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 Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1498 ◽  
Author(s):  
Abdul Hafeez ◽  
Zareen Akhter ◽  
John F. Gallagher ◽  
Nawazish Ali Khan ◽  
Asghari Gul ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spectroscopic Characterization ◽  
Spectroscopic Techniques ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Electrically Conductive ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

scholarly journals Spectroscopic characterization of nanoErythrosomes in the absence and presence of conjugated polyethyleneglycols: an FTIR and 31P-NMR study

2002 ◽  
Vol 1564 (2) ◽  
pp. 317-324 ◽  
Author(s):  
Roxane Pouliot ◽  
Audrey Saint-Laurent ◽  
Camille Chypre ◽  
Ritchie Audet ◽  
Isabelle Vitté-Mony ◽  
...  
Keyword(s):  
31P Nmr ◽  
Spectroscopic Characterization ◽  
Nmr Study

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.

Infrared, 57Fe Mössbauer, and 31P NMR Spectroscopic Characterization of Fe(CO)4L (L = Phosphine and Phosphite)

1987 ◽  
Vol 42 (5) ◽  
pp. 573-578 ◽  
Author(s):  
Hidenari Inoue ◽  
Takashi Nakagome ◽  
Takeshi Kuroiwa ◽  
Tsuneo Shirai ◽  
Ekkehard Fluck
Keyword(s):  
31P Nmr ◽  
Chemical Shifts ◽  
Spectroscopic Characterization ◽  
Negative Slope ◽  
Positive Slope ◽  
Carbonyl Ligands ◽  
Trigonal Bipyramidal ◽  
Back Donation ◽  
Donor Capability

A series of trigonal bipyramidal Fe(CO)4L complexes has been prepared and characterized by infrared, 57Fe Mössbauer and 31P NMR spectroscopy. A linear correlation, with a negative slope, between the CO stretching frequencies and the isomer shifts demonstrates that the triple bond nature of the carbonyl ligands is strengthened with increasing iron-to-phosphorus back donation. The linear dependence of the quadrupole splittings on the isomer shifts with a positive slope has revealed that the σ-donor capability of the phosphine or phosphite ligand is offset by the π-acceptor capability. The formation of Fe(CO)4L complexes from the corresponding free ligands is accompanied by a downfield shift of 31P NMR chemical shifts. The coordination shifts are linearly correlated with the Mössbauer isomer shifts.

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