Group 4 lanthanide and actinide organometallic inclusion complexes

Raj K. Das; Eyal Barnea; Tamer Andrea; Moshe Kapon; Natalia Fridman; Mark Botoshansky; Moris S. Eisen

doi:10.1021/om501103v

Group 4 lanthanide and actinide organometallic inclusion complexes

Raj K. Das, Eyal Barnea, Tamer Andrea, Moshe Kapon, Natalia Fridman, Mark Botoshansky, Moris S. Eisen^*

^*Corresponding author for this work

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

23 Scopus citations

Abstract

Reaction of the f-element complexes ThCl₄(THF)₃, Cp∗₂Sm(μ-Cl)₂MgCl(THF)₂, NdCl₃, Cp∗₂UMe₂, and Cp∗₂ZrMe₂ with an excess of catecholborane (HBCat) yields macrocyclic complexes where the metal is encapsulated inside a 15-membered, hexaoxo, trianionic macrocycle built from alternating catechol and catecholborate fragments. With ThCl₄(THF)₃ as the starting material, the reaction produced a macrocyclic complex with one chloride ligand and three solvent molecules in the apical positions; however, for the zirconium and uranium complexes the apical positions are occupied by one C₅Me₅ ligand and a THF solvent molecule. In the samarium and neodymium complexes, only solvent molecules occupy the apical positions. Transmetalation of the ligand among different complexes in refluxing THF were performed. When the zirconium macrocycle was treated with a slight excess of ThCl₄ or NdCl₃, the corresponding (η²-catechol-μ-catecholborate)₃ThCl(C₄H₈O)₃·C₄H₈O (2) and (η²-catechol-μ-catecholborate)₃Nd(C₄H₈O)₃·C₄H₈O (4) macrocycles were obtained in 87% and 79% yields, respectively. In addition, the reaction of the samarium macrocycle complex (η²-catechol-μ-catecholborate)₃Sm(C₄H₈O)₃·C₄H₈O (3) with a slight excess of ThCl₄ allowed the formation of complex 2 in 76% yield. While some of the pentamethylcyclopentadienyl (Cp∗)-containing inclusion complexes were found to be catalytically inactive in the polymerization of ε-caprolactone, the lanthanides and thorium complexes were found to be active, yielding only short chains of polycaprolactone. The X-ray molecular structures for all of the complexes are presented and discussed. Experiments performed with Cp∗₂ThMe₂ and catecholborane allowed us to trap the intermediate Cp∗ (H)BH₂BH₂ complex, which was trapped in situ and characterized by ¹¹B NMR, allowing us to propose a possible mechanism for the formation of the macrocycle.

Original language	English
Pages (from-to)	742-752
Number of pages	11
Journal	Organometallics
Volume	34
Issue number	4
DOIs	https://doi.org/10.1021/om501103v
State	Published - 23 Feb 2015
Externally published	Yes

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@article{dda8e86c8ca94bc5b9069843c8a1a118,

title = "Group 4 lanthanide and actinide organometallic inclusion complexes",

abstract = "Reaction of the f-element complexes ThCl4(THF)3, Cp∗2Sm(μ-Cl)2MgCl(THF)2, NdCl3, Cp∗2UMe2, and Cp∗2ZrMe2 with an excess of catecholborane (HBCat) yields macrocyclic complexes where the metal is encapsulated inside a 15-membered, hexaoxo, trianionic macrocycle built from alternating catechol and catecholborate fragments. With ThCl4(THF)3 as the starting material, the reaction produced a macrocyclic complex with one chloride ligand and three solvent molecules in the apical positions; however, for the zirconium and uranium complexes the apical positions are occupied by one C5Me5 ligand and a THF solvent molecule. In the samarium and neodymium complexes, only solvent molecules occupy the apical positions. Transmetalation of the ligand among different complexes in refluxing THF were performed. When the zirconium macrocycle was treated with a slight excess of ThCl4 or NdCl3, the corresponding (η2-catechol-μ-catecholborate)3ThCl(C4H8O)3·C4H8O (2) and (η2-catechol-μ-catecholborate)3Nd(C4H8O)3·C4H8O (4) macrocycles were obtained in 87% and 79% yields, respectively. In addition, the reaction of the samarium macrocycle complex (η2-catechol-μ-catecholborate)3Sm(C4H8O)3·C4H8O (3) with a slight excess of ThCl4 allowed the formation of complex 2 in 76% yield. While some of the pentamethylcyclopentadienyl (Cp∗)-containing inclusion complexes were found to be catalytically inactive in the polymerization of ε-caprolactone, the lanthanides and thorium complexes were found to be active, yielding only short chains of polycaprolactone. The X-ray molecular structures for all of the complexes are presented and discussed. Experiments performed with Cp∗2ThMe2 and catecholborane allowed us to trap the intermediate Cp∗ (H)BH2BH2 complex, which was trapped in situ and characterized by 11B NMR, allowing us to propose a possible mechanism for the formation of the macrocycle.",

author = "Das, {Raj K.} and Eyal Barnea and Tamer Andrea and Moshe Kapon and Natalia Fridman and Mark Botoshansky and Eisen, {Moris S.}",

note = "Publisher Copyright: {\textcopyright} 2015 American Chemical Society.",

year = "2015",

month = feb,

day = "23",

doi = "10.1021/om501103v",

language = "英语",

volume = "34",

pages = "742--752",

journal = "Organometallics",

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TY - JOUR

T1 - Group 4 lanthanide and actinide organometallic inclusion complexes

AU - Das, Raj K.

