Crystal structures of zinc(II) complexes with β-hydroxypyridinecarboxylate ligands: examples of structure-directing effects used in inorganic crystal engineering

The coordination properties of four hydroxypyridinecarboxylates, designed for the treatment of iron-overloading conditions as bidentate O,O′-donor ligands, have been studied with ZnII in the solid state. The coordination compounds [Zn(A1)2(H2O)2] (1), [Zn(A2)2(H2O)] (2), [Zn(A3)2(H2O)]·2H2O (3) and [Zn2(B1)4(H2O)2]·4H2O (4), where the ligands are 1-methyl-4-oxidopyridinium-3-carboxylate (A1, C7H6NO3), 1,6-dimethyl-4-oxidopyridinium-3-carboxylate (A2, C8H8NO3), 1,5-dimethyl-4-oxido-pyridinium-3-carboxylate (A3, C8H8NO3) and 1-methyl-3-oxidopyridinium-4-carboxylate (B1, C7H6NO3), have been synthesized and analysed by single-crystal X-ray diffraction. The ligands were chosen to probe (i) the electronic effects of inverting the positions of the O-atom donor groups (i.e. A1 versus B1) and (ii) the electronic and steric effects of the addition of a second methyl group in different positions on the pyridine ring. Two axially coordinated water molecules resulting in a six-coordinated symmetrical octahedron complement the bis-ligand complex of A1. Ligands A2 and A3 form five-coordinated trigonal bipyramidal complexes with one additional water molecule in the coordination sphere, which is a rarely reported geometry for ZnII complexes. Ligand B1 shows a dimeric structure, where the two Zn2+ dications have slightly distorted octahedral geometry and the pyridinolate O atom of the neighbouring complex bridges them. The coordination spheres of the Zn2+ dications and the supramolecular structures are discussed in detail. The packing arrangements of 1–3 are similar, having alternating hydrophilic and hydrophobic layers, however the similarity is broken in 4. The obtained coordination geometries are compared with their previously determined CuII analogues. The study of the individual complexes is complemented with a comprehensive analysis of ZnII complexes with oxygen donor ligands with data from the Cambridge Structural Database.

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Synthesis, Characterization, and Ethylene Oligomerization and Polymerization by 2-Quinoxalinyl-6-iminopyridine Chromium Chlorides

Australian Journal of Chemistry ◽

10.1071/ch08016 ◽

2008 ◽

Vol 61 (5) ◽

pp. 397 ◽

Cited By ~ 21

Author(s):

Saliu A. Amolegbe ◽

Maliha Asma ◽

Min Zhang ◽

Gang Li ◽

Wen-Hua Sun

Keyword(s):

High Selectivity ◽

Ethylene Oligomerization ◽

Distorted Octahedral Geometry ◽

Electronic Effects ◽

X Ray Diffraction ◽

Reaction Conditions ◽

Co Catalyst ◽

X Ray ◽

Catalytic Activities ◽

Distorted Octahedral

A series of chromium(iii) complexes ligated by N^N^N tridentate 2-quinoxalinyl-6-iminopyridine were synthesized and characterized by elemental analysis and infrared spectroscopy. Single-crystal X-ray diffraction analysis for the structure of complex C3 reveals a distorted octahedral geometry. When methylaluminoxane was employed as the co-catalyst, the chromium complexes showed high activities for ethylene oligomerization and polymerization. The distribution of oligomers obtained followed Schulz–Flory rules with high selectivity for α-olefins. Both steric and electronic effects of coordinated ligands affected the catalytic activities as well as the properties of the catalytic products. The parameters of the reaction conditions were also investigated to explore the optimum catalytic potentials of these complexes.

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Zinc Barbiturate Complexes with Bidentate N-Donor Ligands: Syntheses, Crystal Structures, Spectroscopic, Thermal and Voltammetric Studies

Zeitschrift für Naturforschung B ◽

10.1515/znb-2006-0306 ◽

2006 ◽

Vol 61 (3) ◽

pp. 275-280 ◽

Cited By ~ 14

Author(s):

Fatih Yilmaz ◽

Veysel T. Yilmaz ◽

Ender Bicer ◽

Orhan Büyükgüngör

Keyword(s):

