Synthesis, structure, and electrochemistry of cobalt(III) complexes with bis(benzoylacetone)ethylenediimine Schiff base

2002 ◽  
Vol 80 (9) ◽  
pp. 1196-1203 ◽  
Author(s):  
Mehdi Amirnasr ◽  
Rasoul Vafazadeh ◽  
Amir H Mahmoudkhani
Keyword(s):  
Schiff Base ◽  
Reduction Potential ◽  
Crystal And Molecular Structure ◽  
Acetonitrile Solution ◽  
Potential Range ◽  
Carbon Electrode ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
C Nmr

A series of complexes of the type trans-[Co((BA)2en)(amine)2]ClO4 — where (BA)2en is the bis(benzoylacetone)ethylenediimine dianion and the amines are morpholine (mrpln) 1, aniline (aniln) 2, benzylamine (bzlan) 3, piperidine (pprdn) 4, p-toluidine (p-toldn) 5, and pyrrolidine (prldn) 6 — has been synthesized and characterized by elemental analysis, UV–vis, 1H NMR, and 13C NMR spectroscopy. The crystal and molecular structure of trans-[Co((BA)2en)(mrpln)2]ClO4 (1) has been determined by X-ray crystallography. The electrochemical reduction of these complexes at a glassy-carbon electrode, in the potential range of 0.5 to –2.0 V (vs. Ag/AgCl), in acetonitrile solution, indicates that the first reduction potential of Co(III/II) is irreversible, which is accompanied by the dissociation of the axial amine–cobalt bonds. This potential is dependent on the pKa of the axial amines. The second reduction potential of Co(II/I) shows reversible behavior and is also independent of the axial amine pKa. These results indicate the loss of the axial amines in the first redox process and the involvement of a four-coordinate species in the second redox step.Key words: Schiff base, cobalt(III), axial amine, electrochemical properties, crystal structure.

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.

[Zn(phen)2(CX3COO)]+, X = H orCl; Influence of X on the Coordination Mode of the Carboxylate Group (phen = 1,10-Phenanthroline)

2005 ◽  
Vol 60 (10) ◽  
pp. 1049-1053 ◽  
Author(s):  
Zeanab Talaei ◽  
Ali Morsali ◽  
Ali R. Mahjoub
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Coordination Mode ◽  
Bidentate Ligand ◽  
Carboxylate Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Coordinate Geometry ◽  
C Nmr

Two new ZnII(phen)2 complexes with trichloroacetate and acetate anions, [Zn(phen)2(CCl3COO)- (H2O)](ClO4) and [Zn(phen)2(CH3COO)](ClO4), have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. The single crystal X-ray data of these compounds show the Zn atoms to have six-coordinate geometry. From IR spectra and X-ray crystallography it is established that the coordination of the COO− group is different for trichloroacetate and acetate. The former acts as a monodentate whereas the latter acts as a bidentate ligand.

scholarly journals Synthesis and characterization of a new bis-NHC palladium complex and its catalytic activity in the Mizoroki–Heck reaction

2020 ◽  
Vol 44 (11-12) ◽  
pp. 684-688
Author(s):  
Can Feng ◽  
Cheng-xin Liu ◽  
Yu-fang Wang ◽  
Jin Cui ◽  
Ming-jie Zhang
Keyword(s):  
Palladium Complex ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Heck Coupling ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Excellent Stability ◽  
C Nmr

A new bis- N-heterocyclic carbene palladium complex, (C13H9N2F2)2PdCl2, is synthesized by a three-step reaction and characterized by 1H NMR and 13C NMR spectroscopy as well as by X-ray crystallography. This new bis- N-heterocyclic carbene palladium complex has excellent stability and is capable of efficiently catalyzing the Mizoroki–Heck coupling reaction of aryl halides with acrylates.

1,2-Bis(1-aryl-3-alkyltriazen-3-yl)ethanes and related compounds

1998 ◽  
Vol 76 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Donald L Hooper ◽  
Ian R Pottie ◽  
Marc Vacheresse ◽  
Keith Vaughan
Keyword(s):  
Nmr Spectroscopy ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Ir And Nmr Spectroscopy ◽  
Diazonium Coupling ◽  
Significant Line ◽  
Related Compounds ◽  
C Nmr

