Author: Omar Ali Sabbak
Publisher:
ISBN:
Category :
Languages : en
Pages : 100
Book Description
Isocyanide Complexes of Cobalt
Author: Omar Ali Sabbak
Publisher:
ISBN:
Category :
Languages : en
Pages : 100
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 100
Book Description
Low-Valent Iron and Cobalt Isocyanide Complexes
Author: Charles Cameron Mokhtarzadeh
Publisher:
ISBN:
Category :
Languages : en
Pages : 434
Book Description
This dissertation describes the targeted attempts at the generation of transition metal species that function as precise electronic structure mimics to the well known spin triplet (S =1) metal carbonyls fragments Fe(CO)4 and CpCo(CO). These unsaturated fragments have been shown to display a wide range reactivity, and competency towards important reaction chemistry such as alkane and N2 binding, and E-H bond activation due to a unique interplay of a strong ligand field, formal dn count, and orbital symmetry, rendering these fragments primed for bond activation. Accordingly, ligand architectures that can accurately mimic the ligand field provided by CO to kinetically stabilize these fragments could provide new inroads to novel small molecule activation pathways. To this end, sterically encumbering m-terphenyl isocyanides serve as isolobal ligand surrogates for carbon monoxide (CO). Additionally isocyanides have the added benefit of providing kinetic stabilization by virtue of readily tunable isocyano-R (CN-R) group. The first section of this dissertation describes the synthesis and protonation of an encumbered tetra-isocyanide iron dianion, Na2[Fe(CNArMes2)4] (ArMes2 = 2,6-(2,4,6 --Me3C6H2)2C6H3), which serves as a platform for targeting species of the formulation Fe(CNArMes2)4. It is shown that the reactivity of the electronically unsaturated Fe(CNR)4 fragment upon protonation of Na2[Fe(CNArMes2)4] and subsequent alkylation of Na[HFe(CNArMes2)4], yields the dinitrogen stabilized species Fe(N2)(CNArMes2)4. Fe(N2)(CNArMes2)4 is shown to readily undergo intramolecular C-H activation of the ligand scaffold upon liberation N2 under ambient conditions purportedly through and insipient [Fe(CNArMes2)4] fragment. Further more, ability of Na2[Fe(CNArMes2)4] to facilitate the reductive disproportionation of CO2, in addition to CO2 capture with electrophilic silyl sources is presented culminating in a rare class of low valent Fe-aminocarbyne complexes. The second vignette of this dissertation focuses on the generation of species that mimic the formulation CpCo(L). It is shown that with less encumbering m-terphenyl isocyanides that aggregation akin to the unsaturated carbonyl congeners is realized. Use of encumbering m-terphenyl isocyanides provides access to the three memebered electron transfer series [([mu]2-CNArMes2)2[CpCo]2]n (n = 0,-1, -2). Notably, this series is the first of its kind to span all three ostensible electronic states (e.g. d8-d8, d8-d9, and d9-d9), previously unavailable with other [pi]-acidic ligand frameworks. Additionally this allows for a systematic reassessment of the metal-metal bonding within this class of dimeric species. Evidence is put forth in favor of no M-M bonding interactions occur within these systems and the integrity of the dimeric framework is in fact mitigated through a unique interplay of the metal d-manifold and the isocyanide [pi]*-system. Modulation of the steric profile of the m-terphenyl isocyanide and the Cp unit to Cp* so as to increase the steric pressure provides access to the first reported mono-nuclear Cp*Co(N2)L fragments. It is shown that these species function as viable sources of Cp*Co(CNR) for a number of bond activation processes including Si-H, H-H, and P-P bond scission. Moreover, the reactivity of these species culminates with the isolation of the second example of a structurally authenticated transition metal nitrous oxide (N2O) adduct, which exhibits an unprecedented [eta]2-(N,N) coordination mode to Co. Finally, the reduction of the encumbered Cp*Co(CNArTripp2) (CNArTripp2 2,6-(2,4,6-(i-Pr)3C6H3)2C6H3) fragment provide access to the unique dianion K2[Cp*Co≡CNArTripp2]. It is shown that the dianion K2[Cp*Co≡CNArTripp2] exhibits 3-fold bonding between Co and the isocyanide -Ciso through an extreme case of M-->(CN) [pi]*-back donation and gives rise to the first example of a Co-carbyne complex. The reactivity and electronic structure are presented for K2[Cp*Co≡CNArTripp2] and it is concluded that this reactive dianion behaves as a potent metal based nucleophile and source of [Cp*Co(CNR)]2- for a number of bond activation process.
