Joel S A Miller, D. Dixon, J. Calabrese
Jan 3, 1990
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0
Influential Citations
77
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Quality indicators
Journal
Journal of the American Chemical Society
Abstract
Hexaazaoctadecahydrocoronene and its mono-, di-, tri-, and tetracations, (HOC){sup n} (n = 0, 1+, 2+, 3+, 4+), have been prepared and characterized by X-ray diffraction, EPR, magnetic susceptibility, and electronic and vibrational spectroscopies. HOC, (HOC){sup {sm bullet}+} (BF{sub 4}){sup {minus}}, (HOC){sup {sm bullet}+}(TCNE){sup {sm bullet}{minus}} (TCNE = tetracyanoethylene), (HOC){sup {sm bullet}+} (F{sub 3}CSO{sub 3}){sup {minus}}, (HOC){sup 2+}((PF{sub 6}){sup {minus}}){sub 2}, (HOC){sup 2+}((BF{sub 4}){sup {minus}}){sub 2}, (HOC){sup 2+}((C(CN){sub 3}){sup {minus}}){sub 2}, (HOC){sup 2+}(C(C(CN){sub 2}){sub 3}){sup 2{minus}}, (HOC){sup 2+}(Ni(S{sub 2}-C{sub 2}(CF{sub 3}){sub 2}){sub 2}{sup {sm bullet}{minus}}){sub 2}, (HOC){sup {sm bullet}3+}((PF{sub 6}){sup {minus}}){sub 3}, (HOC){sup {sm bullet}3+}((SbF{sub 6}){sup {minus}}){sub 3}, and (HOC){sup 4+}((SbF{sub 6}){sup {minus}}){sub 4}{center dot}MeCn have been studied by single-crystal X-ray diffraction. Solid-state magnetic susceptibility measurements show that the n = 0, 2+, and 4+ compounds are diamagnetic and that the n = 1+ and 3+ salts are S = {1/2} paramagnets that obey the Curie-Weiss expression between 2 and 320 K. The effective moments, {mu}{sub eff}, and Curie-Weiss constants, {theta}, are 1.77 and 1.75 {mu}{sub B} and {theta} = -3.3 and -0.9 K for the mono- and trications, respectively. The n = 1+ and 3+ radical cations are fluxional in solution. The EPR spectrum of (HOC){sup {sm bullet}+} in themore » fast-exchange limit (25{degree}C) shows that all protons and N's have the same hyperfine splitting (2.56 G, g = 2.00315). Solid-state magnetic susceptibility measurements for those (HOC){sup 2+} with singlet-triplet gaps less than 4.0 kcal/mol show increases in susceptibilities at higher temperatures, consistent with the presence of thermally populated triplet excited states.« less