Linear trinuclear manganese(II) complexes: crystal structures and magnetic properties

Two new trinuclear manganese(II) complexes, [Mn₃(O₂CCH(CH₃)₂)₆(N–N)₂] (N–N is 1,10′-phenanthroline (1) and 2,2′-bipyridine (2)) have been prepared and fully characterized. Single crystal X-ray diffraction analysis confirmed a linear arrangement of three Mn(II) centers bridged by six isobutyric carboxylate groups. The magnetic measurements showed that both complexes exhibit an S_T = 5/2 spin ground state induced by antiferromagnetic interactions between the Mn(II) sites: J/k_B = −2.31(2) and −2.67(2) K for 1 and 2, respectively.     

A MnII5 tetragonal pyramid stabilized by p-tert-butylcalix[8]arene: Synthesis,structure and magnetic property

A compound, [Mn₅(H₄C8A)(OH)₂(C₃H₆NO₂)(DMF)₅(CH₃O)_1.5(HCO₂) (C₂H₃O₂)_0.5]·2DMF·CH₃OH (1) (H₈C8A = p-tert-butylcalix[8]arene, DMF = N,N′-dimethylformamide), was synthesized by the solvothermal method in the mixed CH₃OH/DMF (1:1) solvent. Compound 1 is featured with a tetragonal pyramid-like Mn^II₅ cluster encircled within a calix[8]arene molecule with a ‘pleated loop’ conformation. Magnetic study indicates that the Mn^II centers exhibit antiferromagnetic interactions.     

Two new carboxylate–oxygen bridged trinuclear M(II) (MMn and Co) compounds with zwitterionic dicarboxylate ligands: crystal structures and magnetism

Two new Mn(II) and Co(II) coordination polymers with azide and zwitterionic dicarboxylate ligands L¹ and L² (L¹ = [4-((1-carboxylatobenzyl)pyridimium-3-yl) benzoic acid] chloride, L² = [1,1′-bis(4-carboxylatobenzyl)-4,4′-bipyridinium] dichloride) were synthesized and structurally and magnetically characterized. They are formulated as [Mn₃(L¹)₄(N₃)(CH₃CH₂OH)(H₂O)]ClO₄·4H₂O (1) and [Co₃(L²)₄(N₃)₂(H₂O)₂]·4NO₃ (2). Compound 1 contains two different linear trinuclear [Mn₃(COO)₈(CH₃CH₂OH)₂]^2 − and [Mn₃(COO)₆(H₂O)₂(N₃)₂]^2 − units built from the mixed bridges of (μ-COO)₂(μ₂-O_carboxylate). The trinuclear units are alternately linked into 1D chains by L¹. Compound 2 contains linear trinuclear [Co₃(N₃)₂(COO)₄(H₂O)₂] units built from the mixed bridges (μ-COO)₂(μ-H₂O). Magnetic studies demonstrated that the mixed triple bridges are antiferromagnetic in compounds 1 and 2.     

New members in the [Mn10] supertetrahedron family

Two manganese complexes, [Mn^II₄Mn^III₆Cl₄(CH₃OCH₂CH₂O)₁₂ O₄][Mn^II₃Ti^IVCl₆(CH₃OCH₂CH₂O)₆] (1) and [Mn^II₄Mn^III₆Cl₄(CH₃OCH₂CH₂O)₁₂O₄] [Mn₄^II Cl₁₀(CH₃OCH₂CH₂OH)₄]∙0.5CH₃OCH₂CH₂OH, (2) have been obtained and characterized by single-crystal X-ray diffraction. Both structures consist of the decametallic dicationic [Mn^II₄Mn^III₆Cl₄(CH₃OCH₂CH₂O)₁₂O₄]^2 + core constructed by four vertex-sharing [Mn^III₃Mn^IIO]^9 + tetrahedra. Also, these compounds contain the different tetrametallic dianions: [Mn^II₃Ti^IVCl₆(CH₃OCH₂CH₂O)₆]^2 − (in complex 1) and [Mn₄^IICl₁₀(CH₃OCH₂CH₂OH)₄]^2 − (in complex 2). Magnetic dc and ac susceptibility measurements for compound (1) show that the dicationic decanuclear magnetic cluster possesses an S = 12 ± 1 spin ground-state.     

Synthesis and characterization of a new 2D trimetallic Mn/Ca/Na complex

A new tri-metallic Mn/Ca/Na coordination polymer, {[Mn₃NaCa(sal)₆(H₂O)₆]·7H₂O}_n (1·7H₂O), has been synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy, and magnetic measurements. The X-ray analysis shows 1 consists of a 2D homochiral (6,3) network with chiral [Mn₃Na] clusters and chiral Ca ions as alternating nodes. Magnetic property study reveals the existence of weak antiferromagnetic couplings between Mn(III) ions with the interaction parameter J being ? 0.438 cm^? 1 within the complex.     

