61639-32-5Relevant academic research and scientific papers
Mechanistic Analysis of Solid-State Colorimetric Switching: Monoalkoxynaphthalene-Naphthalimide Donor-Acceptor Dyads
Wight, Christopher D.,Xiao, Qifan,Wagner, Holden R.,Hernandez, Eduardo A.,Lynch, Vincent M.,Iverson, Brent L.
, p. 17630 - 17643 (2020/11/12)
There is growing interest in creating solids that are responsive to various stimuli. Herein we report the first molecular-level mechanistic picture of the thermochromic polymorphic transition in a series of MAN-NI dyad crystals that turn from orange to yellow upon heating with minimal changes to the microscopic morphology following the transition. Detailed structural analyses revealed that the dyads assemble to create an alternating bilayer type structure, with horizontal alternating alkyl and stacked aromatic layers in both the orange and yellow forms. The observed dynamic behavior in the solid state moves as a yellow wavefront through the orange crystal. The overall process is critically dependent on a complex interplay between the layered structure of the starting crystal, the thermodynamics of the two differently colored forms, and similar densities of the two polymorphs. Upon heating, the orange form alkyl chain layers become disordered, allowing for some lateral diffusion of dyads within their own layer. Moving to either adjacent stack in the same layer allows a dyad to exchange a head-to-head stacking geometry (orange) for a head-to-tail stacking geometry (yellow). This transition is unique in that it involves a nucleation and growth mechanism that converts to a faster cooperative wavefront mechanism during the transition. The fastest moving of the wavefronts have an approximately 38° angle with respect to the long axis of the crystal, corresponding to a nonconventional C-H···O hydrogen bond network of dyad molecules in adjacent stacks that enables a transition with cooperative character to proceed within layers of orange crystals. The orange-to-yellow transition is triggered at a temperature that is very close to the temperature at which the orange and yellow forms exchange as the more stable, while being lower than the melting temperature of the original orange, or final yellow, solids.
Time-dependent solid-state polymorphism of a series of donor-acceptor dyads
Peebles, Cameron,Alvey, Paul M.,Lynch, Vincent,Iverson, Brent L.
, p. 290 - 299 (2014/01/17)
In order to exploit the use of favorable electrostatic interactions between aromatic units in directing the assembly of donor-acceptor (D-A) dyads, the present work examines the ability of conjugated aromatic D-A dyads with symmetric side chains to exhibit solid-state polymorphism as a function of time during the solid formation process. Four such dyads were synthesized, and their packing in the solid state from either slower (10-20 days) or faster (1-2 days) evaporation from solvent was investigated using single crystal X-ray analysis and powder X-ray diffraction. Two of the dyads exhibited tail-to-tail (A-A) packing upon slower evaporation from solvent and head-to-tail (D-A) packing upon faster evaporation from solvent. A combination of single-crystal analysis and XRD patterns were used to create models, wherein a packing model for the other two dyads is proposed. Our findings suggest that while side chain interactions in asymmetric aromatic dyads can play an important role in enforcing segregated D-A dyad assembly, slowly evaporating symmetrically substituted aromatic dyads allows for favorable electrostatic interactions between the aromatic moieties to facilitate the organization of the dyads in the solid state.
Synthesis of novel structurally simplified estrogen analogues with electron-donating groups in ring A
Tietze, Lutz F.,Vock, Carsten A.,Krimmelbein, Ilga K.,Nacke, Linda
experimental part, p. 2040 - 2060 (2009/12/27)
A library of 25 novel estrogen analogues were prepared in five to eight steps from mostly commercially available substituted anisoles via bromination, formylation, Corey-Fuchs reaction, elimination, and Sonogashira reaction. Georg Thieme Verlag Stuttgart.
Benzophenalenofurans
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, (2008/06/13)
The compounds are benzophenalenofurans having pharmacological activity, in particular, coronary vasodilator activity.
