A Zirconium Hydrazide as a Synthon for a Metallanitrene Equivalent: Atom‐by‐Atom Assembly of [EN₂]²⁻ Units (E=S, Se) by Chalcogen‐Atom Transfer in the Coordination Sphere of a Transition Metal

Abstract

Stück für Stück: Die N‐N‐Bindungen von Hydraziden an Zirconiumzentren werden leicht gespalten. Diese Spezies reagieren daher wie Metallanitrene, sodass verbrückende Dinitridosulfat(IV)‐ und Dinitridoselenat(IV)‐Liganden Atom für Atom aufgebaut werden können (siehe Schema; TBS=tBuMe2Si).

Synthesis and Structural Characterization of a Lithium Alkynyl(hydrazinediido)zirconate and its Protonolysis to an Alkynylhydrazido(1–)zirconium Complex

“…Reaction of the hydrazinediido complex 1 12a with lithiated phenylacetylene selectively gave the lithium alkynyl(hydrazinediido)zirconate [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(py)] ( 2 ), which reacted with one molar equivalent of TMEDA to afford the corresponding Li‐TMEDA derivative [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(TMEDA)] ( 3 ) (Scheme ).…”

“…A consequence of the coordination of the lithium acetylide is the formation of an almost planar Zr–N–Li–C metallacycle [RMSD 0.02 Å]. The zirconium–N α distance of 1.937(2) Å is slightly greater than for the corresponding Zr–N bond in the hydrazinediido starting material 1 [1.899(2) Å] 12a. However, it is shorter than the Zr–N distance observed in hydrazido(1–)‐Zr compounds such as the previously reported [Zr(N 2 TBS N py )(HNNPh 2 ) 2 ] [2.082(1) Å] 13.…”

“…Elemental analyses were recorded by the analytical service of the Heidelberg Chemistry Department. The hydrazinediido complex [Zr(N 2 TBS N py (NNPh 2 )(py)] ( 1 ) was prepared as reported previously 12a. All other reagents were obtained from commercial sources and used as received unless explicitly stated.…”

Synthesis and Structural Characterization of a Lithium Alkynyl(hydrazinediido)zirconate and its Protonolysis to an Alkynylhydrazido(1–)zirconium Complex

“…Reaction of the hydrazinediido complex 1 12a with lithiated phenylacetylene selectively gave the lithium alkynyl(hydrazinediido)zirconate [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(py)] ( 2 ), which reacted with one molar equivalent of TMEDA to afford the corresponding Li‐TMEDA derivative [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(TMEDA)] ( 3 ) (Scheme ).…”

“…A consequence of the coordination of the lithium acetylide is the formation of an almost planar Zr–N–Li–C metallacycle [RMSD 0.02 Å]. The zirconium–N α distance of 1.937(2) Å is slightly greater than for the corresponding Zr–N bond in the hydrazinediido starting material 1 [1.899(2) Å] 12a. However, it is shorter than the Zr–N distance observed in hydrazido(1–)‐Zr compounds such as the previously reported [Zr(N 2 TBS N py )(HNNPh 2 ) 2 ] [2.082(1) Å] 13.…”

“…Elemental analyses were recorded by the analytical service of the Heidelberg Chemistry Department. The hydrazinediido complex [Zr(N 2 TBS N py (NNPh 2 )(py)] ( 1 ) was prepared as reported previously 12a. All other reagents were obtained from commercial sources and used as received unless explicitly stated.…”

Bonding and Bending in Zirconium(IV) and Hafnium(IV) Hydrazides

“…The formation of the linearly coordinated hydrazide in 5 and 6 is characterised by 15 N NMR spectroscopy resonances of δ =287.8 ppm for ZrN α ( δ =289.1 ppm for HfN α ) and 178.2 ppm for the N β Ph 2 nuclei in 5 (173.6 ppm in 6 ). The molecular structure of 5 was established by X‐ray diffraction8 and is depicted in Figure 3.…”

Redox Non‐Innocent Behavior of a Terminal Iridium Hydrazido(2−) Triple Bond

“…Consequently, the field has experienced substantial growth in the past 25 years: several imido and oxo complexes of the late transition metals (Groups 8–10) have been synthesized, but examples of heteroatom‐functionalized multiply bound ligands, such as terminal hydrazido(2−) and alkoxyimidos, are extremely limited . Such terminal moieties are attractive synthetic targets because they are important intermediates along N 2 reduction cycles and in other catalytic reactions, in which they can serve as built‐in oxidants through cleavage of the N ‐heteroatom bond . Furthermore, terminal hydrazidos have the potential to access redox non‐innocent manifolds through a contribution from the β‐N lone pair (hydrazido(2−)/1,1‐isodiazene resonance), which may allow for redox reactions that would be otherwise inaccessible without such metal–ligand cooperativity.…”

Synthesis and Structural Characterization of a Lithium Alkynyl(hydrazinediido)zirconate and its Protonolysis to an Alkynylhydrazido(1–)zirconium Complex

“…Reaction of the hydrazinediido complex 1 12a with lithiated phenylacetylene selectively gave the lithium alkynyl(hydrazinediido)zirconate [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(py)] ( 2 ), which reacted with one molar equivalent of TMEDA to afford the corresponding Li‐TMEDA derivative [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(TMEDA)] ( 3 ) (Scheme ).…”

