scholarly journals Synthesis and structures of anionic rhenium polyhydride complexes of boron–hydride ligands and their application in catalysis

2020 ◽  
Vol 11 (36) ◽  
pp. 9994-9999 ◽  
Author(s):  
Liam J. Donnelly ◽  
Simon Parsons ◽  
Carole A. Morrison ◽  
Stephen P. Thomas ◽  
Jason B. Love
Keyword(s):  
Ligand Exchange ◽  
Boron Hydride ◽  
Hydride Ligands

Exhaustive deoxygenation of perrhenate by pinacol borane forms a new Re anion of boron and hydride ligands only that undergoes borane ligand exchange, stoichiometric C–H boration, and catalytic pyridine hydroboration.

Wolfram-Carbonylkomplexe mit Stickstoff-Wasserstoff-Liganden [1] / Tungsten Carbonyl Complexes with Nitrogen Hydride Ligands [1]

1978 ◽  
Vol 33 (5) ◽  
pp. 542-553 ◽  
Author(s):  
Dieter Sellmann ◽  
Alfred Brandl ◽  
Ralf Endeil
Keyword(s):  
Ligand Exchange ◽  
Nmr Spectra ◽  
Base Catalysis ◽  
Coupling Constants ◽  
Carbonyl Complexes ◽  
H Nmr ◽  
Nitrogen Hydride ◽  
Tungsten Carbonyl ◽  
Synthesis Properties ◽  
Hydride Ligands

Abstract Synthesis, properties and reactions of [(OC)5W]2N2H2, [(OC)5W]2N2H4, (OC)5WN2H4, (OC)5WNH3, [(OC)4PØ3W]2N2H4, [(OC)4PØ3WN2H4], [(OC)5W-N2H2-W(CO)4PØ3], [(OC)5W-N2H2-W(CO)4P(CH3)3] and [(OC)5WNHCH3NHC6H5] are reported. The hydrazine complexes are synthesized by ligand exchange from the corresponding tetra-hydrofuran complexes. Oxidation by various oxidizing agents yields the diazene complexes, in most cases very low yields. Substitution of CO by phosphanes leads to reduced stability of the compounds. All complexes undergo base catalysed H-D exchange yielding the corresponding ND derivatives; the diazene complexes show a much faster exchange than the corresponding hydrazine and ammonia complexes, which is explained by the higher acidity of the N2H2 protons. The diazene complexes disproportionate under base catalysis to hydrazine and dinitrogen compounds, the latter of which loose the N2 ligand immediately. The diazene ligand of [(OC)5W]2N2H2 cannot be alkylated by reactions with (CH3)2SO4, LiCH3 or CH2N2; instead, LiCH3 as well as CH2N2 cause disproportionation to N2H4 and N2 complexes. UV irradiation of [(OC)5W]2N2H2 in THF leads to substitution of CO by THF. The THF complexes can be converted to the phosphane substituted diazene complexes. The IR, UV-VIS and 1H NMR spectra of the (OC)5W complexes are nearly identical to those of the analogous Cr and Mo compounds. The unsymmetrical phosphane diazene complexes, however, show a quartet of the N2H2 protons in the 1H NMR spectra with coupling constants of 25-26 Hz for the protons on the NN double bond. This value points to a trans configuration of the diazene ligand and its complexes respectively.

Synthesis and reactivity of iron nitrosyl hydrides substituted with triphenyl phosphine

1983 ◽  
Vol 61 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
Jean-Louis A. Roustan ◽  
Alain Forgues ◽  
Jean-Yves Merour ◽  
Narinder D. Venayak ◽  
B. A. Morrow
Keyword(s):  
Atmospheric Pressure ◽  
Ligand Exchange ◽  
Striking Difference ◽  
Boron Hydride ◽  
Exchange Reactions ◽  
Triphenyl Phosphine ◽  
Cobalt Carbonyl ◽  
Decomposition Products ◽  
Iron Nitrosyl ◽  
Hb C

