Mononuclear Molecules Research Articles

(4-Hydroxy-2-oxidobenzaldehyde thiosemicarbazonato-κ3O2,N1,S)(1,10-phenanthroline-κ2N,N′)zinc(II) dimethyl sulfoxide disolvate monohydrate

The ZnII atom in the title compound, [Zn(C8H7N3O2S)(C12H8N2)]·2C2H6OS·H2O, is N,N′-chelated by the N-heterocycle and N,O,S-chelated by the deprotonated Schiff base in a distorted square-pyramidal enviroment. Hydrogen bonds link the mononuclear mol­ecule, the water and the dimethyl sulfoxide (DMSO) mol­ecules into a linear chain motif. One DMSO mol­ecule is disordered over two positions in respect of the S atom in an approximate 1:1 ratio.

Synthesis of heteroligand complex Nd(Phen){(iso-C4H9)2PS2}2(NO3). Crystal structure of [Nd(Phen){(iso-C4H9)2PS2}3] and luminescent properties of these compounds

The heteroligand complex Nd(Phen){(iso-C4H9)2PS2}2(NO3) (I) was synthesized and its IR spectrum was analyzed. The anions (iso-C4H9)2PS2/− and N3/− act as bidentate cyclic ligands. The single crystals of [Nd(Phen){iso-C4H9)2PS2}3] (II) were obtained on evaporation of a solution of complex I in a mixture CH2Cl2-hexane and were studied by X-ray diffraction. Crystals II are triclinic: a = 10.5509(5); b = 14.7432(8), c = 16.8503(10) A; α = 102.882(2)°, β = 97.211(2)°, γ= 108.087(2)°, V = 2374(2) A3, Z = 2, ρ(calcd.) = 1.332 g/cm3, space group \( P\bar 1 \). The coordination polyhedron of the Nd atom in a separate mononuclear molecule II is a distorted dodecahedron N2S6. The molecules are bound by weak van der Waals and π-π interactions. The photoluminescence spectra of complexes I, II were measured and interpreted.

Synthesis and characterization of two manganese tert-butylphosphonate complexes

Two manganese(II) phosphonate complexes, Mn 2( t-BuPO 3H) 4(bipy) 2 1 (bipy = 2,2′-bipyridine) and [Mn(H 2O) 6][ t-BuPO 3H] 2·6H 2O 2 have been synthesized with identical procedure from similar system containing tert-butylphosphonic acid and bipy ligands in different ratio at different temperature. The complexes have been characterized by single crystal X-ray diffraction, IR spectroscopy, X-ray powder diffraction, magnetic measurement and thermal analysis. Compound 1 crystallizes in the triclinic space group P-1 with C 2 v symmetry, and exhibits infinite double-chains linked by hydrogen bonds and the double-chains are further packed into two-dimensional network via the π–π stacking interactions, whereas compound 2 crystallizes in a monoclinic space group P 2(1)/ c, and the mononuclear molecules in 2 are linked by hydrogen bonds to form sandwich-like two-dimensional formation. The magnetic measurement reveals weak antiferromagnetic exchange interactions between the manganese(II) ions in compound 1.

Copper(II) and cobalt(II) complexes with a chiral 5-pyrazolone derivative obtained from the terpene (+)-3-carene: Synthesis and properties

The complexes [CuLCl2] (I), [CoLCl2] (II), and CuLBr2 (III) (where L is the derivative of optically active 5-pyrazolone prepared from the terpene (+)-3-carene) were obtained and characterized. According to X-ray diffraction data, crystal structures I and II (orthorhombic crystal system) are built from mononuclear acentric molecules. In the resulting complexes, the Cu2+ or Co2+ ion coordinates two N atoms of the chelating bidentate ligand L and two Cl atoms, thus making a distorted tetrahedron. Intermolecular contacts and the hydrogen bonds Cl(1)…H-O(1) give rise to columns parallel to axis y. For complexes I and III, μeff = 1.83 and 1.81 μB, respectively; these values correspond to the electronic configuration d 9 . For complex II, μeff = 4.42 μB, which suggests the tetrahedral structure of the coordination entity CoCl2N2. Complexes I and III were studied by EPR spectroscopy.

