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Dynamic Conformational Behavior in Stable Pentaorganosilicates
Author(s) -
van der Boon Leon J. P.,
Hendriks Jesper H.,
Roolvink Danny,
O'Kennedy Sean J.,
Lutz Martin,
Slootweg J. Chris,
Ehlers Andreas W.,
Lammertsma Koop
Publication year - 2019
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201900641
Subject(s) - chemistry , denticity , conformational isomerism , biphenyl , transition metal , nuclear magnetic resonance spectroscopy , ligand (biochemistry) , crystallography , organometallic chemistry , stereochemistry , computational chemistry , catalysis , molecule , crystal structure , organic chemistry , biochemistry , receptor
Silicates with five organic groups are conformationally dynamic even with two bidentate ligands. Symmetry breaking by incorporating a single nitrogen or phosphorus atom provides insight into their dynamic behavior. N‐containing silicates with bidentate 2‐phenylpyridine, biphenyl, and a Me ( 8 ), Et ( 9 ) or Ph ( 10 ) ligand were studied comprehensively by NMR spectroscopy and DFT theory to reveal two isoenergetic conformers with a barrier of ca. 10 kcal mol –1 . P‐containing silicate 14 with bidentate triphenylphosphane, biphenyl, and Me ligands is subject to multiple Berry pseudorotations, turnstile rotations, and conformational flexibility of the P‐center. The stability increased by masking the P‐center with a BH 3 group ( 16 ). DFT and NMR modeling reveal two isoenergetic conformers for 16 with a barrier of ca. 19 kcal‧mol –1 for a complex interconversion pathway. This barrier bodes well for the design of configurationally stable chiral‐at‐metal transition metal catalysts.