Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Submitted Manuscript

Publication Date

6-14-2021

Journal or Book Title

Organometallics

Volume

40

Issue

11

First Page

1654

Last Page

1669

DOI

10.1021/acs.organomet.1c00162

Abstract

Three new hydridosilazido ligands, −N(SiHMe2)Aryl (Aryl = Ph, 2,6-C6Me2H3 (dmp), 2,6-C6iPr2H3 (dipp)) and their rare-earth complexes Ln{N(SiHMe2)Aryl}3(THF)n (Ln = Sc, Y, Lu; Aryl = Ph, n = 2; Aryl = dmp, n = 1; Aryl = dipp, n = 0) were synthesized to study the relationships among ligand steric properties, secondary Ln↼H–Si bonding, and the reactivity of amide and SiH groups. In these compounds, the steric encumbrance of the aryl group was systematically increased from phenyl to 2,6-dimethylphenyl to 2,6-diisopropylphenyl. NMR, IR, and X-ray diffraction studies of the complexes characterize the number of secondary interactions and additional THF ligands coordinated to the rare-earth centers. The complexes with the smallest phenylsilazido ligands, Ln{N(SiHMe2)Ph}3(THF)2, contain features associated with three nonbridging 2-center-2-electron (2c-2e) Si–H bonds. Characterization of intermediate-sized Ln{N(SiHMe2)dmp}3THF reveals three and two Ln↼H–Si interactions for yttrium and lutetium analogues, respectively, with both metals having one coordinated THF per complex. Ln{N(SiHMe2)dipp}3 is formed solvent-free, and all three ligands adopt Ln↼H–Si bonding modes. The reaction between Ln{N(SiHMe2)dipp}3 and ketones provides the hydrosilylated product via addition of C═O and Si–H bonds, which occurs rapidly even at low temperature. This reaction is proposed to occur through an associative mechanism on the basis of negative activation entropy measured for substitution of pyridine in Ln{N(SiHMe2)dipp}3·NC5H5.

Comments

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Organometallics, copyright © American Chemical Society after peer review. To access the final edited and published work see DOI: 10.1021/acs.organomet.1c00162 Posted with permission.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Published Version

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