“…A consequence of the coordination of the lithium acetylide is the formation of an almost planar Zr–N–Li–C metallacycle [RMSD 0.02 Å]. The zirconium–N α distance of 1.937(2) Å is slightly greater than for the corresponding Zr–N bond in the hydrazinediido starting material 1 [1.899(2) Å] 12a. However, it is shorter than the Zr–N distance observed in hydrazido(1–)‐Zr compounds such as the previously reported [Zr(N 2 TBS N py )(HNNPh 2 ) 2 ] [2.082(1) Å] 13.…”

“…Elemental analyses were recorded by the analytical service of the Heidelberg Chemistry Department. The hydrazinediido complex [Zr(N 2 TBS N py (NNPh 2 )(py)] ( 1 ) was prepared as reported previously 12a. All other reagents were obtained from commercial sources and used as received unless explicitly stated.…”

Bonding and Bending in Zirconium(IV) and Hafnium(IV) Hydrazides

“…The formation of the linearly coordinated hydrazide in 5 and 6 is characterised by 15 N NMR spectroscopy resonances of δ =287.8 ppm for ZrN α ( δ =289.1 ppm for HfN α ) and 178.2 ppm for the N β Ph 2 nuclei in 5 (173.6 ppm in 6 ). The molecular structure of 5 was established by X‐ray diffraction8 and is depicted in Figure 3.…”

Redox Non‐Innocent Behavior of a Terminal Iridium Hydrazido(2−) Triple Bond

“…Consequently, the field has experienced substantial growth in the past 25 years: several imido and oxo complexes of the late transition metals (Groups 8–10) have been synthesized, but examples of heteroatom‐functionalized multiply bound ligands, such as terminal hydrazido(2−) and alkoxyimidos, are extremely limited . Such terminal moieties are attractive synthetic targets because they are important intermediates along N 2 reduction cycles and in other catalytic reactions, in which they can serve as built‐in oxidants through cleavage of the N ‐heteroatom bond . Furthermore, terminal hydrazidos have the potential to access redox non‐innocent manifolds through a contribution from the β‐N lone pair (hydrazido(2−)/1,1‐isodiazene resonance), which may allow for redox reactions that would be otherwise inaccessible without such metal–ligand cooperativity.…”

Synthesis and Structural Characterization of a Lithium Alkynyl(hydrazinediido)zirconate and its Protonolysis to an Alkynylhydrazido(1–)zirconium Complex

“…Reaction of the hydrazinediido complex 1 12a with lithiated phenylacetylene selectively gave the lithium alkynyl(hydrazinediido)zirconate [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(py)] ( 2 ), which reacted with one molar equivalent of TMEDA to afford the corresponding Li‐TMEDA derivative [(N 2 TBS N py )Zr{μ‐NNPh 2 ‐1 κN :2 κN }{μ‐PhCC‐1 κC :2 κC }‐Li(TMEDA)] ( 3 ) (Scheme ).…”

“…A consequence of the coordination of the lithium acetylide is the formation of an almost planar Zr–N–Li–C metallacycle [RMSD 0.02 Å]. The zirconium–N α distance of 1.937(2) Å is slightly greater than for the corresponding Zr–N bond in the hydrazinediido starting material 1 [1.899(2) Å] 12a. However, it is shorter than the Zr–N distance observed in hydrazido(1–)‐Zr compounds such as the previously reported [Zr(N 2 TBS N py )(HNNPh 2 ) 2 ] [2.082(1) Å] 13.…”

“…Elemental analyses were recorded by the analytical service of the Heidelberg Chemistry Department. The hydrazinediido complex [Zr(N 2 TBS N py (NNPh 2 )(py)] ( 1 ) was prepared as reported previously 12a. All other reagents were obtained from commercial sources and used as received unless explicitly stated.…”

Bonding and Bending in Zirconium(IV) and Hafnium(IV) Hydrazides

“…The formation of the linearly coordinated hydrazide in 5 and 6 is characterised by 15 N NMR spectroscopy resonances of δ =287.8 ppm for ZrN α ( δ =289.1 ppm for HfN α ) and 178.2 ppm for the N β Ph 2 nuclei in 5 (173.6 ppm in 6 ). The molecular structure of 5 was established by X‐ray diffraction8 and is depicted in Figure 3.…”

Redox Non‐Innocent Behavior of a Terminal Iridium Hydrazido(2−) Triple Bond

“…Consequently, the field has experienced substantial growth in the past 25 years: several imido and oxo complexes of the late transition metals (Groups 8–10) have been synthesized, but examples of heteroatom‐functionalized multiply bound ligands, such as terminal hydrazido(2−) and alkoxyimidos, are extremely limited . Such terminal moieties are attractive synthetic targets because they are important intermediates along N 2 reduction cycles and in other catalytic reactions, in which they can serve as built‐in oxidants through cleavage of the N ‐heteroatom bond . Furthermore, terminal hydrazidos have the potential to access redox non‐innocent manifolds through a contribution from the β‐N lone pair (hydrazido(2−)/1,1‐isodiazene resonance), which may allow for redox reactions that would be otherwise inaccessible without such metal–ligand cooperativity.…”