Revisiting the main group cyclopentadienyl metal complexes in terms of the through-space coupling concept

Cyclopentadienyl Dicarbonyl Iron‐Bismuth Compounds – Synthesis, Structure, and Reactivity

“…Some of these complexes offer potential as single source precursors, but the choice of the ligands is still a challenge with regard to the problem of carbon contamination in the final product. It is well known that ligands from the cyclopentadienyl family serve as stabilizing ligands for unusual compounds but they also serve as good leaving groups in CVD processes 23–29. Thus, bismuthanes with bismuth bound to [Cp(CO) n M ] fragments might be interesting candidates for decomposition processes.…”

Crystal structures and thermal properties of Ba(1,2,4-t-Bu3C5H2)2 and Sr(1,2,4-t-Bu3C5H2)2: Precursors for atomic layer deposition

“…1). The two independent molecules have g 5 -coordinated ligands and bent structure typical for alkaline-earth and rare-earth metallocenes [11][12][13][14][15]. Cyclopentadienyl rings in both molecules of the asymmetric unit are eclipsed (twist angles are in Table 1) and rotated approximately 72°c ompared to each other so that on the opening side of the sandwich wedge two t-butyl groups are parallel in the middle.…”

“…In the light of previous studies in addition to steric factors Cp(centroid)-M-Cp(centroid) bending angles are also affected by electrostatic factors (electronic configuration) like polarization of the core electrons and d-orbital involvement [13,18,19]. Also attractive van der Waals forces between substituents has been proposed and studied [15,20,21]. Another feature of these metallocenes is the varying relative orientation of the cyclopentadienyl ligands [11,16] which is affected by both the ligands and the metals.…”

“…Most of the base free metallocenes of heavier alkaline-earth metals (Ca, Sr, Ba) have structures with non parallel rings in the solid state and as well in the gas phase [11][12][13][14][15][16][17]. The only reported exception, Ba(i-Pr 5 C 5 ) 2 [10] with Cp(centroid)-M-Cp(centroid) angle of 180°, is a compound where the metal has sterically extremely crowded environment.…”

Exploring the coordination chemistry of N-heterocyclic phosphenium/phosphido ligands using nickelocene as a synthon

“…Cyclopentadienyl (Cp) ligands are pervasive in organometallic chemistry and, while the η 5 coordination mode is by far the most common, Cp ligands can also adopt η 1 and η 3 binding modes using a combination of both σ and π donation. The coordination of cyclopentadienyl fragments to main group elements has also been studied extensively, revealing a variety of binding modes, rearrangements, and fluxional processes.…”