β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten

Stanislav K. Ignatov, Andrey Y. Khalimon, Nicholas H. Rees, Alexei G. Razuvaev, Philip Mountford, Georgii I. Nikonov

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Reactions of bls(imldo) compounds (RN) 2Mo(PMe 3) n {n = 2, R = tBu; n = 3, R =2,6-dlmethylphenyl (Ar′) and 2,6-dlisopropylphenyl (Ar)) and (RN) 2W(PMe 3) 3 (R = 2,6-dimethylphenyl and 2,6-dlisopropylphenyl) with sllanes afford four types of products: the β-agostic silylamldo compounds (RN)(η 3-RN-SiR′ 2-H ⋯)MCl(PMe 3) 2 (M = Mo and W), mono(lmides) (RN)MCl 2(PMe 3) 3 (M = Mo and W), silyl hydride bis(imido) derivative (ArN) 2W(PMe 3)(H)(SiMeCl 2), and Si - Cl⋯W bridged product (ArN)(η 2-ArN- SiHMeCl-Cl ⋯)WCl(PMe 3) 2. Reactions of molybdenum compounds (RN) 2Mo(PMe 3) m (m=2 or 3) with mono- and dichlorosilanes HSiCl nR′ 3-n (R′ = Me, Ph; n = 1,2) afford mainly the agostic compounds (RN)(η 3-RN- SiR′ 2-H ⋯)MoCl(PMe 3) 2, accompanied by small amounts of mono(lmido) derivatives (RN) MoCl 2(PMe 3) 3. In contrast, the latter compounds are the only transition metal products in reactions with HSiCl 3, the silicon co-product being the sllanlmine dlmer (RNSiHCl) 2. The reaction of (ArN) 2W(PMe 3) 3 with HSiCl 2Me under continuous removal of PMe 3 affords the silyl hydride species (ArN) 2W(PMe 3)(SiMeCl 2)H, characterized by NMR and X-ray diffraction. This product is stable in the absence of phosphine, but addition of catalytic amounts of PMe3 causes a fast rearrangement into the Si-Cl⋯W bridged product (ArN)(η 2-ArN-SiHMeCl-Cl⋯) WCl(PMe 3) 2. The mechanism of silane addition to complexes (RN) 2Mo(PMe 3) n has been elucidated by means of density functional theory calculations of model complexes (MeN) 2Mo(PMe 3) n (n=1-3). Complex (MeN) 2Mo(PMe 3) 2 is found to be the most stable form. It undergoes facile silane-to-imldo addition reactions that afford sllylamido hydride complexes stabilized by additional Si ⋯ H interactions. The ease of this addition increases from HSiMe 2Cl 3 to HSiCl 3, consistent with experimental observations. The most stable final products of silane addition are the agostlc complexes (MeN)(η 3- MeN-SiR 2-H - ⋯) MoCl(PMe 3) 2 (R 2 = Me 2, MeCl, Cl 2) and Cl-brldged silylamldo complexes (MeN)(η-MeN-SiRH-Cl ⋯)MoCl(PMe 3) 2 (R = Me or Cl). In the case of HSiMeCl 2 addition the former is the most stable, but for HSiCl 3 addition the latter ls the preferred product. In all cases, the isomeric silyl hydride species (MeN) 2Mo(PMe 3)(H)(SiClR 2) are less stable by about 6 kcal mol -1. Silane additions to the imido ligand of the tris(phosphine) (MeN) 2Mo(PMe 3) 3 afford octahedral sllylamido hydride derivatives. The different isomers of these addition products are destabilized relative to (MeN) 2Mo(PMe 3) 3 only by 7-24 kcal mol -1 (for the HSiMe 2Cl additions), but since the starting tris(phosphlne) ls 14.8 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2, silane addition to the latter ls a more preferred pathway. A double phosphine dissociation pathway via the species (MeN) 2Mo(PMe 3) was ruled out because this complex is by 24.7 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2.

Original languageEnglish
Pages (from-to)9605-9622
Number of pages18
JournalInorganic Chemistry
Volume48
Issue number20
DOIs
Publication statusPublished - 2009
Externally publishedYes

Fingerprint

phosphine
Silanes
Tungsten
Molybdenum
Hydrides
molybdenum
tungsten
silanes
products
hydrides
Derivatives
Molybdenum compounds
phosphines
Hydrogen
Addition reactions
Silicon
Isomers
Transition metals
Density functional theory
Nuclear magnetic resonance

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Physical and Theoretical Chemistry

Cite this

Ignatov, S. K., Khalimon, A. Y., Rees, N. H., Razuvaev, A. G., Mountford, P., & Nikonov, G. I. (2009). β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten. Inorganic Chemistry, 48(20), 9605-9622. https://doi.org/10.1021/ic900591e

β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten. / Ignatov, Stanislav K.; Khalimon, Andrey Y.; Rees, Nicholas H.; Razuvaev, Alexei G.; Mountford, Philip; Nikonov, Georgii I.

