Hydrophobic-hydrophilic Interactions Research Articles

Interactions in ( l-alanine/ l-threonine + aqueous glucose/aqueous sucrose) systems at (298.15–323.15) K

Densities and speeds of sound of ( l-alanine + 1 mol L −1 aqueous glucose/1 mol L −1 aqueous sucrose) and ( l-threonine + 1 mol L −1 aqueous glucose/1 mol L −1aqueous sucrose) systems have been measured as a function of molal concentration of l-alanine and l-threonine at temperatures: (298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K. The partial molar volumes, transfer partial molar volumes, partial molar isentropic compressibilities and transfer partial molar isentropic compressibilities have been evaluated using the experimentally measured values of density and speed of sound. The trends of variations of experimental and computed parameters have been discussed in terms of ionic–hydrophilic, hydrophilic–hydrophilic and hydrophilic–hydrophobic interactions operative in the systems.

Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale (nanoparticles). Nanoparticles can be engineered in a precise fashion where their size, composition and surface chemistry can be carefully controlled. This enables unprecedented freedom to modify some of the fundamental properties of their cargo, such as solubility, diffusivity, biodistribution, release characteristics and immunogenicity. Since their inception, nanoparticles have been utilized in many areas of science and medicine, including drug delivery, imaging, and cell biology(1-4). However, it has not been fully utilized outside of "nanotechnology laboratories" due to perceived technical barrier. In this article, we describe a simple method to synthesize a polymer based nanoparticle platform that has a wide range of potential applications. The first step is to synthesize a diblock co-polymer that has both a hydrophobic domain and hydrophilic domain. Using PLGA and PEG as model polymers, we described a conjugation reaction using EDC/NHS chemistry(5) (Fig 1). We also discuss the polymer purification process. The synthesized diblock co-polymer can self-assemble into nanoparticles in the nanoprecipitation process through hydrophobic-hydrophilic interactions. The described polymer nanoparticle is very versatile. The hydrophobic core of the nanoparticle can be utilized to carry poorly soluble drugs for drug delivery experiments6. Furthermore, the nanoparticles can overcome the problem of toxic solvents for poorly soluble molecular biology reagents, such as wortmannin, which requires a solvent like DMSO. However, DMSO can be toxic to cells and interfere with the experiment. These poorly soluble drugs and reagents can be effectively delivered using polymer nanoparticles with minimal toxicity. Polymer nanoparticles can also be loaded with fluorescent dye and utilized for intracellular trafficking studies. Lastly, these polymer nanoparticles can be conjugated to targeting ligands through surface PEG. Such targeted nanoparticles can be utilized to label specific epitopes on or in cells(7-10).

Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale (nanoparticles). Nanoparticles can be engineered in a precise fashion where their size, composition and surface chemistry can be carefully controlled. This enables unprecedented freedom to modify some of the fundamental properties of their cargo, such as solubility, diffusivity, biodistribution, release characteristics and immunogenicity. Since their inception, nanoparticles have been utilized in many areas of science and medicine, including drug delivery, imaging, and cell biology1-4. However, it has not been fully utilized outside of "nanotechnology laboratories" due to perceived technical barrier. In this article, we describe a simple method to synthesize a polymer based nanoparticle platform that has a wide range of potential applications. The first step is to synthesize a diblock co-polymer that has both a hydrophobic domain and hydrophilic domain. Using PLGA and PEG as model polymers, we described a conjugation reaction using EDC/NHS chemistry5 (Fig 1). We also discuss the polymer purification process. The synthesized diblock co-polymer can self-assemble into nanoparticles in the nanoprecipitation process through hydrophobic-hydrophilic interactions. The described polymer nanoparticle is very versatile. The hydrophobic core of the nanoparticle can be utilized to carry poorly soluble drugs for drug delivery experiments6. Furthermore, the nanoparticles can overcome the problem of toxic solvents for poorly soluble molecular biology reagents, such as wortmannin, which requires a solvent like DMSO. However, DMSO can be toxic to cells and interfere with the experiment. These poorly soluble drugs and reagents can be effectively delivered using polymer nanoparticles with minimal toxicity. Polymer nanoparticles can also be loaded with fluorescent dye and utilized for intracellular trafficking studies. Lastly, these polymer nanoparticles can be conjugated to targeting ligands through surface PEG. Such targeted nanoparticles can be utilized to label specific epitopes on or in cells7-10.