Synthesis and structure of the mononuclear octacoordinate complex [Pb(Phen)2(iso-Bu2PS2)2] and polynuclear complex [Pb(4,4′-Bipy)(iso-Bu2PS2)2] n : Formation of ribbons and supramolecular assemblies in their crystalline structures

Heteroligand complexes [Pb(Phen)2(iso-Bu2PS2)2] (I) and [Pb(4,4′-Bipy(iso-Bu2PS2)2]n (II) were synthesized, and their crystal structures were determined. The crystals of complex I are monoclinic: a = 17.2011(9) A, b = 14.1695(7) A, c = 19.8727(12) A; β = 115.644(1)°, V = 4366.5(4) A3, Z = 4, ρcalcd = 1.500 g/cm3, space group C2/c. The crystals of complex II are triclinic: a = 11.9283(2)A, b = 12.3814(2) A, c = 14.0917(3) A; α = 74.705(1)°, β = 87.240(1)°, γ = 61.448(1)°, V = 1755.86(6) A3, Z = 2, ρcalcd = 1.479 g/cm3, space group P\( \bar 1 \). The structure of complex I consists of mononuclear molecules. The coordination polyhedron of the Pb atom is a distorted tetragonal antiprism N4S4 formed by the bidentate chelating ligands Phen and iso-Bu2PS2−. Continuous zigzag ribbons along the c axis are formed through contacts of the peripheral atoms of the Phen molecules of the adjacent complexes. Polynuclear complex II has a chain structure. The coordination polyhedron of the Pb atom is a distorted octahedron N2S4 formed by the bidentate chelating iso-Bu2PS2− ligands and bidentate bridging 4,4′-Bipy molecules. Short intermolecular contacts between the Pb and S atoms of the adjacent chains in structure II result in the formation of supramolecular two-chain assemblies as volume columns parallel to the b axis. The environment of the Pb atoms in the assembly is formed by pentagonal bipyramids N2S4 + 1.

A photoluminescent 8-fold [4 + 4] interpenetrating diamond network formed through strong hydrogen bonds

A new complex with a hydrogen-bonded diamond network, [Zn(2,2′-bipy) 2(HBBDC) 2] ( 1) has been synthesized by the assembly of H 2BBDC, Zn(II) and 2,2′-bipy (H 2BBDC = bibenzyl-4,4′-dicarboxylic acid and 2,2′-bipy = 2,2′-bipyridine). The coordination of two 2,2′-bipy ligands and two carboxylate groups around Zn(II) interplays with the hydrogen-bonding involving the deprotonated and protonated carboxylate, making the mononuclear molecule an unusual supramolecular tetrahedral building unit for the diamond network. The long bridging ligand leads to 8-fold interpenetration of the net in the abnormal [4 + 4] mode. Compound 1 shows a strong fluorescent emission at 400 nm in solid state at room temperature.

Synthesis and structure of Cu(II) and Pd(II) coordination compounds with chiral α-thiooxime, a derivative of natural terpenoid (−)-α-pinene

The paramagnetic complex Cu(HL)Cl2(I) (μeff = 1.88 μB) and the diamagnetic complex Pd(HL)Cl2(II) with chiral α-thiooxime, a derivative of natural terpenoid (−)-α-pinene (HL), were synthesized. The crystal structures of these complexes were determined from single-crystal X-ray diffraction data (X8 APEX diffractometer, MoK α radiation, 2975 F hkl , R = 0.0258 for I and 3270 F hkl , R = 0.0222 for II). The crystals of complex I are monoclinic, a = 9.3376(3) A, b = 6.8619(2) A, c = 14.6540(5) A, β = 97.814(1)°, V = 930.22(5) A3, Z = 2, ρcalc = 1.513 g/cm3, space group P21. The crystals of complex II are orthorhombic, a = 7.0084(6) A, b = 9.2113(9) A, c = 29.081(3) A, V = 1877.4(3) A3, Z = 4, ρcalc = 1.651 g/cm3, space group P212121. The structures are composed of mononuclear molecules. The coordination cores MNSCl2 (M = Cu, Pd) are tetrahedrally distorted squares. According to NMR data, complex II has a similar structure in a CDCl3 solution. The intermolecular contacts in structure I generate supramolecular polymeric ribbons lying parallel to axis b. No short intermolecular contacts are present in complex II.

