scholarly journals High-spin binuclear Co(II) complexes with a pendant octaazamaclocycle and carboxylates

2007 ◽  
Vol 72 (12) ◽  
pp. 1295-1308 ◽  
Author(s):  
G. Vuckovic ◽  
S.B. Tanaskovic ◽  
Z.M. Miodragovic ◽  
V. Stanic
Keyword(s):  
Antibacterial Activity ◽  
Terephthalic Acid ◽  
Chair Conformation ◽  
Molar Conductivity ◽  
Mixed Ligand ◽  
Boat Conformation ◽  
Trans Position ◽  
Oxidation Of Co ◽  
Elemental Analyses ◽  
Cv Measurements

Three new binuclear Co(II) mixed-ligand complexes with N,N?,N??,N???-tetrakis( 2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and mono- or dicarboxylate ligands were prepared and some of their physical properties were determined. The general formulas: [Co2(HCOO)2tpmc](ClO4)2?4H2O, [Co2(CH3COO)2tpmc](ClO4)2 and [Co2(tpht)tpmc](ClO4)2?4H2O (tphtH2 = terephthalic acid) were proposed on the basis of elemental analyses (C,H,N) and molar conductivity. UV/Vis absorption and IR spectra, magnetic and CV measurements were used to study their geometries and properties. For the monocarboxylate complexes, an exo coordination of Co(II) with four nitrogens from tpmc and bis-bidentate bonded HCOO-/CH3COO- in the trans position is assumed. Tpmc adopts the chair conformation. For the dicarboxylate complex, it is supposed that a terephthalate dianion, as well as methylene chains from cyclam bridge two Co(II) atoms, while tpmc is in the boat conformation. The complexes were stable against chemical and electrochemical oxidation of Co(II) to Co(III). The data are compared with those for the previously published Cu(II) complexes containing the corresponding ligands and mutual similarities or differences were considered. Finally, some antibacterial activity of the complexes was found.

scholarly journals Cobalt(II) complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms

2005 ◽  
Vol 70 (8-9) ◽  
pp. 1121-1129 ◽  
Author(s):  
Gordana Vuckovic ◽  
V. Stanic ◽  
Sofija Sovilj ◽  
M. Antonijevic-Nikolic ◽  
J. Mrozynski
Keyword(s):  
Cyclic Voltammetry ◽  
Ir Spectroscopy ◽  
Chair Conformation ◽  
Trans Position ◽  
Cyclic Voltammetric ◽  
Aromatic Carboxylates ◽  
Elemental Analyses ◽  
Electrical Conductivities ◽  
Pendant Arms ◽  
Voltammetric Measurements

Novel binuclear Co(II) complexeswithN-functionalized cyclam N,N?,N",N???-tetrakis( 2-pyridylmethyl)tetraazacyclotetradecane (tpmc) and one of the aromatic monoor dicarboxylato ligands (benzoate, phthalate or isophthalate ions) were prepared. They were analyzed and studied by elemental analyses (C, H, N), electrical conductivities, VIS and IR spectroscopy andmagnetic as well as cyclic voltammetric measurements. In [Co2(C6H5COO)2tpmc]ClO4)2.3H2O, the benzoate ligands are most probably coordinated as chelates in the trans-position to each Co(II) and the macrocycle adopts a chair conformation. In the complexes [Co2(Y)tpmc]ClO4)2.zH2O, (Y = phthalate or i-phthalate dianizon, z = 2; 4) it is proposed that the isomeric dicarboxylates are bonded combined as bridges and chelates. The composition and the assumed geometries of the complexes are compared with the, earlier reported, corresponding Cu(II) complexes. Cyclic voltammetry measurements showed that the compounds are electrochemically stable.

scholarly journals Mixed Ligand Complexes of Hg-tetrazole-thiolate with phosphine, Synthesis and spectroscopic studies.

2019 ◽  
Vol 24 (5) ◽  
pp. 10 ◽  
Author(s):  
Osama'a A. Y. Al-Samrai ◽  
Ahmed S. M. Al-Janabi2 ◽  
Eman A. Othman1
Keyword(s):  
Sulfur Atom ◽  
Thiol Group ◽  
Spectroscopic Studies ◽  
Ethanol Solution ◽  
Molar Conductivity ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Diphosphine Ligands ◽  
Tetrahedral Geometry ◽  
Elemental Analyses

Seven new complexes [Hg(k1-ptt)2](1), [Hg(k1-ptt)2(dppm)](2), [Hg(k1-ptt)2(dppe)](3), [Hg(k1-ptt)2(dppp)](4), [Hg(k1-ptt)2(dppb)](5), [Hg(k1-ptt)2(dppf)] (6), and [Hg(k1-ptt)2(PPh3)2] (7) have been synthesized and characterized. The reaction of two moles equivalent of 1-Phenyl-1H-tetrazole-5-thiol (Hptt) with one mole equivalent of  Hg(oAc)2.xH2O in ethanol solution afford [Hg(k1-ptt)2] (1). Treatment of (1) with one mole equivalent of diphos (diphos : dppm, dppe, dppp, dppb, dppf) or two moles equivalent of PPh3 afforded a complexes of the types [Hg(k1-ptt)2(diphos)] (2-6) or [Hg(k1-ptt)2(PPh3)2] (7). The prepared complexes have been characterized by CHNS elemental analyses, molar conductivity, IR and NMR (1H, 13C and 31P) spectroscopy. In all complexes, the ptt- ligand is bonded through the sulfur atom of deprotonated thiol group, whereas the diphosphine ligands bonded as bidentate chelating and PPh3 bonded as a monodentate, to afford a tetrahedral geometry around the Hg+2 ion.   http://dx.doi.org/10.25130/tjps.24.2019.083

scholarly journals Synthesis, characterization and cytotoxicity of mixed ligand Mn(II), Co(II) and Ni(II) complexes

