Formate complexes of titanium(IV) supported by a triamido-amine ligand

A. Paparo, F. D. Van Krüchten, T. P. Spaniol, J. Okuda

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The terminal formate complex [(OCHO)Ti(N3N)] (3) containing the trianionic triamido-amine ligand (Me3SiNCH2CH2)3N3- (N3N) was prepared via salt metathesis of [ClTi(N3N)] (1) with sodium formate or alternatively by treatment of the alkyl complex [nBuTi(N3N)] (2) with ammonium formate [HNEt3][OCHO]. Deprotonation of 3 with potassium hexamethyldisilazide gave a polymeric helical chain of the oxo complex {K[OTi(N3N)]}n (4). Reaction of 2 with the trityl salt [Ph3C][B(3,5-Cl2C6H3)4] or the Brønsted acid [HNEt3][B(C6F5)4] gave [(Et2O)Ti(N3N)][BR4] (6[BR4]·Et2O) with R = 3,5-Cl2C6H3 or C6F5. The diethyl ether ligand was easily replaced by other L-type donor ligands such as tetrahydrofuran, pyridine, and 4-dimethylaminopyridine to give 6[BR4]·L with L = thf, py, and dmap. Reaction of 6[BR4]·Et2O with a stoichiometric amount of CO2 gave the dimeric, dicationic bis(carbamate)-bridged complexes [Ti{N(CH2CH2NSiMe3)2(CH2CH2NSiMe3(μ-CO2-ηO:ηO′))}]2[BR4]2 (7[BR4]2) through insertion of one CO2 into one of the titanium-amido bonds. Addition of pyridine to 7[B(C6F5)4]2 formed the monomeric carbamate complex [(py)Ti{((O2C-κ2O,O′)NSiMe3CH2CH2)N(CH2CH2NSiMe3)2}][B(C6F5)4] (8[B(C6F5)4]·py). The cationic formate-bridged species [(Ti(N3N))2(μ-OCHO-ηO:ηO′)][BR4] (10[BR4]) readily formed when the terminal formate complex 3 was reacted with the cationic 6[BR4]. The reactivity of triamido-amine stabilized titanium(iv) complexes is shown to differ considerably from that of related titanium tris(anilide) complexes.

Original languageEnglish
Pages (from-to)3530-3537
Number of pages8
JournalDalton Transactions
Volume47
Issue number10
DOIs
Publication statusPublished - 14 Mar 2018
Externally publishedYes

Cite this

Paparo, A. ; Van Krüchten, F. D. ; Spaniol, T. P. ; Okuda, J. / Formate complexes of titanium(IV) supported by a triamido-amine ligand. In: Dalton Transactions. 2018 ; Vol. 47, No. 10. pp. 3530-3537.
@article{7e3324dce033439ab507f4071ea7f708,
title = "Formate complexes of titanium(IV) supported by a triamido-amine ligand",
abstract = "The terminal formate complex [(OCHO)Ti(N3N)] (3) containing the trianionic triamido-amine ligand (Me3SiNCH2CH2)3N3- (N3N) was prepared via salt metathesis of [ClTi(N3N)] (1) with sodium formate or alternatively by treatment of the alkyl complex [nBuTi(N3N)] (2) with ammonium formate [HNEt3][OCHO]. Deprotonation of 3 with potassium hexamethyldisilazide gave a polymeric helical chain of the oxo complex {K[OTi(N3N)]}n (4). Reaction of 2 with the trityl salt [Ph3C][B(3,5-Cl2C6H3)4] or the Br{\o}nsted acid [HNEt3][B(C6F5)4] gave [(Et2O)Ti(N3N)][BR4] (6[BR4]·Et2O) with R = 3,5-Cl2C6H3 or C6F5. The diethyl ether ligand was easily replaced by other L-type donor ligands such as tetrahydrofuran, pyridine, and 4-dimethylaminopyridine to give 6[BR4]·L with L = thf, py, and dmap. Reaction of 6[BR4]·Et2O with a stoichiometric amount of CO2 gave the dimeric, dicationic bis(carbamate)-bridged complexes [Ti{N(CH2CH2NSiMe3)2(CH2CH2NSiMe3(μ-CO2-ηO:ηO′))}]2[BR4]2 (7[BR4]2) through insertion of one CO2 into one of the titanium-amido bonds. Addition of pyridine to 7[B(C6F5)4]2 formed the monomeric carbamate complex [(py)Ti{((O2C-κ2O,O′)NSiMe3CH2CH2)N(CH2CH2NSiMe3)2}][B(C6F5)4] (8[B(C6F5)4]·py). The cationic formate-bridged species [(Ti(N3N))2(μ-OCHO-ηO:ηO′)][BR4] (10[BR4]) readily formed when the terminal formate complex 3 was reacted with the cationic 6[BR4]. The reactivity of triamido-amine stabilized titanium(iv) complexes is shown to differ considerably from that of related titanium tris(anilide) complexes.",
author = "A. Paparo and {Van Kr{\"u}chten}, {F. D.} and Spaniol, {T. P.} and J. Okuda",
year = "2018",
month = "3",
day = "14",
doi = "10.1039/c7dt04859a",
language = "English",
volume = "47",
pages = "3530--3537",
journal = "Journal of the Chemical Society. Dalton Transactions",
issn = "1477-9226",
publisher = "The Royal Society of Chemistry",
number = "10",

}

Paparo, A, Van Krüchten, FD, Spaniol, TP & Okuda, J 2018, 'Formate complexes of titanium(IV) supported by a triamido-amine ligand', Dalton Transactions, vol. 47, no. 10, pp. 3530-3537. https://doi.org/10.1039/c7dt04859a

Formate complexes of titanium(IV) supported by a triamido-amine ligand. / Paparo, A.; Van Krüchten, F. D.; Spaniol, T. P.; Okuda, J.

