Synthesis and Properties of Cyclic [5]<i>meta</i>-Phenyleneacetylene and Its Corresponding Cyclophane Polyone, [25](1,3)Cyclophanedecaone

Yamakawa, Jun; Ohkoshi, Masanori; Takahashi, Futoshi; Nishiuchi, Tomohiko; Kuwatani, Yoshiyuki; Nishinaga, Tohru; Yoshida, Masato; Iyoda, Masahiko

doi:10.1246/cl.2008.784

Cited by 11 publications

(4 citation statements)

References 19 publications

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“…These findings suggest that 3 , in spite of its conjugated covalent nature, is easily distorted. This proposal is supported by the X-ray crystallographic studies of related substances. − The equilibrium geometry of 3 is influenced by Coulomb repulsion between the lone pairs of the nitrogen atoms, which repulsion is neutralized upon complexation of a cation in 2a – c . The strain introduced by rearrangement of 3 from its equilibrium geometry to the geometries found in 2a , b is slightly negative (ca.…”

Section: Resultsmentioning

confidence: 82%

Symmetric Halogen Bonding Is Preferred in Solution

et al. 2012

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Halogen bonding is a recently rediscovered secondary interaction that shows potential to become a complementary molecular tool to hydrogen bonding in rational drug design and in material sciences. Whereas hydrogen bond symmetry has been the subject of systematic studies for decades, the understanding of the analogous three-center halogen bonds is yet in its infancy. The isotopic perturbation of equilibrium (IPE) technique with (13)C NMR detection was applied to regioselectively deuterated pyridine complexes to investigate the symmetry of [N-I-N](+) and [N-Br-N](+) halogen bonding in solution. Preference for a symmetric arrangement was observed for both a freely adjustable and for a conformationally restricted [N-X-N](+) model system, as also confirmed by computation on the DFT level. A closely attached counterion is shown to be compatible with the preferred symmetric arrangement. The experimental observations and computational predictions reveal a high energetic gain upon formation of symmetric, three-center four-electron halogen bonding. Whereas hydrogen bonds are generally asymmetric in solution and symmetric in the crystalline state, the analogous bromine and iodine centered halogen bonds prefer symmetric arrangement in solution.

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Section: Resultsmentioning

confidence: 82%

Symmetric Halogen Bonding Is Preferred in Solution

et al. 2012

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“…The syntheses of 1c and 1d were reported by Moore et al 20 and Iyoda et al, respectively. 21 Macrocycles 1a and 1b were prepared from 1c by ester-exchange reactions (see ESI †).…”

Section: Resultsmentioning

confidence: 99%

Molecular pentagonal tiling: self-assemblies of pentagonal-shaped macrocycles at liquid/solid interfaces

et al. 2011

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We present a systematic scanning tunneling microscopy study on the 2D self-assembly of pentagonal shaped macrocycles at the liquid/solid interface to gain insight about 2D pentagonal molecular crystallization. Macrocycles with alkyl ester groups form an anti-parallel type linear pattern mainly via favorable intermolecular interactions between the interdigitated alkyl chains at the 1,2,4trichlorobenzene (TCB)/graphite interface. On the other hand, at the TCB/Au(111) interface, they showed a random pattern and an anti-parallel type linear pattern. The selection between both motifs is ascribed to the balance between the intermolecular and molecule-substrate interactions. Most interestingly, the parent molecule forms dense anti-parallel and parallel linear patterns reflecting the intrinsic pentagonal core shape. Moreover, bright and mobile spots were often observed in the networks to occupy free spaces, including the cavity of the macrocycles, which we attribute to a coadsorbed solvent molecule or Au ion.

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“…As a pentagonal shaped molecule, we chose [5]CMPA because of its planar and rigid pentagonal π-core. 32 Furthermore, it is also large enough to be clearly identified by STM. Structural optimization of [5]CMPA by a DFT calculation (B3LYP/6-31g(d)) in vacuum confirms that it adopts a regular D5h symmetric structure with side lengths of 1.0 nm and vertex angles of 108° (Fig.…”

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confidence: 99%

“…Synthesis of [5]CMPA was reported before. 32 [14]ISODBA was newly synthesized according to the procedure reported before (See ESI). 33,34 [5]CMPA and First, we attempted STM observations of SAMNs formed by [5]CMPA.…”

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confidence: 99%