Mn Coordination Polymers Research Articles

Two new coordination polymers of Mn(II) and Co(II) based on a tripyridyl derivative ligand: Synthesis, crystal structures and properties

Two coordination polymers, [Mn(cpt)2)]n (C56H36MnN6O6)(1) and [Co(cpt)2)]n (C56H36CoN6O6) (2), have been synthesized under hydrothermal conditions using 4′-(4-(4-carboxyphenyloxy)phenyl)-4,2′:6′,4′-tripyridine (Hcpt) as the ligand. These ploymers have been structurally characterized. The crystal structure analyses of the two synthesized compounds revealed that both Mn(Ⅱ) and Co(Ⅱ) are six-coordinated, exhibiting a distorted octahedral coordination geometry. Additionally, the compounds share an isostructural two-dimensional framework. The various intermolecular interactions within the crystal structures were further examined using Hirshfeld surface analysis. The in vitro antimicrobial assay of the two compounds demonstrated good antibacterial activity against P.aeruginosa and S. aureus. Furthermore, the fluorescence, magnetic properties, and photocatalytic properties were investigated at room temperature.

Influence of the ancillary ligand on the crystalline structures and magnetic properties of mesaconato‐bridged Mn coordination polymers

Abstract{[Mn(mes)(dmb)(H2O)] ⋅ H2O}n (1) and [Mn(mes)(bpy)]n (2); (mes=mesaconato; dmb=5,5’‐dimethyl‐2,2’‐bipyridine; bpy=2,2’‐bipyridine), were obtained by self‐assembly solution reaction at ambient conditions, and structurally characterized by single crystal X‐ray diffraction. 1 crystallizes in an orthorhombic system with a Pbca space group and forms a one‐dimensional (1D) coordination polymer; the six‐coordinated Mn(II) centers display a distorted‐trigonal prismatic configuration. 2 crystallizes in an orthorhombic system with a P21212 space group yielding a two‐dimensional (2D) coordination array, their metal centers having a distorted octahedral geometry. Magnetic susceptibility measurements reveal that 1 is paramagnetic, while 2 shows weak antiferromagnetic coupling.

1D Mn coordination polymer derived from sulfanilic acid: Synthesis, structure, adsorption properties and Hirshfeld surfaces analysis

A one-dimensional Mn coordination polymer formulated; [Mn2(C6H7NO3S)2Cl4O4]n (1) (where = C6H7NO3S is sulfanilic acid) was synthesized via the hydrothermal method by reacting aqueous solutions of MnCl2·4H2O and sulfanilic acid. The X-ray studies demonstrate layered arrangement of monomers in the coordination polymer interconnected by weak hydrogen bonds. The vibrational frequencies of functional groups and bonds within the polymer were analyzed using infrared spectroscopy. The thermal degradation of the coordination polymer structure was studied under non-isothermal conditions in an argon atmosphere using thermogravimetric (TG) and differential thermal analysis (DTA), revealing a decomposition process occurring in four to five distinct stages. The sorption properties of the coordination polymer were investigated using N2 gas in an Autosorb IQ device at 77 K, resulting in a surface area of 318.4642 m²/g. Additionally, the sorption behavior of benzene and water vapor on the polymer was investigated at room temperature, yielding a result of 70.82 m²/g for benzene vapor and 172.66 m²/g for water vapor. The molecular fragment, [Mn2(C6H7NO3S)2Cl4O4] as the monomer unit are used for calculating the Hirshfeld surface of this compound that reveals strong N-H∙∙∙Cl intermolecular hydrogen bonding and π–π interactions.

Terephthalato and succinato bridged Mn(II) and Zn(II) coordination polymers involving structure-guiding H-bonded tetrameric assemblies: Antiproliferative evaluation and theoretical studies

