Self-Assembly with Postmodification:  Kinetically Stabilized Metalla-Supramolecular Rectangles

Abstract

Interaction of a predesigned molecular "clip" (4) with rigid dipyridyl bridging ligands, in acetone/water mixtures, leads to the formation of molecular rectangles (5-8) in 92-97% isolated yields via spontaneous self-assembly. Characterization was accomplished with multinuclear NMR and UV-vis spectroscopy, FAB mass spectrometry, and X-ray crystallography. The length of these metallamacrocycles ranges from 2 to 3 nm. Postmodification via non-nucleophilic counterion exchange results in enhanced structural integrity for the assemblies.

Mesoscopic self-organization of a self-assembled supramolecular rectangle on highly oriented pyrolytic graphite and Au(111) surfaces

“…5, which is published as supporting information on the PNAS web site). The size of these lines is consistent with the dimension of the rectangle, as determined from the previously reported x-ray crystallographic data (28). Therefore, one bright line corresponds to a single rectangle standing vertically with its long edge standing on the underlying HOPG surface.…”

“…4B, upper right corner). The molecular size of the rectangle was determined to be 3.0 Ϯ 0.2 by 1.1 Ϯ 0.2 nm, consistent with the size of the rectangle determined from the x-ray crystallographic data (28). From the intermolecular distance and adlayer symmetry, a unit cell was determined.…”

“…In this article, we describe scanning tunneling microscopy (STM) studies of the self-assembled supramolecular metallacyclic rectangle, cyclobis[(1,8-bis(transPt(PEt 3 ) 2 )anthracene)(1,4Ј-bis(4-ethynylpyridyl)benzene](PF 6 ) 4 , (Fig. 1) (28). The dimensions of a single rectangle molecule were independently determined to be 3.1 nm long by 1.2 nm wide, from the previously reported x-ray crystallographic data (28).…”

“…1) (28). The dimensions of a single rectangle molecule were independently determined to be 3.1 nm long by 1.2 nm wide, from the previously reported x-ray crystallographic data (28). The molecular adlayers were prepared on highly oriented pyrolytic graphite (HOPG) and Au(111) surfaces to investigate the effect of substrate on adlayer formation.…”

Coordination-Driven Face-Directed Self-Assembly of Trigonal Prisms. Face-Based Conformational Chirality

“…There is ample precedent for this behavior, and for restricted ring rotational equilibration. 21,36,37 The pyridyl proton resonances of 3 are shifted slightly to lower field as expected due to the loss of electron density that occurs upon coordination. The only exception was the resonance of one H α nucleus of 3d at 8.20 ppm, which shifts to higher field relative to the starting ligand 1d (8.51 ppm).…”