Publisher:
ISBN:
Category :
Languages : en
Pages : 434
Book Description
This dissertation describes the targeted attempts at the generation of transition metal species that function as precise electronic structure mimics to the well known spin triplet (S =1) metal carbonyls fragments Fe(CO)4 and CpCo(CO). These unsaturated fragments have been shown to display a wide range reactivity, and competency towards important reaction chemistry such as alkane and N2 binding, and E-H bond activation due to a unique interplay of a strong ligand field, formal dn count, and orbital symmetry, rendering these fragments primed for bond activation. Accordingly, ligand architectures that can accurately mimic the ligand field provided by CO to kinetically stabilize these fragments could provide new inroads to novel small molecule activation pathways. To this end, sterically encumbering m-terphenyl isocyanides serve as isolobal ligand surrogates for carbon monoxide (CO). Additionally isocyanides have the added benefit of providing kinetic stabilization by virtue of readily tunable isocyano-R (CN-R) group. The first section of this dissertation describes the synthesis and protonation of an encumbered tetra-isocyanide iron dianion, Na2[Fe(CNArMes2)4] (ArMes2 = 2,6-(2,4,6 --Me3C6H2)2C6H3), which serves as a platform for targeting species of the formulation Fe(CNArMes2)4. It is shown that the reactivity of the electronically unsaturated Fe(CNR)4 fragment upon protonation of Na2[Fe(CNArMes2)4] and subsequent alkylation of Na[HFe(CNArMes2)4], yields the dinitrogen stabilized species Fe(N2)(CNArMes2)4. Fe(N2)(CNArMes2)4 is shown to readily undergo intramolecular C-H activation of the ligand scaffold upon liberation N2 under ambient conditions purportedly through and insipient [Fe(CNArMes2)4] fragment. Further more, ability of Na2[Fe(CNArMes2)4] to facilitate the reductive disproportionation of CO2, in addition to CO2 capture with electrophilic silyl sources is presented culminating in a rare class of low valent Fe-aminocarbyne complexes. The second vignette of this dissertation focuses on the generation of species that mimic the formulation CpCo(L). It is shown that with less encumbering m-terphenyl isocyanides that aggregation akin to the unsaturated carbonyl congeners is realized. Use of encumbering m-terphenyl isocyanides provides access to the three memebered electron transfer series [([mu]2-CNArMes2)2[CpCo]2]n (n = 0,-1, -2). Notably, this series is the first of its kind to span all three ostensible electronic states (e.g. d8-d8, d8-d9, and d9-d9), previously unavailable with other [pi]-acidic ligand frameworks. Additionally this allows for a systematic reassessment of the metal-metal bonding within this class of dimeric species. Evidence is put forth in favor of no M-M bonding interactions occur within these systems and the integrity of the dimeric framework is in fact mitigated through a unique interplay of the metal d-manifold and the isocyanide [pi]*-system. Modulation of the steric profile of the m-terphenyl isocyanide and the Cp unit to Cp* so as to increase the steric pressure provides access to the first reported mono-nuclear Cp*Co(N2)L fragments. It is shown that these species function as viable sources of Cp*Co(CNR) for a number of bond activation processes including Si-H, H-H, and P-P bond scission. Moreover, the reactivity of these species culminates with the isolation of the second example of a structurally authenticated transition metal nitrous oxide (N2O) adduct, which exhibits an unprecedented [eta]2-(N,N) coordination mode to Co. Finally, the reduction of the encumbered Cp*Co(CNArTripp2) (CNArTripp2 2,6-(2,4,6-(i-Pr)3C6H3)2C6H3) fragment provide access to the unique dianion K2[Cp*Co≡CNArTripp2]. It is shown that the dianion K2[Cp*Co≡CNArTripp2] exhibits 3-fold bonding between Co and the isocyanide -Ciso through an extreme case of M-->(CN) [pi]*-back donation and gives rise to the first example of a Co-carbyne complex. The reactivity and electronic structure are presented for K2[Cp*Co≡CNArTripp2] and it is concluded that this reactive dianion behaves as a potent metal based nucleophile and source of [Cp*Co(CNR)]2- for a number of bond activation process.
