Metallaborane Reaction Chemistry. Part 7. B-Frame Supported Bimetallics: Ligand-to-β-Metal Organometallic Interaction in Dimetallaboranes and an Interesting Ligand Displacement Cascade

1999 ◽  
Vol 64 (6) ◽  
pp. 938-946 ◽  
Author(s):  
Young-hee Kim ◽  
Yvonne M. McKinnes ◽  
Paul A. Cooke ◽  
Robert Greatrex ◽  
John D. Kennedy ◽  
...  
Keyword(s):  
Metal Atom ◽  
Phenyl Group ◽  
Phosphine Ligand ◽  
Platinum Atom ◽  
Displacement Cascade ◽  
Ligand Displacement

Reaction of [PtCl2(PMe2Ph)2] with [(PMe2Ph)2PtB10H12] generates [(PMe2Ph)2-μ-η1(Pt)- η1-(Pt')-{PMe2(C6H4)}-closo-Pt2B10H9(PMe2Ph)] in which the phenyl group of a phosphine ligand on one platinum atom exhibits ortho-cyclometallation to the second metal atom, whereas reaction of PPh3 with [(PMe2Ph)2PtB9H9Ru(pcym)] generates [(PMe2Ph)2-μ-η6(Ru)- η1(Pt)-(C6H5PPh2)-closo-PtRuB9H9] in which the phenyl group of a phosphine ligand on the platinum atom exhibits tridentate η6 coordination to the second metal atom.

3,5-Dimethylpyrazolylphosphine molybdenum(0) and tungsten(0) carbonyl complexes

1980 ◽  
Vol 58 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Harry B. Davis ◽  
James K. Hoyano ◽  
Ping Yuen Leung ◽  
Louis K. Peterson ◽  
Brian Wolstenholme
Keyword(s):  
General Formula ◽  
Metal Atom ◽  
Phosphorus Atom ◽  
Phenyl Ring ◽  
Octahedral Geometry ◽  
Phosphine Ligand ◽  
Carbonyl Complexes ◽  
Coordination Sites ◽  
And Tungsten

Complexes with the general formula [LnM(CO)m], where [Formula: see text] x = 0–2, n = 1 or 2, M = Mo(0) or W(0), m = 3 or 4, were prepared by thermal or photolytic methods by the reaction of the appropriate 3,5-dimethylpyrazolyl phosphine ligand with M(CO)6, norbornadienemetaltetracarbonyl [C7H8M(CO)4], cycloheptatrienylmetaltricarbonyl [C7H8M(CO)3], [(Me2N(CH2)3NMe2)M(CO)4], [(CH3CN)2M(CO)4], or [(CH3CN)3M(CO)3]. Structural evidence indicates octahedral geometry about the metal atom centre, and several modes of coordination for the ligands in those complexes isolated and characterized. For x = 2, the ligand [Formula: see text] was monodentate, via phosphorus in [Formula: see text] and bidentate in [Formula: see text] where coordination by P and the 2N site of the pyrazolyl ring yielded four-membered [Formula: see text] metallocycles. For x = 1, the [Formula: see text] ligand was bidentate, via the phosphorus atom and one of the 2N sites of one of the pyrazolyl substituents, thus giving the four-membered [Formula: see text] metallocycle in [Formula: see text] and tridentate in [Formula: see text] where three facial CO's, two 2N atoms of the pyrazolyl rings, and a part of the phenyl ring occupy the six coordination sites. For x = 0, the P(Me2pz)3 ligand was tridentate via the 2N atoms of all three pyrazolyl rings, thus giving tricyclic systems [P(Me2pz)3M(CO)3] (VIII, IX).

Experimental and Computational Studies of Phosphine Ligand Displacement in Iridium–Pincer Complexes Employing Pyridine or Acetonitrile

2020 ◽  
Vol 39 (19) ◽  
pp. 3461-3468
Author(s):  
Sara Shafiei-Haghighi ◽  
Aneelman Brar ◽  
Daniel K. Unruh ◽  
Anthony F. Cozzolino ◽  
Michael Findlater
Keyword(s):  
Phosphine Ligand ◽  
Pincer Complexes ◽  
Computational Studies ◽  
Ligand Displacement ◽  
Iridium Pincer Complexes

Intramolecular hydrogen transfer from the alkyl substituent of a phosphine ligand to a metal atom upon the irradiation of tungsten phosphine hydride complexes