Synthesis and characterization of two cobalt complexes derived from the system containing phenylphosphonic acid

A single-chain cobalt phosphonate complex [Co(phen)(4,4′-bpy)(PhPO 3H) 2] n ·0.5H 2O 1 (phen = 1,10-phenanthroline, 4,4′-bpy = 4,4′-bipyridine) and a mononuclear cobalt complex [Co(pic) 2(H 2O) 2]·0.5H 2O 2 (picH = picolinic acid) have been synthesized with identical procedure from similar system containing phenylphosphonic acid and N-containing ligands. Both complexes have been characterized by single crystal X-ray diffraction, IR spectroscopy, magnetic measurement and thermal analysis. Compound 1 crystallizes in the tetragonal system with a P4 32 12 space group, and exhibits a 1-D cobalt chain connected by 4,4′-bpy bridges propagated along a axis direction, and the chains are linked by strong hydrogen bonds to form a two-dimensional grid like coordination network, whereas compound 2 crystallizes in the monoclinic system with space group P2 1/ n, and the mononuclear molecules in 2 are linked by hydrogen bonds to form infinite double-chains and the double-chains are further crosslinked to create a two-dimensional supramolecular network. The magnetic measurement reveals overall weak antiferromagnetic exchange interactions between the cobalt ions in both complexes 1 and 2.

Fe(II) complex with chiral pyrazolylquinoline L and Fe(II), Co(II), and Cu(II) complexes with achiral pyrazolylquinoline L1: Synthesis and properties. The crystal structures of [ML1Cl2] (M = Fe, Co, and Cu)

The complexes FeLCl2 (I), [FeL1Cl2] (II), [CoL1Cl2] (III), and [CuL1Cl2] (IV) (where L and L1 are chiral and achiral pyrazolylquinolines, respectively) were obtained. Complexes II–IV were structurally characterized by single-crystal X-ray diffraction analysis. Crystals of complexes II and III are triclinic (space group P % MathType!MTEF!2!1!+- % feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBqj3BWbIqubWexLMBb50ujbqegm0B % 1jxALjharqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqr % Ffpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0F % irpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaa % GcbaGabGymayaaraaaaa!3A3A! $$ \bar 1 $$ ) and crystals of complex IV are monoclinic (space group P21/n). Structures II–IV are built from discrete mononuclear acentric molecules. In these complexes, the M2+ ion (M = Fe, Co, and Cu) coordinates two N atoms of the bidentate chelating ligand L1 and two Cl atoms. The coordination cores MCl2N2 are distorted tetrahedra. For complexes I and II, μeff = 5.05 and 5.07 μB, respectively, correspond to the high-spin configuration d 6. For complex III, μeff = 4.51 μB (high-spin configuration d 7) and for complex IV, μeff = 1.80 μB (configuration d 9).

Crystal and molecular structures of the Rh[(C2H5O)2PS2]3 and Co[(C6H5O)2PS2]3 chelate compounds

The crystal structures of the Rh[(EtO)2PS2]3 (I) and Co[(PhO)2PS2]3 (II) chelate compounds were determined from X-ray diffraction (XRD) data (CAD-4 diffractometer, MoKβ radiation, 1193 Fhkl, R = 0.0516 for I and 513 Fhkl, R = 0.0305 for II). Crystals I are monoclinic: a = 14.233(3) A, b = 13.570(3) A, c = 14.272(3) A; β = 90.66(3)°, V = 2756.3(10) A3, Z = 4, ρcalc = 1.587 g/cm3, space group C2/c. Crystals II are trigonal: a = 15.149(2) A, c = 30.306(6) A; V = 6023.2(16) A3, Z = 6, ρcalc = 1.493 g/cm3, space group R3¯. Structures I and II consist of discrete mononuclear molecules. The coordination polyhedra of the M atoms (M = Rh, Co) are distorted octahedra formed by six sulfur atoms of three cyclic bidentate (RO)2 PS2− ligands.

Mixed-ligand complex compounds [Pb(Phen)×{(iso-C4H9)2PS2}2] and [Pb(2,2′-Bipy){(iso-C4H9)2PS2}2] and formation of supramolecular assemblies in their crystal structures

