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Crystalline fibers of the hydrogen-bonded framework bis(guanidinium) naphthalene-1,5-disulfonate, (G)2(1,5-NDS), with ethanol guest molecules twist as they grow when deposited from solution under conditions that favor low nucleation densities and high branching rates. Spherulites comprising helicoidal fibers with a pitch of 3.4 ± 0.5 μm display rhythmic concentric variations in interference colors between crossed polarizers. Tightly packed fibers and platelets, systematically change orientations between flat-on and edge-on crystallites with respect to the substrate surface. Mueller matrix imaging reveals periodic oscillations in the absolute magnitude of the linear retardance and an associated bisignate circular retardance. Single-crystal X-ray diffraction data demonstrates that the twisted (G)2(1,5-NDS)⊃EtOH crystals adopt a bilayer packing motif with ethanol as guest molecules (space group P1 ̅). When the banded spherulite films were subsequently heated at 130°C, the solvated phase was converted to a guest-free crystalline phase (space group P21/c). This transition resulted in loss of linear retardance.
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Bent and Twisted: Synthesis of an Alkoxy-Substituted (1,5)Naphthalene-paracyclophanediene
This contribution describes the synthesis of [2.2](1,5)naphthalenoparacyclophane-1,13-diene in four steps from 1,5-bis(bromomethyl)naphthalene and 1,4-benzenedimethanethiol. Consisting of 2,6-dioctyloxynaphthalene and benzene moieties, the effects of differing arene size on the structure, strain energy, and chemical reactivity of the cyclophanediene are examined. Despite a strain energy of 24.3 kcal/mol, the naphthalenoparacyclophanediene was unreactive towards a library of olefin metathesis catalysts. This diminished reactivity can be explained by the steric hindrance of the twisted olefin. Incorporation of an electron donor (naphthalene) into the rigid paracyclophanediene structure can allow for applications in optoelectronics, chiral ligands, and planar chiral materials.
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- Award ID(s):
- 2203929
- PAR ID:
- 10494055
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- The Journal of Organic Chemistry
- Volume:
- 88
- Issue:
- 18
- ISSN:
- 0022-3263
- Page Range / eLocation ID:
- 12971 to 12977
- Subject(s) / Keyword(s):
- Polymers, chemistry, self-assembly
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1021/acs.joc.3c00880