Interactions in (glycylglycine + 1 M aqueous glucose/1 M aqueous sucrose) systems at 298.15–323.15 K

Density and speed of sound values of (glycylglycine+1M aqueous glucose/1M aqueous sucrose) systems have been measured as a function of molal concentration of glycylglycine at temperatures: 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15K by an oscillating-tube density and sound velocity meter. The partial molar volumes, isentropic compressibilities and partial molar isentropic compressibilities of the (glycylglycine+1M aqueous glucose/1M aqueous sucrose) systems have been computed from the experimental density and speed of sound data at different temperatures. The isentropic compressibility values decrease with an increase in molal concentration of glycylglycine as well as temperature. The partial molar volumes increase whereas partial molar isentropic compressibilities decrease with an increase in temperature. The trends of variations of experimental and computed parameters have been discussed in terms of ionic–hydrophilic, hydrophilic–hydrophilic and hydrophobic–hydrophilic interactions operative in the systems.

Supramolecular polymer micelles prepared by steric effect tuned self-assembly: a new strategy for self-assembly

Low molecular weight poly(e-caprolactone) (PCL) and α-cyclodextrin (α-CD) favor forming crystallized peseudopolyrotaxanes in most of solvents, which impedes their biomedical application. This work provides an example of site-specific polymer functionalization of PCL to control the hierachical assembly with CDs to form novel supramolecular polymer micelles (SMPMs). The unique design of functional PCL includes the introduction of anticancer drug doxorubicin (Dox) with a larger molecular volume as the steric group into the backbone of PCL to realize the partial inclusion complex of PCL with α-CD. This inclusion complex can then self assemble into SMPMs with an average size of around 20 nm in aqueous solution due to the hydrophobic–hydrophilic interaction. The structure and morphology of the SMPMs were investigated and revealed by comprehensive characterizations including 1HNMR, XRD and TEM, TGAetc., their controlled drug release and cell internalization behavior were also explored. The above proof of concept paves the way for a new strategy for self-assembly and overcomes the dispersion of pseudopolyrotaxanes, also, the micelles formed show great promise in biomedical applications, especially in controlled drug release.

Density and viscosity of α-amino acids in aqueous solutions of cetyltrimethylammonium bromide

The densities and viscosities of aqueous solution of cetyltrimethylammonium bromide (0.01 mol kg−1) (CTAB) and solutions of CTAB containing amino acids, viz., glycine, l-serine, and l-valine (0.01–0.05 mol kg−1), were determined in the temperature range 298.15—313.15 K. Apparent molar volumes of the amino acids were calculated from the density and viscosity values. The calculated apparent molar volumes were used to calculate standard partial molar volumes (-V20) and standard partial molar volumes of transfer of amino acids from water to an aqueous solution of CTAB. The viscosity values were used for the calculation of the viscosity coefficients A and B in the Jones—Dole equation. The linear dependences of -V20 and B on the number of carbon atoms in the alkyl chains of the amino acids were found. The results obtained were used in analysis of hydrophilic-hydrophilic, hydrophilic-hydrophobic, and hydrophobic-hydrophobic interactions that occur during dissolution of amino acids in an aqueous solution of CTAB.

Synthesis and characterisation of temperature responsive poly (2-ethyl-2-oxazolines

A bifunctional Poly(2-ethyl-2-oxazolines) containing hydrophobic end groups at both end of the polymer chains were synthesised by terminating a living cationic polymerisation with 4- bromomethyl benzoic acid. The results obtained for the clouding point measurement using UVvisible spectrophotometer shows that bifunctional polymer containing 20 monomer units (DP 20) exhibited a lower critical solution temperature (LCST) near 49oC due to formation of hydrophobic domains by the polymer end-groups. In contrast, the polymer with 50 monomer units does not exhibit any LCST between 20 to 70oC due to the imbalance in the hydrophilic-hydrophobic interaction in this polymer.

