scholarly journals Double Palindrome Water Chain in Cu(II) Theophylline Complex. Synthesis, Characterization, Biological Activity of Cu(II), Zn(II) Complexes with Theophylline

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 97 ◽  
Author(s):  
Michał Gacki ◽  
Karolina Kafarska ◽  
Anna Pietrzak ◽  
Izabela Korona-Głowniak ◽  
Wojciech M. Wolf

Two metal complexes of theophylline were synthesized. Namely, 1 with the formula [Cu(theop)2(H2O)3]·2H2O and 2, [Zn(theop)2]∙H2O (where: theop = theophylline ion). Their properties were thoroughly investigated by the elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) that were augmented by antimicrobial and antioxidant analyses. Their radical scavenging ability (RSA) is notably higher than that of a pure theophylline itself. Similarly to theophylline complexes already studied by us 3, [Mn(theop)2(H2O)4] 4, [Co(theop)2(H2O)4] and 5, [Ni(theop)2(H2O)4] title compounds are inactive against Gram-negative bacteria, but they show moderate or mild activity against Gram-positive rods. The low temperature, single crystal X-ray diffraction technique determines the crystal structure of 1. Its supramolecular crystal topology is affected by the unique, double palindrome water chain that formed by two conserved and a sole coordinated water molecules. Crystal packing arrangements were characterized by fingerprint plots that were derived from the Hirshfeld surfaces (HS), as calculated for all structures in the series 1, 3, 4, 5.

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3099 ◽  
Author(s):  
Michał Gacki ◽  
Karolina Kafarska ◽  
Anna Pietrzak ◽  
Izabela Korona-Głowniak ◽  
Wojciech M. Wolf

Three metal complexes of mefenamato ligand 1 were synthesized: [Co2(mef)4(EtOH)2(H2O)4]: 2; [Co(mef)2(MeOH)4]∙2MeOH: 3; and [Ni(mef)2(MeOH)4]∙2MeOH: 4. Their compositions and properties were investigated by elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Crystal structures were determined by the single crystal X-ray diffraction technique. Additionally, their antioxidant and antimicrobial activity were established, thus proving good/moderate bioactivity against Gram-positive bacteria and yeasts. In the crystal structure of 2, an apical water molecule is shared between two adjacent cobalt(II) ions, resulting in the formation of a polymeric chain extending along the [100] direction. Meanwhile, structures 3 and 4 have strong intermolecular hydrogen bonds with diverse topologies that yield unique quasi-isostructural arrangements. The packing topology is reflected by the Hirshfeld surface analysis of intermolecular contacts.


2002 ◽  
Vol 57 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Chirantan Roy Choudhury ◽  
Subrata Kumar Dey ◽  
Sutapa Sen ◽  
Bappaditya Bag ◽  
Samiran Mitra ◽  
...  

The single pyrazine-bridged polymeric complex {[Ni(pyz)(H2O)4](NO3)2.2H2O}n has been synthesised and characterised by elemental analyses, IR and UV-vis spectra, and a single-crystal X-ray diffraction study. The coordination around the Ni centre is perfectly octahedral. The Ni(H2O)4 coordination planes are bridged by pyrazine ligands forming an infinite chain structure. Two nitrate anions and two water molecules exist in the lattice and are linked by intermolecular hydrogen bonds to the coordinated water molecules.


Author(s):  
Hristina I. Sbirkova-Dimitrova ◽  
Boris Shivachev

The structure of 4′,6-diamidine-2-phenylindole (DAPI) bound to the synthetic B-DNA oligonucleotide d(CGTGAATTCACG) has been solved in space groupP212121by single-crystal X-ray diffraction at a resolution of 2.2 Å. The structure is nearly isomorphous to that of the previously reported crystal structure of the oligonucleotide d(CGTGAATTCACG) alone. The adjustments in crystal packing between the native DNA molecule and the DNA–DAPI complex are described. DAPI lies in the narrow minor groove near the centre of the B-DNA fragment, positioned over the A–T base pairs. It is bound to the DNA by hydrogen-bonding and van der Waals interactions. Comparison of the two structures (with and without ligand) shows that DAPI inserts into the minor groove, displacing the ordered spine waters. Indeed, as DAPI is hydrophobic it confers this behaviour on the DNA and thus restricts the presence of water molecules.