1987 ◽  
Vol 36 (5) ◽  
pp. 928-930 ◽  
Author(s):  
A. P. Pivovarov ◽  
L. M. Ioffe ◽  
Yu. V. Gak ◽  
V. D. Makhaev ◽  
A. P. Borisov ◽  
...  
Keyword(s):  
Metal Atom ◽  
Hydrogen Transfer ◽  
Alkyl Substituent ◽  
Phosphine Ligand ◽  
Hydride Complexes ◽  
Intramolecular Hydrogen

Metall-π-Komplexe von Benzolderivaten, XXI [1]. Bis(η1.2.3.4.4a.9a-anthracen)chrom und Bis(η1.2.3.4.4a.9a-9.10-dihydroanthrancen)- chrom durch Metallatom-Ligand-Cokondensation / Metal-π-Complexes of Benzene Derivatives, XXI [1]. Bis(η1.2.3.4.4a.9a-anthracene)chromium and Bis(η1.2.3.4.4a.9a-9,10-dihydroanthracene)chromium via Metal Atom Ligand Cocondensation

1984 ◽  
Vol 39 (3) ◽  
pp. 375-383 ◽  
Author(s):  
Christoph Elschenbroich ◽  
Reinhart Möckel ◽  
Edgar Bilger
Keyword(s):  
Radical Cation ◽  
Metal Atom ◽  
Esr Spectroscopy ◽  
Fluid Solution ◽  
Benzene Derivatives ◽  
Mild Conditions ◽  
Ligand Displacement ◽  
Π Complex ◽  
Anthracene Vapor ◽  
C Nmr

Cocondensation of chromium atoms with anthracene vapor affords bis(η1.2.3.4.4a.9a-anthracene)- chromium (1) which was characterized as the radical cation 1+̣ in fluid solution by means of ESR spectroscopy. Conspicuous features of this new π-complex are the ease of ligand displacement (τ1/2 ≈ 10 min. THF, 233 K) and the ready hydrogenation in 9,10-position of the ligand which already occurs under mild conditions (e.g. methanol). The product of hydrogenation, bis (η1.2.3.4.4a.9a-9,10-dihydroanthracene)chromium (2) was synthesized independently and studied by 1H, 13C NMR (2) and ESR(2+̣) spectroscopy. A qualitative rationalization is given for the observed trend of increasing lability and propensity to hydrogenation: (η6-biphenyl)2chromium < (η6-phenanthrene)2chromium < (η6-naphthalene)2chromium < (η6-anthracene)2chromium.

Electronic properties of quasi two-dimensional transition metals chalcogenides with low-dimensional magnetism

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 87-95
Author(s):  
M. S. Baranava ◽  
P. A. Praskurava
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Exchange Interaction ◽  
Electronic Properties ◽  
Metal Atom ◽  
Transition Metal Atom ◽  
Two Dimensional ◽  
Transition Metal Atoms ◽  
Ground Magnetic ◽  
Low Dimensional

The search for fundamental physical laws which lead to stable high-temperature ferromagnetism is an urgent task. In addition to the already synthesized two-dimensional materials, there remains a wide list of possible structures, the stability of which is predicted theoretically. The article suggests the results of studying the electronic properties of MAX3 (M = Cr, Fe, A = Ge, Si, X = S, Se, Te) transition metals based compounds with nanostructured magnetism. The research was carried out using quantum mechanical simulation in specialized VASP software and calculations within the Heisenberg model. The ground magnetic states of twodimensional MAX3 and the corresponding energy band structures are determined. We found that among the systems under study, CrGeTe3 is a semiconductor nanosized ferromagnet. In addition, one is a semiconductor with a bandgap of 0.35 eV. Other materials are antiferromagnetic. The magnetic moment in MAX3 is localized on the transition metal atoms: in particular, the main one on the d-orbital of the transition metal atom (and only a small part on the p-orbital of the chalcogen). For CrGeTe3, the exchange interaction integral is calculated. The mechanisms of the formation of magnetic order was established. According to the obtained exchange interaction integrals, a strong ferromagnetic order is formed in the semiconductor plane. The distribution of the projection density of electronic states indicates hybridization between the d-orbital of the transition metal atom and the p-orbital of the chalcogen. The study revealed that the exchange interaction by the mechanism of superexchange is more probabilistic.

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