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Creators/Authors contains: "Boateng, Stephen"

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  1. ; ; ; ; ; ; ; ; ; (, Proceedings of the National Academy of Sciences)
    π-stacking in ground-state dimers/trimers/tetramers ofN-butoxyphenyl(naphthalene)diimide (BNDI) exceeds 50 kcal ⋅ mol−1in strength, drastically surpassing that for the*3[pyrene]2excimer (∼30 kcal ⋅ mol−1; formal bond order = 1) and similar to other weak-to-moderate classical covalent bonds. Cooperative π-stacking in triclinic (BNDI-T) and monoclinic (BNDI-M) polymorphs effects unusually large linear thermal expansion coefficients (αa, αb, αc, β) of (452, −16.8, −154, 273) × 10−6⋅ K−1and (70.1, −44.7, 163, 177) × 10−6⋅ K−1, respectively. BNDI-T exhibits highly reversible thermochromism over a 300-K range, manifest by color changes from orange (ambient temperature) toward red (cryogenic temperatures) or yellow (375 K), with repeated thermal cycling sustained for over at least 2 y. 
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