Toggle Main Menu Toggle Search

Open Access padlockePrints

Synthesis and reactions of sterically encumbered, heteroleptic lanthanum phosphides. Structural characterization of [{(Me3Si)2CH}-(C6H4-2-Ch2NMe 2)P]2La(OR) and [{(Me3Si)2CH}- (C6)H4-2-CH2NMe2)P]La(THF)[P(C6H4-2-CH2NMe2)-{CH(SiMe 3)(SiMe2CH2)}] [R =i-Pr, t-Bu]

Lookup NU author(s): Dr Keith Izod, Dr Stephen Liddle, Emeritus Professor William McFarlane, Emeritus Professor Bill CleggORCiD


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Metathesis between LaI3 and 2 equiv of {R(C6H 4-2-CH2NMe2)P}K gives the heteroleptic complex {R(C6H4-2-CH2NMe2)P}2LaI (1), which reacts in situ with 1 equiv of KOR′ to give the corresponding mixed phosphide/alkoxide complexes {R(C6H4-2-CH 2NMe2)P}2La(OR′) [R = (Me 3Si)2CH, R′ = t-Bu (2), i-Pr (3)]. A similar in situ reaction between 1 and 1 equiv of any of the alkali metal organometallics R′K [R′ = PhCH2, Me3SiCH2, (Me 3Si)2CH] yields the cyclometalated product {([Me 3Si]2CH)(C6H4-2-CH 2NMe2)P}La(THF)[P(C6H4-2-CH 2NMe2)-[CH{SiMe3}{SiMe2CH 2}] (4) and R′H. Reaction between the homoleptic tris(alkyl) {(Me3Si)2CH}3La and 2 equiv of the secondary phosphine R(C6H4-2-CH2NMe2)PH yields 4 as the exclusive product, suggesting that the cyclometalation reaction is intramolecular in nature. Compounds 2-4 have been characterized by multielement NMR spectroscopy and X-ray crystallography. Variable-temperature 31P and 1H NMR spectra and 2-D NMR experiments reveal that 4 is subject to dynamic processes in toluene solution, which may be attributed to rapid, reversible inversion at phosphorus, which results in rapid equilibria between stereoisomers; La-C cleavage is slow on the NMR time scale.

Publication metadata

Author(s): Izod K, Liddle ST, McFarlane W, Clegg W

Publication type: Article

Publication status: Published

Journal: Organometallics

Year: 2004

Volume: 23

Issue: 11

Pages: 2734-2743

ISSN (print): 0276-7333

ISSN (electronic): 1520-6041

Publisher: American Chemical Society


DOI: 10.1021/om0498798


Altmetrics provided by Altmetric