Cobalt Cyanide and Isocyanide Complexes, Their Preparation, Structure, and Bonding
Author: Leo Dale Brown
Publisher:
ISBN:
Category :
Languages : en
Pages : 332
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 332
Book Description
Crystal Structure Analysis of Some Gold (I) Isocyanide Complexes and Cobalt Complexes of N, N'-Bis-(2'-Pyridinecarboxamide)-1, 2-Benzene
Author: Wing-Tak Wong
Publisher: Open Dissertation Press
ISBN: 9781374741676
Category :
Languages : en
Pages :
Book Description
This dissertation, "Crystal Structure Analysis of Some Gold (I) Isocyanide Complexes and Cobalt Complexes of N, N'-bis-(2'-pyridinecarboxamide)-1, 2-benzene" by Wing-tak, Wong, 黃永德, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3120843 Subjects: Gold
Publisher: Open Dissertation Press
ISBN: 9781374741676
Category :
Languages : en
Pages :
Book Description
This dissertation, "Crystal Structure Analysis of Some Gold (I) Isocyanide Complexes and Cobalt Complexes of N, N'-bis-(2'-pyridinecarboxamide)-1, 2-benzene" by Wing-tak, Wong, 黃永德, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3120843 Subjects: Gold
The Vitamin D Cure
Author: Lamberto Malatesta
Publisher: Wiley-Interscience
ISBN:
Category : Health & Fitness
Languages : en
Pages : 216
Book Description
Groundbreaking new research has traced the source of a wide array of to a single common factor—vitamin D deficiency. Leading rheumatologist and researcher Dr. James Dowd reveals the causes of vitamin D deficiency and offers a simple, easy-to-follow five-step program that can eliminate or alleviate a host of seemingly incurable conditions, such as arthritis, in as little as six weeks. Better yet, by staying on the program, you can enjoy robust health and improved fitness for the rest of your life.
Publisher: Wiley-Interscience
ISBN:
Category : Health & Fitness
Languages : en
Pages : 216
Book Description
Groundbreaking new research has traced the source of a wide array of to a single common factor—vitamin D deficiency. Leading rheumatologist and researcher Dr. James Dowd reveals the causes of vitamin D deficiency and offers a simple, easy-to-follow five-step program that can eliminate or alleviate a host of seemingly incurable conditions, such as arthritis, in as little as six weeks. Better yet, by staying on the program, you can enjoy robust health and improved fitness for the rest of your life.
Isocyanide-metal Complexes
Author: Robert Bruce King
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Isocyanide Complexes of Manganese
Author: Glen E. Dirreen
Publisher:
ISBN:
Category :
Languages : en
Pages : 238
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 238
Book Description
Crystal Structure Analysis of Some Gold (I) Isocyanide Complexes and Cobalt Complexes of N, N'-bis-(2'-pyridinecarboxamide)-1, 2-benzene
Author: Wing-tak Wong (M.Phil.)
Publisher:
ISBN:
Category : Gold
Languages : en
Pages : 488
Book Description
Publisher:
ISBN:
Category : Gold
Languages : en
Pages : 488
Book Description
Low-Valent Cobalt Isocyanides
Author: Alex Edward Carpenter
Publisher:
ISBN: 9781321887969
Category :
Languages : en
Pages : 390
Book Description
A synthetic and structural investigation of cobalt complexes stabilized by m-terphenyl isocyanides was conducted. These species were studied as isolable mimics to unsaturated cobalt carbonyls and as platforms to access coordination complexes with unusual dn/valence combinations. Through these studies, a critical assessment of isocyanide for carbonyl substitution is presented. This assessment includes a comparative study on the electronic influence of isocyanides (C[equivalence]N--R), as a function of R-group identity, in Cr(CNR)(CO)5 complexes. Structural mimics to all three conformational isomers of Co2(CO)8 were prepared using the m-terphenyl isocyanides CNArMes2 (ArMes2 = 2,6-(2,4,6-Me3C6H2)C6H3) and CNArDipp2 (ArDipp2 = 2,6-(2,6-i-Pr2C6H3)C6H3). Solid-state X-ray diffraction data showed that 1,1-Co2(CO)6 (CNArMes2)2 adopts a "D2d-type" conformation, analogous to the elusive D2d isomer of Co2(CO)8. The cobalt hydride HCo(CNArMes2)4 was synthesized and structurally characterized. As a potential analogue to HCo(CO)4, a broad survey of its reactivity was undertaken. In the course of this study, HCo(CNArMes2)4 was found to mediate 1,1-hydrogenation and 1,1-hydrosilylation of CNArMes2. Complementing this work, a complete series of mixed carbonyl-isocyanide cobalt metallates, [Co(CO)4-n(CNArMes2)n]-, and hydrides, HCo(CO)4-n(CNArMes2)n, were prepared. The synthesis and solution-phase properties of a zwitterionic cobalt metallate is presented. 