scholarly journals Interactions of Trivalent Lanthanide Cations with a New Hexadentate Di-Schiff Base: New Lanthanide(III) Complexes from (NE,N′E)-2,2′-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine)

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Mantha Tsiouri ◽  
Konstantina Skorda ◽  
Christos Papadimitriou ◽  
Yang Li ◽  
J. Derek Woollins ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Schiff Base Ligand ◽  
Direct Reaction ◽  
The Novel ◽  
Trivalent Lanthanide ◽  
Lanthanide Cations ◽  
Oxygen Atoms

The novel lanthanide(III) complexes[Ln(NO3)2L](NO3)⋅3MeOH (Ln = La1, Pr2) and[Ln(NO3)3L](NO3)⋅2MeOH (Ln = Gd3, Yb4), where L = (NE,N′E)-2,2′-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine), have been obtained by direct reaction of the Schiff base ligand and the corresponding hydrated lanthanide(III) nitrates in methanol. All complexes were characterized spectroscopically and thermogravimetrically. Complex4was also characterized with crystallographic studies: orthorhombic P212121,a=10.6683(14),b=13.4752(15),c=19.3320(26) Å. In the molecular structure of4, Yb(III) is surrounded by all donor atoms of the Schiff base (four nitrogen and two oxygen atoms) and four oxygen atoms belonging to two bidentate chelating nitrato ligands.

scholarly journals Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

2021 ◽  
Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Structural Characterization ◽  
Schiff Base Ligand ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

scholarly journals Synthesis and Crystal Structure of Binuclear and Pentanuclear Nickel(II) Complexes Containing 4-(salicylaldiminato)antipyrine Schiff base

2015 ◽  
Vol 4 (6) ◽  
pp. 282
Author(s):  
Mohamed N. EL-Kaheli ◽  
Ramadan G. Abuhmaiera ◽  
Fathia A. Treish ◽  
Mufida M. Ben Yunes ◽  
Ramadan Mohamed Elmehdawi ◽  
...  
Keyword(s):  
Schiff Base ◽  
Azomethine Nitrogen ◽  
Water Molecules ◽  
The Novel ◽  
Synthesis And Crystal Structure ◽  
Nickel Ions ◽  
Distorted Octahedral ◽  
Intramolecular Hydrogen ◽  
Binuclear Unit ◽  
Oxygen Atoms

<div class="WordSection1"><p>The new title binuclear Ni (II) compound <strong> </strong>(<strong>1</strong>) and the novel pentanuclear Ni (II) cluster {[   } <strong>(2) </strong>are formed from the reaction of an asymmetric Schiff base ligand <strong>L </strong>(L = 4-(salicylaldiminato)antipyrine) with Ni .4  in the former or Ni(ClO<sub>4</sub>)<sub>2</sub>.6H<sub>2</sub>O in presence of malonate in the later.  Complex (<strong>1</strong>) consists of ( ]<sup>+ </sup>cation) and one uncoordinated tetraphenylborate anion.  The cation adopts a distorted octahedral arrangement around each metal center.  In the binuclear unit both Ni(II) ions are linked through two phenolate (µ<sub>2</sub>-O) oxygen atoms of L, and two oxygen atoms of a  bridging carboxylate group. Each Ni (II) coordinates to four oxygen atoms at the basal plane, two oxygen atoms from two bridging phenolate groups, one from pyrazolone ring and the last of an aqua molecule, and at the axial positions to a bridging carboxylate-O atom and an azomethine nitrogen atom.  In the pentanuclear cluster (<strong>2</strong>) consisting of [ ]<sup>+2 </sup>cation and two tetraphenylborate anions, the core of the cation is assembled by four [Ni( )] units, linked to the central Ni-ion by two bridging water molecules. The resulting coordination sphere for the external symmetry related nickel ions is a pseudo octahedron.  The central Ni-atom unusually adopts dodecahedron geometry through its coordination to eight bridging water molecules. In complex (<strong>1</strong>) each Ni-atom is coordinated to one tridentate <strong>L</strong> ligand and in complex (<strong>2</strong>) each [Ni ( )] unit is coordinated to two bidentate <strong>L</strong> ligands.  Inter-and intramolecular hydrogen bonds are present in both crystal structures.</p></div>

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