A series of novel bistriazenes, the 1,2-bis(1-aryl-3-methyltriazen-3-yl)ethanes, Ar-N T N-NMe-CH2CH2-NMe-N T N-Ar, have been synthesized by diazonium coupling with N,N'-dimethylethylenediamine. These bistriazenes are stable crystalline compounds and have been unequivocally characterized by IR and NMR spectroscopy (1H and 13C), and elemental analysis. The structures of two compounds in the series have been confirmed by X-ray crystallography. The 1H NMR spectra show significant line broadening of the N-methyl resonances arising from the restricted rotation around the N2-N3 bond of the triazene units. The presence of strongly electron-withdrawing groups on the aryl ring restricts the rotation to the point where the N-methyl signals of the rotamers are distinct even at room temperature; four resonances of the N-methyl signal are clearly evident and these can be assigned to the anti-anti, syn-syn, and syn-anti conformations of the bistriazene. Diazonium coupling with N,N'-diethylethylenediamine affords the N,N'-diethyl homologues of the bistriazenes, which have been similarly characterized. As model compounds to assist in spectroscopic analysis, a series of related triazenes, the 1-(1-aryl-3-methyltriazen-3-yl)-N,N-dimethyl-2-ethanamines, were prepared by diazonium coupling with N,N,N'-trimethylethylenediamine. These dialkyltriazenes exist mainly as oils, but characterization was achieved by IR, 1H NMR, and 13C NMR spectroscopy, also showing the presence of two rotamers in solution when strongly electron-withdrawing substituents are bonded to the aryl moiety.Key words: triazene, bistriazene, diazonium, ethylenediamine, molecular dynamics, NMR.

The reaction of chloro(triphenylphosphine)gold(I) with 1-methylthymine

1987 ◽  
Vol 65 (7) ◽  
pp. 1568-1575 ◽  
Author(s):  
R. Faggiani ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
M. A. Turner
Keyword(s):  
Aqueous Methanol ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Cell Dimensions ◽  
Cell Data ◽  
Unit Cell Data ◽  
Related Compounds ◽  
C Nmr

1-Methylthyminato-N3-triphenylphosphinegold(I) was prepared by reacting chloro(triphenylphosphine)gold(I) with 1-methylthymine in aqueous methanol at pH 11. The product was examined by X-ray crystallography and was found to have the orthorhombic space group C2221 (no. 20) with cell dimensions a = 12.760(7) Å, b = 11.530(2) Å, c = 31.893(5) Å, and eight formula units in the unit cell. Data were collected with use of MoKα radiation and a Syntex P21, diffractometer. The crystal structure was determined by standard methods and refined to R = 0.112 and Rw = 0.076 on the basis of 4760 unique reflections. Bond lengths and bond angles are normal. Packing in the crystal lattice is dominated by the triphenylphosphine rings which arrange roughly as blades of a propellor and are the source of the crystal's chirality. The title and related compounds were also examined by 1H nmr, 13C nmr, and vibrational spectroscopy.

Structure and spectroscopy of uranyl salicylaldiminate complexes

2013 ◽  
Vol 101 (10) ◽  
pp. 631-636 ◽  
Author(s):  
A. L. Tamasi ◽  
C. L. Barnes ◽  
J. R. Walensky
Keyword(s):  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Coordination Sphere ◽  
Ancillary Ligand ◽  
Schiff Base Ligands ◽  
Uranyl Complexes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chloride Ligand ◽  
C Nmr

Summary The synthesis of uranyl complexes coordinated to tridentate, monoanionic salicylaldiminate (Schiff base) ligands was achieved by the reaction of UO2Cl2(THF)3, 1, with one equivalent of the corresponding sodium salicylaldiminate salts affording [(C9H6N)N=C(H)C6H2t Bu2O]UO2Cl(THF), 2, [(NC5H4)N=C(H)C6H2 t Bu2O]UO2Cl(THF), 3, and [(C6H4SCH3)N=C(H)C6H2tBu2O]UO2Cl(THF), 4. These are uncommon examples of uranyl complexes with a monoanionic ancillary ligand to stabilize the coordination sphere and one chloride ligand. Compounds 2-4 have been characterized by 1H and 13C NMR spectroscopy as well as IR and UVVis spectroscopy and their structures determined by X-ray crystallography.

scholarly journals Synthesis, characterization and crystal structures of the bidentate Schiff baseN,N′-bis(2-nitrocinnamaldehyde)ethylenediamine and its complex with CuNCS and triphenylphosphane

2015 ◽  
Vol 71 (7) ◽  
pp. 578-583 ◽  
Author(s):  
William Clegg ◽  
Ross W. Harrington ◽  
Kazem Barati ◽  
Mohammad Hossein Habibi ◽  
Morteza Montazerozohori ◽  
...  
Keyword(s):  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Nitro Group ◽  
Bidentate Ligand ◽  
Molar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Bite Angle ◽  
Elemental Analyses

Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff baseN,N′-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1′E,2E,2′E)-N,N′-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1′E,2E,2′E)-N,N′-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ2N,N′}(thiocyanato-κN)(triphenylphosphane-κP)copper(I)], [Cu(NCS)(C20H18N4O4)(C18H15P)] or [Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and1H NMR spectroscopy, and X-ray crystallography [from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with atransconformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinatingviathe imine N atoms to the CuIatom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattenedgaucheconformation, resulting in a rather bowed shape overall for the ligand. The NCS−ligand is coordinated through its N atom. The geometry around the CuIatom is distorted tetrahedral, with a small N—Cu—N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN—Cu—P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands.