2014 ◽  
Vol 70 (7) ◽  
pp. 726-731 ◽  
Author(s):  
Alexander D. Burns ◽  
Brian O. Patrick ◽  
Anita E. Lam ◽  
David Dreisinger

Two new solid-state uranium(IV) sulfatex-hydrate complexes (wherexis the total number of coordinated plus solvent waters), namelycatena-poly[[pentaaquauranium(IV)]-di-μ-sulfato-κ4O:O′] monohydrate], {[U(SO4)2(H2O)5]·H2O}n, and hexaaquabis(sulfato-κ2O,O′)uranium(IV) dihydrate, [U(SO4)2(H2O)6]·2H2O, have been synthesized, structurally characterized by single-crystal X-ray diffraction and analyzed by vibrational (IR and Raman) spectroscopy. By comparing these structures with those of four other known uranium(IV) sulfatex-hydrates, the effect of additional coordinated water molecules on their structures has been elucidated. As the number of coordinated water molecules increases, the sulfate bonds are displaced, thus changing the binding mode of the sulfate ligands to the uranium centre. As a result, uranium(IV) sulfatex-hydrate changes from being fully crosslinked in three dimensions in the anhydrous compound, through sheet and chain linking in the tetra- and hexahydrates, to fully unlinked molecules in the octa- and nonahydrates. It can be concluded that coordinated waters play an important role in determining the structure and connectivity of UIVsulfate complexes.


2018 ◽  
Vol 37 (1) ◽  
pp. 61 ◽  
Author(s):  
Nilgun Sen

A 1:1 co-crystal of trinitrotoluene (TNT) and 2,3-diaminotoluene was prepared by solvent evapo- ration, and the structure of the co-crystal was determined by single-crystal and powder X-ray diffraction. The results indicate that the main mechanism of co-crystallization originates from the intermolecular hy- drogen bonding (amino-nitro) and π-π stacking. We also examined the Hirshfeld surfaces and associated fingerprint plots of the co-crystal and reveal that the structures are stabilized by H…H, O–H, O…O and C…C (π-π) intermolecular interactions. We analyzed the crystal packing and show its influence upon im- pact sensitivity. The results highlight that co-crystallization is an effective way to modify the sensitivity, oxygen balance and density of explosives. 


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 758
Author(s):  
Ali Rayes ◽  
Stephany Zárate-Roldán ◽  
Irene Ara ◽  
Manel Moncer ◽  
Necmi Dege ◽  
...  

Two new organic–inorganic salts of perhalidometallates with protonated organic amine cations have been synthesized and characterized by X-ray diffraction and thermal analysis. (CHBMAH2)ZnBr4·3/2H2O 1 and (CHBMAH2)ZnCl4 4 [(CHBMAH2)2+: 1,3-cyclohexanebis(methylammonium)] were obtained in single-crystal form. The crystal packing in all of the obtained compounds is governed by the formation of various non-covalent intermolecular forces between tetrahalidometallate anions and organic cations, assisted by water molecules in the hydrates. Hirshfeld surface analysis denotes that the most important contributions to the crystal packing are X···H/H···X (X: Cl, Br, I) and H···H interactions. Interestingly, the compound 1,3-cyclohexanebis(methylammonium)tetrachloridozincate (II) dihydrate, (CHBMAH2)ZnCl4·2H2O 2, undergoes thermally-triggered single-crystal-to-single-crystal (SCSC) transformation upon dehydration to produce a supramolecular solid compound, 1,3-cyclohexanebis(methylammonium) tetrachloridozincate (II), (CHBMAH2)ZnCl4 4. The SCSC transformation causes changes in the lattice parameters and a structural rearrangement. Furthermore, the catalytic properties of (CHBMAH2)ZnCl4·2H2O 2 and (CHBMAH2)CdI4·2H2O 3 have been explored in the acetalization process using various uncommon alcohols, beyond methanol or ethanol, for the first time in the literature, with outstanding results, and opening the door to the formation of alternative acetals.


