Lewis Base Stabilized Dicarbon: Predictions from Theory

Abstract

Neue C‐Liganden? Inspiriert durch jüngste Arbeiten über Hauptgruppenelementallotrope wurde eine theoretische Studie von Phosphan‐ und NHC‐stabilisiertem Dikohlenstoff durchgeführt. Danach haben die Phosphan‐ und NHC‐Addukte von C2 deutlich verschiedene elektronische Strukturen und sollten beide Arten von Molekülen effiziente, difunktionelle kohlenstoffbasierte Liganden sein.

C4 Cumulene and the Corresponding Air‐Stable Radical Cation and Dication

“…The HOMO and HOMO−3 of 1 show strong π‐interactions along C21C21i and C1C21/C21iC1i bonds with additional electron densities localized on the nitrogen lone pairs (Figure 5 a). A similar electron density distribution was reported by Dutton and Wilson in the DFT study of NHC‐stabilized C 2 analogues 13a. Selected natural localized molecular orbitals (NLMOs) of the C21C21i bond (at M06‐2X/TZVP//M06‐2X/SVP level) are plotted to emphasize the bonding environment along the C1C21C21iC1i (C 4 ) backbone (Figure 5 b).…”

“…To evaluate the Lewis basicity of the C 4 species, we have calculated the energies for BH 3 association with 1 and 1 .+ moieties. Formation of the BH 3 adduct 1 ⋅BH 3 is more favorable (Δ G 298 =6.2 kcal mol −1 for 1 vs. 20.5 kcal mol −1 for 1 .+ ) than 1 .+ ⋅BH 3 13a. The calculated ionization energies of 1 , 1 .+ , and 1 2+ are 5.1, 8.8, and 13.5 eV, respectively, which are comparable to those reported in (cAAC) 2 P 2 species 4.…”

Recent Advances in the Field of Main‐Group Mono‐ and Diatomic “Allotropes” Stabilised by Neutral Ligands

“…[25] We have performed a theoretical study on bis-NHC (12)-and bis-phosphine (13)-stabilised C 2 . [26] Unlike the C 1 case, substantial differences were apparent in the geometries of the C 2 species with the two classes of ligands. The phosphine-stabilised C 2 exhibits a trans-bent structure about the central carbon atoms, while the NHC-ligated species optimised to a nearly linear geometry.…”

Mit N‐heterocyclischem Gallylen stabilisierte niedervalente Ge2‐ und Ge4‐Spezies

“…(Entsprechende Werte aus DFT-Rechnungen für 1 auf dem BP86/SVP-Niveau sind in Klammern angegeben.) Ausgewählte Abstände [] des Ge 4 Ga 2 -Kerns von 2: Ge(1)-Ge(1') 2.4545(9), Ge(1)-Ge(2) 2.4637(6), Ge(2)-Ge(2') 2.4609(9), Ga(1)-Ge(1) 2.5062(6), Ga(1')-Ge(2) 2.4750(6) . Weitere Details zur molekularen Strukturbestimmung und Bindungsparameter von 1 und 2 werden in Tabelle S1 der Hintergrundinformationen.…”