| 1. |
- Abu-Youssef, Morsy A.M., et al.
(author)
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1D, 2D and 3D cadmium(II) polymeric complexes with quinoline-4-carboxylato anion, quinazoline and 2,5-dimethylpyrazine
- 2006
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In: Polyhedron. - : Elsevier BV. - 0277-5387. ; 25:5, s. 1187-1194
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Journal article (peer-reviewed)abstract
- Three new cadmium(II) complexes, namely [Cd(Qux)2(H2O)]n (1), [Cd(Quz)2(N3)2]n (2) and [Cd(dmpz)(N3)2]n (3) (Qux = quinoline-4-carboxylato anion, Quz = quinazoline, dmpz = 2,5-dimethylpyrazine), have been synthesized and characterized by spectroscopic and crystallographic methods. The structure of 1 contains CdO6 slightly distorted octahedral geometry around the Cd(II) atoms, axialy coordinated to two bridging water molecules forming the 1D chain and four oxygen atoms from four different μ-O,O′-bridging caboxylato groups of (Qux) in the equatorial plane. The 1D chains are further held together through hydrogen bonds between the μ-aqua molecule and the meta non-coordinated nitrogen atom of the quinoline moiety. In complex 2, two quinazoline ligands are linked to the central Cd(II) ion in a trans position through the meta hetero nitrogen atom and di(EE), (μ1,3-N3) groups and show a two dimensional (2D) topology. In complex 3 the central cadmium(II) atom is simultaneously coordinated to di(EE), (μ1,3-N3) groups (NCdN, 180.0°) forming a sheet structure in the bc plane and further bridging μ-N,N′-dimethylpyrazine ligand in the a-direction (NCdN, 180.0°) giving rise to a 3D network structure. The IR spectra of the three complexes were measured and they confirm the X-ray structural data.
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| 2. |
- Abu-Youssef, Morsy A.M., et al.
(author)
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1D and 2D FeII Azide Coordination Polymers with Ferromagnetic Canting
- 2008
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In: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-0682. ; 2008:1, s. 112-118
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Journal article (peer-reviewed)abstract
- The two compounds [FeII(pyridine)2(N3)2(H2O)] (1) and [FeII(4-acetylpyridine)2(N3)2] (2) were prepared. The X-ray crystal structures show end-to-end (EE) bridging azides in both cases with a 1D Fe-NNN-Fe chain for 1 and a 2D Fe-NNN-Fe net in 2. Both compounds show similar magnetic behaviour where the high-temperature data are consistent with antiferromagnetic couplings and the low-temperature data indicate ferrimagnetic ordering based on spin canting at 20 and 45 K. Compound 2 also shows a hysteresis loop. These findings are compared to the related 3D coordination polymer [Fe(N3)2(4,4'-bipyridine)]. According to network analyses the latter compound was shown to contain the new uninodal six-connected-network topology (510 · 64 · 7)-jsm.
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| 3. |
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| 4. |
- Abu-Youssef, Morsy A. M., et al.
(author)
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Molecular, supramolecular structures combined with hirshfeld and dft studies of centrosymmetric m(Ii)-azido {m=ni(ii), fe(ii) or zn(ii)} complexes of 4-benzoylpyridine
- 2021
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In: Symmetry. - : MDPI AG. - 2073-8994. ; 13:11
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Journal article (peer-reviewed)abstract
- The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4 (N3 )2 ]; 1, [Ni(4bzpy)4 (N3 )2 ]; 2 and [Zn(4bzpy)2 (N3 )2 ]n; 3 with 4-benzoylpyridine (4bzpy) were presented. All complexes contain hexa-coordinated divalent metal ions with a slightly distorted octahedral MN6 coordination sphere. Complexes 1 and 2 are monomeric with terminal azido groups while 3 is one-dimensional coordination polymer containing azido groups with µ(1,1) and µ(1,3) bridging modes of bonding. Hirshfeld analysis was used to quantitatively determine the different contacts affecting the molecular packing in the studied complexes. The most common interactions are the polar O … H and N … H interactions and the hydrophobic C … H contacts. The charges at the M(II) sites are calculated to be 1.004, 0.847, and 1.147 e for complexes 1–3, respectively. The degree of asymmetry is the highest in the case of the terminal azide in complexes 1 and 2 while was found the lowest in the µ(1,1) and µ(1,3) azide bonding modes in the Zn(II) complex 3. These facts were further explained in terms of atoms in molecules (AIM) topological parameters.
