Formation of Racemate and Mesocate Complexes from an Achiral
Tripodal Ligand Containing Three Benzimidazole Groups
Yue-Peng Cai
Cheng-Yong Su
Chun-Long Chen
Yue-Ming Li
Bei-Sheng Kang
Albert S. C. Chan
Wolfgang Kaim
10.1021/ic025934y.s001
https://acs.figshare.com/articles/dataset/Formation_of_Racemate_and_Mesocate_Complexes_from_an_Achiral_Tripodal_Ligand_Containing_Three_Benzimidazole_Groups/3610041
Two complexes of the achiral tripodal ligand tris(1-benzimidazolylethyl)amine (nteb), viz., [Mn(nteb)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>·CH<sub>3</sub>OH, <b>1</b>, and [Ag<sub>2</sub>(nteb)<sub>2</sub>](CF<sub>3</sub>CO<sub>2</sub>)<sub>2</sub>·2H<sub>2</sub>O, <b>2</b>, have been synthesized and characterized by IR, <sup>1</sup>H NMR, and EPR
spectroscopy (<b>1</b>), electrospray mass spectrometry, thermogravimetric analysis, and X-ray crystallography. Compound
<b>1</b> contains chiral complex cations due to the same handedness of two nteb ligands (δδ or λλ) but crystallizes as
a racemate, while <b>2</b> contains a dinuclear mesocate because of the opposite handedness (δλ) of two nteb ligands.
Crystal data for <b>1</b>: space group <i>P</i>1̄ with<i> a</i> = 9.471(4) Å, <i>b</i> = 16.884(7) Å, <i>c</i> = 19.906(8) Å, α = 77.930(7)°, β
= 88.063(7)°, γ = 89.706(7)°, <i>V</i> = 3111(2) Å<sup>3</sup>, and <i>Z</i> = 2. Crystal data for <b>2</b>: space group <i>P</i>1̄ with<i> a</i> =
9.3390(12) Å, <i>b</i> = 10.2168(13) Å, <i>c</i> = 16.382(2) Å, α = 75.721(3)°, β = 87.857(3)°, γ = 71.738(3)°, <i>V</i> =
1437.2(3) Å<sup>3</sup>, and <i>Z</i> = 1. In <b>1</b>, water serves as an auxiliary ligand, connected to one imidazole N atom of each
nteb ligand through a H-bridge; the cationic complexes are associated intermolecularly via π···π interactions. In
contrast to <b>1</b>, the coordination to the Ag<sup>+</sup> ions in <b>2</b> occurs in a heterochiral manner and produces a dinuclear
mesocate.
2002-11-28 00:00:00
EPR
ligand
nteb
OH
imidazole N atom
1 H NMR
H 2 O
CH
CO
handednes
dinuclear mesocate
2. Crystal data
complex
IR
CF
Achiral Tripodal Ligand Containing
Ag