Related Experiment Video
Updated: Jun 26, 2026

Synthesis of Triazole and Tetrazole-Functionalized Zr-Based Metal-Organic Frameworks Through Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Base-free molybdenum and tungsten bicyclic silylene complexes stabilized by a homoaromatic contribution
Kazunori Takanashi1, Vladimir Ya Lee, Taka Yokoyama
1Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
Abstract:
Unprecedented base-free bicyclic silylene complexes of molybdenum and tungsten 3a,b (a, M = Mo; b, M = W) were prepared by the reaction of the calcium salt of 1,2,3,4-tetrakis(di-tert-butylmethylsilyl)tetrasilabicyclo[1.1.0]butane-2,4-diide 2(2-) x Ca(2+) with Cp(2)MCl(2) (M = Mo, W). The unusual structural features of 3b (long SiW double bond, short skeletal (sp(2)-Si)-(sp(3)-Si) bonds and extremely long Si-Si bridge) are indicative of a contribution from the zwitterionic resonance form W(delta-)-Si(delta+), in which the electrophilic silicon center is stabilized by the Si(3)-homoaromatic conjugation. This was supported by the theoretical calculations (NBO, NPA) revealing the presence of pi(WSi) and sigma(Si-Si bridge) interactions.
More Related Videos
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
07:14Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
Related Concept Videos
Hybridization of Atomic Orbitals I
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Frost Circles for Different Conjugated Systems
Valence Bond Theory
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry