Preparation and Characterization of a Novel Gadolinium Triple-Decker Sandwich-Type Complex with Tetrabenzoporphyrin Ligand

2013 ◽  
Vol 690-693 ◽  
pp. 573-576
Author(s):  
Qi Feng Liu
Keyword(s):  
Room Temperature ◽  
Spectroscopic Properties ◽  
Magnetic Interactions ◽  
Antiferromagnetic Coupling ◽  
Magnetic Studies ◽  
Conjugated Systems ◽  
Type Complex ◽  
Vis Spectroscopy ◽  
Sandwich Type

A novel gadolinium triple-decker sandwich-type complex containing tetrabenzoporphyrin (TBP) ligands-Gd (TBP)3was prepared from porphyrin 1 and Gd (acac)3.nH2O in boiling 1, 2, 4-Tcb for 45~48 h under Ar. Its structure is characterized by Uv-Vis spectroscopy and HR-MS. The spectroscopic properties show that its longest-wavelength visible band (600-800 nm) is obviously red-shifted due to the extension of the π conjugated systems derived from the linear benzoannulation in the TBP ring. The magnetic studies also indicate that there is no magnetic interactions between two Gd (III) ions in the triple-deckers in the range from room temperature down to 20K and very weak antiferromagnetic coupling exists between two Gd (III) ions below 20K.

Preparation and Properties of Gadolinium Homoleptic Double-and Triple-Decker Complexes Containing Tetrabenzoporphyrin Ligand

2013 ◽  
Vol 750-752 ◽  
pp. 1816-1821
Author(s):  
Qi Feng Liu
Keyword(s):  
Room Temperature ◽  
Spin Exchange ◽  
Spectroscopic Studies ◽  
Magnetic Interactions ◽  
Antiferromagnetic Coupling ◽  
Ir Absorption ◽  
Magnetic Studies ◽  
Absorption Bands ◽  
Near Ir ◽  
Sandwich Type

Two novel gadolinium sandwich-type complexes containing tetrabenzoporphyrin (TBP) ligands-Gd (TBP)2and Gd (TBP)3were prepared from porphyrin 1 and Gd (acac)3. nH2O under Ar by boiling 1, 2, 4-Tcb for 15~17h and 45~48 h respectively. Their structures are characterized by Uv-Vis, HR-MS and IR. The spectroscopic studies show that their longest-wavelength visible and near-IR absorption bands are obviously red-shifted due to the extension of the π conjugated systems in the TBP ring. The magnetic studies indicate that the observed value of χMT for Gd (TBP)2is close to the combined value of Gd (III) and porphyrin radical anion at room temperature and that antiferromagnetic interaction possibly results from the intramolecular spin exchange between the porphyrin π-radical electron and that the gadolinium f unpaired electrons dominates its magnetic properties over the whole temperature range while there is no magnetic interactions between two Gd (III) ions in Gd (TBP)3in the range from room temperature down to 20K and very weak antiferromagnetic coupling exsits between two Gd (III) ions below 20K.

Synthesis, Properties of Gadolinium Double-Decker Sandwich-Type Complex Containing Tetrabenzoporphyrin Ligand

2012 ◽  
Vol 190-191 ◽  
pp. 571-574 ◽  
Author(s):  
Hai Yun Xu ◽  
Chun Hua Hu ◽  
Qi Feng Liu ◽  
Wen Xian Zhao ◽  
Ying Liu
Keyword(s):  
Spin Exchange ◽  
Spectroscopic Characterization ◽  
Spectroscopic Properties ◽  
Ir Absorption ◽  
Magnetic Studies ◽  
Group 4 ◽  
Type Complex ◽  
Double Decker ◽  
Synthesis Properties ◽  
Sandwich Type

A novel gadolinium double-decker sandwich-type complex with tetrabenzoporphyrin (TBP) ligands-Gd(TBP)2 was synthesized by the reaction of porphyrin 1 with Gd(acac)3. nH2O in boiling 1, 2, 4-Tcb for 15~17 h under Ar. Its structure is characterized byUv-Vis-NIR and HR-MS. The spectroscopic properties show that the longest-wavelength visible band (600-800 nm) and the strong near-IR absorption band centered near 1340 nm of Gd (TBP)2 complex are obviously red-shifted due to the extension of the π conjugated systems derived from the linear benzoannulation in the TBP ring. The magnetic studies also indicate that the observed value of χMT of Gd(TBP)2 complex is close to the combined value of Gd(III) and porphyrin radical anion at room temperature, and antiferromagnetic interaction that possibly results from the intramolecular spin exchange between the porphyrin π-radical electron, and the gadolinium f unpaired electrons dominates its magnetic properties over the whole temperature range. Since the first report of bis(porphyrinato) metal complexes M(Por)2 such as a cerium(IV) bisporphyrinate, Ce(TPP)2 and hydrogen praseodymium(III), PrH(TPP)2 in 1983[1], sandwich-type rare earth complexes with porphyrin ligands have received increasing attentions due to the unusual physical, spectroscopic, redox, electron transfer, and/or conductivity properties resulting from their strong π-π interactions[2-4]. Whereas the chemistry and properties of homoleptic sandwich complexes containing the same pophyrinato ligands of various lanthanide, actinides and group 4 transition metals have been extensively studied[5-6], actually all of them are confined to the sandwich-type complexes containing meso-substituted porphyrin ligands except for octaethylporphyrin (OEP) or octamethylporphyrin (OMP). Little is known about sandwich-like complexes with aromatic ring-fused porphyrin ligands that contain a more delocalized π system. In this paper, we will describe the preparation of a novel gadolinium homoleptic double-decker sandwich-type complex with tetrabenzoporphyrin (TBP) ligand (see Fig.1) as well as their spectroscopic characterization and magnetic studies.

