Chiral Recognition between Metallohelicates via Strong H Bonds: Homochiral Bishelical Coupling and Mesohelical Polymerization

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• 作者：Jes煤s Sanmart铆n-Matalobos ; Cristina Portela-Garc铆a ; Matilde Fondo ; Ana M. Garc铆a-Deibe
• 刊名：Crystal Growth & Design
• 出版年：2015
• 出版时间：September 2, 2015
• 年：2015
• 卷：15
• 期：9
• 页码：4318-4323
• 全文大小：524K
• ISSN：1528-7505

文摘

A rigid, one-dimensional, and monotopic ligand containing both a proton donor and a proton acceptor, 2-[(1H-imidazol-2-yl)methyleneamino]phenol (H₂L), has been used to attain three hierarchically assembled supramolecular polymers. The handedness of these hydrogen-bonded metallo-supramolecular structures is modulated by a selective coupling, via strong H bonds with significant covalent character. Thus, alternate 螖 and 螞 enantiomers of Cd(HL)₂ form a one-dimensional supramolecular polymer via mutual strong N鈥揌路路路O interactions (2.58 脜), which are associated with a hydrogen bond energy value of 鈭?1.5 kcal mol^鈥?. In contrast, homochiral self-recognition of enantiomers of M(HL)₂ and [M(H₂L)₂]²⁺ (M = Cu^II and Ni^II) gives rise to dinuclear bishelicates, whose metallohelical units are held together by two strong O鈥揌路路路O bonds (2.41鈥?.44 脜), which are associated with hydrogen bond energies in the range of 25鈥?5 kcal mol^鈥?.