In: Inorganic Chemistry, Vol. 48, No. 20, 2009, p. 9605-9622.

Research output: Contribution to journalArticle

Ignatov, SK, Khalimon, AY, Rees, NH, Razuvaev, AG, Mountford, P & Nikonov, GI 2009, 'β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten', Inorganic Chemistry, vol. 48, no. 20, pp. 9605-9622. https://doi.org/10.1021/ic900591e
Ignatov, Stanislav K. ; Khalimon, Andrey Y. ; Rees, Nicholas H. ; Razuvaev, Alexei G. ; Mountford, Philip ; Nikonov, Georgii I. / β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten. In: Inorganic Chemistry. 2009 ; Vol. 48, No. 20. pp. 9605-9622.
@article{522435d55b254c07b1a3fd533c1c2d41,
title = "β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten",
abstract = "Reactions of bls(imldo) compounds (RN) 2Mo(PMe 3) n {n = 2, R = tBu; n = 3, R =2,6-dlmethylphenyl (Ar′) and 2,6-dlisopropylphenyl (Ar)) and (RN) 2W(PMe 3) 3 (R = 2,6-dimethylphenyl and 2,6-dlisopropylphenyl) with sllanes afford four types of products: the β-agostic silylamldo compounds (RN)(η 3-RN-SiR′ 2-H ⋯)MCl(PMe 3) 2 (M = Mo and W), mono(lmides) (RN)MCl 2(PMe 3) 3 (M = Mo and W), silyl hydride bis(imido) derivative (ArN) 2W(PMe 3)(H)(SiMeCl 2), and Si - Cl⋯W bridged product (ArN)(η 2-ArN- SiHMeCl-Cl ⋯)WCl(PMe 3) 2. Reactions of molybdenum compounds (RN) 2Mo(PMe 3) m (m=2 or 3) with mono- and dichlorosilanes HSiCl nR′ 3-n (R′ = Me, Ph; n = 1,2) afford mainly the agostic compounds (RN)(η 3-RN- SiR′ 2-H ⋯)MoCl(PMe 3) 2, accompanied by small amounts of mono(lmido) derivatives (RN) MoCl 2(PMe 3) 3. In contrast, the latter compounds are the only transition metal products in reactions with HSiCl 3, the silicon co-product being the sllanlmine dlmer (RNSiHCl) 2. The reaction of (ArN) 2W(PMe 3) 3 with HSiCl 2Me under continuous removal of PMe 3 affords the silyl hydride species (ArN) 2W(PMe 3)(SiMeCl 2)H, characterized by NMR and X-ray diffraction. This product is stable in the absence of phosphine, but addition of catalytic amounts of PMe3 causes a fast rearrangement into the Si-Cl⋯W bridged product (ArN)(η 2-ArN-SiHMeCl-Cl⋯) WCl(PMe 3) 2. The mechanism of silane addition to complexes (RN) 2Mo(PMe 3) n has been elucidated by means of density functional theory calculations of model complexes (MeN) 2Mo(PMe 3) n (n=1-3). Complex (MeN) 2Mo(PMe 3) 2 is found to be the most stable form. It undergoes facile silane-to-imldo addition reactions that afford sllylamido hydride complexes stabilized by additional Si ⋯ H interactions. The ease of this addition increases from HSiMe 2Cl 3 to HSiCl 3, consistent with experimental observations. The most stable final products of silane addition are the agostlc complexes (MeN)(η 3- MeN-SiR 2-H - ⋯) MoCl(PMe 3) 2 (R 2 = Me 2, MeCl, Cl 2) and Cl-brldged silylamldo complexes (MeN)(η-MeN-SiRH-Cl ⋯)MoCl(PMe 3) 2 (R = Me or Cl). In the case of HSiMeCl 2 addition the former is the most stable, but for HSiCl 3 addition the latter ls the preferred product. In all cases, the isomeric silyl hydride species (MeN) 2Mo(PMe 3)(H)(SiClR 2) are less stable by about 6 kcal mol -1. Silane additions to the imido ligand of the tris(phosphine) (MeN) 2Mo(PMe 3) 3 afford octahedral sllylamido hydride derivatives. The different isomers of these addition products are destabilized relative to (MeN) 2Mo(PMe 3) 3 only by 7-24 kcal mol -1 (for the HSiMe 2Cl additions), but since the starting tris(phosphlne) ls 14.8 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2, silane addition to the latter ls a more preferred pathway. A double phosphine dissociation pathway via the species (MeN) 2Mo(PMe 3) was ruled out because this complex is by 24.7 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2.",
author = "Ignatov, {Stanislav K.} and Khalimon, {Andrey Y.} and Rees, {Nicholas H.} and Razuvaev, {Alexei G.} and Philip Mountford and Nikonov, {Georgii I.}",
year = "2009",
doi = "10.1021/ic900591e",
language = "English",
volume = "48",
pages = "9605--9622",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - β-agostic silylamido and silyl-hydrido compounds of molybdenum and tungsten

