ja5b04386_si_002.cif (3.32 MB)
Metal–Organic Nanotube with Helical and Propeller-Chiral Motifs Composed of a C10-Symmetric Double-Decker Nanoring
dataset
posted on 2015-06-24, 00:00 authored by Hiroshi Yamagishi, Takahiro Fukino, Daisuke Hashizume, Tadashi Mori, Yoshihisa Inoue, Takaaki Hikima, Masaki Takata, Takuzo AidaCoassembly
of an achiral ferrocene-cored tetratopic pyridyl ligand
(FcL) with AgBF4 in CH2Cl2/MeCN (7:3 v/v) containing chiral Bu4N+ (+)-
or (−)-menthylsulfate (MS*–) results in the
formation of an “optically active” metal–organic
nanotube (FcNT) composed of a C10-symmetric double-decker nanoring featuring 10 FcL units and 20 Ag+ ions. The circular dichroism spectrum
of FcNT along with its 2D X-ray diffraction (2D XRD)
pattern indicates that the constituent metal–organic nanorings
in FcNT stack one-handed helically on top of each other.
A crystal structure of the dimeric double-decker model complex (Ag2(FcL′)2) from a ditopic ferrocene
ligand (FcL′) and AgBF4 allowed for
confirming the binding of MS*– onto the Ag+ center of the complex. The results of detailed spectroscopic studies
indicate that in its double-decker aromatic arrays, FcNT possibly possesses propeller-chiral twists in addition to the helically
chiral structure, where the former is considerably more dynamic than
the latter. Notably, both chiral structural motifs responded nonlinearly
to an enantiomeric excess of MS*– (majority rule)
though with no stereochemical influence on one another.