scholarly journals Synthesis and Insecticidal Activities of Novel Derivatives of 1β,4α,6α,9α-Tetrahydroxy-2β,12-epoxymethano-β-dihydroagarofuran

2013 ◽  
Vol 8 (6) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Jiwen Zhang ◽  
Zhan Hu ◽  
Shengkun Li ◽  
Shuding Yang ◽  
Wenjun Wu
Keyword(s):  
2D Nmr ◽  
Root Bark ◽  
Mythimna Separata ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Important Intermediate ◽  
Derivatives Of ◽  
C Nmr ◽  
Insecticidal Activities

In order to develop novel biorational pesticides, twelve new ether derivatives of 1β,4α,6α,9α-tetrahydroxy-2β,12-epoxymethano-β-dihydroagarofuran (3) were synthesized. The structure of the important intermediate 3 was confirmed by X-ray crystallography, and the new derivatives (3.1–3.12) were elucidated by IR, 1H NMR, 13 C NMR and 2D NMR spectroscopic and ESI-MS analysis. Insecticidal activities of these derivatives were tested against the third-instar larvae of Mythimna separata. Though most of the derivatives (3.1–3.4, 3.6, 3.8, 3.9–3.12) revealed no obvious activities at the concentration of 10 mg/mL –1, two compounds 3.5 and 3.7, with KD50 values of 12.9 (μg/g-1 and 7.8 μg/g –1, respectively, showed much higher insecticidal activities than celangulin-V, with a KD50 of 321.4 μg·g–1, the main insecticidal component from the root bark of Chinese bittersweet, Celastrus angulatus Max. The results showed that β-dihydroagarofuran has the potential to be a lead structure for semi-synthetic green insecticides.

2,2'-Bipyridine Mercury(II) Complexes [Hg(bpy)(NO2)X] (X = NO2 –, SCN– , CH3COO–); Π-Π Stacking In The Crystal Structure Of [Hg(bpy)(NO2)2]

2005 ◽  
Vol 60 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Ali Ramazani ◽  
Ali Morsali ◽  
Leila Dolatyari ◽  
Bijan Ganjeie
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Aromatic Rings ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Π Stacking ◽  
Π Stacking Interaction ◽  
Coordinate Geometry ◽  
C Nmr

The mercury(II) complexes of 2,2′-bipyridine (bpy), [Hg(bpy)(NO2)2], [Hg(bpy)(NO2) (CH3COO)], and [Hg(bpy)(NO2)(NCS)] have been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The structure of [Hg(bpy)(NO2)2] has been confirmed by X-ray crystallography. The complex is a monomer and the Hg atom has an unsymmetrical six-coordinate geometry, formed by two nitrogen atoms of the bpy ligand and four oxygen atoms of the two nitrite anions. There is a short intermolecular π-π stacking interaction between parallel aromatic rings

Coordination Behavior of tBu2PH towards [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene): Crystal and Molecular Structure of [{Rh(μ-Cl)(tBu2PH)2}2]

2008 ◽  
Vol 63 (9) ◽  
pp. 1035-1039 ◽  
Author(s):  
Hans-Christian Böttcher ◽  
Peter Mayer
Keyword(s):  
Molecular Structure ◽  
Nmr Spectroscopy ◽  
Crystal And Molecular Structure ◽  
Molar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molar Ratios ◽  
H Nmr ◽  
Coordination Behavior ◽  
Independent Synthesis

The reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with tBu2PH in different solvents in various molar ratios was investigated. Working with a molar ratio of Rh to P = 1 : 2 in heptane overnight afforded [{Rh(μ-Cl)(tBu2PH)2}2] (1) in nearly quantitative yield. Upon tuning the molar ratio (Rh/P) in the range from 1 : 2 to 1 : 0.5, 31P{1H} NMR spectroscopy indicated the formation of [(tBu2PH)2Rh(μ-Cl)2Rh(coe)2] (3) besides the complexes [{Rh(μ-Cl)(coe)(tBu2PH)}2] (cis, 2a; trans, 2b). The constitution of 3 was established by an independent synthesis mixing 1 with [{Rh(μ- Cl)(coe)2}2] or [{Rh(μ-Cl)(cod)}2] (cod = 1.4-cyclooctadiene), respectively, which also yielded [(tBu2PH)2Rh(μ-Cl)2Rh(cod)] (4). Single crystals of 1 have been analyzed by X-ray crystallography (monoclinic, Cc, Z = 8, a = 32.7375(3), b = 11.1294(1), c = 24.5134(3)Å ; β = 106.7228(4)◦; V = 8553.70(15) Å3; T = 200 (2) K).

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