AU - Ignatov, Stanislav K.

AU - Khalimon, Andrey Y.

AU - Rees, Nicholas H.

AU - Razuvaev, Alexei G.

AU - Mountford, Philip

AU - Nikonov, Georgii I.

PY - 2009

Y1 - 2009

N2 - Reactions of bls(imldo) compounds (RN) 2Mo(PMe 3) n {n = 2, R = tBu; n = 3, R =2,6-dlmethylphenyl (Ar′) and 2,6-dlisopropylphenyl (Ar)) and (RN) 2W(PMe 3) 3 (R = 2,6-dimethylphenyl and 2,6-dlisopropylphenyl) with sllanes afford four types of products: the β-agostic silylamldo compounds (RN)(η 3-RN-SiR′ 2-H ⋯)MCl(PMe 3) 2 (M = Mo and W), mono(lmides) (RN)MCl 2(PMe 3) 3 (M = Mo and W), silyl hydride bis(imido) derivative (ArN) 2W(PMe 3)(H)(SiMeCl 2), and Si - Cl⋯W bridged product (ArN)(η 2-ArN- SiHMeCl-Cl ⋯)WCl(PMe 3) 2. Reactions of molybdenum compounds (RN) 2Mo(PMe 3) m (m=2 or 3) with mono- and dichlorosilanes HSiCl nR′ 3-n (R′ = Me, Ph; n = 1,2) afford mainly the agostic compounds (RN)(η 3-RN- SiR′ 2-H ⋯)MoCl(PMe 3) 2, accompanied by small amounts of mono(lmido) derivatives (RN) MoCl 2(PMe 3) 3. In contrast, the latter compounds are the only transition metal products in reactions with HSiCl 3, the silicon co-product being the sllanlmine dlmer (RNSiHCl) 2. The reaction of (ArN) 2W(PMe 3) 3 with HSiCl 2Me under continuous removal of PMe 3 affords the silyl hydride species (ArN) 2W(PMe 3)(SiMeCl 2)H, characterized by NMR and X-ray diffraction. This product is stable in the absence of phosphine, but addition of catalytic amounts of PMe3 causes a fast rearrangement into the Si-Cl⋯W bridged product (ArN)(η 2-ArN-SiHMeCl-Cl⋯) WCl(PMe 3) 2. The mechanism of silane addition to complexes (RN) 2Mo(PMe 3) n has been elucidated by means of density functional theory calculations of model complexes (MeN) 2Mo(PMe 3) n (n=1-3). Complex (MeN) 2Mo(PMe 3) 2 is found to be the most stable form. It undergoes facile silane-to-imldo addition reactions that afford sllylamido hydride complexes stabilized by additional Si ⋯ H interactions. The ease of this addition increases from HSiMe 2Cl 3 to HSiCl 3, consistent with experimental observations. The most stable final products of silane addition are the agostlc complexes (MeN)(η 3- MeN-SiR 2-H - ⋯) MoCl(PMe 3) 2 (R 2 = Me 2, MeCl, Cl 2) and Cl-brldged silylamldo complexes (MeN)(η-MeN-SiRH-Cl ⋯)MoCl(PMe 3) 2 (R = Me or Cl). In the case of HSiMeCl 2 addition the former is the most stable, but for HSiCl 3 addition the latter ls the preferred product. In all cases, the isomeric silyl hydride species (MeN) 2Mo(PMe 3)(H)(SiClR 2) are less stable by about 6 kcal mol -1. Silane additions to the imido ligand of the tris(phosphine) (MeN) 2Mo(PMe 3) 3 afford octahedral sllylamido hydride derivatives. The different isomers of these addition products are destabilized relative to (MeN) 2Mo(PMe 3) 3 only by 7-24 kcal mol -1 (for the HSiMe 2Cl additions), but since the starting tris(phosphlne) ls 14.8 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2, silane addition to the latter ls a more preferred pathway. A double phosphine dissociation pathway via the species (MeN) 2Mo(PMe 3) was ruled out because this complex is by 24.7 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2.