Two new coordination polymers of Mn(II) and Zn(II) viz. {[Mn(µ-tp)(3-Ampy)2(H2O)2]2(3-Ampy)·2(H2O)}n (1) and {[Zn(µ-succ)(3-Ampy)2]·2H2O}n (2) (tp = terephthalate, 3-Ampy = 3-aminopyridine, succ = succinate) have been synthesized and characterized using elemental and spectroscopic analyses, TGA and single crystal X-ray diffraction techniques. Uncoordinated 3-AMpy and water molecules of the polymeric co-crystal hydrate 1 are involved in the formation of cyclic tetrameric {(3-Ampy)2(H2O)2} assembly which provide rigidity to the structure. The presence of guest 3-Ampy and water molecules in the voids of supramolecular Mn(II) host tetramer in 1 provides additional reinforcement to the crystal structure. The lattice water molecules of 2 are aggregated via non-covalent interactions to form discrete cyclic {(H2O)4} tetrameric clusters in the crystal structure. Density functional theory (DFT), non-covalent index (NCI) plot and quantum theory of atoms in molecules (QTAIM) computational analyses reveal that the supramolecular H-bonded cyclic tetrameric structure-guiding synthon in 1 and the (H2O)4 cyclic water clusters in 2 have significant energetic contribution towards the stability of the polymers. In vitro anticancer activities of the compounds considering trypan blue and apoptosis assays revealed that the compounds induce concentration dependent cytotoxicity in Dalton’s lymphoma (DL) cancer cells with nominal effects in normal peripheral blood mononuclear cells (PBMC) cells. Comparative analysis reveals that compound 2 induced higher apoptosis in DL cells; which is well consistent with the trypan blue exclusion assay. Molecular docking and pharmacophore modelling studies of the compounds reveal that the compound 2 significantly interacts with the antiapoptotic proteins to establish structure activity relationship (SAR).

Strong proton transfer from phenolic ring to imine functionality in 1D azido and dicyanamido bridged Mn(II) coordination polymers: Synthesis, crystal structure and magnetic studies

In this research, two new 1D coordination polymers of Mn(II), [Mn(LH)2(µ1,5-dca)2]n (1) and [Mn(LH)2(µ1,3-N3)(CH3OH)(N3)]n (2) were synthesized and characterized by elemental analysis, spectroscopic methods, single crystal X-ray analysis and magnetic measurements (LH = Schiff base ligand obtained from the reaction of 2-hydroxy-1-naphthaldehyde and 2-amino-5-chloropyridine). These compounds were synthesized by the reaction of LH, MnCl2·4H2O and NaN(CN)2 (for compound 1) or NaN3 (for compound 2) in 1:1:2 M ratio in methanol. The spectroscopic and structural studies indicated that strong intramolecular proton transfer from naphtholic oxygen to the imine nitrogen is occurred in the ligand and due to this; the nitrogen atom of imine functionality is not coordinated to the metal core. As a result, the ligand is coordinated to the metal core as monodentate neutral ligand. The proton transfer process was attributed to the strong electron withdrawing properties of 5-chloropyridine ring. In the structure of compound 1 and 2, the manganese ions are connected to each other through µ1,5-dca and µ1,3-azide bridges, respectively to form 1D coordination polymers. The magnetic measurements showed the presence of antiferromagnetic interactions between Mn∙∙∙Mn cores in both of the obtained 1D coordination polymers, whereat the exchange interaction is an order of magnitude stronger in azido compared to dicyanamido bridged compound (–3.7 cm−1 vs. –0.30 cm−1).

Evolution from discrete mononuclear complexes to trinuclear linear cluster and 2D coordination polymers of Mn(II) with dihydrazone Schiff bases: Preparation, structure and thermal behavior

Four Mn(II) coordination compounds based on the 2,6-diacetylpyridine bis(isonicotinoylhydrazone) (H2L1) and 2,6-diacetylpyridine bis(nicotinoylhydrazone) (H2L2), were prepared using different synthetic conditions and starting manganese salts: discrete mononuclear [Mn(H2L1)2(H2O)2](NO3)2 (1) and trinuclear [Mn3(H2L1)2(NCS)2Cl4(H2O)2] (2) complexes and two 2D coordination polymers {[Mn3(L1)3(H2O)2]·1.5C2H5OH}n (3) and {[MnL2]·dmf}n (4), where dmf = N,N-dimethylformamide. Single-crystal X-ray diffraction study shows that H2L1 and H2L2, which differ only by para- or meta- position of radicals with respect to the nitrogen atoms in the terminal pyridyl fragments, demonstrate chelate or chelate-bridging coordination mode with N3O2, or N4O2 and N5O2 donor atoms, respectively. The planar-chelate coordination of these ligands provides the pentagonal-bipyramidal surrounding of Mn(II) and the terminal pyridyl moieties promote bridging function and structure expansion in 2–4 as well as octahedral Cl2N4 coordination geometry for one of Mn(II) atoms in the trinuclear complex 2. All compounds have been investigated in the solid state by IR spectroscopy and thermal analysis in order to understand the influence of the inorganic anion presence/absence on the stability of synthesized compounds.

A Zn(II)-Coordination Polymer for the Instantaneous Cleavage of Csp3-Csp3 Bond and Simultaneous Reduction of Ketone to Alcohol.

