)

Spectral and crystallographic data are presented for the title nickel(II) complex containing a new terdentate ligand with a planar NNN donor set and both uni-dentate and almost symmetrically bidentate nitrato-groups.

Crystal structure of anhydrous nitrates and their complexes. Part VII. 1.5 Dinitrogen tetroxide solvate of iron(III) nitrate

Crystal structure determination has shown that this solvate exists in the form [NO]+3[NO3]–[Fe(NO3)4]–2 in which there is close association between the three [NO]+ and the [NO3]– ions to form a grouping [N4O6]2+. The nitrogen atom of each [NO]+ lies approximately along the bisector of each O–N–O angle of the nitrate ion with ON+⋯ O2NO2 distances ranging from ca. 2.4 to 2.8 A and the NO+ axes tilted at angles ranging 10–51° out of the plane of the nitrate ion. The two crystallographically independent tetranitratoferrate(III) ions have the same trigonal dodecahedral structure as found in the tetraphenylarsonium salt with symmetrically bidentate nitrato-groups.

Raman spectra of titanium (IV) and tin (IV) nitrates

New bands are reported in the Raman spectra of titanium (IV) and tin (IV) nitrates. Force constant calculations indicate the necessity for partial reassignment of the vibrational spectra of compounds containing bidentate nitrato-groups.

Mono- and bi-dentate nitrato and cationic 4-ethoxypyridine N-oxide complexes with metal nitrates

Synthetic and characterization studies of 4-ethoxypyridine N-oxide (EPNO) complexes with CoII, NiII, CuII and ZnII nitrates are reported. The following structural assignments were made on the basis of spectral, magnetic and conductance studies: [M(EPNO)2(O2NO)2] (M = Co, Ni, Zn), essentially Oh symmetry with coordinated bidentate nitrato groups; [Cu(EPNO)2(ONO2)2], essentially planar symmetry; [Co(EPNO)3(ONO2)2], involves penta-coordinated CoII; the last two complexes have been coordinated monodentate nitrato groups; [M(EPNO)6](NO3)2 (M = Co, Ni), distorted Oh symmetry; [Cu(EPNO)4](NO3)2, essentially planar symmetry. Mono- and bi-dentate nitrato groups, as well as ionic NO3−, are easily distinguishable from the IR spectra of the new complexes. A Cs symmetry was assigned to the coordinated monodentate nitrato group, and a C2ν symmetry to the bidentate nitrato group.

Complexes of transition metals with oxygen donor ligands. Part II. Some complexes of 2,6-dimethyl-4-pyrone with metal nitrates

The preparation of cobalt(II), nickel(II), copper(II), and zinc(II) nitrate complexes of 2,6-dimethyl-4-pyrone (dmp) is reported. Spectroscopic studies, together with other physical measurements, indicate that the complexes Co(dmp)2(NO3)2 and Ni(dmp)2(NO3)2 are six-co-ordinate with two bidentate nitrato-groups. The Cu(dmp)2(NO3)2 and Zn(dmp)2(NO3)2 complexes probably have a similar structure. The i.r. spectra of the complexes are discussed with reference to the co-ordinated dmp- and nitrato-groups.

The crystal and molecular structure of [(pyridine)2Cu(NO3)2]2,C5H5N: a centrosymmetric dimer with bridging nitrato-groups

The compound [(py)2Cu(NO3)2]2,C5H5N is a centrosymmetric dimer of novel structure containing asymmetric bidentate nitrato-groups which also form bridges of the type Cu–[graphic omitted]–Cu to effect dimerisation.

The similarity of the far-infrared spectra of complexes containing mono- and bi-dentate nitrato-groups

The similarity of the far-infrared spectra of complexes containing mono- and bi-dentate nitrato-groups