Cyclic alkyl(amino)iminates (CAAIs) as strong 2σ,4π-electron donor ligands for the stabilisation of boranes and diboranes(4): a synthetic and computational study.
Silvia HuynhMerle ArrowsmithLukas MeierMaximilian DietzMarcel HärterichMaximilian MichelAnnalena GärtnerHolger BraunschweigPublished in: Dalton transactions (Cambridge, England : 2003) (2023)
Singly and doubly cyclic alkyl(amino)iminate (CAAI)-substituted boranes and diboranes(4) were synthesised by halosilane elimination between a silylimine and halo(di)borane precursors. 11 B NMR-spectroscopic studies show that the CAAI ligand is a much stronger electron donor than amino ligands. X-ray crystallographic analyses reveal that the degree of B-N CAAI double bonding increases with the electron-withdrawing capacity of the other substituents at boron. The C-N-B bond angle displays a great flexibility, ranging from 131° to near-linear 176°, the narrowest angles being observed for NMe 2 -substituted derivatives and the widest angles for highly sterically demanding substituents. Density functional theory (DFT) calculations on the electronic structures of the anionic CAAI ligand compared to unsaturated and saturated N-heterocyclic iminate (NHI) ligands show that the former is the best σ donor of the three but less π-donating than the unsaturated NHI. Nevertheless, the linear (CAAI)BH 2 complex displays somewhat stronger C-N and N-B π bonding than the corresponding ((S)NHI)BH 2 complexes.
Keyphrases
- density functional theory
- molecular docking
- high resolution
- molecular dynamics
- electron microscopy
- ionic liquid
- solar cells
- molecular dynamics simulations
- electron transfer
- magnetic resonance
- gene expression
- magnetic resonance imaging
- mass spectrometry
- biofilm formation
- cystic fibrosis
- dna methylation
- pseudomonas aeruginosa
- escherichia coli
- solid state