Spectroscopic studies, crystal structures and antimicrobial activities of a new lasalocid 1-naphthylmethyl ester

2008 ◽  
Vol 891 (1-3) ◽  
pp. 481-490 ◽  
Author(s):  
Adam Huczyński ◽  
Izabela Paluch ◽  
Małgorzata Ratajczak-Sitarz ◽  
Andrzej Katrusiak ◽  
Joanna Stefańska ◽  
...  
2005 ◽  
Vol 737 (2-3) ◽  
pp. 159-164 ◽  
Author(s):  
Hüseyin Ünver ◽  
Mustafa Yıldız ◽  
Başaran Dülger ◽  
Özen Özgen ◽  
Engin Kendi ◽  
...  

1981 ◽  
Vol 34 (10) ◽  
pp. 2139 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White

The preparation of a series of novel compounds of general formula [Ni5L4(NO2)8(OH)2] formed by ethane-1,2-diamine or one of five N-substituted ethane-1,2-diamines (L) is described. The crystal and molecular structures of the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine and N,N-dimethylethane-1,2-diamine complexes are reported. Each compound contains a planar, pentameric arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite ligands. The details of the nitrite bridges differ among the complexes, causing differences in their electronic and infrared spectra. The structural variations are probably caused by the differing steric requirements of the amine substituents.


1981 ◽  
Vol 34 (10) ◽  
pp. 2095 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
BW Skelton ◽  
...  

The crystal and molecular structures of the compounds [Ni(py)4(ONO)2],2py, [Ni(γmpy),(ONO)2] and [Ni(prz)4(ONO)2] are reported.�All three are trans nitrito complexes, the pyridine (py) compound containing two pyridine molecules of solvation. The aromatic rings in the first two complexes adopt 'paddle wheel' conformations with pitch angles varying between 40 and 70�. The nitrite ions are positioned so as to minimize repulsive interactions with the amines, and it seems likely that these groups bond through oxygen rather than nitrogen because this allows a lesser degree of interligand steric interference. The amine rings in [Ni(prz)4(ONO)2] are orthogonal to the plane containing the nickel and coordinated pyrazole nitrogen atoms; the nitrito groups are disordered between two inequivalent positions, each of which involves hydrogen bonding with the pyrazole NH groups. The nitrite infrared frequencies are similar to those observed for other nickel(II) nitrito complexes except that the antisymmetric NO stretching mode of one of the groups in the pyrazole complex is much lower in energy than expected, being in the range normally associated with a nitrogen-bonded or chelated nitrite group. It is suggested that this deviation may be caused by the hydrogen bonding in the complex. The electronic spectra of the compounds yield 10Dq values of 9100 and 8500 cm-1 for the nitrite ligands in [Ni(py)4(ONO)2] and Ni(prz)4(ONO)2], respectively, placing the nitrito group towards the weaker end of the spectro-chemical series.


2013 ◽  
Vol 2013 (36) ◽  
pp. 6170-6174 ◽  
Author(s):  
Yingjie Zhang ◽  
Mohan Bhadbhade ◽  
Inna Karatchevtseva ◽  
Jiabin Gao ◽  
Jason R. Price ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
K. Savithri ◽  
B. C. Vasantha Kumar ◽  
H. K. Vivek ◽  
H. D. Revanasiddappa

A bidentate (N- and O-) imine-based ligand (L1) and its metal complexes of types [CuII(L1)2] (C1), [CuII(L1)(Phen)] (C2), [CoIII(L1)2] (C3), and [CoIII(L1)(Phen)] (C4) (L1 = 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol and phen = 1,10-phenanthroline) were synthesized as potential chemotherapeutic drug candidates. The prepared complexes were structurally characterized by spectral techniques (NMR, FT-IR, LC-MS, EPR, and electronic absorption), thermogravimetric analysis (TGA/DTA), magnetic moment, and CHNO elemental analysis. Spectroscopic studies suggested the distorted octahedral structure for all complexes. In vitro bioassay studies include binding and nuclease activities of the ligand and its complexes with target calf thymus- (CT-) DNA were carried out by employing UV-Vis, fluorescence spectroscopy, viscosity, and gel electrophoresis techniques. The extent of binding propensity was determined quantitatively by Kb and Ksv values which revealed a higher binding affinity for C2 and C4 as compared to C1 and C3. In addition, the scavenging superoxide anion free radical (O∙-2) activity of metal complexes was determined by nitroblue tetrazolium (NBT) light reduction assay. Molecular docking studies with DNA and SOD enzyme were also carried out on these compounds. The antimicrobial study has shown that all the compounds are potential antibacterial agents against Gram-negative bacterial strains and better antifungal agents with respect to standard drugs used.


1981 ◽  
Vol 34 (10) ◽  
pp. 2113 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White

The crystal structures and spectroscopic properties of the complexes cis-tetrakis(2-methy1imidazole)-(nitrito-O,O')nickel(II) nitrate-methanol (2/1) and trans-tetrakis(2-methylimidazole)dinitritonickel(II) are reported. The nitrite group in the former compound chelates, giving a distorted octahedral ligand coordination geometry. The ligand stereochemistry in the second complex is also a distorted octahedron, with both anions coordinating as trans nitrito groups though with significantly different Ni-O bond lengths and the nickel(II) ion being raised out of the plane of the four imidazole ligand nitrogen atoms towards the closer nitrite group. The Ni-O bond directions also deviate substantially from the fourfold symmetry axis in this latter complex. These distortions apparently occur in order to minimize ligand-ligand repulsions, particularly those associated with the amine methyl substituents. The electronic spectra of both complexes show significant band splittings due to the departure of the ligand field from regular octahedral symmetry and these are discussed in terms of the relative field strengths of the imidazole and nitrito ligands. The structure of hexakis(imidazole)nickel(II) nitrate (redetermination) is also reported.


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