Two coordination polymers of Zn(II) and Cu(II) with n-butylmalonic acid have been achieved in this work. The crystallographic structural descriptions along with the sedimentary rock-type microstructural morphology of these two coordination polymers (CPs) have been explored. The reactivity of β-hydroxy ketones with these two CPs has also been investigated. The Zn(II)-CP shows a specific reactivity with β-hydroxy ketone at room temperature and in open air conditions. Through a microcolumn-based filtration technique, the Zn(II)-CP shows the capability to break the Csp3-Csp3 σ bonds of β-hydroxy ketone and simultaneously reduce the associated ketone to alcohol. Such conversion has been progressed without the use of any additional external reducing agent and any chemical workup or column chromatographic purification protocol. Other similar type CPs of Cu(II) and Mn(II) with n-butylmalonic acid completely failed to show similar reactivity with β-hydroxy ketone. On the basis of much experimental evidence, the most possible mechanistic pathway of the reactivity between β-hydroxy ketone and Zn(II)-CP has also been proposed through this work.

Metal ion-induced capacitance modulation in near-isostructural complexes-derived electrochromic coordination polymers

Coordination polymers and metal–organic frameworks have attracted immense attention across different fields of science as materials with numerous functional applications. Herein, we report the use of coordination polymers obtained from near-isostructural metal (Mn2+, Fe2+, and Co2+) bipyridine complexes as electrode materials in a symmetric supercapacitor test cell. The variation in the central metal ion (Mn2+ vs. Fe2+ vs. Co2+) in these nearly identical coordination complexes was found to dictate the capacitive performance of the coordination polymers obtained via Pd(II) cross-linking. The central metal ion not only influences the porosity, Brunauer–Emmett–Teller (BET) surface area (6.5 (Mn), 10.4 (Fe), and 29.7 (Co) m2/g), and the areal capacitance, but also the performance parameters such as the cycling stability and charge–discharge kinetics as well as the charge transfer mechanism. A 3:4:5 ratio for the areal capacitance values (9.1 (Mn), 12.2 (Fe), and 15.4 (Co) mF cm−2 at a scan rate of 5 mV/s) corroborates the modulative effect of the metal center. The cycling stabilities of these coordination polymers also followed the same order. At higher current densities (>0.50 mA cm−2), the supercapacitors fabricated from the Mn-coordination polymer were found to charge and discharge at faster rates, whereas those fabricated from Fe- or Co-coordination polymers continued to discharge at similar rates, indicating similar pore volumes for the latter as confirmed by BET surface area measurements. Although the materials used in this study resulted in modest capacitive performance, the possibilities to enhance their surface area and crystallinity is envisaged to result in the development of new, multifunctional non-carbon electrode materials with efficient electrochemical storage characteristics and tunable electro-optical properties.

Similarities and differences between Mn(II) and Zn(II) coordination polymers supported by porphyrin-based ligands: synthesis, structures and nonlinear optical properties.

Four coordination polymers (CPs) Mn-TMPP (1), Zn-TMPP (2), Mn-THPP (3), and Zn-THPP (4) have been synthesized and characterized (H2TMPP = meso-tetrakis (6-methylpyridin-3-yl) porphyrin; H2THPP = meso-tetrakis (6-(hydroxymethyl) pyridin-3-yl) porphyrin). The one-dimensional (1D) chain compound 1 is formed via a head-to-tail connection of the Mn-TMPP unit, wherein the central Mn2+ features a square pyramidal geometry coordinated by four N atoms from the porphyrin skeleton and one additional N atom from an adjacent Mn-TMPP unit. Compound 2 features an octahedral Zn2+ center associated with four N atoms from the porphyrin skeleton to define the equatorial plane and two additional N donors at the axial positions to give a two-dimensional (2D) CP. The 1D chain of 1 and the 2D layer of 2 possess distinctive molecular structures but nearly identical molecular arrangements in their unit cells viewed along all three crystallographic axes. By contrast, Mn- and Zn-based CPs 3 and 4 supported by the THPP ligand share both identical molecular connectivities and crystal packing. In 3/4, each Mn/Zn center is chelated by four N donors of the porphyrin interior to define the equatorial plane of an octahedron, whose axial sites are occupied by two alcoholic OH groups from a pair of trans-located pyridinemethanol moieties. The third-order nonlinear optical properties of 1-4 investigated using the Z-scan technique at 532 nm revealed reverse saturable absorption and self-focusing effects for all four CPs, with hyperpolarizability values (γ) in the range 1.42 × 10-28 esu to 7.64 × 10-28 esu. These high γ values are comparable to the best porphyrin-based molecular assemblies, demonstrating potential for these materials in optical limiting applications.