Novel 18-membered hexanuclear metallamacrocycle: Synthesis,crystal structure,and magnetic properties

The novel 18-metallacrown-6 metallamacrocycle, with the formula of [Mn₆(amshz)₆(CH₃OH)₆]·6H₂O (amshz = N-acetyl-3-methyl-salicylhydrazide), has been prepared and characterized. Six Mn(III) ions and six deprotonated N-acetyl-3-methyl-salicylhydrazide (amshz^3?) ligands construct a planar 18-membered ring based on Mn–N–N–Mn linkage. Due to the coordination, the ligand enforces the stereochemistry of the Mn³⁺ ions as a propeller shape with alternating …ΔΛΔΛ… configurations. The magnetic properties of the metallacrown molecules are characterized by a weak antiferromagnetic exchange interaction, with μ_eff = 5.12 μ_B at 300 K between the Mn³⁺ ion spins with S = 2 in the cyclic system.     

Structural characterization of a layered double salt Mn3(OH)2(SO4)2(H2O)2 · K2SO4

The title layered double salt Mn₃(OH)₂(SO₄)₂(H₂O)₂ · K₂SO₄ (1) was obtained from a simple hydrothermal reaction of CdSO₄ · 8/3H₂O, MnCl₂ · 4H₂O, α-aminopyridine (apy) and KI. X-ray analysis reveals that the two-dimensional (2-D) sheet of 1 is built up of the dimers of edge-sharing Mn(1) octahedral, extended by the apices of Mn(2) octahedral together with μ₃ and μ₄ SO₄ groups. With free K⁺ ion as guest species, the 2-D sheets are further self-assembled into a 3-D supramolecular network with 1-D channels through the Ow-H ⋯ O hydrogen-bonded interactions. The magnetic property of 1 was investigated, and a classical behavior is observed with an antiferromagnetic order below 12.5 K.     

Synthesis,characterization and crystal structure of one Mn(II) complex with 4,4′-bisimidazolylbiphenyl and 4,4′-sulfonyldibenzoic acid

One new title compound [Mn₃(BIBP)(sdb)(NO₂⁻)₂(H₂O)₂]_n·2DMF (1) (BIBP = 4,4′-bisimidazolylbiphenyl, sdb = 4,4′-sulfonyldibenzoic acid) has been synthesized under hydrothermal condition. The title compound was characterized by IR spectra, thermal analysis, single crystal and powder X-ray diffraction. Magnetic susceptibility measurements indicate that compound 1 exhibits antiferromagnetic coupling interaction.     

First hexanuclear manganese(II) μ6-Cl centered carboxylate anion: Synthesis,structure and magnetic properties

Reaction of manganese(II) polymer [Mn₅Cl(OH)(Piv)₈(MeCN)(HPiv)(H₂O)]_n (1, HPiv is pivalic acid) and 2-benzoylpyridine (L) in MeCN produces the ionic complex [Mn₃(Piv)₅L₂(MeCN)]⁺[Mn₆Cl(Piv)₁₂]⁻ · MeCN (3) containing the unusual hexanuclear {Mn₆(μ₆-Cl)} anion. An analogous anion was also observed in the complex [Mn₆Cl(Piv)₁₂]⁻(NEt₄)⁺ · 5MeCN (4) prepared by the reaction of the polymer [Mn(Piv)₂(EtOH)]_n (2) with NEt₄Cl in MeCN. Complexes 3 and 4 were characterized by the X-ray diffraction and magnetic susceptibility.     

A new two-dimensional manganese(II) coordination polymer with alternating double end-on and single end-to-end azido bridges: Crystal structure and magnetic properties

A new azido-bridged Mn(II) coordination polymer, [MnL(N₃)₂]n (1) (L = (E)-3-(dimethylamino)-1-(pyridin-2-yl)prop-2-en-1-one), has been synthesized and characterized by elemental analysis, IR, single crystal X-ray diffraction and magnetic measurement. X-ray analysis shows that complex 1 is a 2D network with (6, 3) layers, in which double end-on (EO) azido-bridged dimers are linked by single end-to-end (EE) azido bridges. Magnetic susceptibilities of 1 were measured under a magnetic field of 2 KOe applied over the temperature range 300–1.8 K. The analysis of magnetic data indicates that the EO- and EE-azido bridges mediate the ferromagnetic and antiferromagnetic exchange interactions, respectively, with the antiferromagnetic coupling between Mn(II) ions dominating the magnetic properties of 1.     