Mixed-ligand complex compounds [Pb(Phen)(i-Bu2PS2)]2 (I) and [Pb(2,2′-Bipy)(i-Bu2PS2)]2 (II) were synthesized. Their structures were determined from X-ray diffraction data (X8 APEX diffractometer, MoK α radiation, 6392 Fhkl , R = 0.0233 for I and 3937 F hkl , R = 0.0252 for II). Crystals I are triclinic: a = 10.2662(3) A, b = 12.3037(2) A, c = 14.8444(4) A; α = 92.054(1)°, β = 103.473(1)°, γ = 105.561(1)°, V = 1746.89(8) A3, Z = 2, ρcalc = 1.532 g/cm3, space group P $$\bar 1$$ . Crystals II are monoclinic: a = 9.3462(3) A, b = 26.3310(12) A, c = 28.5345(13) A; β = 96.436(1)°, V = 6977.9(5) A3, Z = 8, ρcalc = 1.489 g/cm3, space group P21/n. The structures are built from mononuclear molecules. In both structures, the intermolecular contacts between the Pb and S atoms of the neighboring mononuclear molecules form supramolecular assemblies involving two molecules. The environment of the Pb atoms in the assemblies is a pentagonal bipyramid, N2S4+1. The assemblies are joined into ribbons by π-π interactions of the Phen rings in I and C…C short contacts between the pyridine rings in II.

Crystal and molecular structure of the [Y(Phen){(i-C4H9)2PS2}2NO3] mixed-ligand compound

The [Y(Phen){(i-C4H9)2PS2}2NO3] mixed-ligand compound (I) was synthesized. Its structure was determined by X-ray diffraction analysis (X8 APEX diffractometer, λMoK α , 3788 F hkl , R = 0.0677). Crystals I are orthorhombic: a = 10.6495(8) A, b = 20.006(2) A, c = 35.317(4) A, V = 7524.4(13) A3, Z = 8, ρcalc = 1.324 g/cm3, space group Pbca. The structure is built of mononuclear discrete molecules. The N2O2S4 coordination polyhedron of the Y atom is a distorted dodecahedron.

Coordination compounds of bis(5-tetrazolyl)amine with manganese(ii), zinc(ii) and cadmium(ii): synthesis, structure and magnetic properties

Six coordination compounds of bis(5-tetrazolyl)amine (H2bta) with different metal ions, M{M3(mu3-X)(bta)3(H2O)6}2] (X = OH for M = Mn(II) 1, and Cd(II) 2; X = F for M = Mn(II) 3), [Mn(bta)(H2O)3].0.5H2O (4), [Zn(bta)(NH3)2]0.5H2O (5) and [Zn(Hbta)2(H2O)2]H2O (6) have been described. The compounds were synthesized using one-pot hydrothermal methods involving the in situ generation of the ligand from dicyanamide and azide (1-4, 6), or by the methods using the pre-synthesized H2bta ligand (4, 5). The bta ligand in 1-3 assumes the mu3 tetradentate mode with both 1,2- and 1,4-tetrazole bridges, generating an unusual 2D layer, in which [M3(mu3-X)] triangular motifs act as three-connecting nodes and the mononuclear motifs acting as six-connecting nodes that are inter-linked by the ligands. The 2D layer in 1 and 3 represents a novel type of a geometrically spin-frustrated lattice. Both 4 and 5 consist of co-crystallized binuclear motifs and 1D polymeric chain motifs, which arise from two different mu2 tridentate bridging modes of bta with 1,2- and 1,4-tetrazole bridges, respectively. In 6, the mono-anionic Hbta ligands chelate Zn in the non-bridging bidentate mode to generate mononuclear molecules, which are assembled through extended hydrogen bonds to generate a 3D architecture with a ten-connected net topology. Magnetic investigations revealed that interactions through the different bridges in 3 and 4 are all antiferromagnetic, and also confirmed that 3 is a geometrically-frustrated antiferromagnet (T(N) = 2.5 K).

Hydrothermal Synthesis and Crystal Structure of Lanthanum Orotate Supermolecule with A Honeycomb Structure Constructed from Mononuclear Molecules via Hydrogen Bonds

A new complex of lanthanum orotate [La(C 5H 3N 2O 4) 2(OH)(H 2O) 6] · 2(C 5H 4N 2O 4) · 9H 2O was synthesized using a hydrothermal method. The crystal structure was determined with help of single crystal X-ray diffraction analysis. The complex crystallized in orthorhombic system, Cmc2(1) space group. In the complex, the center lanthanum (III) ion was nine-coordinated with coordination geometry of a distorted monocapped square antiprism, in which two of the nine coordinated oxygen atoms were from two orotate ligands in a monodentate mode, one oxygen atom from a hydroxyl, and the others from six coordinated water molecules. The mononuclear complex [La(C 5H 3N 2O 4) 2(OH)(H 2O) 6] · 2(C 5H 4N 2O 4) · 9H 2O was linked through the hydrogen bonds into an infinite supermolecular honeycomb structure.