Ce-Mn coordination polymer derived hierarchical/porous structured CeO2-MnOx for enhanced catalytic properties.

Catalytic performance is largely dependent on how the structures/compositions of materials are designed. Herein, CeO2-MnOx binary oxide catalysts with a hierarchical/porous structure are prepared by a facile and efficient method, which involves the preparation of the hierarchical Ce-Mn coordination polymer (CPs) precursor, followed by a thermal treatment step. The obtained CeO2-MnOx catalysts not only well inherit the hierarchical structure of Ce-Mn CPs, but also possess porous and hollow features due to the removal of organic ligands and heterogeneous contraction during the calcination process. In addition, the effect of the Mn/Ce ratio is also studied to optimize catalytic performance. Specifically, the as-prepared CeO2-MnOx (5 : 5) catalyst exhibits excellent catalytic performance toward CO oxidation and selective catalytic reduction (SCR) of NO with NH3 at low temperatures. Based on the characterization results, we propose that the special hierarchical structure, high surface area, strong synergistic interaction between CeO2 and MnOx, and high content of active Ce3+, Mn4+ and Osurf are collectively responsible for its remarkable catalytic performance.

Design and development of several polymeric metal–organic frameworks, spectral characterization, and their antimicrobial activity

Coordination polymers were obtained by the reaction of metal acetates, M(CH 3 COO) 2 · x H 2 O {where M = Mn(II), Co(II), Ni(II) and Cu(II)} with AFP ligand (AFP = 5,5'-(piperazine-1,4-diylbis(methylene))bis(2-aminobenzoic acid). The AFP ligand was prepared by the one-pot, two-step reaction of formaldehyde, 2-aminobenzoic acid, and piperazine. Structural and spectroscopic properties have been studied by elemental, spectral (FT-IR, 1 H NMR, 13 C NMR, and UV–vis), and thermogravimetric analysis. UV–vis spectra and magnetic moment values indicate that Mn(II), Co(II), and Ni(II) polymer–metal complexes are octahedral, while Cu(II) and Zn(II) polymer–metal complexes are distorted octahedral and tetrahedral, respectively. The analytical data confirmed that the coordination polymers of Mn(II), Co(II), Ni(II), and Cu(II) are coordinated with two water molecules, which are further supported by infrared spectra and thermogravimetric analysis data. The prepared polymer–metal complexes showed good antibacterial activities against all tested microorganisms; however, the AFP ligand was also found to be effective, but relatively less than their polymer–metal complexes. Along with antibacterial activity, all the polymer–metal complexes exhibit significant antifungal activity against most of the tested fungal strains. The results of antimicrobial activity reveals that the AFP–Cu(II) showed the highest antibacterial and antifungal activity than other polymer–metal complexes. • AFP ligand derived from 2-aminobenzoic acid, formaldehyde, and piperazine. • Coordination polymers of M(II) ions were obtained by the reaction of metal acetates with AFP ligand. • Characterization was done by various spectroscopic techniques. • The antimicrobial activity of the AFP ligand and their polymer–metal complexes were evaluated.

Synthesis, Solid State Characterization and Thermal Aspects of Coordination Polymers of Some Transition Metal Ions with Sebacoyl bis(isonicotinoylhydrazone)

A series of coordination polymers of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from sebacoyl bis(isonicotinoylhydrazone) (SEBI) ligand and metal salts. The coordination polymers have been characterized using elemental analyses, magnetic susceptibility measurements, spectral (electronic and infrared) studies, powder XRD and thermal analyses. The IR spectral data suggest that sebacoyl bis(isonicotinoylhydrazone) behaves as an octadentate chelating ligand. On the basis of electronic spectral studies and magnetic moment values, an octahedral geometry has been assigned to Mn(II), Co(II), Ni(II) and Cu(II) coordination polymers while tetrahedral geometry to Zn(II) coordination polymer. The thermogravimetric analyses of parent ligand and its metal chelates have shown remarkable differences in mode of thermal decomposition and their thermal stabilities.