An estimation of hydrophilic and hydrophobic interaction of aqueous urea, methylurea, dimethylurea and tetramethylurea from density and apparent molal volume at 30.0°C

Density (ρ) for 0.20–1.0 mol kg−1 of urea, 1-methylurea, 1,3-dimethylurea and 1,1,3,3-tetramethylurea solutions have been measured at an interval of 0.2 mol kg−1. Apparent molal volume (V φ, cm3 mol−1) is calculated from ρ values. Primary data were regressed and extrapolated to zero concentration for the limiting density (ρ0) and limiting apparent molal volume values for solute–solvent interactions.–CH3 (methyl) groups of N-methylureas weaken hydrophilic interaction and enhance hydrophobic interaction. The value of ρ0 and reflect the intermolecular forces due to electrostatic charge. The decreasing value of ρ0 and increasing value of with increasing number of–CH3 groups suggest some weak hydrophilic and strong hydrophobic interactions, so that the structure-breaking effect decreases. It was also found that with increasing concentration, the hydrophilic or hydrophobic interactions become stronger.

Hydrophobic and Hydrophilic Interactions

We are trying to understand mysteries of nature by looking at extra large (Cosmology and Astrophysics) and extra small distances (Weak/Strong interactions High energy Physics) while it can be seen in the physics of life systems. In previous presentations I developed some theoretical vision about conformational motion and non-equilibrium dancing of biological macromolecules by giving definitions of non-equilibrium entropy and geometrical motion. Those two key definitions and formulations are believed to be enough to answer the questions what is big energetic fluctuation is induced by in non-equilibrium systems and how the life system functions properly under that fluctuations. Self-organization is dynamic process where hydrophobic-hydrophilic interactions take a crucial role. Non-equilibrium dancing may induce ‘hydrophobic-hydrophilic’ waves which may be felt by other molecules. One may think that the suggestion about conformational motion may complicate quantitative and qualitative description of hydrophobic-hydrophilic interactions. Nevertheless, geometrical motion itself indicates changes of hydrophobicisity of the surfaces and can be completely described if it is taken into account dynamic processes of the surfaces solvent interactions. Since, in solvents, we have large number of interacting molecules statistical physics supposed to have crucial role in describing those dynamic processes but tusk is complicated by non-equilibrium nature of the processes. Fluctuation theorem guarantees reversibility of non-equilibrium processes but caries probabilistic nature so can not strictly predict whether entropy will decrees or increase in time. The problem becomes solvable in theory of conformational motion which gives possibility to be written time evolution equation of the entropy. Up together, taking into account previously presented equation of conformational motion and non-equilibrium entropy definition, solves hydrophobic-hydrophilic interactions problem. Preliminary calculations show excellent matching with experimental data. Complete picture of hydrophobic-hydrophilic interactions and time evolution equation of the entropy will be presented.

Morphological characteristics of modified freeze-dried poly(N-isopropylacrylamide) microspheres studied by optical microscopy, SEM, and DLS

AbstractInfluence of the initiator and additional hydrophobic copolymer on the morphology of thermosensitive poly(N-isopropylacrylamide) (pNIPAM) microspheres, and their presumed application for the stabilization of biologically active molecules were evaluated in this study. Three different types of pNIPAM were synthesized, applying various components: PN1 is a polymer with terminal anionic groups resulting from potassium persulfate initiator; PN2 was synthesized with a 2,2′-azobis(2-methylpropionamidine) dihydrochloride initiator introducing cationic amidine terminal groups; in the PN3 polymer, anionic terminals were implemented, however, increased hydrophobicity was maintained using N-tert-butyl functional groups. Turbidity measurements of the obtained dispersions confirmed specific thermosensitivity of synthesized microspheres in the range of 32–33°C. The polymerization course was proved by infrared spectroscopy and 1H NMR assessments, whereas the size of the synthesized microspheres, expressed as planar area, was evaluated by dynamic light scattering (DLS), scanning electron microscopy (SEM) and optical microscopy (OM). The respective surface patterns of the freeze-dried microspheres were evaluated by SEM. Planar area of the synthesized macromolecules was in the range between 0.41–3.22 μm, depending on the substrates composition and the method applied for the measurements. The assessments performed in the dry stage gave higher values of the diameter and planar area of the observed microspheres. The measured diameter and planar area increased in the following order for the PN3 microspheres: DLS, OM, SEM. In the case of PN1 and PN2, the observed diameters were positioned as: DLS, SEM, OM. These differences were assigned both to varied intramolecular hydrophobic-hydrophilic interactions of the polymer chains and to the environment, i.e. low pressure in the SEM conditions and aqueous solvent in the DLS measurements. The observed gaps in the freeze-dried PN2 polymer resulted in an attempt to evaluate the application of this polymer for mechanical stabilization of certain macromolecules or nanocrystals in the size range between 10 nm and 20 nm.