Hydrogen Bonds ◽

Zinc Ion ◽

Carbonyl Oxygen ◽

Donor Ligands ◽

Distorted Octahedral Geometry ◽

Cyclic Voltammogram ◽

X Ray Diffraction ◽

Hydrogen Atoms ◽

Space Groups ◽

Voltammetric Behavior

Abstract Two new bis(5,5-diethylbarbiturato) (barb) complexes of zinc, [Zn(barb)2(en)] (1) and [Zn(barb)2(bpy)] ・H2O (2) [en = ethylenediamine, bpy = 2,2’-bipyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in monoclinic space groups. The zinc(II) ions in complex 1 are tetrahedrally coordinated by two barb and an en ligand. The barb ligands are N-coordinated while the en ligand acts as a bidentate chelating ligand. One carbonyl oxygen atom of each barb ligands in complex 2 participates in the bonding with the zinc ion with remarkably long Zn-O bonds resulting in a highly distorted octahedral geometry. Molecules of complex 1 are connected via N-H ···O hydrogen bonds, involving hydrogen atoms of both barb and en ligands, while molecules of complex 2 are linked by N-H ···O and O-H ···O hydrogen bonds and also aromatic π(bpy) ···π(bpy) stacking interactions. The voltammetric behavior of complexes 1 and 2 was investigated in aqueous solution by cyclic voltammetry using a NH3/NH4Cl buffer. The cyclic voltammogram of 1 shows a cathodic peak at −1.260 V and an anodic peak at −1.068 V due to a quasi-reversible two-electron process. Complex 2 yields two reduction peaks at −1.312 and −1.412 V. The former corresponds to a quasi-reversible electrode process of the zinc(II) ions in complex 2, while the latter is attributed to the reduction of the coordinated bpy ligands.

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Synthesis and structural elucidation of new complexes of 2,4- and 3,5-dimethyl diphenyldithiophosphates with cobalt(II)

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s205252061500390x ◽

2015 ◽

Vol 71 (2) ◽

pp. 221-227 ◽

Cited By ~ 2

Author(s):

Sandeep Kumar ◽

Ruchi Khajuria ◽

Amanpreet Kaur Jassal ◽

Maninder S. Hundal ◽

Sushil K. Pandey

Keyword(s):

Chelate Ring ◽

Bidentate Ligand ◽

Donor Ligands ◽

Distorted Octahedral Geometry ◽

X Ray Diffraction ◽

Triclinic Space Group ◽

X Ray ◽

Space Groups ◽

Distorted Octahedral ◽

Elemental Analyses

A new series of donor-stabilized addition complexes of cobalt(II) with disubstituted diphenyldithiophosphates [{(ArO)2PS2}2CoL2] {Ar = 2,4-(CH3)2C6H3[(1)–(3)] and 3,5-(CH3)2C6H3[(4)–(6)];L= C5H5N [(1), (4)], 3,4-(CH3)2C5H3N [(2), (5)] and 4-(C2H5)C5H4N [(3), (6)]} were successfully isolated and characterized by elemental analyses, magnetic moment measurements, IR and single-crystal X-ray analysis. Complexes (3), (4) and (5) crystallize in the monoclinic space groupsP21/n,P21/nandP21/c, respectively, whereas complex (6) crystallizes in the triclinic space group P\bar 1. X-ray diffraction analysis of complexes (3)–(6) reveals a six-coordinated distorted octahedral geometry for the CoS4N2chromophore defined by two chelating diphenyldithiophosphate anions as well as two N-donor ligands. Two diphenyldithiophosphate ligands are coordinated to the cobalt ion as a bidentate ligand chelatingviathe two thiolate S atoms. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Co atom in a mutuallytransposition.

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Xenon Trioxide Adducts of O-Donor Ligands; [(CH3)2CO]3XeO3, [(CH3)2SO]3(XeO3)2, (C5H5NO)3(XeO3)2, and [(C6H5)3PO]2XeO3

10.26434/chemrxiv.7092263.v1 ◽

2018 ◽

Author(s):

Katherine Marczenko ◽

James Goettel ◽

Gary Schrobilgen

Keyword(s):

Room Temperature ◽

Triphenylphosphine Oxide ◽

Donor Ligands ◽

Mechanical Shock ◽

X Ray Diffraction ◽

X Ray ◽

Oxygen Coordination ◽

Xenon Trioxide ◽

Distorted Octahedra ◽

Coordination Spheres

Oxygen coordination to the Xe(VI) atom of XeO3 was observed in its adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine-N-oxide, and acetone. The crystalline adducts were characterized by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Unlike solid XeO3, which detonates when mechanically or thermally shocked, the solid [(C6H5)3PO]2XeO3, [(CH3)2SO]3(XeO3)2, and (C5H5NO)3(XeO3)2 adducts are insensitive to mechanical shock, but undergo rapid deflagration when ignited by a flame. Both [(C6H5)3PO]2XeO3 and (C5H5NO)3(XeO3)2 are air-stable whereas [(CH3)2SO]3(XeO3)2 slowly decomposes over several days and [(CH3)2CO]3XeO3 undergoes adduct dissociation at room temperature. The xenon coordination sphere of [(C6H5)3PO]2XeO3 is a distorted square pyramid which provides the first example of a five-coordinate XeO3 adduct. The xenon coordination spheres of the remaining adducts are distorted octahedra comprised of three Xe---O secondary contacts that are approximately trans to the primary Xe–O bonds of XeO3. Quantum-chemical calculations were used to assess the Xe---O adduct bonds, which are predominantly electrostatic σ-hole bonds between the nucleophilic oxygen atoms of the bases and the σ-holes of the xenon atoms.

