气候变化领域集成服务门户(CCPortal): Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes

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DOI	10.1073/pnas.1612480114
	Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes
	Grdadolnik J.; Merzel F.; Avbelj F.
发表日期	2017
ISSN	0027-8424
起始页码	322
结束页码	327
卷号	114 期号:2
英文摘要	Hydrophobicity plays an important role in numerous physicochemical processes from the process of dissolution in water to protein folding, but its origin at the fundamental level is still unclear. The classical view of hydrophobic hydration is that, in the presence of a hydrophobic solute, water forms transient microscopic "icebergs" arising from strengthened water hydrogen bonding, but there is no experimental evidence for enhanced hydrogen bonding and/or icebergs in such solutions. Here, we have used the redshifts and line shapes of the isotopically decoupled IR oxygen-deuterium (O-D) stretching mode of HDO water near small purely hydrophobic solutes (methane, ethane, krypton, and xenon) to study hydrophobicity at the most fundamental level. We present unequivocal and model-free experimental proof for the presence of strengthened water hydrogen bonds near four hydrophobic solutes, matching those in ice and clathrates. The water molecules involved in the enhanced hydrogen bonds display extensive structural ordering resembling that in clathrates. The number of ice-like hydrogen bonds is 10-15 per methane molecule. Ab initio molecular dynamics simulations have confirmed that water molecules in the vicinity of methane form stronger, more numerous, and more tetrahedrally oriented hydrogen bonds than those in bulk water and that their mobility is restricted. We show the absence of intercalating water molecules that cause the electrostatic screening (shielding) of hydrogen bonds in bulk water as the critical element for the enhanced hydrogen bonding around a hydrophobic solute. Our results confirm the classical view of hydrophobic hydration.
英文关键词	Ab initio molecular dynamics; Electrostatic screening; Hydrogen bonding; Hydrophobic hydration; IR spectroscopy
语种	英语
scopus关键词	deuterium; element; ethane; ice; krypton; methane; oxygen; water; xenon; ab initio calculation; chemical structure; Conference Paper; hydration; hydrogen bond; hydrophobicity; iceberg; infrared spectroscopy; molecular dynamics; priority journal; solute; static electricity; stretching; structure analysis
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160671
作者单位	Grdadolnik, J., Department of Biomolecular Structure, National Institute of Chemistry, Ljubljana, SI 1000, Slovenia; Merzel, F., Department of Biomolecular Structure, National Institute of Chemistry, Ljubljana, SI 1000, Slovenia; Avbelj, F., Department of Biomolecular Structure, National Institute of Chemistry, Ljubljana, SI 1000, Slovenia
推荐引用方式 GB/T 7714	Grdadolnik J.,Merzel F.,Avbelj F.. Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes[J],2017,114(2).
APA	Grdadolnik J.,Merzel F.,&Avbelj F..(2017).Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes.Proceedings of the National Academy of Sciences of the United States of America,114(2).
MLA	Grdadolnik J.,et al."Origin of hydrophobicity and enhanced water hydrogen bond strength near purely hydrophobic solutes".Proceedings of the National Academy of Sciences of the United States of America 114.2(2017).