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.

Synthesis and characterization of novel azo-embedded N-confused tetraphenylporphyrin

2009 ◽  
Vol 13 (02) ◽  
pp. 215-222 ◽  
Author(s):  
Motoki Toganoh ◽  
Takayoshi Hihara ◽  
Kentaro Yonekura ◽  
Yuichi Ishikawa ◽  
Hiroyuki Furuta
Keyword(s):  
Absorption Spectrum ◽  
Effective Interaction ◽  
Coupling Reaction ◽  
Crystallographic Analysis ◽  
Synthesis And Characterization ◽  
X Ray ◽  
H Nmr ◽  
Cis Isomer ◽  
C Nmr

A unique class of azo porphyrin, 5,10,15,20-tetraphenyl-21-phenylazo-(2-aza-21-carbaporphyrin 1, in which an azophenyl group is embedded in N -confused porphyrin, was synthesized and characterized by 1 H NMR, 13 C NMR, UV-vis absorption, MS, and X-ray crystallographic analysis. Synthesis of 1 was achieved through a coupling reaction of 21-amino N -confused tetraphenylporphyrin with nitrosobenzene and subsequent deoxygenation of resulting azoxy derivative with a trioxo rhenium(VII) N -fused porphyrinato catalyst. The azo-conjugate molecule was exclusively obtained as a trans-isomer and no isomerization to the cis-isomer was observed under thermal or photoirradiation. The absorption spectrum of 1 shows a moderate red-shift due to the effective interaction between the porphyrinic π-system and the connecting azophenyl group. Upon protonation, this effect is essentially lost as a result of removing degeneracy of LUMO and LUMO+1.

[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 Optoelectronic Characterization of Some Star-Shaped Oligomers with Benzene and Triphenylamine Cores

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Teofilia Ivan ◽  
Loredana Vacareanu ◽  
Mircea Grigoras
Keyword(s):  
Electrochemical Polymerization ◽  
Coupling Reaction ◽  
Aromatic Aldehydes ◽  
Thermal Characterization ◽  
Cyclic Voltammograms ◽  
Heck Coupling ◽  
Molecular Glasses ◽  
H Nmr ◽  
Ft Ir

Six star-shaped oligomers containing triphenylamine (D1–D3) and benzene unit (D4–D6) as cores have been synthesized by Wittig condensation or Heck coupling reaction using aromatic aldehydes and triphenylphosphonium salts or aromatic halogenated compounds with vinyl triphenylamine. All oligomers have well-defined molecular structure and high purity. Characterization of the oligomers was made by FT-IR, 1H-NMR spectroscopy, UV-Vis, and fluorescence spectroscopy. The electrochemical behavior was studied by cyclic voltammetry (CV). The cyclic voltammograms have revealed that oligomers undergo quasireversible or irreversible redox processes. The irreversible process is associated with electrochemical polymerization of oligomers by dimerization of unsubstituted triphenylamine groups. Thermal characterization was accomplished by TGA and DSC methods and evidenced that all oligomers were stable materials until 250°C and have formed stable molecular glasses after first heating scan.

Syntheses and Characterization of New Mixed-Ligand Mercury(II) Complexes, Hg(bpy)n(SCN)X (X = CH3COO–, NO3– and ClO4–), Crystal Structure of [Hg(bpy)2(SCN)]NO3

2004 ◽  
Vol 59 (10) ◽  
pp. 1109-1113 ◽  
Author(s):  
Ali Reza Mahjoub ◽  
Ali Morsali ◽  
Ramin Ebrahim Nejad
Keyword(s):  
Mixed Ligand ◽  
Lead Atom ◽  
Aromatic Rings ◽  
X Ray ◽  
X Ray Crystallography ◽  
Thiocyanate Ligand ◽  
Π Stacking Interaction ◽  
Coordinate Geometry ◽  
C Nmr

AbstractThe 1:2 and 1:1 mixed-ligand mercury(II) complexes with 2,2’-bipyridine (bpy) containing two different anions, Hg(bpy)n(SCN)X (X= CH3COO−, NO3− and ClO4−), have been synthesized and characterized by elemental analysis, and IR, 1H and 13C NMR spectroscopy. The structure of [Hg(bpy)2(SCN)]NO3 was confirmed by X-ray crystallography. The complex is monomeric and the Hg atom has an unsymmetrical five-coordinate geometry, with four nitrogen atoms of two bpy ligands and one sulfur atom of the thiocyanate ligand as donor atoms. This is in contrast to lead(II) complexes, [Pb(phen)2(NO3)(NCS)], [Pb(phen)(O2CCH3)(NCS)] where the thiocyanate ligands are coordinated to the lead atom via the nitrogen atom. There is a π −π stacking interaction between the parallel aromatic rings.