Crystal structure of triaqua-cis-bis((2-carboxybenzene)sulfonylglycinato) zinc(II), Zn(H2O)3(C9H8NO6S)2

C18H22N2O15S2Zn, orthorhombic, Pnna (no. 52), a = 11.0915(9) A, b = 42.064(4) A, c = 5.0972(4) A, V = 2378.1 A, Z = 4, Rgt(F) = 0.030, wRref(F) = 0.088, T = 292 K. Source of material The mixture of ZnCl2 · 2H2O (1 mmol) and 3-(sulfonyl-glycine)benzoic acid (2 mmol) was stirred into 15mL aqueous solution at room temperature. Then the pH was adjusted to approximately 7 with 1 M KOH solution. And then 5 mL ethanol solution of 4,4 bipyridine (1 mmol) was added. The reaction mixture was then heated on awater bath for 6 h at 70 °C, and then filtered. Colorless crystal were obtained from themother liquor by slow evaporation at room temperature after 6 weeks. Experimental details All hydrogen atoms were first found in the difference electron densitymaps, and then placed in the calculated positions. The hydrogen atoms of carboxylate group and water molecules were found from Fourier difference maps and refined freely. The remaining H atoms were refined by riding model with Ueq(H) = 1.2Ueq(C). Discussion Crystal engineering ofmetal-organic frameworks (MOFs) is realizable by the choice of metals and the numerous choice and design of ligands, which bears the weight of prospective applications in new chemical separation, ion exchange, and gas adsorption [1-6]. In particular, carboxylate ligands have been frequently employed in the construction of microporous inorganic/organic hybrid materials for gas storage purposes. In this context, benzenedicarboxylic acid and their derivatives (such as 1,3-benzenedicarboxylic acid, 1,4-benzenedicarboxylic acid or 5-hydroxyisophtalic acid) are widely used as building blocks to link metal ions to produce interesting metal-organic framework structures and properties [7-10]. However, much fewer studies on coordination chemistry of flexible carboxylate-containing ligands have been carried out. On the other hand, the main strategies used in the field of crystal engineering are basically on the use of either conventional coordinative bonds or weak interactions. Among the non-covalent interactions, hydrogen bonding interactions play important role in designing superstructures and have attracted much interest due to their relative strength and directionality [11-12]. 3-(Sulfonyl-glycine)benzoic acid can act not only as hydrogen bond acceptors but also as hydrogen bond donors,whichmake it a wonderful candidate for the construction of supramolecular networks. The crystal structure consists of the mononuclear molecules. The coordinating 3-(sulfonyl-glycine)benzoic acid exists as a monoanion acting as a monodentate ligand. In the complex, zinc atom is five-coordinated in a distorted trigonal-bipyramidal ZnO5 environment, in which the basal coordination sites are occupied by three oxygen atoms (O1, O1A, O7), with the bond lengths of 1.968(1) A, 1.968(1) A and 2.071(3) A, respectively. The axial position is occupied by two oxygen atoms (O8, O8A) fromwater molecules, with the bond lengths of both 2.076(2) A. There exist intermolecular hydrogen bonds between carboxylate oxygen atoms fromC6H5COOgroup (O···O distances of 2.635A), forming 1D hydrogen bonded chains in which six-membered-ring and mononuclear units are alternately arranged along [100]. These chains are assembled by hydrogen bonds between carboxylate oxygen atoms from amino acid and water molecules from adjacent chains to give rise to 2D layer supramolecular structure (O···O distances of 2.835 A). At the same time, several weaker O–H···O hydrogen bonds are formed: (a) hydrogen bonding between water oxygen atoms and oxygen atoms of sulfonamide groups (O8–H2W···O5) with the bond distance of 3.211(2) A and bond angle of 117(3)°, (b) hydrogen bonding betweenwater oxygen atoms and oxygen atoms of amino acid groups (O7–H3W···O1 and O7–H3W···O2), with the bond distances of 3.117(3) A and 3.035(2)Aandbond angles of 118(3)° and 147(4)°, respectively. Z. Kristallogr. NCS 222 (2007) 435-436 / DOI 10.1524/ncrs.2007.0184 435 © by Oldenbourg Wissenschaftsverlag, Munchen

Triaquabis(4-formylbenzoato-κ2 O,O′)cadmium(II) trihydrate

The title complex, [Cd(C8H5O3)2(H2O)3]·3H2O, is a neutral mononuclear molecule consisting of a CdII atom chelated by two 4-formylbenzoate ligands and coordinated by three water molecules in a pentagonal–bipyramidal geometry. A three-dimensional hydrogen-bonded supramolecular network is formed by intermolecular hydrogen bonds.

