C. L. Boyd, A. E. Guiducci, Stuart R. Dubberley, Ben R. Tyrrell, P. Mountford
{"title":"Titanium imido complexes of pendant arm functionalised benzamidinate ligands","authors":"C. L. Boyd, A. E. Guiducci, Stuart R. Dubberley, Ben R. Tyrrell, P. Mountford","doi":"10.1039/B207184C","DOIUrl":null,"url":null,"abstract":"Reactions of the lithiated pendant arm functionalised benzamidinates Li{Me2NCH2CH2NC(Ph)NSiMe3} and Li{Me2NCH2CH2CH2NC(Ph)NSiMe3} with the compounds [Ti(NR)Cl2(py)3] \n(R = \ntBu, 2,6-Me2C6H3, 2,6-iPr2C6H3) afforded five-coordinate [Ti(NR){Me2NCH2CH2NC(Ph)NSiMe3}Cl] \n1–3 and [Ti(NR){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl] \n4–6, respectively. Reaction of [Ti(NtBu){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl] \n4 with C6F5NH2 gave elimination of tBuNH2 and the corresponding perfluoroarylimido complex 7. The X-ray crystal structures of [Ti(NtBu){Me2NCH2CH2NC(Ph)NSiMe3}Cl] \n1 and [Ti(N-2,6-R2C6H3){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl] \n(R = Me 5 or iPr 6) have been determined. Reaction of either 1 or 4 with H2N-2,6-Me2C6H3 in C6D6 afforded the corresponding arylimido compounds 2 and 5, but this route is not amenable to easy scale-up. For better evaluation of the effects of the pendant NMe2 donor group in 1–6, the bis(pyridine) compound [Ti(NtBu){MeCH2CH2NC(Ph)NSiMe3}Cl(py)2] \n9 was prepared from Li{MeCH2CH2NC(Ph)NSiMe3} \n8 and [Ti(NtBu)Cl2(py)3]. The compounds 1–3 with two-carbon pendant arms are quite sensitive to adventitious protonation, and the X-ray crystal structures of the products of two such reactions, namely [Ti2{Me2NCH2CH2NC(Ph)N(H)SiMe3}2(NtBu)2Cl2(μ-Cl)2] \n10 and [Ti2(N-2,6-C6H3Me2)2Cl2(μ-O){Me2NCH2CH2NC(Ph)N(H)SiMe3}2] \n11, have been determined. Both possess amidine ligands that show interesting intramolecular N–H⋯X (X = \nμ-Cl or μ-O) hydrogen bonds.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":"3 1","pages":"4175-4184"},"PeriodicalIF":0.0000,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"20","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Chemical Society-dalton Transactions","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1039/B207184C","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 20
Abstract
Reactions of the lithiated pendant arm functionalised benzamidinates Li{Me2NCH2CH2NC(Ph)NSiMe3} and Li{Me2NCH2CH2CH2NC(Ph)NSiMe3} with the compounds [Ti(NR)Cl2(py)3]
(R =
tBu, 2,6-Me2C6H3, 2,6-iPr2C6H3) afforded five-coordinate [Ti(NR){Me2NCH2CH2NC(Ph)NSiMe3}Cl]
1–3 and [Ti(NR){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
4–6, respectively. Reaction of [Ti(NtBu){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
4 with C6F5NH2 gave elimination of tBuNH2 and the corresponding perfluoroarylimido complex 7. The X-ray crystal structures of [Ti(NtBu){Me2NCH2CH2NC(Ph)NSiMe3}Cl]
1 and [Ti(N-2,6-R2C6H3){Me2NCH2CH2CH2NC(Ph)NSiMe3}Cl]
(R = Me 5 or iPr 6) have been determined. Reaction of either 1 or 4 with H2N-2,6-Me2C6H3 in C6D6 afforded the corresponding arylimido compounds 2 and 5, but this route is not amenable to easy scale-up. For better evaluation of the effects of the pendant NMe2 donor group in 1–6, the bis(pyridine) compound [Ti(NtBu){MeCH2CH2NC(Ph)NSiMe3}Cl(py)2]
9 was prepared from Li{MeCH2CH2NC(Ph)NSiMe3}
8 and [Ti(NtBu)Cl2(py)3]. The compounds 1–3 with two-carbon pendant arms are quite sensitive to adventitious protonation, and the X-ray crystal structures of the products of two such reactions, namely [Ti2{Me2NCH2CH2NC(Ph)N(H)SiMe3}2(NtBu)2Cl2(μ-Cl)2]
10 and [Ti2(N-2,6-C6H3Me2)2Cl2(μ-O){Me2NCH2CH2NC(Ph)N(H)SiMe3}2]
11, have been determined. Both possess amidine ligands that show interesting intramolecular N–H⋯X (X =
μ-Cl or μ-O) hydrogen bonds.