In: Dalton Transactions, Vol. 47, No. 10, 14.03.2018, p. 3530-3537.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Formate complexes of titanium(IV) supported by a triamido-amine ligand

AU - Paparo, A.

AU - Van Krüchten, F. D.

AU - Spaniol, T. P.

AU - Okuda, J.

PY - 2018/3/14

Y1 - 2018/3/14

N2 - The terminal formate complex [(OCHO)Ti(N3N)] (3) containing the trianionic triamido-amine ligand (Me3SiNCH2CH2)3N3- (N3N) was prepared via salt metathesis of [ClTi(N3N)] (1) with sodium formate or alternatively by treatment of the alkyl complex [nBuTi(N3N)] (2) with ammonium formate [HNEt3][OCHO]. Deprotonation of 3 with potassium hexamethyldisilazide gave a polymeric helical chain of the oxo complex {K[OTi(N3N)]}n (4). Reaction of 2 with the trityl salt [Ph3C][B(3,5-Cl2C6H3)4] or the Brønsted acid [HNEt3][B(C6F5)4] gave [(Et2O)Ti(N3N)][BR4] (6[BR4]·Et2O) with R = 3,5-Cl2C6H3 or C6F5. The diethyl ether ligand was easily replaced by other L-type donor ligands such as tetrahydrofuran, pyridine, and 4-dimethylaminopyridine to give 6[BR4]·L with L = thf, py, and dmap. Reaction of 6[BR4]·Et2O with a stoichiometric amount of CO2 gave the dimeric, dicationic bis(carbamate)-bridged complexes [Ti{N(CH2CH2NSiMe3)2(CH2CH2NSiMe3(μ-CO2-ηO:ηO′))}]2[BR4]2 (7[BR4]2) through insertion of one CO2 into one of the titanium-amido bonds. Addition of pyridine to 7[B(C6F5)4]2 formed the monomeric carbamate complex [(py)Ti{((O2C-κ2O,O′)NSiMe3CH2CH2)N(CH2CH2NSiMe3)2}][B(C6F5)4] (8[B(C6F5)4]·py). The cationic formate-bridged species [(Ti(N3N))2(μ-OCHO-ηO:ηO′)][BR4] (10[BR4]) readily formed when the terminal formate complex 3 was reacted with the cationic 6[BR4]. The reactivity of triamido-amine stabilized titanium(iv) complexes is shown to differ considerably from that of related titanium tris(anilide) complexes.

AB - The terminal formate complex [(OCHO)Ti(N3N)] (3) containing the trianionic triamido-amine ligand (Me3SiNCH2CH2)3N3- (N3N) was prepared via salt metathesis of [ClTi(N3N)] (1) with sodium formate or alternatively by treatment of the alkyl complex [nBuTi(N3N)] (2) with ammonium formate [HNEt3][OCHO]. Deprotonation of 3 with potassium hexamethyldisilazide gave a polymeric helical chain of the oxo complex {K[OTi(N3N)]}n (4). Reaction of 2 with the trityl salt [Ph3C][B(3,5-Cl2C6H3)4] or the Brønsted acid [HNEt3][B(C6F5)4] gave [(Et2O)Ti(N3N)][BR4] (6[BR4]·Et2O) with R = 3,5-Cl2C6H3 or C6F5. The diethyl ether ligand was easily replaced by other L-type donor ligands such as tetrahydrofuran, pyridine, and 4-dimethylaminopyridine to give 6[BR4]·L with L = thf, py, and dmap. Reaction of 6[BR4]·Et2O with a stoichiometric amount of CO2 gave the dimeric, dicationic bis(carbamate)-bridged complexes [Ti{N(CH2CH2NSiMe3)2(CH2CH2NSiMe3(μ-CO2-ηO:ηO′))}]2[BR4]2 (7[BR4]2) through insertion of one CO2 into one of the titanium-amido bonds. Addition of pyridine to 7[B(C6F5)4]2 formed the monomeric carbamate complex [(py)Ti{((O2C-κ2O,O′)NSiMe3CH2CH2)N(CH2CH2NSiMe3)2}][B(C6F5)4] (8[B(C6F5)4]·py). The cationic formate-bridged species [(Ti(N3N))2(μ-OCHO-ηO:ηO′)][BR4] (10[BR4]) readily formed when the terminal formate complex 3 was reacted with the cationic 6[BR4]. The reactivity of triamido-amine stabilized titanium(iv) complexes is shown to differ considerably from that of related titanium tris(anilide) complexes.

UR - http://www.scopus.com/inward/record.url?scp=85043351641&partnerID=8YFLogxK

U2 - 10.1039/c7dt04859a

DO - 10.1039/c7dt04859a

M3 - Article

VL - 47

SP - 3530

EP - 3537

JO - Journal of the Chemical Society. Dalton Transactions

JF - Journal of the Chemical Society. Dalton Transactions

SN - 1477-9226

IS - 10

ER -