Titanium(IV) alkoxy-N-heterocyclic carbenes: Structural preferences of alkoxide and bromide adducts

S A  Mungur; A J  Blake; C  Wilson; J  McMaster; P L  Arnold; Polly Arnold

doi:10.1021/om0508839

Titanium(IV) alkoxy-N-heterocyclic carbenes: Structural preferences of alkoxide and bromide adducts

S A Mungur, A J Blake, C Wilson, J McMaster, P L Arnold, Polly Arnold

Research output: Contribution to journal › Article › peer-review

Abstract

A series of titanium(IV) adducts of an amido-tethered N-heterocyclic carbene (NHC) of the form Ti(L)((OPr)-Pr-i)(n)(Br)(3-n) (n = 1-3, L = (BuNHCH2CH2)-Bu-t[C{(NBu)-Bu-t(CHCH)N}]) have been synthesized and characterized. Structural characterization of the n = 2 complex shows marked bending of the two ligands cis (and perpendicular) to the plane of the NHC group in the direction of the carbene, suggestive of a pseudo-back-bonding interaction between adjacent ligands and the carbene p orbital, consistent with a bonding model recently proposed for d(0) metal-NHC complexes. However, inspection of a space-filling model and the calculation of bond order using DFT methods suggest that the bending is due to repulsions between lone pairs on the adjacent pi-donor ligands in the complexes and not any specific interaction between the NHC and cis pi-donor ligands.

Original language	English
Pages (from-to)	1861-1867
Number of pages	7
Journal	Organometallics
Volume	25
Issue number	8
DOIs	https://doi.org/10.1021/om0508839
Publication status	Published - 10 Apr 2006

Keywords / Materials (for Non-textual outputs)

CRYSTAL-STRUCTURES
COMPLEXES
LIGANDS
POLYMERIZATION
APPROXIMATION
CATALYSTS
BEHAVIOR
METALS
ENERGY
SILVER

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10.1021/om0508839

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title = "Titanium(IV) alkoxy-N-heterocyclic carbenes: Structural preferences of alkoxide and bromide adducts",

abstract = "A series of titanium(IV) adducts of an amido-tethered N-heterocyclic carbene (NHC) of the form Ti(L)((OPr)-Pr-i)(n)(Br)(3-n) (n = 1-3, L = (BuNHCH2CH2)-Bu-t[C{(NBu)-Bu-t(CHCH)N}]) have been synthesized and characterized. Structural characterization of the n = 2 complex shows marked bending of the two ligands cis (and perpendicular) to the plane of the NHC group in the direction of the carbene, suggestive of a pseudo-back-bonding interaction between adjacent ligands and the carbene p orbital, consistent with a bonding model recently proposed for d(0) metal-NHC complexes. However, inspection of a space-filling model and the calculation of bond order using DFT methods suggest that the bending is due to repulsions between lone pairs on the adjacent pi-donor ligands in the complexes and not any specific interaction between the NHC and cis pi-donor ligands.",

keywords = "CRYSTAL-STRUCTURES, COMPLEXES, LIGANDS, POLYMERIZATION, APPROXIMATION, CATALYSTS, BEHAVIOR, METALS, ENERGY, SILVER",

author = "Mungur, {S A} and Blake, {A J} and C Wilson and J McMaster and Arnold, {P L} and Polly Arnold",

year = "2006",

month = apr,

day = "10",

doi = "10.1021/om0508839",

language = "English",

volume = "25",

pages = "1861--1867",

journal = "Organometallics",

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TY - JOUR

T1 - Titanium(IV) alkoxy-N-heterocyclic carbenes: Structural preferences of alkoxide and bromide adducts

AU - Mungur, S A

AU - Blake, A J

AU - Wilson, C

AU - McMaster, J

AU - Arnold, P L

AU - Arnold, Polly

PY - 2006/4/10

Y1 - 2006/4/10

N2 - A series of titanium(IV) adducts of an amido-tethered N-heterocyclic carbene (NHC) of the form Ti(L)((OPr)-Pr-i)(n)(Br)(3-n) (n = 1-3, L = (BuNHCH2CH2)-Bu-t[C{(NBu)-Bu-t(CHCH)N}]) have been synthesized and characterized. Structural characterization of the n = 2 complex shows marked bending of the two ligands cis (and perpendicular) to the plane of the NHC group in the direction of the carbene, suggestive of a pseudo-back-bonding interaction between adjacent ligands and the carbene p orbital, consistent with a bonding model recently proposed for d(0) metal-NHC complexes. However, inspection of a space-filling model and the calculation of bond order using DFT methods suggest that the bending is due to repulsions between lone pairs on the adjacent pi-donor ligands in the complexes and not any specific interaction between the NHC and cis pi-donor ligands.

AB - A series of titanium(IV) adducts of an amido-tethered N-heterocyclic carbene (NHC) of the form Ti(L)((OPr)-Pr-i)(n)(Br)(3-n) (n = 1-3, L = (BuNHCH2CH2)-Bu-t[C{(NBu)-Bu-t(CHCH)N}]) have been synthesized and characterized. Structural characterization of the n = 2 complex shows marked bending of the two ligands cis (and perpendicular) to the plane of the NHC group in the direction of the carbene, suggestive of a pseudo-back-bonding interaction between adjacent ligands and the carbene p orbital, consistent with a bonding model recently proposed for d(0) metal-NHC complexes. However, inspection of a space-filling model and the calculation of bond order using DFT methods suggest that the bending is due to repulsions between lone pairs on the adjacent pi-donor ligands in the complexes and not any specific interaction between the NHC and cis pi-donor ligands.

KW - CRYSTAL-STRUCTURES

KW - COMPLEXES

KW - LIGANDS

KW - POLYMERIZATION

KW - APPROXIMATION

KW - CATALYSTS

KW - BEHAVIOR

KW - METALS

KW - ENERGY

KW - SILVER

U2 - 10.1021/om0508839

DO - 10.1021/om0508839

M3 - Article

SN - 0276-7333

VL - 25

SP - 1861

EP - 1867

JO - Organometallics

JF - Organometallics

IS - 8

ER -

Titanium(IV) alkoxy-N-heterocyclic carbenes: Structural preferences of alkoxide and bromide adducts

Abstract

Keywords / Materials (for Non-textual outputs)

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