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 Synthesis and Spectroscopic Characterization of Some New Biological Active Azo–Pyrazoline Derivatives

2012 ◽  
Vol 9 (3) ◽  
pp. 1613-1622 ◽  
Author(s):  
Farouq E. Hawaiz ◽  
Mohammad K. Samad
Keyword(s):  
Addition Reaction ◽  
Coupling Reaction ◽  
Spectroscopic Characterization ◽  
Hydroxyl Group ◽  
Significant Activity ◽  
H Nmr ◽  
Ft Ir ◽  
High Yields ◽  
C Nmr

A number of 3-[4-(benzyloxy)-3-(2-Chlorophenylazo)-phenyl]-5-(substituted-phenyl)-1-substituted-2-pyrazolines( 4a-j) and (5a-j) have been synthesized by diazotization of 2-chloroaniline and its coupling reaction with 4-hydroxy acetophenone, followed by benzyloxation of the hydroxyl group to give the substrate [4-benzyloxy-3-(2-chlorophenylazo)-acetophenone (1)].The prepared starting material (1) has been reacted with different substituted benzaldehydes to give a new series of chalcone derivatives 1-[(4-benzyloxy)-3-(2-chloro-phenylazo)-phenyl]-3-(substituted phenyl)-2-propen-1-one (3a-j), in high yields and in a few minutes, and the later compounds were treated with hydrazine hydrate according to Michael addition reaction to afford a new biolological active target compounds (4a-j) and (5a-j). Furthermore, The structures of the newly synthesized compounds were confirmed by FT-IR,13C-NMR,13C-DEPT &1H-NMR spectral data. The chalcone and pyrazoline derivatives were evaluated for their anti bacterial activity againstEscherichia colias gram negative andStaphylococcus aureusas gram positive, the results showed significant activity against both types of bacteria.

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.

Synthesis and characterization of silver(I) complexes of thioureas and thiocyanate: crystal structure of polymeric (1,3-diazinane-2-thione)thiocyanato silver(I)

2015 ◽  
Vol 70 (8) ◽  
pp. 541-546 ◽  
Author(s):  
Muhammad Nawaz Tahir ◽  
Anvarhusein A. Isab ◽  
Fozia Afzal ◽  
Kashif Raza ◽  
Shah Muhammad ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectrum ◽  
Coordination Environment ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Ir And Nmr Spectroscopy ◽  
A Chain ◽  
Distorted Tetrahedral Coordination ◽  
C Nmr

AbstractSilver(I) complexes of thioureas and thiocyanate, [(Tu)AgSCN], [(Metu)AgSCN], [(Dmtu)AgSCN], [(Tmtu)(AgSCN)1.5], [(Imt)AgSCN], and [(Diaz)AgSCN] (where Tu = thiourea, Metu = N-methylthiourea, Dmtu = N,N′-dimethylthiourea, Tmtu = N,N,N′,N′-tetramethylthiourea, Imt = 1,3-imidazolidine-2-thione, and Diaz = 1,3-diazinane-2-thione), have been prepared and characterized by elemental analysis, IR and NMR spectroscopy, and thermal analysis. The crystal structure of one of them, [(Diaz)Ag(SCN)] (1), was determined by X-ray crystallography. The crystal structure of 1 shows that the complex exists in the form of a chain-like polymer comprising [Ag(μ2-Diaz)(μ2-SCN)] units. The silver atoms are bridged by μ2-thione sulfur atoms of Diaz and μ2-thiocyanate sulfur atoms. Thereby each silver atom adopts a distorted tetrahedral coordination environment comprising four sulfur atoms, two from thione and two from thiocyanate ligands. An upfield shift in the >C=S resonance of thiones in 13C NMR and a downfield shift in the N–H resonance in 1H NMR are consistent with the sulfur coordination to silver(I). The appearance of a band around 2100 cm–1 in the IR and a resonance around 125 ppm in the 13C NMR spectrum indicates the binding of thiocyanate to silver(I).

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.

scholarly journals Green synthesis and structural characterization of novel N1-substituted 3,4-dihydropyrimidin-2(1H)-ones

2019 ◽  
Vol 8 (1) ◽  
pp. 230-234 ◽  
Author(s):  
Min Wang ◽  
Shun Zhang ◽  
Hong X. Jiang ◽  
Hao H. Zhang
Keyword(s):  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Aromatic Aldehydes ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Solvent Free Conditions ◽  
Biginelli Condensation ◽  
C Nmr

Abstract Novel N1-substituted 3,4-dihydropyrimidin-2(1H)-one derivatives were synthesized through Biginelli condensation of aromatic aldehydes, β-ketoesters, and monosubstituted (thio)ureas in the presence of copper methanesulfonate at 90°C under solvent-free conditions. The screening of the catalysts showed the copper methanesulfonate was the best. Its catalytic activity remained after three times of use. The products were characterized by IR, 1H NMR, 13C NMR, elemental analysis, and X-ray single crystal diffraction technique. A reasonable reaction mechanism was proposed.

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