Remarkable Dinitrogen Activation and Cleavage by the Gd Dimer: From Dinitrogen Complexes to Ring and Cage Nitrides

Abstract

Dinitrogen activation and its chemical transformations are one of the most challenging subjects in chemistry. Coordination of N 2 to transition-metal or f-element metal complexes is often an effective strategy for activation because it weakens the s and/or p bonds of N 2 through side-on or end-on coordination. Many dinitrogen complexes exhibit subsequent reactivity at the N 2 unit that can lead to its further activation, complete N À N bond cleavage, and functionalization. [1][2][3] Reactions of metal atoms and small clusters with dinitrogen serve as ideal models for fundamental understanding of the multifaceted mechanisms of dinitrogen activation by d-and fmetal complexes and surfaces.Previous investigations have demonstrated N À N bond cleavage by some transition-metal atoms and dimers. [4, 5] Herein we report a joint matrix-isolation infrared-spectroscopic and theoretical study of the reaction of Gd 2 with N 2 , which proceeds by the initial formation of an unprecedented dinuclear lanthanide dinitrogen complex with a simultaneously side-on and end-on bonded N 2 ligand. The complex isomerizes to a planar cyclic [Gd(m-N) The above-mentioned species were prepared by codeposition of laser-evaporated Gd atoms and clusters with N 2 /Ar mixtures onto a CsI window at 6 K as previously described. [6] Infrared spectra were recorded on a Bruker IFS 66-V spectrometer at 0.5 cm À1 resolution using a liquid-nitrogencooled mercury cadmium telluride (MCT) detector. With relatively high N 2 concentration (0.5 %) and low laser energy (< 5 mJ/pulse), the [Gd(N 2 )] and high-coordinate dinitrogen complexes, which have been previously identified, [7] were produced. The IR spectra in the selected regions with lower N 2 concentration (0.05 %) and higher laser energy (10 mJ/

Formation and Characterization of a BeOBeC Multiple Radical Featuring a Quartet Carbyne Moiety

“…Although the barrier seems quite low, this isomerization reaction is observed only under UV light (250< λ <580 nm) excitation, as the BeCOBe isomer only absorbs in the UV spectral range (Figure S6). The reaction of Be 2 and CO as well as the conversion of the identified species of BeBeCO to BeCOBe and BeOBeC are reminiscent of the previously discovered activation procedure of N 2 on diatomic Gd 2 molecules, where N 2 reacts with Gd 2 to form Gd 2 (μ‐η 2 :η 1 ‐N 2 ), and Gd(μ‐N) 2 Gd in sequence . Similar procedure occurs for Be 2 and O 2 , as is shown before .…”

“…Thereaction of Be 2 and CO as well as the conversion of the identified species of BeBeCO to BeCOBe and BeOBeC are reminiscent of the previously discovered activation procedure of N 2 on diatomic Gd 2 molecules,w here N 2 reacts with Gd 2 to form Gd 2 (m-h 2 :h 1 -N 2 ), and Gd(m-N) 2 Gd in sequence. [33] Similar procedure occurs for Be 2 and O 2 ,asi ss hown before. [23c,d] Therefore the interaction mechanism of N 2 ,O 2 ,and CO on diatomic species provides insight for understanding the activation of small molecules on metal clusters and nanoparticles.…”

Formation and Characterization of a BeOBeC Multiple Radical Featuring a Quartet Carbyne Moiety

“…Although the barrier seems quite low, this isomerization reaction is observed only under UV light (250< λ <580 nm) excitation, as the BeCOBe isomer only absorbs in the UV spectral range (Figure S6). The reaction of Be 2 and CO as well as the conversion of the identified species of BeBeCO to BeCOBe and BeOBeC are reminiscent of the previously discovered activation procedure of N 2 on diatomic Gd 2 molecules, where N 2 reacts with Gd 2 to form Gd 2 (μ‐η 2 :η 1 ‐N 2 ), and Gd(μ‐N) 2 Gd in sequence . Similar procedure occurs for Be 2 and O 2 , as is shown before .…”

Reactions of metal cluster anions with inorganic and organic molecules in the gas phase

“…218 The gas phase reactions between N 2 and bare metal clusters have been studied to understand the size, charge, and metal composition dependence of N 2 adsorption. It is very difficult to reduce due to its very large bond energy (9.7 eV), highly negative electron affinity (−1.8 eV), and huge HOMO-LUMO gap (22.9 eV).…”