A new hemidirected lead(II) complex converted into holodirected by secondary Pb–N interactions

A new extended 2-D lead(II) coordination polymer [Pb₂(ins)₂(CH₃CH₂OH)]_n (1) (H₂ins = N-isonicotinamidosalicylaidimine) was synthesized by solvothermal method and characterized by IR, UV–vis, thermal analysis, elemental analysis and X-ray crystallography. The single-crystal X-ray data show that the neutral [Pb₂(ins)₂] moieties is a tetra-coordinated dimer with hemidirected coordination geometry. There are secondary Pb–N interactions that give rise to 2-D polymer with holodirected geometry. Compound 1 decomposes from 300 to 570 °C.     

Synthesis,crystal structures and properties of two Pd(II) and Pt(II) complexes involving 3,5-diphenylpyrazole and NO2 donor ligands

A pyrazolate bridged binuclear Pd(II) complex [Pd₂(μ-dppz)₂(Hida)₂] · CH₃OH · 2H₂O (1) (dppz = 3,5-diphenylpyrazolate) with monoprotonated iminodiacetate (Hida) and a mononuclear Pt(II) complex containing Hdppz and 2,6-pyridinedicarboxylate (2,6-dipic) [Pt(Hdppz)(2,6-dipic)] · CH₃OH (2) have been synthesized and characterized by elemental analysis, ¹H NMR, ESI-MS and single crystal X-ray diffraction studies. The molecular packing for 1 shows a 2D network while that for 2 constitutes a left-handed 1D helix. Moderate luminescence property and antimicrobial activity against Bacillus subtilis have been noted for both.     

Synthesis,crystal structure,characterization and magnetic property of a new organophosphonate-based polyoxovanadate

A novel organophosphonate-based polyoxovanadate, Cs_1·5Na_3.5[H{V₃(H₂O)O₃}{O₃PC- (OH)(CH₃)PO₃}₃]·15H₂O (1) has been synthesized and further investigated by single-crystal X-ray diffraction analysis, IR spectrum, UV–vis spectroscopy, X-ray powder diffraction, thermogravimetric analysis and X-ray photoelectron spectroscopy. Single-crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic space group P-1 with a = 9.506(3) Å, b = 15.150(5) Å, c = 17.915(6) Å, V = 2437.9(14) ų and Z = 2. Compound 1 exhibits a ring-shaped cluster with three branches of the 1-hydroxyethane 1, 1-diphosphonic acid [HEDP = H₂O₃P(OH)C(CH₃)PO₃H₂] ligands. Furthermore, the magnetic property of compound 1 has also been studied.     

Syntheses,structures, and magnetic properties of ethoxy-bridged dinuclear iron(III) complexes containing tetradentate ligands

Dinuclear iron(III) complexes, [(phenO)Fe(SO₄)]₂·2CH₃OH (1) and [(bpmapO)Fe(NO₃)]₂(NO₃)₂·3CH₃OH (2) have been prepared by the reaction of phenOH/bpmapOH and FeSO₄·7H₂O/Fe(NO₃)₃·9H₂O in methanol, respectively (phenOH = N-(2-pyridylmethyl)-N′-(2-hydroxyethyl)ethylenediamine, bpmapOH = N-(bis(2-pyridylmethyl)amino)-2-methylpropan-2-ol). Both complexes are ethoxy-bridged dinuclear species and the iron(III) ions in 1 and 2 have distorted octahedral geometries. Both complexes show strong antiferromagnetic interactions through the bridged ethoxy groups within the dimeric units.     

Two organic–inorganic hybrid materials based on the penta-nuclear {MMn4} (M = W and Mo) heterometallic clusters and Schiff-base ligands

Two organic–inorganic hybrid compounds with the formula {[Mn^III(Salen)(H₂O)]₄MoO₄}·Cl₂·16H₂O (1) and {[Mn^III(Salen)(H₂O)]₄WO₄}·(CH₃COO)₂·11H₂O (2) (Salen = Di-[2-hydroxyl-3-methoxyl-benzaldehyde] ethylenediamine) have been synthesized and structurally characterized by IR, UV–vis spectroscopy, TG analysis and single crystal X-ray diffraction. Structural analysis revealed that compounds 1 and 2 consist of a [MoO₄]^2 − or [WO₄]^2 − building unit and four {[Mn^III(Salen)(H₂O)]⁺ metal–organic moieties, respectively. In the crystal structure, the [MoO₄]^2 − or [WO₄]^2 − tetrahedra coordinated with four Mn^III ions, resulting in the penta-nuclear heterometallic tetrahedra cluster compounds, which were rarely observed in the Mn-Salen system. Magnetic study revealed that there was antiferromagnetic coupling in the two compounds.     