2014 ◽  
Vol 79 (8) ◽  
pp. 953-964 ◽  
Author(s):  
Souad Osman ◽  
Hanan Mousa ◽  
Yosef Abdallah ◽  
Taghrid Hafez ◽  
Abdallah El-Sawy ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Human Cancer ◽  
Magnetic Moments ◽  
Molar Conductivity ◽  
Mixed Ligand ◽  
Human Cancer Cell ◽  
Srb Assay ◽  
Human Cancer Cell Lines ◽  
Elemental Analyses ◽  
High Cytotoxicity

Complexes of the type [ML'L(OH)(H2O)] {where M= Ni(II), Co(II) or Mn(II), L'= isatin and HL= 3-(2-phenylhydrazono)acetylacetone, 3-(2-(4-chlorophenyl)hydrazono)acetylacetone or 3-(2-(4-bromophenyl)hydrazono)-acetylacetone} have been synthesized by equimolar reaction of a metal(II) chloride with isatin and 3-(2-(aryl)hydrazono)acetylacetone. The resulting complexes have been characterized by elemental analyses, molar conductivity, spectral data (IR, 1H NMR, mass) and magnetic moments. Furthermore, the ligands and their metal complexes have been screened for their cytotoxicity against different human cancer cell lines by using SRB assay. The results showed that most of the mixed ligand metal complexes have high cytotoxicity in comparison with the reference drugs used.

scholarly journals The preparation and characterization of Cu(II) complexes with N, N’, N", N’’’-tetrakis(2-pyridylmethyl)-1, 4, 8, 11-tetraazacyclotetradecane and 2, 6-diacetylpyridine bis (semi/thiosemicarbazone)

2004 ◽  
Vol 69 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Sladjana Tanaskovic ◽  
Gordana Vuckovic
Keyword(s):  
Antibacterial Activity ◽  
Ir Spectroscopy ◽  
Electronic Absorption ◽  
Magnetic Measurement ◽  
Mixed Ligand ◽  
Dinuclear Complex ◽  
Tetranuclear Complex ◽  
Elemental Analyses ◽  
Pentadentate Ligands

Two new Cu(II) mixed-ligand complexes with octadentate N,N?,N",N?"-tetrakis 2-pyridylmethyl))-1,4,8,11-tetraazacyclotetradecane (tpmc) and potentially pentadentate ligands 2,6-diacetylpyridine bis(semicarbazone) (DAPsc2) or 2,6-diacetylpyridine bis(thiosemicarbazone) (DAPtsc2) were prepared. The general formulas: [Cu4DAPsc2(tpmc)2]ClO4)8. 5CH3COCH3. H2O and [Cu2 DAPtsc2(tpmc)](ClO4)4. 7C2H5OH were proposed on the basis of elemental analyses and conductometric measurements. The complexes were characterized by magnetic measurement, electronic absorption and IR spectroscopy. For the dinuclear complex, an exo coordination of Cu(II) with four nitrogens from tpmc and ?-bonded DAPtsc2 through sulfurs and possibly terminal hydrazinic (azomethine) nitrogens is assumed. For the tetranuclear complex, it is supposed that one DAPsc2 bridges two [Cu2tpmc]4+ units using oxygens and terminal hydrazinic nitrogens as ligators. Finally, some antibacterial activity of the complexes was found.

Crystal Structure and Conformation of Ring A of 2β-Bromo-19β,28-epoxy-18α-oleanan-3-one

1993 ◽  
Vol 58 (11) ◽  
pp. 2737-2744 ◽  
Author(s):  
Jiří Novotný ◽  
Jaroslav Podlaha ◽  
Jiří Klinot
Keyword(s):  
Crystal Structure ◽  
Opposite Direction ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Form Ring ◽  
Twist Boat

The crystal structure of β-bromo-19β,28-epoxy-18α-oleanan-3-one was elucidated. The crystal is orthorhombic, P212121, a = 9.686(1), b = 14.355(2), c = 19.687(4) Å, Z = 4, R = 0.042 for 2 410 observed reflections. Rings B, C, D and E adopt the chair conformation, the five membered ether cycle in ring E occurs in the envelope form. Ring A takes the twist-boat conformation turned towards the classical boat with C2 and C5 in the stem-stern position, in contrast to the conformation in solution, which is turned in the opposite direction towards the classical boat with C3 and C10 in the stem-stern positions.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals 7′-Amino-1′H-spiro[cycloheptane-1,2′-pyrimido[4,5-d]pyrimidin]-4′(3′H)-one

2012 ◽  
Vol 68 (8) ◽  
pp. o2546-o2546
Author(s):  
Shu Chen ◽  
Daxin Shi ◽  
Mingxing Liu ◽  
Jiarong Li
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Compound C ◽  
Dimensional Network

The title compound, C12H17N5O, was obtained by cyclocondensation of 2,4-diaminopyrimidine-5-carbonitrile with cycloheptanone. The tetrahydropyrimidine ring has a distorted boat conformation and the cycloheptane ring adopts a chair conformation. In the crystal, molecules are linkedviaN—H...O and N—H...N hydrogen bonds generating a three-dimensional network.