2014 ◽  
Vol 69 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Justin Nenwa ◽  
Patrick L. Djonwouo ◽  
Emmanuel N. Nfor ◽  
Michel M. Bélombé ◽  
Erwann Jeanneau ◽  
...  

The dimeric copper(II) complex [Cu(C2O4)(H2oxado)(H2O)]2 (1), where H2oxado=oxamide dioxime, has been synthesized in water and characterized by elemental and thermal analyses, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is composed of two neutral [Cu(C2O4)(H2oxado)(H2O)] entities connected by Cu-O bonds between oxalate oxygen atoms and copper(II) ions, thereby producing a centrosymmetric dimer, with the Cu(II) centers exhibiting a strongly distorted octahedral coordination. Neighboring dimers are hydrogen-bonded through O- H···O interactions leading overall to a layer structure. Thermal analyses of complex 1 showed two significant weight losses corresponding to the coordinated water molecules, followed by the decomposition of the network. Variable-temperature (10 - 300 K) magnetic susceptibility measurements revealed very weak antiferromagnetic interactions (θ = 0:86 K from Curie-Weiss law behavior) within the dinuclear unit


2011 ◽  
Vol 66 (8) ◽  
pp. 813-818 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Boris-Marko Kukovec ◽  
Vajieh Razavimahmoudabadi

A dinuclear cobalt(II) complex, [Co2(H2O)4(dipic)2(μ-apyz)] (dipicH2 = pyridine-2,6-dicarboxylic (dipicolinic) acid, apyz = 2-aminopyrazine) (1), has been hydrothermally synthesized and characterized by elemental analyses, spectroscopic methods (IR, UV/Vis), thermal analysis as well as by X-ray diffraction studies. The dinuclear complex is composed of two cobalt(II) ions bridged by a 2-aminopyrazine molecule. Each cobalt(II) ion is coordinated by one nitrogen and two oxygen atoms of the tridentate dipicolinate anion, one heterocyclic nitrogen atom of the 2-aminopyrazine and two oxygen atoms of coordinated water molecules. The resulting geometry for the CoN2O4 coordination environment can be described as distorted octahedral. Various hydrogen bonds of the type O-H···O and N-H···O are also present in the crystal structure. This arrangement leads to the formation of a 3D structure.


CrystEngComm ◽  
2015 ◽  
Vol 17 (46) ◽  
pp. 8946-8956 ◽  
Author(s):  
Tayyibah Tahier ◽  
Clive L. Oliver

A mixed-ligand 2D MOF based on ZnSO4, trimesate and 4,4′-bipyridine-N,N′-dioxide shows reversible loss of uncoordinated and coordinated water molecules.


Author(s):  
Anton P. Novikov ◽  
Alexey A. Bezdomnikov ◽  
Mikhail S. Grigoriev ◽  
Konstantin E. German

The molecular and crystal structures of the title compound, C8H4F5NO, were examined by single-crystal X-ray diffraction and Hirshfeld surface analysis. The title compound was synthesized by a new method at the interface of aqueous solutions of LiOH and pentafluorophenylacetonitrile. In the crystal, hydrogen bonds and π–halogen interactions connect the molecules into double layers. Analysis of the Hirshfeld surface showed that the most important contributions to the crystal packing are made by F...F (30.4%), C...F/F...C (22.9%), O...H/H...O (14.9%), H...F/F...H (14.0%) and H...H (10.2%) contacts. The Hirshfeld surfaces of analogues of the title compound were compared and the effect of perfluorination on the crystal packing was shown.


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