Protonation of anion 1 [Fe(CO)3(NO)]−, (Na+) in the presence of P(C6H5)3 yielded the iron nitrosyl hydrides 3 FeH-(CO)2(NO)(P(C6H5)3) and 4 FeH(CO)(NO)(P(C6H5)3)2 or the iron nitrosyl cation 5 [Fe(CO)2(NO)(P(C6H5)3)2]+, [Formula: see text] de- pending upon the conditions. Anions 12 (Li+),[Fe(CO)(NO)(P(C6H5)3)2]− and 15 (Li+),[Fe(CO)2(NO)(P(C6H5)3)]− were formed in the reactions of Li+, −HB(C2H5)313 with hydrides 4 and 3 respectively. Anions 15 resulted also from the reaction of cation 5 with an excess (at least 6 equivalents) of boron hydride 13 and from the reaction of anion 12 with CO at atmospheric pressure. Hydrides 3 and 4 were prone to ligand exchange reactions and could be interconverted easily. This is in contrast to the reluctance of the isoelectronic cobalt hydride CoH(CO)3(P(C6H5)3) to undergo further reaction with P(C6H5)3. Another striking difference between the iron nitrosyl hydrides and the isoelectronic cobalt carbonyl hydrides was found when the reactions which normally yield bimetallic derivatives were investigated. The nature of the decomposition products formed in the thermolysis of 3 and 4, in the reactions of 3 with olefins and dioxygen, and in the reduction reactions of cation 5 suggests that metallic dimers containing a (Fe(NO))2 unit are prone to fast CO and NO exchanges triggering an irreversible fragmentation into monometallic decomposition products, comprising invariably iron dinitrosyl derivatives.

Separation of fudosteine on an achiral C18column by HPLC with chiral ligand-exchange selectors as mobile phase additives

2008 ◽  
Vol 20 (4) ◽  
pp. 585-594 ◽  
Author(s):  
J. Ma ◽  
J. Cao ◽  
M. J. Ding ◽  
L. H. Yuan ◽  
M. J. Zhai ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Mobile Phase ◽  
Chiral Ligand ◽  
Mobile Phase Additives ◽  
Chiral Ligand Exchange

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Voltammetric Studies of Some Novel Fe(III) Complexes with Quadridentate Ligands. The Axial Ligand-Exchange Reactions in DMF and DMSO

1995 ◽  
Vol 60 (7) ◽  
pp. 1140-1157 ◽  
Author(s):  
Ljiljana S. Jovanovic ◽  
Luka J. Bjelica
Keyword(s):  
Oxidation State ◽  
Chemical Reactions ◽  
Ligand Exchange ◽  
Kinetic Data ◽  
Central Atom ◽  
Axial Ligand ◽  
Exchange Reactions ◽  
Ligand Effect ◽  
Condensation Products ◽  
Voltammetric Studies

The electrochemistry of four novel Fe(III) complexes of the type [Fe(L)Cl], involving quadridentate ligands based on the condensation products of benzoylacetone-S-methylisothiosemicarbazone with salicylaldehyde, 5-chlorosalicylaldehyde, 3,5-dichlorosalicylaldehyde or 5-nitrosalicylaldehyde, was studied in DMF and DMSO at a GC electrode. All complexes undergo a two-step one-electron reductions, usually complicated by chemical reactions. In solutions containing Cl-, the ligand-exchange reactions Cl--DMF and Cl--DMSO take place. Stability of the chloride-containing complexes was discussed in terms of the coordinated ligand effect, oxidation state of the central atom and, in particular, of the donor effect of the solvent. Some relevant kinetic data were calculated.

Lead Sulfide Quantum Dot Photodetector with Enhanced Responsivity through a Two-Step Ligand-Exchange Method

2019 ◽  
Vol 2 (10) ◽  
pp. 6135-6143 ◽  
Author(s):  
Haodong Tang ◽  
Jialin Zhong ◽  
Wei Chen ◽  
Kanming Shi ◽  
Guanding Mei ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Lead Sulfide ◽  
Ligand Exchange ◽  
Exchange Method
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