Nature Utilizes Unusual High London Dispersion Interactions for Compact Membranes Composed of Molecular Ladders

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• 作者：J. Philipp Wagner ; Peter R. Schreiner
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2014
• 出版时间：March 11, 2014
• 年：2014
• 卷：10
• 期：3
• 页码：1353-1358
• 全文大小：320K
• 年卷期：v.10,no.3(March 11, 2014)
• ISSN：1549-9626

文摘

London dispersion interactions play a key role in nature, in particular, in membranes that constitute natural barriers. Here we demonstrate that the spatial alignment of 鈥渕olecular ladders鈥?([n]ladderanes), i.e., highly unusual and strained all-trans-fused cyclobutane moieties, leads to much larger attractive dispersion interactions as compared to alkyl chains of the same length. This provides a rationale for the occurrence of peculiar ladderane fatty acids in the dense cell walls of anammox bacteria. Despite the energetic penalty paid for the assembly of such strained polycycles, the advantage lies in significantly higher, dispersion-dominated interaction energies as compared to straight-chain hydrocarbon moieties commonly found in fatty acids. We discern the dispersion contributions to the total interaction energies using a variety of computational methods including modern dispersion-corrected density functional theory and high level ab initio approaches. Utilizing larger assemblies, we also show that the intermolecular interactions behave additively.