Diaquabis[5-(pyrimidin-2-yl-κN)tetrazolato-κN 1]copper(II)

The title compound, [Cu(C5H3N6)2(H2O)2], is isostructural with the manganese(II) analogue, but different from the two-dimensional structures of the zinc(II), iron(II), cobalt(II) and nickel(II) complexes with the same 5-(pyrimidin-2-yl)tetrazolate ligand. Each of the two symmetry-independent but structurally similar mononuclear molecules in the crystallographic asymmetric unit occupies a special position with the CuII atom on an inversion centre. Both CuII atoms have a highly distorted octahedral coordination geometry formed by two trans water molecules and two chelating ligands. Intermolecular O—H...N hydrogen bonds are present, which lead to the formation of a two-dimensional network.

Nickel(II) and copper(II) complexes with chiral bis-α-thiooxime, the derivative of natural terpenoid (+)-3-carene: Synthesis and structures

Chiral bis-α-thiooxime (H2L1), the derivative of the natural monoterpenoid (+)-3-carene, was synthesized and used to prepare paramagnetic complexes of the composition M(H2L1)Cl2 (M=Ni, Cu). The crystal structures of [Ni(H2L1)Cl2] (I) and [Cu(H2L1)Cl2] (II) were determined by X-ray diffraction analysis. Crystals I and II consist of mononuclear acentric molecules. The Ni2+ ion in a molecule of complex I coordinates two N atoms and two S atoms of a tetradentate chelating ligand (the H2L1 molecule) and two Cl atoms. The NiCl2N2S2 coordination core forms octahedron compressed along the apical N atoms. In a molecule of complex II, the Cu2+ ion coordinates two S atoms and the N atom of a tridentate chelating H2L1 ligand and two Cl atoms. The CuCl2NS2 coordination core forms a trigonal bipyramid.

Synthesis, structure and DNA cleavage activity of two 4,4′-dimethyl-2,2′-bipyridyl manganese(II) complexes

Two new mononuclear Mn(II) complexes, Mn(dmbpy) 2(OCN) 2 ( 1) and Mn(dmbpy) 2(dca) 2 ( 2) (dmbpy = 4,4′-dimethyl-2,2′-bipyridine, dca = dicyanamide), have been synthesized and characterized by IR, elemental analysis, and single crystal X-ray analysis. Both complexes have similar molecular structures. The coordination sphere of the Mn(II) ion in 1 or 2 is a seriously distorted octahedron formed by two dmbpy ligands and two OCN − or dca anions in cis positions. For both complexes, the most striking feature is that the mononuclear molecules are linked together by plentiful weak C–H⋯N hydrogen bonds into a compact 3D supramolecular structure. DNA cleavage studies show that the complexes can promote plasmid DNA cleavage in the presence of H 2O 2 under physiological conditions, and their cleavage activities are obviously both pH value and complex concentration-dependent. The cleavage mechanism between the complexes and plasmid DNA is likely to involve hydroxyl radicals as reactive oxygen species.

Different Supramolecular Coordination Polymers of [N,N'-di(pyrazin-2-yl)-pyridine-2,6-diamine]Ni(II) with Anions and Solvent Molecules as a Result of Hydrogen Bonding

Ni(II) complexes of N,N'-di(pyrazin-2-yl)pyridine-2,6-diamine (H2dpzpda) with different anions were synthesized and their structures were determined by X-ray diffraction. Hydrogen bonds between the amino groups and anions assembled the mononuclear molecules into different architectures. The perchlorate complex had a 1-D chain structure, whereas switching the anion from perchlorate to nitrate resulted in a corresponding change of the supramolecular structure from 1-D to 3-D. When the nitrate complex packed with the co-crystallized water, a double chain structure was formed through hydrogen bonding. The magnetic studies revealed values of g = 2.14 and D = 3.11 cm(-1) for [Ni(H2dpzpda)2](ClO4)2 (1) and g = 2.18 and D = 2.19 cm(-1) for [Ni(H2dpzpda)2](NO3)2 (2), respectively.