Salen homonuclear and heteronuclear lanthanide(III) complexes with near-infrared (NIR) luminescence

Two lanthanide complexes are achieved by utilizing H₂salen/acac ligands (H₂salen = N,N′-ethylenebis(salicylideneimine), acac = acetylacetonate). They are homonuclear [Nd₄(μ₃-OH)₂(salen)₂(acac)₆(CH₃OH)₂]·CH₃OH (1) and heteronuclear [NdYb(salen)₂(acac)₂] (2). The structures of the two complexes were determined by X-ray crystallographic studies and their photophysical properties were investigated. The homonuclear Nd₄ complex exhibits characteristic metal-centered NIR emission. The heteronuclear NdYb shows ‘dual emission’ from both neodymium(III) and ytterbium(III) ions.     

Synthesis,crystal structure and magnetic properties of a new 2D cyanide-bridged heterobimetallic Cr(I)–Mn(III) complex

A new two-dimensional cyanide-bridged Cr(I)–Mn(III) coordination polymer {K[Mn(L)]₂[Cr(CN)₅NO]}·CH₃CN (1) (L = N,N-ethylene-bis(3-methoxysalicylideneiminate)) has been successfully synthesized by the reaction of K₃[Cr(CN)₅NO] with [Mn(L)(H₂O)₂]ClO₄ and characterized by elemental analysis, FT-IR and X-ray structure determination. Investigation systematic over magnetic susceptibility of the complex reveals the overall antiferromagnetic interaction between the cyanide-bridged Cr(I) ion and Mn(III) ion and its 3D antiferromagnetic ordering behavior with typical metamagnetic character below 12.5 K.     

Syntheses and magnetic properties of trinuclear trithiocyanurato-bridged manganese(II) complexes involving bidentate aromatic N-donor heterocycles

Trinuclear manganese(II) complexes of the compositions [Mn₃(phen)₆(ttc)](ClO₄)₃ (1), [Mn₃(dmbpy)₆(ttc)](ClO₄)₃? 2H₂O (2) and [Mn₃(bpy)₆(ttc)](ClO₄)₃? 3H₂O (3), where phen = 1,10-phenanthroline, dmbpy = 4,4′-dimethyl-2,2′-bipyridine, bpy = 2,2′-bipyridine and H₃ttc = trithiocyanuric acid (2,4,6-trimercapto-1,3,5-triazine), were prepared and characterized by elemental analysis, FTIR and Raman spectroscopies, MALDI-TOF mass spectrometry, magnetic and conductivity measurements. The magnetic analysis incorporating simultaneous fitting of the temperature dependence and the field dependence of the magnetization using the isosceles triangle spin Hamiltonian model revealed a weak antiferromagnetic exchange within the trinuclear units.     

Novel heterobimetallic Cu/Mn coordination polymers prepared by “direct permanganate” synthesis

Two heterometallic Cu/Mn complexes [Cu(Me₂en)₂][Mn₂(ox)₃] · 2H₂O (1) (Me₂en = N,N-dimethylethylenediamine, H₂ox – oxalic acid) and [Cu(1,3-pn)(ox)(H₂O)][Mn(ox)(H₂O)₂] · H₂O (2) (1,3-pn = 1,3-diaminopropane) are prepared by the one-pot reaction of copper powder, tetrabutylammonium permanganate, oxalic acid and N-chelating ligands. Their structures are investigated by single-crystal X-ray analysis that reveals interesting variation in bridging motives of the oxalate groups composing the Mn-polymeric fragments.     

Binuclear cyano-bridged complex derived from [MnIII(salpn)] and [FeIII(CN)6]: Synthesis,structure and magnetic properties

The reaction of the neutral [Mn(salpn)C(CN)₃(H₂O)] (salpn^2 − = N,N^′-1,3-propylenebis(salicylideneiminato) dianion) with [Fe^III(CN)₆]^3 − in the presence of strong oxidizer (NH₄)₂S₂O₈ yields a binuclear anion complex [NH₃CH₂CH₂CH₂NH₃]^2 +{[Mn^III(salpn)(H₂O)][Fe^III(CN)₆]}^2 − (1). Its structure, DC and AC susceptibility have been studied. Frequency dependence of the AC susceptibility characteristic for single-molecule magnets has been found.