Influence of the Crystallization Solvent on the Molecular Structures of Copper(II) Saccharinato Complexes with Pyridazine: Synthesis, X-Ray Crystallography, Spectroscopy, Photoluminescence, and Thermal Properties

2008 ◽  
Vol 61 (8) ◽  
pp. 634 ◽  
Author(s):  
Veysel T. Yilmaz ◽  
Evrim Senel ◽  
Canan Kazak

X-Ray structural analysis has shown that the products of the reaction of [Cu(sac)2(H2O)4]·2H2O (sac = saccharinate) with pyridazine (pydz) are markedly dependent on the solvent used in the crystallization. The mononuclear complex [Cu(sac)2(H2O)(pydz)2] is obtained by slow evaporation of a 1:2 H2O/methanol solution at room temperature, whereas liquid-phase diffusion of diethyl ether into the same reaction solution produces the polymeric complex [Cu(μ-OH)(μ-sac)(μ-pydz)]n. The individual molecules of [Cu(sac)2(H2O)(pydz)2] are doubly bridged into dimers by O–H…O hydrogen bonds. All ligands in [Cu(sac)2(H2O)(pydz)2] are monodentate, whereas copper(ii) ions in [Cu(μ-OH)(μ-sac)(μ-pydz)]n are triply bridged by all ligands, leading to a one-dimensional chain structure, which is further assembled to form a three-dimensional framework by non-covalent π–π and CH–π stacking interactions. Complex [Cu(sac)2(H2O)(pydz)2] is paramagnetic, whereas complex [Cu(μ-OH)(μ-sac)(μ-pydz)]n exhibits a significantly low μeffective value due to very strong exchange coupling between the copper atoms with a relatively short Cu–Cu distance of 3.360(3) Å. In addition, the full spectroscopic, luminescence, and thermal properties of the complexes are reported.

2017 ◽  
Vol 41 (6) ◽  
pp. 365-369 ◽  
Author(s):  
Chongchong Xue ◽  
Jingwen Shi ◽  
Daopeng Zhang

The coordination polymers {Mg[Fe(L)(CN)5]}n·0.5nH2O and {MgCu2(CH3COO)6}n [L = bis( N-imidazolyl)methane] have been synthesised. X-ray diffraction revealed that {Mg[Fe(L)(CN)5]}n·0.5nH2O has a one-dimensional neutral chain structure consisting of alternating [Mg(L)2(H2O)2)]2+ species and [Fe(L)(CN)5]2– building blocks, which can be further linked into a three-dimensional supramolecular structure by inter-chain p–p interactions. {MgCu2(CH3COO)6}n has a three-dimensional network with the [MgCu2(CH3COO)6] unit as neutral core extended by Mg–O bonds. Magnetic susceptibility studies on {MgCu2(CH3COO)6}n revealed antiferromagnetic interactions between adjacent Cu(II) ions.


1984 ◽  
Vol 37 (10) ◽  
pp. 1991 ◽  
Author(s):  
SW Cowan ◽  
BF Hoskins ◽  
ERT Tiekink

The crystal and molecular structures of the title compounds, (C6H11)2PC(S)N(H)C6H5(1) and (C6H5)2PC(S)N(H)C6H5(2) have been determined by single-crystal three-dimensional X-ray diffraction techniques. Crystals of (1) are monoclinic, space group P21/c, with eight molecules in the unit cell of dimensions a 20.541(4), b 17.784(2), c 10.2564(9) � and β 94.54(1)�; (2) crystallizes in the triclinic space group P1 with two molecules in the unit cell which has the dimensions a 9.242(2), b 9.994(3), c 10.373(3) �, α 68.56(2), β 71.21(2) and γ 86.00(2)�. Both structures were refined by a least-squares procedure, applying anisotropic thermal parameters to all non-hydrogen atoms, with the use of 3119 and 2971 statistically significant reflections for (1) and (2) respectively; final R 0.055 for (1) and R 0.061 (Rw 0.062) for (2). The N, C(l), S moieties of both (1) and (2) display features consistent with the delocalization of π-electrons. There are notable differences in some of the bond angles between (I) and (2) which have been attributed to conformational effects arising from variations in steric pressures; this may account for the observed differences in reactivity between the two compounds.


Author(s):  
Yu-Jin Cui ◽  
Feng Su ◽  
Wei-Jun Jin

Two new co-crystals, tetraiodoethylene–phenanthridine (1/2), 0.5C2I4·C13H9N (1) and tetraiodoethylene–benzo[f]quinoline (1/2), 0.5C2I4·C13H9N (2), were obtained from tetraiodoethylene and azaphenanthrenes, and characterized by IR and fluorescence spectroscopy, elemental analysis and X-ray crystallography. In the crystal structures, C—I...π and C—I...N halogen bonds link the independent molecules into one-dimensional chains and two-dimensional networks with subloops. In addition, the planar azaphenanthrenes lend themselves to π–π stacking and C—H...π interactions, leading to a diversity of supramolecular three-dimensional structural motifs being formed by these interactions. Luminescence studies show that co-crystals 1 and 2 exhibit distinctly different luminescence properties in the solid state at room temperature.