Synthesis, spectral characterization and thermal aspects of coordination polymers of some transition metal ions with adipoyl bis(isonicotinoylhydrazone)

A series of metal coordination polymers of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), obtained by the reaction of metal acetate with newly synthesized adipoyl bis(isonicotinoylhydrazone) (ADBI) have been investigated. The ligand has been characterized by 1H NMR, 13C NMR, FTIR, and ESI mass spectra. Structural and spectroscopic characterization of the coordination polymers have been carried out using elemental analysis, XRD, SEM, infrared and diffused reflectance spectra, magnetic susceptibility measurements and thermogravimetric analytical techniques. Each metal ion is coordinated to the ligand through oxygen of carbonyl group and the nitrogen of azomethine group of ligand forming a stable 5-membered heterocyclic ring. The synthesized ligand coordinates in an octadentate manner. Magnetic and diffused reflectance spectral studies reveal octahedral geometry of Co(II), Cu(II), Fe(II) and Ni(II) coordination polymers and tetrahedral geometry of Mn(II) and Zn(II) coordination polymers. The thermal stability and decomposition steps of all coordination polymers have been studied using TG, DTG and DTA techniques. Moreover, the kinetic parameters such as activation energy (Ea*), order of reaction (n), Arrhenius factor (A), change in entropy (ΔS*), change in enthalpy (ΔH*) and free energy change (ΔG*) were evaluated at each stage of decomposition curve using Coats-Redfern method.

Modification of the structure and magnetic properties of fumarato-bridged Mn coordination polymers through different dimethyl-2,2′-bipyridine co-ligands

Manganese coordination polymers {Mn(fum)(5dmb)(H2O)2} n (1) and {[Mn2(fum)2(4dmb)2]·H2O} n (2) (fum = fumarato; 5dmb = 5,5′-dimethyl-2,2′-bipyridine; 4dmb = 4,4′-dimethyl-2,2′-bipyridine) were obtained from one-pot, solution reactions under ambient conditions. The fum ligand acquires different coordination modes in the presence of the different dmb ancillary ligands, promoting distinctive crystal structures, including divergent dimensionalities. Thus, X-ray single-crystal data reveal that complex 1 crystallizes in a monoclinic system with C2/c space group and forms an infinite one-dimensional polymer. The Mn(II) center is six-coordinated and displays a distorted octahedral configuration. In addition, the solid-state self-assembly of the polymeric structure of 1 gives rise to a two-dimensional (2D) supramolecular framework, mainly through hydrogen bonding. In contrast, complex 2 crystallizes in a monoclinic system with a Cc space group and forms an infinite 2D coordination polymer having dinuclear units. The Mn(II) center has a distorted octahedral configuration. The thermal stabilities of both coordination polymers were investigated. Variable-temperature magnetic measurements show that complex 1 is paramagnetic, while complex 2 exhibits weak antiferromagnetic coupling between adjacent Mn(II) centers.

Syntheses, crystal structures and magnetic studies of new manganese(II) coordination polymers with ditopic N-pyridinylisonicotinohydrazide ligand and dicyanamide

Two new coordination polymers of Mn(II) with dicyanamide anion (dca) and isonicotinohydrazone based ligands, {[Mn2(L1)2(dca)2(CH3OH)2]·H2O}n (1) and [Mn2(L2)2(μ-dca)2]n (2), were synthesized and characterized by elemental analyses and spectroscopic methods where HL1=(E)-N′-(phenyl(pyridin-2-yl)methylene)isonicotinohydrazide and HL2=(E)-N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide. The IR spectra of 1 and 2 show the characteristic stretching vibration bands of a dicyanamide ligand as three bands. Structures of the compounds were characterized by X-ray diffraction analysis which indicates that the isonicotinohydrazone ligands act as a ditopic ligand and coordinate to manganese ions via the N2O-donor set and pyridine group of the isonicotine part. The magnetic susceptibility measurements studies indicated the presence of an antiferromagnetic coupling between high spin Mn(II) ions. Antiferromagnetic coupling for 2 is stronger than that of 1 which is due to connection of Mn(II) ions through dicyanamide bridges in the former.

A novel Mn(II) complex with 3-(2,5-dicarboxyl)-5-carboxylpyridine: Synthesis, crystal structure, and interaction with DNA

A novel Mn coordination polymer, {[Mn2(L)6] · 2H2O}n, has been synthesized by the reaction of C4H6MnO4 · 4H2O (manganese acetate) with 3-(2,5-dicarboxyl)-5-carboxylpyridine (L). Elemental analysis, IR spectra, thermal analyses, and X-ray single crystal diffraction (CIF file CCDC no. 1061752) were carried out to determine the composition and crystal structure of the complex. The polymer was characterized by UV spectrum, fluorescence spectrum showing that the complex has the ability of interaction with DNA, Gel electrophoresis assay demonstrated the ability of the complex to cleave the HL-60 DNA (HL-60 DNA, which was extracted by ourselves). Further more, the apoptotic test indicates that the complex has an apoptotic effect on JEKO.