Volumetric properties of amino acids in aqueous solution of nonionic surfactant

The volumetric properties of amino acids ( dl-glycine, dl-alanine, dl-serine, l-aspartic acid, l-lysine, and l-leucine) in aqueous solution of nonionic surfactant hexadecyl poly[oxyethylene(25)] alcohol (C 16A 25) are studied. The values of apparent molar volumes V ϕ , partial molar volumes V 2 , m 0 and volumes of transfer Δ t 2 V 2 , m 0 are calculated. The changes of volumes of transfer are discussed in terms of hydrophilic–hydrophobic interactions. The linear correlation of V 2 , m 0 for a amino acids is utilized to calculate the contribution of the charge groups ( N H 3 + , CO O − ) , CH 2 group and other alkyl chains of amino acids to V 2 , m 0 .

Effect of cholesterol on the structure of a phospholipid bilayer

Cholesterol plays an important role in regulating the properties of phospholipid membranes. To obtain a detailed understanding of the lipid-cholesterol interactions, we have developed a mesoscopic water-lipid-cholesterol model. In this model, we take into account the hydrophobic-hydrophilic interactions and the structure of the molecules. We compute the phase diagram of dimyristoylphosphatidylcholine-cholesterol by using dissipative particle dynamics and show that our model predicts many of the different phases that have been observed experimentally. In quantitative agreement with experimental data our model also shows the condensation effect; upon the addition of cholesterol, the area per lipid decreases more than one would expect from ideal mixing. Our calculations show that this effect is maximal close to the main-phase transition temperature, the lowest temperature for which the membrane is in the liquid phase, and is directly related to the increase of this main-phase transition temperature upon addition of cholesterol. We demonstrate that no condensation is observed if we slightly change the structure of the cholesterol molecule by adding an extra hydrophilic head group or if we decrease the size of the hydrophobic part of cholesterol.

Use of photophysically active units of ionic polypseudorotaxanes for analysis of the supramolecular structure of the polymer necklace

The structure and supramolecular ordering of polymer complexes formed as the result of a combination of ionic and hydrophobic-hydrophilic interactions are determined. The efficiency of the combined use of the X-ray diffraction analysis, the second-harmonic generation technique, and luminescence spectroscopy in solids for determining the structure and supramolecular ordering is demonstrated using ionic polypseudorotaxane, which is based on poly(2-acrylamido-2-methyl-propanesulfonic acid), N,N-dimethyl-N′-(4-nitrophenyl)-decane-1,10-diamine, and α-cyclodextrin and contains photophysically active groups in side chains.

Self-assembly of physically crosslinked micelles of poly(2-acrylamido-2-methyl-1-propane sulphonic acid-co-isodecyl methacrylate)-copper(II) complexes