2D EXSY NMR studies and isotopic labeling experiments demonstrate that [Eta]2-PPNCo(CNArMes2)3, functions as a masked source of [Co(CNArMes2)3]1-, a 16 valence electron isocyano metallate. Electrophillic functionalization of [Eta]2-PPNCo(CNArMes2)3, with TMSCl, provided access to Co(SiMe3)(CNArMes2)3. This complex was structurally characterized by X-ray diffraction. The previously reported ability of Co(SiMe3)(CNArMes2)3 to form a [alpha]-complex with n-hexane at low-temperature in the solid state is contextualized with variable temperature IR and NMR studies. Reduction of Co(SiMe3)(CNArMes2)3 generated the highly reduced isocyano metallate K2[Co(SiMe3)(CNArMes2)3]. This dissertation concludes with the synthesis and characterization of the first examples of terminal transition metal antimony trifluoride (SbF3) and antimony difluoride (SbF2) complexes.
Publisher:
ISBN: 9781321887969
Category :
Languages : en
Pages : 390
Book Description
A synthetic and structural investigation of cobalt complexes stabilized by m-terphenyl isocyanides was conducted. These species were studied as isolable mimics to unsaturated cobalt carbonyls and as platforms to access coordination complexes with unusual dn/valence combinations. Through these studies, a critical assessment of isocyanide for carbonyl substitution is presented. This assessment includes a comparative study on the electronic influence of isocyanides (C[equivalence]N--R), as a function of R-group identity, in Cr(CNR)(CO)5 complexes. Structural mimics to all three conformational isomers of Co2(CO)8 were prepared using the m-terphenyl isocyanides CNArMes2 (ArMes2 = 2,6-(2,4,6-Me3C6H2)C6H3) and CNArDipp2 (ArDipp2 = 2,6-(2,6-i-Pr2C6H3)C6H3). Solid-state X-ray diffraction data showed that 1,1-Co2(CO)6 (CNArMes2)2 adopts a "D2d-type" conformation, analogous to the elusive D2d isomer of Co2(CO)8. The cobalt hydride HCo(CNArMes2)4 was synthesized and structurally characterized. As a potential analogue to HCo(CO)4, a broad survey of its reactivity was undertaken. In the course of this study, HCo(CNArMes2)4 was found to mediate 1,1-hydrogenation and 1,1-hydrosilylation of CNArMes2. Complementing this work, a complete series of mixed carbonyl-isocyanide cobalt metallates, [Co(CO)4-n(CNArMes2)n]-, and hydrides, HCo(CO)4-n(CNArMes2)n, were prepared. The synthesis and solution-phase properties of a zwitterionic cobalt metallate is presented. 2D EXSY NMR studies and isotopic labeling experiments demonstrate that [Eta]2-PPNCo(CNArMes2)3, functions as a masked source of [Co(CNArMes2)3]1-, a 16 valence electron isocyano metallate. Electrophillic functionalization of [Eta]2-PPNCo(CNArMes2)3, with TMSCl, provided access to Co(SiMe3)(CNArMes2)3. This complex was structurally characterized by X-ray diffraction. The previously reported ability of Co(SiMe3)(CNArMes2)3 to form a [alpha]-complex with n-hexane at low-temperature in the solid state is contextualized with variable temperature IR and NMR studies. Reduction of Co(SiMe3)(CNArMes2)3 generated the highly reduced isocyano metallate K2[Co(SiMe3)(CNArMes2)3]. This dissertation concludes with the synthesis and characterization of the first examples of terminal transition metal antimony trifluoride (SbF3) and antimony difluoride (SbF2) complexes.
Monomeric Iron and Cobalt Compounds with Cyanide and Isocyanide Ligands
Author: Anthony John Pesiri
Publisher:
ISBN:
Category : Hydrogenase
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Hydrogenase
Languages : en
Pages :
Book Description