Ions and hydrogen bonding in a hydrophobic environment: CCl(4).
نویسندگان
چکیده
It is generally expected that ions in an aqueous ionic solution in contact with a hydrophobic phase enter the hydrophobic phase accompanied by a hydration shell. This expectation suggests that the ion mole fraction in the hydrophobic phase is less than, or at most, equal to that of water. Both gravimetric and spectroscopic evidence shows that for a model hydrophobic phase, carbon tetrachloride, this is not the case: In contact with a 1 M simple salt solution (sodium or potassium halide), the salt concentration in carbon tetrachloride ranges from 1.4 to nearly 3 times that of water. Infrared spectra of the OH stretch region support a model in which water associates with the cation, primarily as water monomers. Salts containing larger, more polarizable anions can form outer-sphere ion pairs that support water dimers, giving rise to a spectral signature at 3440 cm(-1). In CCl(4), the infrared spectral signature of the normally strongly ionized acid HCl clearly shows the presence of molecular HCl. Additionally, the presence of a Q branch for HCl indicates restricted rotational motion. The spectral and gravimetric data provide compelling evidence for ion clusters in the hydrophobic phase, which is a result that may have implications for hydrophobic matter in both biological and environmental systems.
منابع مشابه
The Impact of Wettability on Effective Properties of Cathode Catalyst Layer in a Proton Exchange Membrane Fuel Cell
The produced liquid water in cathode catalyst layer (CCL) has significant effect on the operation of proton exchange membrane fuel cell (PEMFC). To investigate this effect, the transport of oxygen in CCL in the presence of immiscible liquid water is studied applying a two-dimensional pore scale model. The CCL was reconstructed as an agglomerated system. To explore the wettability effects, diffe...
متن کاملThe effect of hydrophobic and hydrophilic channel walls on the structure and diffusion of water and ions
Molecular dynamics simulations are carried out to determine the effects of channel wall structure on water and ion properties. We compare hydrophobic ~Lennard-Jones 5-3 and atomic! and molecular-hydrophilic cylindrical pores of 2–6 Å in effective radius, relevant to the study of most significant biological ion channels including gramicidin A, ACh, and potassium channels, and to the study of man...
متن کامل4-Methyl-N′-(2,2,2-trichloroethanimidoyl)benzene-1-carboximidamide
The title compound, C(10)H(10)Cl(3)N(3), features a delocalized unsaturated N C N C N chain and strong intra-molecular N-H⋯N hydrogen bonding across the chelate ring and also intra-molecular N-H⋯Cl contacts to a CCl(3)-group Cl atom. The only inter-molecular contacts in the lattice are non-classical hydrogen bonds between methyl and CCl(3) groups. The pseudo-six-membered ring is distinctly non-...
متن کاملThe Role of Interfacial Molecular Structure in the Adsorption of Ions at the Liquid-Liquid Interface
One of the most common and important interfaces is the boundary layer between an aqueous phase solution of ions and a hydrophobic medium. Whether the hydrophobic medium is a membrane, a macromolecular assembly, or a simple organic liquid, our molecular-level understanding of how ions in an adjacent aqueous phase approach, alter, and transport across the boundary is still quite deficient, largel...
متن کاملOptimized Hydrophobic Interactions and Hydrogen Bonding at the Target-Ligand Interface Leads the Pathways of Drug-Designing
BACKGROUND Weak intermolecular interactions such as hydrogen bonding and hydrophobic interactions are key players in stabilizing energetically-favored ligands, in an open conformational environment of protein structures. However, it is still poorly understood how the binding parameters associated with these interactions facilitate a drug-lead to recognize a specific target and improve drugs eff...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The journal of physical chemistry. A
دوره 114 12 شماره
صفحات -
تاریخ انتشار 2010