2019 ◽  
Vol 75 (8) ◽  
pp. 1142-1149 ◽  
Author(s):  
Zhi-Chao Shao ◽  
Xiang-Ru Meng ◽  
Hong-Wei Hou

Changing the pH value of a reaction system can result in polymers with very different compositions and architectures. Two new coordination polymers based on 1,1′-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium) (L 2−), namely catena-poly[[[tetraaquacadmium(II)]-μ2-1,1′-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium)] 1.66-hydrate], {[Cd(C22H14N2O8)(H2O)4]·1.66H2O} n , (I), and poly[{μ6-1,1′-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium)}cadmium(II)], [Cd(C22H14N2O8)] n , (II), have been prepared in the presence of NaOH or HNO3 and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each CdII ion is coordinated by two halves of independent L 2− ligands, forming a one-dimensional chain structure. In the crystal, these chains are further connected through O—H...O hydrogen bonds, leading to a three-dimensional hydrogen-bonded network. In polymer (II), each hexadentate L 2− ligand coordinates to six CdII ions, resulting in a three-dimensional network structure, in which all of the CdII ions and L 2− ligands are equivalent, respectively. The IR spectra, thermogravimetric analyses and fluorescence properties of both reported compounds were investigated.


Author(s):  
S. Cusack ◽  
J.-C. Jésior

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).


2020 ◽  
Vol 75 (9-10) ◽  
pp. 851-857
Author(s):  
Chong Chen ◽  
Fule Wu ◽  
Jiao Ji ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.


1988 ◽  
Vol 21 (4) ◽  
pp. 429-477 ◽  
Author(s):  
W. Kühlbrandt

As recently as 10 years ago, the prospect of solving the structure of any membrane protein by X-ray crystallography seemed remote. Since then, the threedimensional (3-D) structures of two membrane protein complexes, the bacterial photosynthetic reaction centres of Rhodopseudomonas viridis (Deisenhofer et al. 1984, 1985) and of Rhodobacter sphaeroides (Allen et al. 1986, 1987 a, 6; Chang et al. 1986) have been determined at high resolution. This astonishing progress would not have been possible without the pioneering work of Michel and Garavito who first succeeded in growing 3-D crystals of the membrane proteins bacteriorhodopsin (Michel & Oesterhelt, 1980) and matrix porin (Garavito & Rosenbusch, 1980). X-ray crystallography is still the only routine method for determining the 3-D structures of biological macromolecules at high resolution and well-ordered 3-D crystals of sufficient size are the essential prerequisite.


2020 ◽  
Vol 75 (4) ◽  
pp. 341-345
Author(s):  
Xiao-Li Liu ◽  
Jing-Long Liu ◽  
Hong-Mei Yang ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang

AbstractCo-crystallization of C-propyl-pyrogallol[4]arene (PgC3) with 4,4′-bipyridine (bpy) in ethanol afforded a multi-component complex (PgC3) · 3(bpy) ·(EtOH) (1) that consists of a one-dimensional brick-wall framework, which was formed by four pyrogallol[4]arene molecules and two juxtaposed bpy molecules, entrapping two other bpy molecules as guests within each cavity. Heating a mixture of PgC3 and trans-1,2-bis-(4-pyridyl)ethylene (bpe) in an ethanol-water mixed solvent allowed the isolation of a multi-component complex (PgC3) ·(bpe) · 2(EtOH) ·(H2O) (2), which has a two-dimensional wave-like polymer structure with the bpe molecules embedded in the wave trough between two PgC3 molecules. Single-crystal X-ray crystallography was utilized to investigate the hydrogen bonding networks of the multi-component complexes 1 and 2.


2021 ◽  
Vol 28 (3) ◽  
Author(s):  
A. M. Kalitenko

A numerical study of the effect of betatron oscillations on the second harmonic generation in free-electron lasers (FELs) is presented. Analytical expressions for the effective coupling strength factors are derived that clearly distinguish all contributions in subharmonics and each polarization of the radiation. A three-dimensional time-dependent numerical FEL code that takes into account the main FEL effects and the individual contribution of each electron to the second harmonic generation is presented. Also, the X- and Y-polarizations of the second harmonic are analyzed. The second harmonic was detected in experiments at the Advanced Photon Source (APS) Low Energy Undulator Test Line (LEUTL) and Linac Coherent Light Source (LCLS) in the soft X-ray regime. The approach presented in the article can be useful for a comprehensive study and diagnostics of XFELs. In the paper, the LCLS and Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL) experiments are modeled. The simulation results are in a good agreement with the experimental data.


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