Metal complexes were prepared by the reaction of Cu(II) chloride with sodium salt of random copolymers of 2-acrylamido-2-methylpropane sulphonic acid, AMPS, and isodecyl methacrylate, i-DMA. Composition was varied in the feed to obtain copolymers and their corresponding metal chelates with different content of i-DMA hydrophobic monomer. The copolymers and their metal chelates were characterized by Fourier transformed IR spectroscopy (FTIR) and scanning electron microscopy (SEM) as well as energy-dispersive X-ray spectroscopy (EDS). The X-ray diffraction studies revealed that the polymers and their chelates were amorphous. Also, the stabilities of the copolymers and their metal chelates were investigated using thermal methods such as TGA and DSC analysis. Lower thermal stability was found for the polymer–metal complexes compared to that of the copolymers.Fluorescence spectroscopy was used to further confirm the copolymers and their Cu(II) metal complexes self-aggregate in water. Critical micellar concentrations become lower by metal complexation. A synergistic effect in self-assembly behaviour in water solutions of Cu(II) polycomplexes is attributed to the interplay between hydrophilic–hydrophobic interactions and electrostatic forces with Cu2+ ions. Physical crosslinking of polymeric micelles obtained by metal complexation led to more stable micelles. Sodium salt copolymers led to secondary aggregation while ionic crosslinking provided lonely micelles distributed through the substrate as seen by SEM. These results point to a mechanism in which cation-assisted-polymer-modified water structure plays a central role in the phase separation behaviour.

X-ray microscopy study of chromonic liquid crystal dry film texture

Soft x-ray spectromicroscopy has been used to investigate the degree of the molecular alignment of sulfonated benzo[de]benzo[4.5]imidazo[2,1-a]isoquinoline[7,1], a lyotropic chromonic liquid crystal (LCLC). LCLC thin films cast from concentrated aqua solution (20%wt.) , aligned by shear flow and dried, show strong linear dichroism in their C-, N-, O-, S- K edge near edge x-ray spectra (NEXAFS). The carbon K edge has been used for quantitative evaluation of the orientational texture of the films at a submicron spatial scale. This has verified there is predominantly in-plane alignment of the LC director. To highlight the role of hydrophobic-hydrophilic interactions, two stereoisomers of the same dye has been synthesized with different positioning of terminal sulfonate groups, in the form of a mixture of isomers with sulfonate groups in 2,10 and 2,11 positions (Y104 compound) and in a 5,10-disulfo arrangement (Y105). Both compounds develop characteristic herringbone-type texture with similar domain sizes. Polarized optical microscopy and higher resolution x-ray microscopy show sinusoidal-like undulations of the molecular director, with occasional crisscross appearance. Such behavior is found to be consistent with earlier observation of striations, characteristic of the columnar phase. The drastic difference in the degree of undulation ( +/-15 degrees in Y104 and +/-7 degrees in Y105 films) and long period of undulation (approaching the film thickness) requires further analysis. It was also found that the degree of in-plane order within domains changes from 0.8 for Y104 to >0.9 in Y105 films.

Synthesis and Characterization of a Praseodymium–Adipate Framework Templated with 1,2-bis(4-Pyridyl)ethane: Host–Guest Interactions and Structural Survey

A new templated metal–organic framework has been synthesized and characterized: [Pr2(C6H8O4)3(H2O)2]·(C12H12N2). This structure represents the completion of a series of lanthanide–adipate metal–organic framework materials that have been templated with 4,4′-bipyridine-derived template molecules. Host–guest interactions have been qualitatively analyzed within this system along with previously templated systems. On the basis of these observations, a series of guidelines have been established to predict template occlusion. These guidelines include hard–soft acid–base considerations, hydrophobic–hydrophilic interactions, hydrogen bonding, and geometric considerations. These criteria may aide in the future utilization of templates in the topological control of metal–organic frameworks.