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| 5. |
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| 6. |
- Abu-Youssef, Morsy A. M., et al.
(author)
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New Polymeric Manganese Azide Derivatives with Quinazoline
- 2005
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In: European Journal of Inorganic Chemistry. - 1434-1948 .- 1099-0682. ; 2005:22, s. 4659 - 4664
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Journal article (peer-reviewed)abstract
- Two new polymeric derivatives of the (azido)MnII system with formula [Mn(H2O)(μ-N3)(N3)(quinaz)2]n (1) and [Mn(μ-N3)2(quinaz)2]n (2) (quinaz = quinazoline) have been structurally and magnetically characterised. Compound 1 crystallises in the triclinic system, space group P-1, and consists of 1D chains with single end-to-end azido bridges. These chains give a two-dimensional supramolecular arrangement by means of H-bond interactions. Compound 2 crystallises in the monoclinic system, space group C2/c, and contains a square alternating 2D network bridged by azido ligands in the end-to-end coordination mode. Compound 2 exhibits some unusual features, such as the unprecedented linear coordination of the azido bridge. Magnetic analysis reveals moderate antiferromagnetic coupling, with J values in good agreement with the expected range, as a function of the Mn-N-N bond angles.
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| 7. |
- Abu-Youssef, Morsy A.M., et al.
(author)
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Synthesis, a case of isostructural packing, and antimicrobial activity of silver(I)quinoxaline nitrate, silver(I)(2,5-dimethylpyrazine) nitrate and two related silver aminopyridine compounds
- 2006
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In: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 2006:21, s. 2542-2550
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Journal article (peer-reviewed)abstract
- The synthesis and low temperature crystal structures of [Ag(quinoxaline)]n(NO3)n, 1, [Ag(2,5-dimethylpyrazine)(NO3)]n, 2 and [Ag4(3-aminopyridine)4(NO3)4]n 3 are presented. The quinoxaline compound forms a 1D coordination polymer with the characteristic linear 2-coordination figure of silver(I), the NAgN angle being 164.2(1)°, and only weak silvernitrate interactions. In addition there is an interaction giving pairs of parallel chains as the main structural theme. The 2,5-dimethylpyrazine compound has approximately trigonal-planar coordination, also binding one nitrate at the relatively short AgO distances 2.444(3)Å and 2.484(3)Å, respectively, for the two crystallographically different silver atoms. This also results in a 1D coordination polymer that, despite the large differences in the Ag(I) coordination environment, is isostructural with 1. [Ag4(3-aminopyridine)4(NO3)4]n 3 forms a 2D coordination polymer by bridging nitrate ions. The antimicrobial activity of 13, and also of [Ag3(2-aminopyridine)4](NO3)3, 4 was screened for 13 different pathogens and substantial activity was shown for 1 against Escherichia coli and Pseudomonas aeruginosa (MIC 4 µg cm3) and somewhat lower activity was registered against Sarcina lutea and Salmonella typhi for 1, Bordetella bronchiseptica for 2, Salmonella typhi and Pseudomonas aeruginosa for 3, and Escherichia coli and Shigella sonnie for 3 (MIC 8 µg cm3). Only low activity was shown against the yeast Candida albicans for 1, 2 and 4 whereas no activity against this pathogen was registered for 3.
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| 8. |
- Abu-Youssef, Morsy A.M., et al.
