An unusual ditantalum (Ta:Ta) compound with a bridging oxo ligand

1983 ◽  
Vol 22 (6) ◽  
pp. 868-870 ◽  
Author(s):  
F. Albert Cotton ◽  
Wieslaw J. Roth
Keyword(s):  
2017 ◽  
Vol 36 (10) ◽  
pp. 2042-2051 ◽  
Author(s):  
Nikola S. Lambic ◽  
Caleb A. Brown ◽  
Roger D. Sommer ◽  
Elon A. Ison
Keyword(s):  

1988 ◽  
Vol 41 (1) ◽  
pp. 151 ◽  
Author(s):  
SF Colmanet ◽  
MF Mackay

The reaction of sodium 1,2-dicyanoethenedithiolate with [AsPh4][TcOCl4] in ethanol yields crystals of [AsPh4][ TcO ( mnt )2] (1). Crystals of (1) are monoclinic and belong to the space group P21/c with a 12.636(1), b 13.749(1), c 18.484(1)Ǻ, β 93.49(1)� with Z 4. Refinement on 3669 data measured with Cu Kα radiation converged at R 0.063. The structure consists of [ TcO ( mnt )2]- anions and [AsPh4]+ cations. The technetium(V) atom is five-coordinate with the four sulfur atoms in the basal positions and the oxo ligand in the apical position, to give a distorted square-pyramidal environment about the technetium. The Tc =O bond distance is 1.655(6)Ǻ.


1991 ◽  
Vol 46 (2) ◽  
pp. 235-244 ◽  
Author(s):  
S. Schmid ◽  
J. Strähle

PhNCO reacts with oxo ligands at metal centers to form phenyl nitrene complexes. As an intermediate of this reaction we obtained with ReO2I(PPh3)2 (1) the trimeric complex [ORe(OCONPh)I(PPh3)]3 (2) in which the PhNCO moiety was added to an oxo ligand to form an N -phenyl carbamato group. This group acts as a bridging ligand chelating one Re atom via its N and one O atom and coordinating an other Re atom by its second O atom . 2 crystallizes as 2 · 2 CHCl3 in the triclinic space group P1̄ with a = 1423.1(5), b = 2443.3(7), c = 1403.8(6) pm , α = 92.31(3), β = 94.76(3), γ = 81.48(3)°, and Z = 2. From the mother liquor of 2 after a few days Re(NPh)(NH2Ph)I2(PPh3)(OCONHPh) (3) is formed as a partial hydrolysis product. 3 is monoclinic with the space group P21/n and a = 1163.0(4), b = 2527.0(3), c = 1243.9(5) pm, β = 98.04°, Z = 4. The Re atom exhibits an octahedral coordination w ith the two I atom s in a ?ra«s-arrangem ent and the phenyl nitrene ligand trans to the m onodentate PhN HCO2 group. The coordination is completed by a phosphine and an aniline ligand. Reaction of 2 with excess PPh3 yields 1. It crystallizes from CHCl3 as 1 · CHCl3 in the monoclinic space group P21/n with a = 975.9(3), b = 2731(1), c = 1417.3(6) pm , β = 93.35° and Z = 4. In 1 the Re atom is pentacoordinated in form of a trigonal bipyram id with the two phosphine ligands in axial positions. A solution of 2 in THF forms Re(NPh)(NH2Ph)I2(PPh3) (OReO3) (4) upon exposure to air at room temperature. 4 is obtained as orthorhombic crystals with the space group Pca21 and a = 1727(1), b = 1064.2(4), c = 1765.7(9) pm , Z = 4, and is an analogue of 3 from which it can be derived by substituting the carbamato ligand by a perrhenat ion. In 3 and 4 the phenyl nitrene ligand is bound by a Re = N triple bond of 172 pm in a linear arrangement Re = N - Ph .


