A Triatomic Silicon(0) Cluster Stabilized by a Cyclic Alkyl(amino) Carbene

Abstract

Reduction of the neutral carbene tetrachlorosilane adduct (cAAC)SiCl4 (cAAC=cyclic alkyl(amino) carbene :C(CMe2)2(CH2)N(2,6‐iPr2C6H3) with potassium graphite produces stable (cAAC)3Si3, a carbene‐stabilized triatomic silicon(0) molecule. The Si−Si bond lengths in (cAAC)3Si3 are 2.399(8), 2.369(8) and 2.398(8) Å, which are in the range of Si−Si single bonds. Each trigonal pyramidal silicon atom of the triangular molecule (cAAC)3Si3 possesses a lone pair of electrons. Its bonding, stability, and electron density distributions were studied by quantum chemical calculations.

Carbones as Ligands in Novel Main‐Group Compounds E[C(NHC)2]2 (E=Be, B+, C2+, N3+, Mg, Al+, Si2+, P3+): A Theoretical Study

“…L [2] opened aw ide field of theoretical and experimental research with increasinga ctivities until today. [3] The expansion from carbon to heavierg roup-14 ylidones EL 2 (E = Si-Pb), [4,5] to isoelectronic boron homologues( BH)L 2 [6,7] and (B À )L 2 [8] and to the nitrogen species( N + )L 2 [9] indicates that two-coordinatedm olecules with dative bonds are not restricted to species with carbon as central atom.T he enlargementt ot wo-center complexes (E 2 )L 2 of Group 14 (E = C-Sn), [10] Group 15 (E = N-As) [11] and to boron in BL 2 [12] and very recently to three-center adducts (B 3 ) + L 3 [13] and (Si 3 )L 3 [14] demonstrates the immense scope of the young and still expanding area of chemistry.T he ligands that were employeds of ar are phosphines (PR 3 ); [15] carbenes (CR 2 ), with NHC (N-heterocyclic carbene) [16] and cAAC (cyclic alkyl-amino carbene) [17] as most prominent examples;C O; and N 2 .T he group of Fujii lately reported the extensiono ft he range of carbones to chalcogen-stabilized systems Ph 2 E!C ! SPh 2 (NMe) (E = S, Se) which exhibit intriguing reactivities.…”

Neue Wege in der s‐Block‐Chemie – Komplexe mit Beryllium in der Oxidationsstufe Null

“…, in welchen zwei cyclische Alkyl-Amino-Carbene (cAAC) ein Berylliumatom in der formalen Oxidationsstufe Null stabilisieren, wobei Beryllium zweifach und nicht wie in 1 dreifach koordiniert vorliegt, wie es fürd ie NHC-Komplexe vorhergesagt wurde (Abbildung 1). Der cAAC-Ligand wurde 2005 von Bertrand eingeführt [9] und hat sich fürd ie Isolierung von ein-, [10] zwei- [11] und dreiatomigen [12] Addukten [E n (cAAC) m ](n = 1-3) von nullwertigen Gruppe-13-und Gruppe-14-Elementena ls sehr erfolgreich erwiesen. [13] cAAC-Liganden sind bessere s-Donoren und p-Akzeptoren als NHCs,w as zu erkennbar unterschiedlichen Eigenschaften der Komplexe führt.…”

Oligomerization of N‐Heterocyclic Silylene into Zwitterionic Silenes

“…[3] Thereactivity and stability of NHSiscan be tuned by ac areful choice of substituents at low-valent silicon and overall cyclic backbones. [4] Therecent applications of NHCsa nd their silicon analogs include the isolation of various elusive species including :EH 2 ,H 2 E=EH 2 , [5] cyclic triatomic Si 3 molecule, [6] and "neutral" atomic E( E = Si, Ge). [7] Forf urther development of the chemistry of NHSis, it is highly important to understand the key factors leading to their stabilization or destabilization.…”