scholarly journals Synthesis, IR spectroscopic and structural studies of erbium and nickel complexes with N,N'-tetraethyl-N''-trifluoroacetylphosphoroustriamide

Author(s):  
V.O. Zozulia ◽  
V.A. Ovchynnikov ◽  
T.Yu. Sliva ◽  
O.S. Panteleieva ◽  
J.A. Rusanova ◽  
...  

A synthesis procedure was developed and a new carbacylamidophosphate type ligand N,N'-tetraethyl-N''-trifluoroacetylphosphoroustriamide (CF3C(O)NHP(O)(NC2H5)2, HL) that contains C(O)NP(O) chelating fragment was isolated in the crystalline state. A mononuclear erbium complex [Er(HL)3(NO3)3] and a tetranuclear nickel complex [Ni4L4(OCH3)4(CH3OH)4] were isolated in the crystalline state. The suggestion about the type and coordination mode of the ligand in complexes was made based on IR spectroscopic investigations: deprotonated (acido-) form in bidentate manner in nickel complex and neutral form in monodentate manner in erbium complex. According to X-ray structural studies, different coordination modes of the ligand in complexes were determined: bidentate chelate manner via the oxygen atoms of the phosphoryl and carbonyl groups of the ligand with the formation of six-membered chelate cycles in case of nickel complex and monodentate manner via the oxygen atom of the phosphoryl group of the ligand in case of erbium complex, the coordination polyhedron of which was interpreted as a distorted three-handed trigonal prism.

2001 ◽  
Vol 56 (3) ◽  
pp. 249-254 ◽  
Author(s):  
Victor A. Trush ◽  
Jolanta Swiatek-Kozlowska ◽  
Victor V. Skopenko ◽  
Vladimir M. Amyrkhanov

Abstract A new type of binuclear coordination compound of lutetium, {Lu2L6 · μ-(γ,γ '-dipy)} (where L = dimethyl-N-trichloroacetylamidophosphate anion and γ,γ '-dipy = 4,4'-dipyridyl), has been obtained. The IR spectroscopic data reveal that the ambidentate phosphoryl ligand is coordinated to the metal center in a bidentate manner via the phosphoryl and carbonyl oxygen atoms. The crystal and molecular structure of {Ln2L6-μ-(γ ,γ '-dipy)} has been determined by means of X-ray diffraction (triclinic, space group P i with parameters: a = 9.259(2), b = 12.530(3), c = 16.548(3) Å, α = 85.44(3)°, β = 75.64(3)°, γ = 70.56(3)°, Z = 1). The structure is made up of centrosymmetric binuclear molecules, in which the neutral heterocyclic ligand is coordinated to the metal centers in a bidentate bridging manner via its nitrogen atoms. The coordination number of each Lu(III) atom is 7 [60(L-) + N((γ ,γ '-dipy)]. Phosphoryl and carbonyl groups of the L- ligands are disposed in syn-position and are included in the six-membered chelate metallocycles. The coordination polyhedron of lutetium can be described as distorted mono-capped octahedron.


1997 ◽  
Vol 52 (10) ◽  
pp. 1194-1198 ◽  
Author(s):  
Vladimir M. Amirkhanov ◽  
Joachim Sieler ◽  
Victor A. Trush ◽  
Vladimir A. Ovchynnikov ◽  
Konstantin V. Domasevitch

A new dioxouranium(VI) nitrate complex with N,N′-tetraethyl-N″-trichloracetylphosphortriamide (HL = CCl3C(O)N(H)P(O)(NEt2)2) of composition UO2 (HL)2(NO3)2 (1) has been synthesised. The IR spectroscopic data reveal that the ambidentate ligand is coordinated to the metal center in a monodentate manner via the phosphoryl oxygen atom. The crystal and molecular structure of 1 has been determined from X-ray diffraction data (triclinic, space group P1̄ with a = 9.225(2), b = 10.360(2), c = 12.249(2) Å, α = 100.02 (1), β = 103.81(1), γ = 108.80 (1)°, Z = 1; R = 0.037 for 4092 unique reflections. The structure is made up of centrosymmetric molecules in which the neutral ligands HL are monocoordinated. Phosphoryl and carbonyl groups of the HL moieties are in the trans positions to each other. The axial vertices of the distorted hexagonal bipyramid of uranium are occupied by two oxo ligands [U-O 1.753(5) Å] while six oxygen atoms of phosphoryl and nitrate groups lie in the equatorial plane [U-O 2.347(5)-2.547(6)Å],


1984 ◽  
Vol 39 (6) ◽  
pp. 744-753 ◽  
Author(s):  
Heinrich Nöth ◽  
Ekkehard Fluck

AbstractThe structures of four compounds containing the P-NH-P unit have been determined by X-ray methods in order to detect prototropism. Ph2P-NH-PPh2 in the solid state is indeed a bis(diphenylphosphino)amin having C2 molecular symmetry. Its bisborane(3) ad­duct possesses the structure Ph2P(BH3)-NH-P(BH3)Ph2 with the BH3 -groups in transoid position. The P-NH-P unit is also observed in (PhO)2P(O)-NH-P(O)(OPh)2 and (PhO)2P(O)-NH-P(O)(C2H5)2. These two compounds show weak intermolecular hydrogen bonding in the solid state to the oxygen atom of a phosphoryl group. The PN bond distances depend on the group X bonded to phosphorus and decrease in the series with X = BH3 > S > O, e.g. with the electron withdrawing ability of X.


Author(s):  
James A. Lake

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.


Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.


2019 ◽  
Author(s):  
Swaraj Sengupta ◽  
Sahanwaj Khan ◽  
Shyamal K. Chattopadhyay ◽  
Indrani Banerjee ◽  
Tarun K. Panda ◽  
...  

Synthesis and characterisation of one trinuclear copper complex, ([Cu<sub>3</sub>L<sub>3</sub>O]ClO<sub>4</sub>) (<b>1</b>) and one nickel complex ([Ni(L'H)<sub>2</sub>(dmso)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>) (<b>2</b>) with Schiff base ligands: (3Z)-3-((Z)-(1-(thiophen-2-yl)ethylidene)hydrazono)butan-2-one oxime (LH) and 1-(pyridin-2-yl)ethylidene)hydrazono)butan-2-one oxime (L<sup>'</sup>H). <b>1</b> shows high catecholase activity and has also been tested as a catalyst for the synthesis of benzylimine. <b>2 </b> shows phenoxazinone synthase activity.


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