The Experts below are selected from a list of 492 Experts worldwide ranked by ideXlab platform
Eric Rivard - One of the best experts on this subject based on the ideXlab platform.
-
application of the donor acceptor concept to intercept low oxidation state group 14 element hydrides using a wittig reagent as a lewis base
Inorganic Chemistry, 2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.
-
Application of the Donor–Acceptor Concept to Intercept Low Oxidation State Group 14 Element Hydrides using a Wittig Reagent as a Lewis Base
2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3PCMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry
John E Bercaw - One of the best experts on this subject based on the ideXlab platform.
-
cyclopentadienyl and olefin substituent effects on insertion and β hydrogen elimination with group 4 metallocenes kinetics mechanism and thermodynamics for zirconocene and hafnocene alkyl hydride derivatives
Organometallics, 2005Co-Authors: John E BercawAbstract:Reactions of group 4 metallocene Dihydrides, (RnCp)2MH2 (RnCp = alkyl-substituted cyclopentadienyl; M = Zr, Hf), with olefins afford stable metallocene alkyl hydride complexes of the general formula (RnCp)2M(CH2CHR‘2)(H) (R‘ = H, alkyl). For sterically crowded, monomeric Dihydrides, Cp*2ZrH2 (Cp* = η5-C5Me5), Cp*(η5-C5Me4H)ZrH2, Cp*(η5-C5Me4Et)ZrH2, Cp*2HfH2, and Cp*(η5-C5H3-1,3-(CMe3)2)HfH2, second-order rate constants for olefin insertion have been measured. For Cp*2HfH2, the relative rates of olefin insertion have been found to be 1-pentene > styrene ≫ cis-2-butene > cyclopentene > trans-2-butene > isobutene. The rate of isobutene insertion into Cp*(η5-C5Me4H)ZrH2 is 3.8 × 103 times greater than that for Cp*2ZrH2 at −63 °C, demonstrating the striking steric effect for isobutene insertion imposed by a tenth methyl substituent on the two cyclopentadienyl ligands. A primary kH/kD of 2.4(3) at 23 °C and a linear free energy correlation to σ (ρ = −0.46(1)) for para-substituted styrene insertion indicate tha...
-
preparation and characterization of monomeric and dimeric group iv metallocene Dihydrides having alkyl substituted cyclopentadienyl ligands
Organometallics, 1999Co-Authors: Michael W Day, John E BercawAbstract:A series of zirconocene dihydride complexes of the general form [(RnCp)2ZrH2]x having substituted cyclopentadienyl ligands has been prepared by hydrogenation of the corresponding dimethyl complexes...
Anindya K Swarnakar - One of the best experts on this subject based on the ideXlab platform.
-
application of the donor acceptor concept to intercept low oxidation state group 14 element hydrides using a wittig reagent as a lewis base
Inorganic Chemistry, 2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.
-
Application of the Donor–Acceptor Concept to Intercept Low Oxidation State Group 14 Element Hydrides using a Wittig Reagent as a Lewis Base
2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3PCMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry
Robert Mcdonald - One of the best experts on this subject based on the ideXlab platform.
-
application of the donor acceptor concept to intercept low oxidation state group 14 element hydrides using a wittig reagent as a lewis base
Inorganic Chemistry, 2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.
-
Application of the Donor–Acceptor Concept to Intercept Low Oxidation State Group 14 Element Hydrides using a Wittig Reagent as a Lewis Base
2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3PCMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry
-
Germyl- and Germylene-Bridged Complexes of Rh/Ir and Subsequent Chemistry of a Bridging Germylene Group
2012Co-Authors: Md Hosnay Mobarok, Michael J Ferguson, Robert Mcdonald, Martin CowieAbstract:A series of neutral and cationic germylene-bridged complexes and a neutral germyl(germylene) complex have been synthesized and characterized by NMR spectroscopy and X-ray crystallography. Reaction of 1 equiv of primary germanes, RGeH3 (R = Ph, tBu), with [RhIr(CO)3(dppm)2] (1) at low-temperature yields [RhIr(GeH2R)(H)(CO)3(dppm)2] (R = Ph (3) or tBu (4)), the products of single Ge–H bond activation, which upon warming transform to the germylene-bridged Dihydrides, [RhIr(H)2(CO)2(μ-GeHR)(dppm)2] (R = Ph (5) or tBu (6)) by activation of a second Ge–H bond accompanied by CO loss. Both classes of compounds have the diphosphines folded back in a “cradle-shaped” geometry. Although compound 5 reacts with additional phenylgermane at −40 °C to give a germylene-bridged/germyl product, [RhIr(GeH2Ph)(H)2(CO)2(κ1-dppm)(μ-GeHPh)(μ-H)(dppm)] (7), warming results in decomposition. However, reaction of 5 with 1 equiv of diphenylgermane at ambient temperature results in a novel mixed bis(μ-germylene) complex, [RhIr(CO)2(μ-GeHPh)(μ-GePh2)(dppm)2] (8), containing both mono- and disubstituted germylene fragments. Reaction of 1 equiv of diphenylgermane with complex 1 produces a similar monogermylene-bridged product, [RhIr(H)2(CO)2(μ-GePh2)(dppm)2] (9), while reaction of 1 with 2 equiv of diphenylgermane yields the germyl/germylene product [RhIr(H)(GeHPh2)(CO)3(κ1-dppm)(μ-GePh2)(dppm)] (10). The above reactions, incorporating first one and then a second equivalent of primary and secondary germanes, were studied by low-temperature multinuclear NMR spectroscopy, revealing details about the stepwise activations of multiple Ge–H bonds. Reaction of diphenylgermane with the cationic complex [RhIr(CH3)(CO)2(dppm)2][CF3SO3] (2) leads to a cationic A-frame-type germylene- and hydride-bridged product, [RhIr(CO)2(μ-H)(μ-GePh2)(dppm)2][CF3SO3] (3), which reversibly activates H2, yielding a germyl-bridged dihydride and reacts stoichiometrically with water, methanol, and HCl to yield the respective germanol, germamethoxy, and germylchloride products
Michael J Ferguson - One of the best experts on this subject based on the ideXlab platform.
-
application of the donor acceptor concept to intercept low oxidation state group 14 element hydrides using a wittig reagent as a lewis base
Inorganic Chemistry, 2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.
-
Application of the Donor–Acceptor Concept to Intercept Low Oxidation State Group 14 Element Hydrides using a Wittig Reagent as a Lewis Base
2014Co-Authors: Anindya K Swarnakar, Sean M Mcdonald, Kelsey C Deutsch, Paul Choi, Michael J Ferguson, Robert Mcdonald, Eric RivardAbstract:This article outlines our attempts to stabilize the Group 14 element Dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3PCMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry
-
Germyl- and Germylene-Bridged Complexes of Rh/Ir and Subsequent Chemistry of a Bridging Germylene Group
2012Co-Authors: Md Hosnay Mobarok, Michael J Ferguson, Robert Mcdonald, Martin CowieAbstract:A series of neutral and cationic germylene-bridged complexes and a neutral germyl(germylene) complex have been synthesized and characterized by NMR spectroscopy and X-ray crystallography. Reaction of 1 equiv of primary germanes, RGeH3 (R = Ph, tBu), with [RhIr(CO)3(dppm)2] (1) at low-temperature yields [RhIr(GeH2R)(H)(CO)3(dppm)2] (R = Ph (3) or tBu (4)), the products of single Ge–H bond activation, which upon warming transform to the germylene-bridged Dihydrides, [RhIr(H)2(CO)2(μ-GeHR)(dppm)2] (R = Ph (5) or tBu (6)) by activation of a second Ge–H bond accompanied by CO loss. Both classes of compounds have the diphosphines folded back in a “cradle-shaped” geometry. Although compound 5 reacts with additional phenylgermane at −40 °C to give a germylene-bridged/germyl product, [RhIr(GeH2Ph)(H)2(CO)2(κ1-dppm)(μ-GeHPh)(μ-H)(dppm)] (7), warming results in decomposition. However, reaction of 5 with 1 equiv of diphenylgermane at ambient temperature results in a novel mixed bis(μ-germylene) complex, [RhIr(CO)2(μ-GeHPh)(μ-GePh2)(dppm)2] (8), containing both mono- and disubstituted germylene fragments. Reaction of 1 equiv of diphenylgermane with complex 1 produces a similar monogermylene-bridged product, [RhIr(H)2(CO)2(μ-GePh2)(dppm)2] (9), while reaction of 1 with 2 equiv of diphenylgermane yields the germyl/germylene product [RhIr(H)(GeHPh2)(CO)3(κ1-dppm)(μ-GePh2)(dppm)] (10). The above reactions, incorporating first one and then a second equivalent of primary and secondary germanes, were studied by low-temperature multinuclear NMR spectroscopy, revealing details about the stepwise activations of multiple Ge–H bonds. Reaction of diphenylgermane with the cationic complex [RhIr(CH3)(CO)2(dppm)2][CF3SO3] (2) leads to a cationic A-frame-type germylene- and hydride-bridged product, [RhIr(CO)2(μ-H)(μ-GePh2)(dppm)2][CF3SO3] (3), which reversibly activates H2, yielding a germyl-bridged dihydride and reacts stoichiometrically with water, methanol, and HCl to yield the respective germanol, germamethoxy, and germylchloride products