2014 ◽  
Vol 16 (41) ◽  
pp. 22611-22622 ◽  
Author(s):  
Baharan Karamzadeh ◽  
Devendra Singh ◽  
Wonwoo Nam ◽  
Devesh Kumar ◽  
Sam P. de Visser

Computational studies show that the perceived nonheme iron(v)–oxo is actually an iron(iv)–oxo ligand cation radical species.


2000 ◽  
Vol 53 (9) ◽  
pp. 779 ◽  
Author(s):  
Edward R. T. Tiekink ◽  
Aston A. Eagle ◽  
Charles G. Young

Reaction of (NEt4)2[WS4] and [S2PPh2]2 in acetonitrile results in the formation of diamagnetic, orange syn-W2S2(µ-S) 2(S2PPh2)2 by an induced internal redox process. Crystals of the toluene solvate W2S2(µ-S) 2(S2PPh2)2 . C7H8 are triclinic and belong to space group P1– with a 13.845(5), b 16.536(7), c 8.387(2) Å, α 99.75(3), β 95.51(3), γ 83.08(3)˚, and Z 2. Refinement of 5445 data converged at R 0.038 and Rw 0.038. The complex possesses a syn-[W V 2S2(µ-S)2]2+ core with a W–W bond of 2.8161(5) Å and two terminal W=S bonds of 2.097(3) and 2.096(3) Å. The W-(µ-S) bond distances are in the range 2.310(2)–2.315(2) Å. Each of the five-coordinate, square-pyramidal tungsten atoms is further coordinated by a bidentate dithiophosphinate ligand with W–S bond distances ranging from 2.464(2) to 2.481(2) Å. Extended reaction of (NH4)2[WSe4] and [S2CNEt2]2 in acetonitrile produces green WS(Se2)(S2CNEt2)2 and red WO(Se2)(S2CNEt2)2 in 40% and 15% yields, respectively. Crystals of WO(Se2)(S2CNEt2)2 are monoclinic and belong to space group P21/n with a 9.609(6), b 15.053(7), c 13.120(9) Å, β 100.08(4)˚, and Z 4. Refinement of 2473 data converged at R 0.039 and Rw 0.039. The seven-coordinate, pentagonal bipyramidal complex features C1 symmetry, an axial oxo ligand (W=O 1.705(6) Å), an equatorial, side-on bonded diselenido ligand (W–Se(1) 2.509(1), W–Se(2) 2.547(1) Å, Se(1)–Se(2) 2.306(2) Å) and two bidentate dithiocarbamate ligands.


2020 ◽  
Vol 21 (22) ◽  
pp. 8787
Author(s):  
Abderrahim Titi ◽  
Mouslim Messali ◽  
Rachid Touzani ◽  
Mohammed Fettouhi ◽  
Abdelkader Zarrouk ◽  
...  

A new double-open-cubane core Cd(II)-O-Cu(II) bimetallic ligand mixed cluster of type [Cl2Cu4Cd2(NNO)6(NN)2(NO3)2].CH3CN was made available in EtOH/CH3CN solution. The 1-hydroxymethyl-3,5-dimethylpyrazole (NNOH) and 3,5-dimethylpyrazole (NNH) act as N,O-polydentate anion ligands in coordinating the Cu(II) and Cd(II) centers. The structure of the cluster in the solid state was proved by XRD study and confirmed in the liquid state by UV-vis analysis. The XRD result supported the construction of two octahedral and one square pyramid geometries types around the four Cu(II) centers and only octahedral geometry around Cd(II) two centers. Interestingly, NNOH ligand acts as a tetra-µ3-oxo and tri-µ2-oxo ligand; meanwhile, the N-N in NNH acts as classical bidentate anion/neutral ligands. The interactions in the lattice were detected experimentally by the XRD-packing result and computed via Hirschfeld surface analysis (HSA). The UV-vis., FT-IR and Energy Dispersive X-ray (EDX), supported the desired double-open cubane cluster composition. The oxidation potential of the desired cluster was evaluated using a 3,5-DTB-catechol 3,5-DTB-quinone as a catecholase model reaction.


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