1,2-Bis(2-benzimidazolyl)-1,2-ethanediol, a chiral, tridentate, facially coordinating ligand

Isele, Katharina; Broughton, Vanessa; Matthews, Craig J.; Williams, Alan F.; Bernardinelli, Gérald; Franz, Patrick; Decurtins, Silvio (2002). 1,2-Bis(2-benzimidazolyl)-1,2-ethanediol, a chiral, tridentate, facially coordinating ligand. Journal of the Chemical Society, Dalton Transactions(20), pp. 3899-3905. Royal Society of Chemistry 10.1039/b203229e

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The ligand 1,2-bis(1H-benzimidazol-2-yl)-1,2-ethanediol, 1, and its methylated derivative 2 are readily synthesized from tartaric acid, and act as chiral, facially coordinating tridentate ligands, forming complexes of composition ML2 with octahedral transition metals. The copper(II) complexes show distorted 4 + 2 coordination with benzimidazoles occupying the equatorial sites and alcohol functions weakly binding in the axial sites. Nickel(II) complexes in three different states of protonation show regular octahedral geometry with the alcohols mutually cis. Deprotonation of the coordinated alcohol produces little structural change but the monodeprotonated complex forms a hydrogen bonded dimer. Magnetic measurements show the hydrogen bonded bridge to offer a pathway for weak antiferromagnetic coupling. UV-Visible spectroscopy shows the ligand to have a field intermediate between water and pyridine. The diastereoselectivity of complexation depends on the geometry: nickel(II) shows a weak preference for the homochiral complex, whereas copper(II) forms almost exclusively homochiral complexes.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

Decurtins, Silvio

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

1472-7773

Publisher:

Royal Society of Chemistry

Language:

English

Submitter:

Silvio Decurtins

Date Deposited:

20 May 2015 10:40

Last Modified:

21 May 2015 20:52

Publisher DOI:

10.1039/b203229e

BORIS DOI:

10.7892/boris.68539

URI:

https://boris.unibe.ch/id/eprint/68539

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