AB - Reactions of bls(imldo) compounds (RN) 2Mo(PMe 3) n {n = 2, R = tBu; n = 3, R =2,6-dlmethylphenyl (Ar′) and 2,6-dlisopropylphenyl (Ar)) and (RN) 2W(PMe 3) 3 (R = 2,6-dimethylphenyl and 2,6-dlisopropylphenyl) with sllanes afford four types of products: the β-agostic silylamldo compounds (RN)(η 3-RN-SiR′ 2-H ⋯)MCl(PMe 3) 2 (M = Mo and W), mono(lmides) (RN)MCl 2(PMe 3) 3 (M = Mo and W), silyl hydride bis(imido) derivative (ArN) 2W(PMe 3)(H)(SiMeCl 2), and Si - Cl⋯W bridged product (ArN)(η 2-ArN- SiHMeCl-Cl ⋯)WCl(PMe 3) 2. Reactions of molybdenum compounds (RN) 2Mo(PMe 3) m (m=2 or 3) with mono- and dichlorosilanes HSiCl nR′ 3-n (R′ = Me, Ph; n = 1,2) afford mainly the agostic compounds (RN)(η 3-RN- SiR′ 2-H ⋯)MoCl(PMe 3) 2, accompanied by small amounts of mono(lmido) derivatives (RN) MoCl 2(PMe 3) 3. In contrast, the latter compounds are the only transition metal products in reactions with HSiCl 3, the silicon co-product being the sllanlmine dlmer (RNSiHCl) 2. The reaction of (ArN) 2W(PMe 3) 3 with HSiCl 2Me under continuous removal of PMe 3 affords the silyl hydride species (ArN) 2W(PMe 3)(SiMeCl 2)H, characterized by NMR and X-ray diffraction. This product is stable in the absence of phosphine, but addition of catalytic amounts of PMe3 causes a fast rearrangement into the Si-Cl⋯W bridged product (ArN)(η 2-ArN-SiHMeCl-Cl⋯) WCl(PMe 3) 2. The mechanism of silane addition to complexes (RN) 2Mo(PMe 3) n has been elucidated by means of density functional theory calculations of model complexes (MeN) 2Mo(PMe 3) n (n=1-3). Complex (MeN) 2Mo(PMe 3) 2 is found to be the most stable form. It undergoes facile silane-to-imldo addition reactions that afford sllylamido hydride complexes stabilized by additional Si ⋯ H interactions. The ease of this addition increases from HSiMe 2Cl 3 to HSiCl 3, consistent with experimental observations. The most stable final products of silane addition are the agostlc complexes (MeN)(η 3- MeN-SiR 2-H - ⋯) MoCl(PMe 3) 2 (R 2 = Me 2, MeCl, Cl 2) and Cl-brldged silylamldo complexes (MeN)(η-MeN-SiRH-Cl ⋯)MoCl(PMe 3) 2 (R = Me or Cl). In the case of HSiMeCl 2 addition the former is the most stable, but for HSiCl 3 addition the latter ls the preferred product. In all cases, the isomeric silyl hydride species (MeN) 2Mo(PMe 3)(H)(SiClR 2) are less stable by about 6 kcal mol -1. Silane additions to the imido ligand of the tris(phosphine) (MeN) 2Mo(PMe 3) 3 afford octahedral sllylamido hydride derivatives. The different isomers of these addition products are destabilized relative to (MeN) 2Mo(PMe 3) 3 only by 7-24 kcal mol -1 (for the HSiMe 2Cl additions), but since the starting tris(phosphlne) ls 14.8 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2, silane addition to the latter ls a more preferred pathway. A double phosphine dissociation pathway via the species (MeN) 2Mo(PMe 3) was ruled out because this complex is by 24.7 kcal mol -1 less stable than (MeN) 2Mo(PMe 3) 2.

UR - http://www.scopus.com/inward/record.url?scp=70350580699&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70350580699&partnerID=8YFLogxK

U2 - 10.1021/ic900591e

DO - 10.1021/ic900591e

M3 - Article

VL - 48

SP - 9605

EP - 9622

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 20

ER -