scholarly journals Synthesis and Spectroscopic Characterization of Two New Dawson Sandwich Complexes: Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O

2012 ◽  
Vol 9 (4) ◽  
pp. 2185-2190 ◽  
Author(s):  
Mohammad Hakimi ◽  
Mohammad Reza Mohammadi ◽  
Salma Behboupour
Keyword(s):  
Divalent Cation ◽  
31P Nmr ◽  
Spectroscopic Characterization ◽  
Sandwich Complexes ◽  
Sandwich Complex ◽  
Sodium Salts ◽  
Vis Spectroscopy ◽  
Sandwich Type ◽  
Anion Complexes

Reaction of the three vacant complex ofa-[P2W15O56]12-anda-[As2W15O56]12-with divalent cation of VO2+in 1:1 mole ratio yields a previously unknown sandwich-type Wells-Dawson complex; Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O (represented as Na2(VO)2P4W30) and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O (represented as Na2(VO)2As4W30). These complexes contain anions in which two divalent VO2+cations with two Na+ions are symmetrically sandwiched between two α-[P2W15O56]12- or α-[As2W15O56]12-groups leading to a “lacunary” sandwich complex. The anion complexes are isolated as sodium salts and characterized by elemental analysis, TGA, IR, 31P NMR and UV-Vis spectroscopy.

scholarly journals Mössbauer Spectroscopy, Structural and Magnetic Studies of Zn2+Substituted Magnesium Ferrite Nanomaterials Prepared by Sol-Gel Method

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yun He ◽  
Xingxing Yang ◽  
Jinpei Lin ◽  
Qing Lin ◽  
Jianghui Dong
Keyword(s):  
Saturation Magnetization ◽  
Room Temperature ◽  
Mössbauer Spectra ◽  
Zinc Concentration ◽  
Sol Gel ◽  
Magnetic Interactions ◽  
Magnesium Ferrite ◽  
Magnetic Studies ◽  
Mossbauer Spectra ◽  
Absorption Area

Zinc substituted magnesium ferrite nanomaterialsMg1-xZnxFe2O4(x= 0, 0.1, 0.3, 0.5, 0.7) powders have been prepared by a sol-gel autocombustion method. The lattice parameter increases with increase in Zn concentration, but average crystallite size tends to decrease by increasing the zinc content. SEM results indicate the distribution of grains and morphology of the samples. Some particles are agglomerated due to the presence of magnetic interactions among particles. Room temperature Mössbauer spectra ofMg1-xZnxFe2O4shows that the A Mössbauer absorption area decreases and the B Mössbauer absorption area increases with zinc concentration increasing. The change of the saturation magnetization can be explained with Néel’s theory. It was confirmed that the transition from ferrimagnetic to superparamagnetic behaviour depends on increase in zinc concentration by Mössbauer spectra at room temperature. Saturation magnetization increases and coercivity decreases with Zn content increasing.

Yttrium Polyoxometalates. Synthesis and Characterization of a Carbonate-Encapsulated Sandwich-Type Complex

2003 ◽  
Vol 42 (26) ◽  
pp. 8600-8602 ◽  
Author(s):  
Xikui Fang ◽  
Travis M. Anderson ◽  
Wade A. Neiwert ◽  
Craig L. Hill
Keyword(s):  
Synthesis And Characterization ◽  
Type Complex ◽  
Sandwich Type

Synthesis and characterization of sandwich-type gadolinium and ytterbium crown ether-substituted phthalocyanines

2000 ◽  
Vol 04 (06) ◽  
pp. 588-590 ◽  
Author(s):  
LUDMILA A. LAPKINA ◽  
ELINA NISKANEN ◽  
HANNU RÖNKKÖMÄKI ◽  
VLADIMIR E. LARCHENKO ◽  
KONSTANTIN I. POPOV ◽  
...  
Keyword(s):  
Crown Ether ◽  
Free Ligand ◽  
Direct Interaction ◽  
Original Method ◽  
Synthesis And Characterization ◽  
Organic Base ◽  
Metal Free ◽  
Vis Spectroscopy ◽  
Sandwich Type

An original method based on metal-free ligand and lanthanide acetate direct interaction in the presence of a strong organic base (DBU) is used to prepare sandwich-type gadolinium and ytterbium crown-ether substituted phthalocyanines bis[4,5,4′,5′,4″,5″,4‴,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninato]gadolinium (ytterbium) and tris[4,5,4′,5′,4″,5″,4‴-,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninato]digadolinium (ytterbium) which are characterized by MALDI-TOF mass spectrometry and UV-vis spectroscopy.

