Hume–Rothery Phase-Inspired Metal-Rich Molecules: Cluster Expansion of [Ni(ZnMe)₆(ZnCp*)₂] by Face Capping with Ni⁰(η⁶-toluene) and Ni^I(η⁵-Cp*)

Abstract

The novel all-hydrocarbon ligand-stabilized binuclear clusters of metal-core composition Ni2Zn7E, [(η(5)-Cp*)Ni2(ZnMe)6(ZnCp*)(ECp*)] (1-Zn, E = Zn; 1-Ga, E = Ga) and [(η(6)-toluene)Ni2(ZnCp*)2(ZnMe)6] (2; Cp* = pentamethylcyclopentadienyl), were obtained via Ga/Zn and Al/Zn exchange reactions using the starting compounds [Ni2(ECp*)3(η(2)-C2H4)2] (E = Al/Ga) and an excess of ZnMe2 (Me = CH3). Compounds 1-Zn and 1-Ga are very closely related and differ only by one Zn or Ga atom in the group 12/13 metal shell (Zn/Ga) around the two Ni centers. Accordingly, 1-Zn is EPR-active and 1-Ga is EPR-silent. The compounds were derived as a crystalline product mixture. All new compounds were characterized by (1)H and (13)C NMR and electron paramagnetic resonance (EPR) spectroscopy, mass spectrometric analysis using liquid-injection field desorption ionization, and elemental analysis, and their molecular structures were determined by single-crystal X-ray diffraction studies. In addition, the electronic structure has been investigated by DFT and QTAIM calculations, which suggest that there is a Ni1-Ni2 binding interaction. Similar to Zn-rich intermetallic phases of the Hume-Rothery type, the transition metals (here Ni) are distributed in a matrix of Zn atoms to yield highly Zn-coordinated environments. The organic residues, ancillary ligands (Me, Cp*, and toluene), can be viewed as the "protecting" shell of the 10-metal-atom core structures. The soft and flexible binding properties of Cp* and transferability of Me substituents between groups 12 and 13 are essential for the success of this precedence-less type of cluster formation reaction.

Formation of a Propeller-Shaped Ni4Ga3 Cluster Supported by Transmetalation of Cp* from Ga to Ni

“…The intermetallic distances, including the unprecedented formal Cp*Ni I –Ga 0 bond, are all in the range of other Ni–Ga interactions. , The M–Cp* centroid distances are distinctly different for M = Ni and Ga, with the Ni–Cp* centroid (av 1.78–1.81 Å) distance being about 0.2 Å shorter than the distance of Ga–Cp* centroid (av 2.01 Å). Both distances are consistent with the values found for comparable compounds in the literature. − The calculated bond distances at the BP86-D3/def2-TZVPP level of theory match well with the crystal structure. Different metal assignments were tested by DFT calculations, without successful convergence.…”

From the discovery of field ionization to field desorption and liquid injection field desorption/ionization-mass spectrometry—A journey from principles and applications to a glimpse into the future

“…Even though the adaptation to a linear quadrupole analyzer has been accomplished, it never really succeeded as the kinetic energy spread of ions emerging from the emitter was not well suited for this type of mass analyzer. [144][145][146] The adaptation of FI, FD, and LIFDI to oaTOFs has been very successful and was commercialized by JEOL with the AccuTOF GC series [147][148][149][150][151][152][153][154][155] and by Waters with the GCT series of instruments. [156][157][158][159][160][161][162][163] As these oaTOF instruments, depending on the actual version of a particular instrument, provide a resolving power of 5000-10000, they are actually better suited for accurate mass measurements than scanning sector instruments.…”

Intermetalloid Clusters: Molecules and Solids in a Dialogue

“…[112] Thei nfluence of directing co-ligands in the selective Ga/ Zn exchange was studied using heteroleptic precursors of the type [M a (GaCp*) b L c ]( L= CO,P R 3 ,C NR). [115] [103] Notably,t he presence of directing co-ligands with suitable electronic properties and moderate steric demand seems to be crucial for the stabilization of oligonuclear TM/Zn species as comparable reactions with homoleptic GaCp*-ligated complexes [M n (GaCp*) m ] (n ! [115] [103] Notably,t he presence of directing co-ligands with suitable electronic properties and moderate steric demand seems to be crucial for the stabilization of oligonuclear TM/Zn species as comparable reactions with homoleptic GaCp*-ligated complexes [M n (GaCp*) m ] (n !…”

“…[103,114] Ther eac- deficient NiCp* and Ni(h 6 -toluene) fragments by Ni(ZnR) 8 units. [115] [103] Notably,t he presence of directing co-ligands with suitable electronic properties and moderate steric demand seems to be crucial for the stabilization of oligonuclear TM/Zn species as comparable reactions with homoleptic GaCp*-ligated complexes [M n (GaCp*) m ] (n ! 2) tend to undergo rapid decomposition and metal precipitation.…”

“…The latter can be understood as a Lewis acid/base adduct of the Lewis‐acidic [Pd(PMe 3 ) 3 ] and Lewis‐basic [Pd(ZnR) 4 (PMe 3 ) 2 ] fragments. A comparable behavior was observed for the stabilization of electron‐deficient NiCp* and Ni(η 6 ‐toluene) fragments by Ni(ZnR) 8 units . The tetranuclear Zn‐rich transition‐metal clusters [Ni 4 GaZn 7 (Cp*) 2 Me 7 (CN t Bu) 7 ] and [{Pd(CNR)} 4 (μ 2 ‐ZnCp*) 4 (ZnMe) 4 ] (R= t Bu, Ph) are formed in Ga/Zn exchange reactions of [Ni 4 (CN t Bu) 7 (GaCp*) 3 ] and [{Pd(CNR)} 4 (GaCp*) 4 ] with ZnMe 2 .…”