Why Do Some Molecules Form Hydrates or Solvates?
Why Do Some Molecules Form Hydrates or Solvates?
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DOI：
10.1021/acs.cgd.8b00160
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发表时间：
2018-03-01
影响因子：
3.8
通讯作者：
Anwar, Jamshed
中科院分区：
文献类型：
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作者：
Boothroyd, Simon;Kerridge, Andy;Anwar, Jamshed
溶剂化物（溶剂融入晶格的晶体结构）的发现可以追溯到化学的萌芽时期。这种现象无处不在，其重要应用范围从药物开发到从大气中捕获二氧化碳的潜力。尽管有这样的兴趣，我们仍然不完全理解为什么某些分子会形成溶剂化物。我们使用溶质和溶剂分子的简单模型进行分子模拟，其相互作用参数可以随意调节，以访问形成或不形成溶剂化物的分子宇宙。我们研究了这些模型溶质-溶剂系统的相行为，作为溶质-溶剂亲和力、分子大小比和溶质浓度的函数。模拟表明，溶剂化物形成的主要标准是溶质-溶剂亲和力必须足以压倒溶质-溶质和溶剂-溶剂亲和力。强的溶质-溶剂亲和力本身并不是溶剂化物形成的充分条件：在没有如此强的亲和力的情况下，只要溶质和溶剂的自亲和力相对较弱，仍然可以形成溶剂化物。我们表明，即使是疏溶剂的分子也可以通过更有效的堆积或由于克服能量损失的高压而产生的 p Delta V 电势而被诱导形成溶剂化物。
The discovery of solvates (crystal structures where the solvent is incorporated into the lattice) dates back to the dawn of chemistry. The phenomenon is ubiquitous, with important applications ranging from the development of pharmaceuticals to the potential capture of CO2 from the atmosphere. Despite this interest, we still do not fully understand why some molecules form solvates. We have employed molecular simulations using simple models of solute and solvent molecules whose interaction parameters could be modulated at will to access a universe of molecules that do and do not form solvates. We investigated the phase behavior of these model solute-solvent systems as a function of solute-solvent affinity, molecule size ratio, and solute concentration. The simulations demonstrate that the primary criterion for solvate formation is that the solute-solvent affinity must be sufficient to overwhelm the solute-solute and solvent-solvent affinities. Strong solute-solvent affinity in itself is not a sufficient condition for solvate formation: in the absence of such strong affinity, a solvate may still form provided that the self-affinities of the solute and the solvent are weaker in relative terms. We show that even solvent-phobic molecules can be induced to form solvates by virtue of a p Delta V potential arising either from a more efficient packing or because of high pressure overcoming the energy penalty.