AU - Barnea, Eyal

AU - Andrea, Tamer

AU - Kapon, Moshe

AU - Fridman, Natalia

AU - Botoshansky, Mark

AU - Eisen, Moris S.

PY - 2015/2/23

Y1 - 2015/2/23

N2 - Reaction of the f-element complexes ThCl4(THF)3, Cp∗2Sm(μ-Cl)2MgCl(THF)2, NdCl3, Cp∗2UMe2, and Cp∗2ZrMe2 with an excess of catecholborane (HBCat) yields macrocyclic complexes where the metal is encapsulated inside a 15-membered, hexaoxo, trianionic macrocycle built from alternating catechol and catecholborate fragments. With ThCl4(THF)3 as the starting material, the reaction produced a macrocyclic complex with one chloride ligand and three solvent molecules in the apical positions; however, for the zirconium and uranium complexes the apical positions are occupied by one C5Me5 ligand and a THF solvent molecule. In the samarium and neodymium complexes, only solvent molecules occupy the apical positions. Transmetalation of the ligand among different complexes in refluxing THF were performed. When the zirconium macrocycle was treated with a slight excess of ThCl4 or NdCl3, the corresponding (η2-catechol-μ-catecholborate)3ThCl(C4H8O)3·C4H8O (2) and (η2-catechol-μ-catecholborate)3Nd(C4H8O)3·C4H8O (4) macrocycles were obtained in 87% and 79% yields, respectively. In addition, the reaction of the samarium macrocycle complex (η2-catechol-μ-catecholborate)3Sm(C4H8O)3·C4H8O (3) with a slight excess of ThCl4 allowed the formation of complex 2 in 76% yield. While some of the pentamethylcyclopentadienyl (Cp∗)-containing inclusion complexes were found to be catalytically inactive in the polymerization of ε-caprolactone, the lanthanides and thorium complexes were found to be active, yielding only short chains of polycaprolactone. The X-ray molecular structures for all of the complexes are presented and discussed. Experiments performed with Cp∗2ThMe2 and catecholborane allowed us to trap the intermediate Cp∗ (H)BH2BH2 complex, which was trapped in situ and characterized by 11B NMR, allowing us to propose a possible mechanism for the formation of the macrocycle.

AB - Reaction of the f-element complexes ThCl4(THF)3, Cp∗2Sm(μ-Cl)2MgCl(THF)2, NdCl3, Cp∗2UMe2, and Cp∗2ZrMe2 with an excess of catecholborane (HBCat) yields macrocyclic complexes where the metal is encapsulated inside a 15-membered, hexaoxo, trianionic macrocycle built from alternating catechol and catecholborate fragments. With ThCl4(THF)3 as the starting material, the reaction produced a macrocyclic complex with one chloride ligand and three solvent molecules in the apical positions; however, for the zirconium and uranium complexes the apical positions are occupied by one C5Me5 ligand and a THF solvent molecule. In the samarium and neodymium complexes, only solvent molecules occupy the apical positions. Transmetalation of the ligand among different complexes in refluxing THF were performed. When the zirconium macrocycle was treated with a slight excess of ThCl4 or NdCl3, the corresponding (η2-catechol-μ-catecholborate)3ThCl(C4H8O)3·C4H8O (2) and (η2-catechol-μ-catecholborate)3Nd(C4H8O)3·C4H8O (4) macrocycles were obtained in 87% and 79% yields, respectively. In addition, the reaction of the samarium macrocycle complex (η2-catechol-μ-catecholborate)3Sm(C4H8O)3·C4H8O (3) with a slight excess of ThCl4 allowed the formation of complex 2 in 76% yield. While some of the pentamethylcyclopentadienyl (Cp∗)-containing inclusion complexes were found to be catalytically inactive in the polymerization of ε-caprolactone, the lanthanides and thorium complexes were found to be active, yielding only short chains of polycaprolactone. The X-ray molecular structures for all of the complexes are presented and discussed. Experiments performed with Cp∗2ThMe2 and catecholborane allowed us to trap the intermediate Cp∗ (H)BH2BH2 complex, which was trapped in situ and characterized by 11B NMR, allowing us to propose a possible mechanism for the formation of the macrocycle.

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U2 - 10.1021/om501103v

DO - 10.1021/om501103v

M3 - 文章

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SN - 0276-7333

VL - 34

SP - 742

EP - 752

JO - Organometallics

JF - Organometallics

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ER -

Group 4 lanthanide and actinide organometallic inclusion complexes

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