TY - JOUR
T1 - Anion-aided Dynamic One-pot Self-assembly of Rectangular Metallacycles
AU - Shiu, Ler Chun
AU - Chuang, Jen Han
AU - Lee, Gene Hsiang
AU - Wu, Tian Shung
AU - Shiu, Kom Bei
N1 - Publisher Copyright:
© 2017 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/6/1
Y1 - 2017/6/1
N2 - The tetracopper(I) complex [{Cu2(μ-dppm)2}2(μ-1,4-O2CC6H4(CO2)2)](BF4)2 (1(BF4)2) and 1,2-bis(4-pyridyl)ethane (bpa) can establish a dynamic equilibrium in CH2Cl2. From the equilibrium mixture containing 1(BF4)2 and bpa with the molar ratio 1(BF4)2/bpa of 1:1, a supramolecular compound [{Cu2(μ-dppm)2}2(μ-1,4-C6H4(CO2)2)(μ-bpa)]2(BF4)4 (2(BF4)4) was obtained as single crystals. The crystal structure was determined by X-ray crystallography to reveal presence of one BF-4 anion inside a cationic rectangular metallacycle {2 ⊂ BF4 }3+. Both structural evidence and DFT-calculated results indicate that the F atoms of the anion exert weak electrostatic attraction with hydrogen atoms of the bound bpa as the framework of the cationic metallacycle. The attractive interactions apparently play an important role in stabilizing some dynamically self-assembled precursors so as to form the final anion-included metallacycle. Without the electrostatic help from the anion, the self-assembly of the empty metallacycle may be hindered by a rather large endothermic free energy. The favorable electrostatic stabilization is present not only for a BF-4 anion but also for other anions such as PF-6, NO-3, and BF-4 even when the flexible bpa is replaced by rigid 4,4′-bipyridine (bpy). Based on the DFT results, the metallacycle 2(BF4)4 can be easily prepared in a one-pot reaction of [Cu(MeCN)4](BF4) with three ligands.
AB - The tetracopper(I) complex [{Cu2(μ-dppm)2}2(μ-1,4-O2CC6H4(CO2)2)](BF4)2 (1(BF4)2) and 1,2-bis(4-pyridyl)ethane (bpa) can establish a dynamic equilibrium in CH2Cl2. From the equilibrium mixture containing 1(BF4)2 and bpa with the molar ratio 1(BF4)2/bpa of 1:1, a supramolecular compound [{Cu2(μ-dppm)2}2(μ-1,4-C6H4(CO2)2)(μ-bpa)]2(BF4)4 (2(BF4)4) was obtained as single crystals. The crystal structure was determined by X-ray crystallography to reveal presence of one BF-4 anion inside a cationic rectangular metallacycle {2 ⊂ BF4 }3+. Both structural evidence and DFT-calculated results indicate that the F atoms of the anion exert weak electrostatic attraction with hydrogen atoms of the bound bpa as the framework of the cationic metallacycle. The attractive interactions apparently play an important role in stabilizing some dynamically self-assembled precursors so as to form the final anion-included metallacycle. Without the electrostatic help from the anion, the self-assembly of the empty metallacycle may be hindered by a rather large endothermic free energy. The favorable electrostatic stabilization is present not only for a BF-4 anion but also for other anions such as PF-6, NO-3, and BF-4 even when the flexible bpa is replaced by rigid 4,4′-bipyridine (bpy). Based on the DFT results, the metallacycle 2(BF4)4 can be easily prepared in a one-pot reaction of [Cu(MeCN)4](BF4) with three ligands.
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U2 - 10.1002/jccs.201700044
DO - 10.1002/jccs.201700044
M3 - Article
AN - SCOPUS:85018593113
VL - 64
SP - 666
EP - 673
JO - Journal of the Chinese Chemical Society
JF - Journal of the Chinese Chemical Society
SN - 0009-4536
IS - 6
ER -