The gridarenes, with well-defined edges and vertices, represent versatile nanoscale building blocks for the installation of frameworks and architectures but suffer from difficulty in stereoselective control during their synthesis. Here we report a diastereoselective gridization of superelectrophilic diazafluorene-containing substrates (AB) with crescent shapes into Drawing Hands grids (DHGs). The meso-selectivity reaches 75.6% diastereomeric excess (de) during the gridization of AB-type substrates and maintains ~80% de during the polygridization of AB-type monomers. Such stereocontrol originates from the centrosymmetric molecular packing of two charge-delocalized superelectrophiles with synergistically π-π stacking attractions and coulombic repulsions. As meso-stereoregular structures show 20∼30 nm in length, the rigid ring/chain-alternating polygrids have a Mark-Houwink exponent of 1.651 and a molecular weight (M) dependence of the hydrodynamic radius R ∼ M. Via the simulation of chain collapse, meso-configured polygridarenes still adopt rod-like conformations that facilitate the high rigidity of organic nanopolymers, distinguished from toroid backbones of rac-type polygrids.
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http://dx.doi.org/10.1038/s41467-020-15401-x | DOI Listing |
Int J Mol Sci
December 2024
Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
Chem Sci
November 2024
Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur West Bengal India-741246
Red emission in crystals has been observed with an ultra-small-single-benzenic -fluorophore () with a molecular weight (MW) of only 197 Da, bettering the literature report of fluorophores with the lowest MW = 252 Da. Supramolecular extensive hydrogen-bonding and J-aggregate type centrosymmetric discrete-dimers or a 1D chain of s led to red emission ( = 610-636 nm) in crystals. Unlike in the solution phase showing one absorption band, in thin films and in crystals the transition from the S state to both the S state and S state becomes feasible.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
The development of molecular switches with tunable properties has garnered considerable interest over several decades. A novel spin-crossover (SCO) material based on iron(II) complexes incorporating 4-acetylpyridine (4-acpy) and [Hg(SCN)] anions was synthesized and formulated as [Fe(4-acpy)][Hg(μ-SCN)] (1). Compound 1 is crystallized in a three-dimensional network in the non-centrosymmetric orthorhombic space group Pna2 with two octahedral [Fe(4-acpy)(NCS)] entities featuring two distinct Fe centers (Fe1 and Fe2).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
November 2024
Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Campus de Beaulieu, 35042 Rennes, France.
Infrared and Raman spectra of three isostructural charge transfer complexes (EDT-TTF-I)TCNQF (n = 0, 1, 2) are studied. The planar molecules in these complexes are arranged in one-dimensional stacks formed by donor-acceptor-donor (DAD) centrosymmetric trimeric units with a different degree of charge transfer between D and A. In the IR electronic spectra two bands attributed to D → D and D → A charge transfer transitions are distinguished.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Strong polar molecular cages have recently emerged as novel functional building units for high-performance infrared nonlinear optical (IR NLO) crystals. However, these highly polar molecular cages often arrange themselves in a way that cancels out their polarity, leading to a more energetically stable state. As a result, most cage crystal formations tend to crystallize in centrosymmetric space groups, which conflicts with the primary requirement for NLO crystals.
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