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Two mixed-ligand coordination polymers based on 2,5-thiophenedicarboxylic acid and flexible N-donor ligands: the protective effect on periodontitis via reducing the release of IL-1β and TNF-α

Open Chemistry ◽

10.1515/chem-2020-0081 ◽

2020 ◽

Vol 18 (1) ◽

pp. 391-398

Author(s):

Shao-Hsuan Wu ◽

Jun-Hui Huang

Keyword(s):

Coordination Polymers ◽

Gingival Crevicular Fluid ◽

Mixed Ligand ◽

Donor Ligands ◽

X Ray Diffraction ◽

Functional Studies ◽

Tnf Α ◽

Mucosal Cells ◽

Ligand Coordination ◽

Crevicular Fluid

AbstractTwo novel mixed-ligand coordination polymers, {[Co(tdc)(btrp)]·0.67DMF}n (1) and {[Zn2(bimb)2(tdc)2]·2H2O}n (2) involving 2,5-thiophenedicarboxylate (H2tdc), and bitopic flexible N-donor ligands, 1,3-bis(1,2,4-triazol-1-yl)propane (btrp) and 1,4-bis((1H-benzo[d]imidazol-1-yl)methyl)benzene (bimb), have been synthesized by the hydrothermal method and characterized via IR, elemental analysis, thermal analysis, and powder X-ray diffraction. The biological functional studies were performed; the treatment activity of the compounds on periodontitis and the specific mechanism was explored. First, the real-time RT-PCR was carried out to determine the inflammatory genes nf-κb and p53 relative expression in periodontal mucosal cells after treating with compounds 1 and 2. Then, the level of the inflammatory cytokine in the gingival crevicular fluid after treating with compounds was also determined by the ELISA detection kit.

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Synthesis and Characterization of Copper (II) Complexes with Some Nitrogen-Oxygen Donor Ligands

Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry ◽

10.1080/00945718608071383 ◽

1986 ◽

Vol 16 (8) ◽

pp. 1089-1101 ◽

Cited By ~ 8

Author(s):

Y. Kumar ◽

M. Sharma ◽

R. P. Singh ◽

S. Chandra

Keyword(s):

Donor Ligands ◽

Synthesis And Characterization ◽

Oxygen Donor

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Strain Measurement by X-ray Diffraction Methods

Aeronautical Quarterly ◽

10.1017/s0001925900000160 ◽

1949 ◽

Vol 1 (3) ◽

pp. 211-224

Author(s):

G. B. Greenough

Keyword(s):

Strain Measurement ◽

Plastic Anisotropy ◽

Stress And Strain ◽

Routine Method ◽

X Ray Diffraction ◽

Strain Measurements ◽

X Ray ◽

The Past ◽

Polycrystalline Metals ◽

The Individual

SummaryMany papers have been written on the measurement of strain by X-ray diffraction methods and on the interpretation of these strains in terms of stresses. Whereas, during the past few years, the experimental methods of determining the strains have. remained largely unchanged, research has shown that the older techniques for calculating stresses from strains are not always valid.In this paper an attempt is made to describe some of the principles of strain measurement by X-ray diffraction methods to those who are unfamiliar with the methods. The types of stress and strain systems which may exist in polycrystalline metals are then considered, particular attention being paid to the effect of the elastic and plastic anisotropy of the individual crystals. Some indication is given as to how the earlier methods of interpreting X-ray strain measurements should be modified, but no rigid routine method is proposed for use in a general case.

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Characterization of bulk crystals of transition metal doped ZnO for spintronic applications

MRS Proceedings ◽

10.1557/proc-799-z8.6 ◽

2003 ◽

Vol 799 ◽

Cited By ~ 2

Author(s):

M. H. Kane ◽

R. Varatharajan ◽

Z. C. Feng ◽

S. Kandoor ◽

J. Nause ◽

...

Keyword(s):

Transition Metal ◽

Lattice Parameter ◽

X Ray Diffraction ◽

Absorption Bands ◽

Growth Technique ◽

Undoped Material ◽

Doped Zno ◽

Metal Doped ◽

The Individual

ABSTRACTIn this work, we report on the material properties of ZnO doped with Mn, Co, and Fe grown by a modified melt growth technique. X-ray diffraction measurements show that transition metals can be incorporated on Zn sites; an increase in the lattice parameter is apparent with increasing doping level. UV-visible transmission and reflectance measurements have also been performed. Absorption bands in the visible regime are distinctive to the individual transition metal dopants. A noticeable shift in the optical band edge has been observed from these Mn/Co/Fe-doped ZnO crystals in comparison with the undoped material. ZnO may also provide a suitable platform for the incorporation of transition metal elements through high temperature near equilibrium growth processes; however, further work is required in order to employ these materials for spintronic applications.

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