Synthesis, structure and magnetic property of a Gd–Mn coordination polymer based on 2,3,5-pyrazinetricarboxylate

A new three-dimensional lanthanide–manganese metal–organic framework [Gd2Mn3(PZTC)4(H2O)12]·5H2O (PZTC=2,3,5-Pyrazinetricarboxylate) has been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, and X-ray diffraction. Single-crystal X-ray diffraction shows that Gd3+ and Mn2+ ions are linked together to form a porous 3D Gd–Mn MOF by the alternative arrangement of two kinds of PZTC3− ligands. Taking the Gd, Mn and PZTC as node, the Schläfli symbol of the topology can be expressed as {4;82}2{42;6}2{42;84}2{43;6;84;102}2{8}. Magnetic study indicates the magnetic coupling between two Mn2+ ions through double monatomic carboxylate–oxo bridges is weak antiferromagnetic, while that between Gd3+ and Mn2+ ions through the carboxylate group in syn–anti-bridging mode is negligible.

Synthesis, characterisation and thermal degradation behaviour of some coordination polymers by using TG–DTG and DTA techniques

The four chelate polymer complexes commonly called as coordination polymers of Mn(II), Co(II), Ni(II) and Cu(II) ions with fbpmpc (fbpmpc=fumaroyl bis (paramethoxyphenylcarbamide)) were synthesized and characterised by elemental analyses, infrared spectroscopy, diffuse reflectance, magnetic moment susceptibility, thermal analysis, X-ray diffraction, electrical conductivity and scanning electron microscopy technique (SEM). SEM investigations of coordination polymers were found in different shapes and sizes, though they are synthesized from a single ligand. Each metal ion is coordinated by a bis (bidentate) manner through oxygen atom of the carboxylato group and the nitrogen atom of an amide group of ligand and two aqua ligands by coordinated bond which formed 6-member heterocyclic ring. In the present article, the main aim of research study is to find out the comparative studies of coordination polymers such as thermogravimetry (TG), derivative thermogravimetry (DTG), differential thermal analysis (DTA), electrical conductivity and morphology behaviour. Furthermore, the electrical conductivities of chelating ligand and coordination polymers were determined in the solid state powder form. The electrical conductivities measurements of undoped and doped ligand, coordination polymers were carried out at room temperature by the four probe technique using an electrometer. Thermal degradation studies of the coordination polymers have been carried out from a non-isothermal condition under nitrogen atmosphere at a heating rate of 10°Cmin−1. The decomposition steps and thermal stabilities of these complexes were confirmed by thermal analysis techniques (TG/DTG/DTA). The thermal studies inferred the presence of crystallized water in all coordination polymers, whereas coordinated water was found in Ni(II) and Cu(II) ions.

The effects of halogen bonding and molecular design on the self-assembly of coordination polymers of Mn(iii)-tetraarylporphyrin with axial bridging ligands

Two new coordination polymers of Mn(iii)-tetra(iodophenyl)porphyrin with isonicotinate and pyrimidine-5-carboxylate linkers have been synthesized. The effect of halogen-bonding interactions on their self-assembly in the crystalline bulk and on a graphite surface has been discussed.

Two New Coordination Polymers of Manganese(II) with O/O- and N/O-Donor Ligands: Synthesis, Structure, Luminescence Study and Thermal Behavior

Two new coordination polymers of Mn(II), of formula C12H18MnN8O6 (1) and C21H16MnO9 (2), have been synthesized by using two different kind of ligands, namely 5-methyl-7-oxo-(1,2,4)triazolo(1,5-a)pyrimidine (HmtpO) and 3-(2-furyl)prop-2-enoic acid (fproH). The X-ray single crystal structure analysis shows that complex 1 is a discrete molecular complex that turns into a 3D network through hydrogen bonding and π–π stacking interactions. Complex 2 is 1D polymeric chain comprising hexacoordinated Mn(II) centers. Luminescence study revealed the presence of intraligand π*–π transitions. The thermal stability of the complexes has been also investigated by thermogravimetric analysis. Two new coordination polymer of Mn(II) have been synthesized. X-ray single crystal structure analysis revealed that complex 1 is 3D via supramolecular interactions and complex 2 is a 1D chain. Luminescence and thermal characterization has been done for the complexes.