Charge-density matching in organic–inorganic uranyl compounds

Abstract Single crystals of [C10H26N2][(UO2)(SeO4)2(H2O)](H2SeO4)0.85(H2O)2 (1), [C10H26N2][(UO2)(SeO4)2] (H2SeO4)0.50(H2O) (2), and [C8H20N]2[(UO2)(SeO4)2(H2O)] (H2O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in pentagonal bipyramidal and tetrahedral coordinations, respectively. The UO7 and SeO4 polyhedra polymerize by sharing common O atoms to form chains (compound 1) or sheets (compounds 2 and 3). In the structure of 1, the layers consisting of hydrogen-bonded [UO2(SeO4)2(H2O)]2− chains are separated by mixed organic–inorganic layers comprising from [NH3(CH2)10NH3]2+ molecules, H2O molecules, and disordered electroneutral (H2SeO4) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO2(SeO4)2]2− sheet. The structure of 3 does not contain disordered (H2SeO4) groups but is based upon alternating [UO2(SeO4)2(H2O)]2− sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH3(CH2)7CH3]+. The structures may be considered as composed of anionic inorganic sheets (2D blocks) and cationic organic blocks self-organized according to competing hydrophilic–hydrophobic interactions. Analysis of the structures allows us to conclude that the charge-density matching principle is observed in uranyl compounds. In order to satisfy some basic peculiarities of uranyl (in general, actinyl) chemistry, it requires specific additional mechanisms: (a) in long-chain-amine-templated compounds, protonated amine molecules interdigitate; (b) in long-chain-diamine-templated compounds, incorporation of acid–water interlayers into an organic substructure is necessary; (c) the inclination angle of the amine chains may vary in order to modify surface area of an organic substructure.

How thionphosphonates inhibit activity of different cholinesterases

Analysis of mechanism of reversible inhibition of human erythrocyte acetylcholinesterase (AChE), of horse serum cholinesterase (ChE), and ChE of optical ganglia tissue of individuals of the Commander squid Berryleuthis magister from various habitat zones was studied under effect of thionphosphonates (P=S), derivatives of piperidine, morpholine, perhydroazepine as well as several heterocyclic model compounds. Data of comparative inhibitory specificity have allowed us to suggest that thionphosphonates are sorbed in the area of cholinesterase esterase center through the phosphoryl part of the inhibitor molecule, rather than through its heterocyclic grouping. An advantage in the antienzyme efficiency of thionphosphonates (P=S) over phosphonates (P=O) is revealed. Effect of the ion strength is used for analysis of contribution of the hydrophobic—hydrophilic interaction in the enzyme—inhibitor system.

Density, viscosity and thermodynamic activation of viscous flow of water + acetonitrile

Densities and viscosities for the system, water + acetonitrile, have been determined for the entire range of composition at temperatures ranging from 303.15 to 323.15 K. Density, excess molar volume, viscosity, thermodynamic activation parameters for viscous flow and some of their excess values have been plotted against the mole fraction of acetonitrile and fitted to appropriate polynomial equations. Results have been explained in terms of hydrophilic effect, hydrophobic hydration, hydrophobic interaction and dipole-dipole interaction.

Charge density matching in organic-inorganic uranyl compounds

Abstract Single crystals of [C10H26N2][(UO2)(SeO4)2(H2O)](H2SeO4)0.85(H2O)2 (1), [C10H26N2][(UO2)(SeO4)2] (H2SeO4)0.50(H2O) (2), and [C8H20N]2[(UO2)(SeO4)2(H2O)] (H2O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in pentagonal bipyramidal and tetrahedral coordinations, respectively. The UO7 and SeO4 polyhedra polymerize by sharing common O atoms to form chains (compound 1) or sheets (compounds 2 and 3). In the structure of 1, the layers consisting of hydrogen-bonded [UO2(SeO4)2(H2O)]2− chains are separated by mixed organic–inorganic layers comprising from [NH3(CH2)10NH3]2+ molecules, H2O molecules, and disordered electroneutral (H2SeO4) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO2(SeO4)2]2− sheet. The structure of 3 does not contain disordered (H2SeO4) groups but is based upon alternating [UO2(SeO4)2(H2O)]2− sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH3(CH2)7CH3]+. The structures may be considered as composed of anionic inorganic sheets (2D blocks) and cationic organic blocks self-organized according to competing hydrophilic–hydrophobic interactions. Analysis of the structures allows us to conclude that the charge-density matching principle is observed in uranyl compounds. In order to satisfy some basic peculiarities of uranyl (in general, actinyl) chemistry, it requires specific additional mechanisms: (a) in long-chain-amine-templated compounds, protonated amine molecules interdigitate; (b) in long-chain-diamine-templated compounds, incorporation of acid–water interlayers into an organic substructure is necessary; (c) the inclination angle of the amine chains may vary in order to modify surface area of an organic substructure.