The Dichloroplatinum(II) and Dichloropalladium(II) Complexes of 1,4-Diazacycloheptane: Preparative, Structural and Conformational Studies

1996 ◽  
Vol 49 (12) ◽  
pp. 1301 ◽  
Author(s):  
GW Allen ◽  
ECH Ling ◽  
LV Krippner ◽  
TW Hambley
Keyword(s):  
Crystal Structures ◽  
Chelate Ring ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Membered Chelate Ring ◽  
Alternative Conformation

The preparation and purification of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] ( hpip = homopiperazine = 1,4-diazacycloheptane) are described. Crystal structures of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] have been determined by X-ray diffraction methods and refined to R values of 0.023 (932 F) and 0.023 (948 F). The crystals of [Pt( hpip )Cl2] are orthorhombic, space group Pbcm , a 7.7019(8), b 9.8080(12), c 12.1944(14) Ǻ, and those of [Pd( hpip )Cl2] are monoclinic, space group P21/m, a 6.1001(9), b 11.527(2), c 6.458(I) Ǻ, β 106.30(2)°. The seven- membered rings of the ligands in both complexes adopt boat-like conformations in which the five- membered chelate ring has an eclipsed N-C-C-N group and the six- membered chelate ring adopts a chair conformation. Molecular mechanics methods were used to investigate whether this conformation was a crystallographic artefact but it was found to be real. An alternative conformation in which the six-membered chelate ring adopts a skew-boat conformation was also investigated. It was found to be less stable than the conformation observed in the crystal structures, but to a degree that depends on whether non-bonded interactions involving the metal atom were included or not.

scholarly journals Synthesis, Characterization and Chelating Properties of Benzimidazole-Salicylic Acid Combined Molecule

2009 ◽  
Vol 6 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Kamlesh V. Patel ◽  
Arun Singh
Keyword(s):  
Salicylic Acid ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Magnetic Moment ◽  
Mannich Reaction ◽  
Conductivity Measurement ◽  
Molar Conductivity ◽  
Spectral Studies ◽  
Aminosalicylic Acid ◽  
Elemental Analyses

Aminomethylation (i.e.Mannich reaction) of benzimidazole was carried out by treating benzimidalzole with formaldehyde and 4-aminosalicylic acid. The resultant compound was designated as 1-(4-carboxy-3-hydroxyphenyl aminomethyl) benzimidazole (BI-SA). The transition metal complexes of Cu2+, Co2+, Ni2+, Mn2+, Zn2+and Fe3+of BI-SA have been prepared and characterized by elemental analyses, spectral studies, magnetic moment determination, molar conductivity measurement and microbicidal activity.

Synthesis, characterization and fluorescence properties of mixed-ligand cobalt(II), copper(II), zinc(II) and cadmium(II) coordination polymer complexes involving 4,4’-bipyridine and 2,5-pyridinedicarboxylic acid

2021 ◽  
Vol 25 (7) ◽  
pp. 147-156
Author(s):  
Ajeet Kumar Maurya ◽  
Ashish Kumar Srivastava ◽  
Krishna Srivastava ◽  
Jagdish Prasad
Keyword(s):  
Coordination Polymer ◽  
Thermal Analyses ◽  
Mixed Ligand ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Polymer Complexes ◽  
Pyridinedicarboxylic Acid ◽  
Elemental Analyses ◽  
Ligand Coordination ◽  
Ft Ir

Four mixed-ligand coordination polymer complexes of cobalt(II), copper(II), zinc(II), and cadmium(II) were synthesized by solvothermal method in 1:1:1 metal: 4,4’-bipy: 2,5-pdc molar ratio using 2,5-pyridinedicarboxylic acid (2,5-pdc) and 4,4’-bipyridine (4,4’-bipy). These complexes are viz; 1. [Co2(4,4'-bipy)(2,5-pdc)2(H2O)4]n 2. [Cu2(4,4'-bipy) (2,5-pdc)2]n 3. [Zn2(4,4'-bipy)(2,5-pdc)2(H2O)4]n and 4. [Cd3(4,4'-bipy)(2,5-pdc)2(OOCCH3)2(H2O)4]n.. All these complexes (1-4) have been characterized by elemental analyses (C,H,N), FT-IR-spectra, thermal analyses (TGA/DTA/DTG), fluorescence spectra and powder X-ray diffraction (PXRD) analyses to arrive at conclusion regarding their geometrical structure.

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