Yttrium Polyoxometalates. Synthesis and Characterization of a Carbonate-Encapsulated Sandwich-Type Complex.

ChemInform ◽  
2004 ◽  
Vol 35 (10) ◽  
Author(s):  
Xikui Fang ◽  
Travis M. Anderson ◽  
Wade A. Neiwert ◽  
Craig L. Hill
Keyword(s):  
Synthesis And Characterization ◽  
Type Complex ◽  
Sandwich Type

Sol–gel synthesis, structural, optical and magnetic characterization of Ag3(2+x)PrxNb4−xO11+δ (0.0 ≤ x ≤ 1.0) nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6336-6341 ◽  
Author(s):  
S. Ramesh ◽  
Jerald V. Ramaclus ◽  
Edgar Mosquera ◽  
B. B. Das
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Magnetic Studies ◽  
Magnetic Characterization ◽  
Optical And Magnetic Properties ◽  
Sol Gel Synthesis

The optical and magnetic properties of sol–gel synthesized nanocrystalline Ag3(2+x)PrxNb4−xO11+δ (x = 0.0, 0.50 and 1.0; S1–S3) were studied by DRS and VSM plots. Magnetic studies reveal that the samples exhibit ferromagnetism at room temperature.

Selective conversion of aldehydes to carboxylic acids by hemoglobin and air

2018 ◽  
Vol 22 (08) ◽  
pp. 679-685 ◽  
Author(s):  
Mahdi Hajimohammadi ◽  
Maryam Khalaji Verjani ◽  
Hoda Ghasemi ◽  
Nasser Safari ◽  
Günther Knör
Keyword(s):  
Carboxylic Acids ◽  
Mass Spectroscopy ◽  
Room Temperature ◽  
Aqueous Media ◽  
Water Soluble ◽  
Feasible Method ◽  
Vis Spectroscopy ◽  
Major Route ◽  
High Valent

A new green, environmentally friendly and economically feasible method for the oxygenation of benzaldehyde, cinnamaldehyde, 4-chlorobenzaldehyde and 4-bromobenzaldehyde to the corresponding carboxylic acids using air in the presence of hemoglobin as a water-soluble catalyst in aqueous media at room temperature is illustrated. The resulting products were obtained with (77–100%) conversion and 100% selectivity within a reasonable amount of time. In addition, the first direct characterization of a high-valent iron intermediate (HbFe[Formula: see text]O) measured using Mass Spectroscopy (MS) and UV-vis spectroscopy proved that the major route for oxidation of aldehydes is (HbFe[Formula: see text]O) production.

scholarly journals Synthesis and Characterization of New Boron Compounds Using Reaction of Diazonium Tetraphenylborate with Enaminoamides

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 367
Author(s):  
Markéta Svobodová ◽  
Jan Svoboda ◽  
Bing-Han Li ◽  
Valerio Bertolasi ◽  
Luboš Socha ◽  
...  
Keyword(s):  
Room Temperature ◽  
15N Nmr ◽  
Boron Compounds ◽  
Reaction Conditions ◽  
X Ray ◽  
Temperature Method ◽  
Mechanism Of Reaction ◽  
Vis Spectroscopy ◽  
11B Nmr

A family of oxazaborines, diazaborinones, triazaborines, and triazaborinones was prepared by reaction of polarized ethylenes, such as β-enaminoamides, with 4-methylbenzenediazonium tetraphenylborates. The reaction conditions (stirring in CH2Cl2 at room temperature (Method A) or stirring with CH3COONa in CH2Cl2 at room temperature (Method B) or refluxing in the CH2Cl2/toluene mixture (Method C)) controlled the formation and relative content of these compounds in the reaction mixtures from one to three products. Substituted oxazaborines gradually rearranged into diazaborinones at 250 °C. The prepared compounds were characterized by 1H NMR, 13C NMR, IR, and UV–Vis spectroscopy, HRMS, or microanalysis. The structure of individual compounds was confirmed by 11B NMR, 15N NMR, 1D NOESY, and X-ray analysis. The mechanism of reaction of enaminoamides with 4-methylbenzenediazonium tetraphenylborate was proposed.

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