(author)
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Synthesis and Structure of Silver Complexes with Nicotinate-Type Ligands Having Antibacterial Activities against Clinically Isolated Antibiotic Resistant Pathogens
- 2007
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 46:15, s. 5893-5903
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Journal article (peer-reviewed)abstract
- The synthesis and low-temperature X-ray crystal structures of five new silver complexes, [Ag2-μ-O,O'(2-aminonicotinium)2(NO3)2]n (7), [Ag(isonicotinamide)2-μ-O,O'(NO3)]2 (8), [Ag(ethyl nicotinate)2](NO3) (9), [Ag(ethyl isonicotinate)2(NO3)] (10), and [Ag(methyl isonicotinate)2(H2O)](NO3) (11), are presented and fully characterized by spectral and elemental analysis. The antimicrobial activities of these complexes were screened using 12 different clinical isolates belonging to four pathogenic bacteria, S. aureus, S. pyogenes, P. mirabilis, and Ps. Aeruginosa, all obtained from diabetic foot ulcers. These tested bacteria were resistant for at least 10 antibiotics commonly used for treatment of diabetic foot ulcers. Compounds 7 and 8 had considerable activity against Ps. Aeruginosa (MIC values 2-8 µg/mL), compound 9 against S. aureus (MIC 4-16 µg/mL) and S. pyogenes (MIC 2-4 µg/mL), and also 9 and 11 against P. mirabilis (MIC 1-16 µg/mL). All complexes were non-toxic for daphnia at concentrations above 512 µg/mL overnight.
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| 9. |
- Abu-Youssef, Morsy A. M., et al.
(author)
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Synthesis, Crystal Structure, Quantum Chemical Calculations, DNA Interactions, and Antimicrobial Activity of [Ag(2-amino-3-methylpyridine)2]NO3 and [Ag(pyridine-2-carboxaldoxime)NO3]
- 2010
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 49:21, s. 9788-9797
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Journal article (peer-reviewed)abstract
- [Ag(2-amino-3-methylpyridine)2]NO3 (1) and [Ag(pyridine-2-carboxaldoxime)NO3] (2) were prepared from corresponding ligands and AgNO3 in water/ethanol solutions, and the products were characterized by IR, elemental analysis, NMR, and TGA. The X-ray crystal structures of the two compounds show that the geometry around the silver(I) ion is bent for complex 1 with nitrate as an anion and trigonal planar for complex 2 with nitrate coordinated. ESI-MS results of solutions of 2 indicate the independent existence in solution of the [Ag(pyridine-2-carboxaldoxime)]+ ion. The geometries of the complexes are well described by DFT calculations using the ZORA relativistic approach. The compounds were tested against 14 different clinically isolated and four ATCC standard bacteria and yeasts and also compared with 17 commonly used antibiotics. Both 1 and 2 exhibited considerable activity against S. lutea, M. lutea, and S. aureus and against the yeast Candida albicans, while 2-amino-3-methylpyridine is slightly active and pyridine-2-carboxaldoxime shows no antimicrobial activity. In addition, the interaction of these metal complexes with DNA was investigated. Both 1 and 2 bind to DNA and reduce its electrophoretic mobility with different patterns of migration, while the ligands themselves induce no change.
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| 10. |
- Abu-Youssef, Morsy A.M., et al.
(author)
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Synthesis, Structure, and Magnetic Behavior of Two New 1D Polymeric Manganese Azido Complexes
- 2006
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In: European Journal of Inorganic Chemistry. ; 2006:16, s. 3177-3184
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Journal article (peer-reviewed)abstract
- Two new MnII one-dimensional compounds with formulae [Mn(μ-N3)2(pyzamid)2]n (1) and [Mn2(3-ampy)4(μ-N3)2(N3)2(H2O)2]n, (2) (pyzamid = pyrazineamide and 3-ampy = 3-aminopyridine) were structurally and magnetically characterized. Compound 1 crystallizes in the monoclinic system, P2/c space group, and polymerizes through double end-on azido bridges giving 1D chains with the MnII atoms in a MnN6 environment. Compound 2 crystallizes in the triclinic system, P-1 space group, and consists of alternate [Mn(3-ampy)2(μ-N3)2(N3)2] and [Mn(3-ampy)2(μ-N3)2(H2O)2] octahedrons (MnN6 - MnN4O2 environments), linked by single end-to-end azido bridges. Both chains show very uncommon topologies. Attemps to obtain manganese/azido derivatives with the qux = quinoline-4-carboxylato anion gave the recently reported compound [Mn(μ-qux)2(μ-H2O)]n (3), which consists of a chain with only carboxylato and aqua bridges with the MnII atoms in a MnO6 slightly distorted octahedron. In good agreement with the expected behavior, magnetic susceptibility measurements show weak ferromagnetic interactions for 1, whereas compound 2 exhibits moderate antiferromagnetic coupling.
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