Theoretical study on the singlet and triplet potential energy surfaces of NH (X3Σ−) + HCNO reaction

Both the singlet and triplet potential energy surfaces (PESs) of the NH (X³Σ^?) + HCNO reaction have been investigated at the BMC-CCSD level based on the UB3LYP/6-311++G(d, p) structures. The results show that the title reaction is more favorable through the singlet potential energy surface than the triplet one. For the singlet potential energy surface of the NH (X³Σ^?) + HCNO reaction, the most feasible association of NH (X³Σ^?) with HCNO is found to be a non-barrier nitrogen-to-carbon attack forming the adduct a (trans-HNCHNO), which can isomerize to the adduct b (cis-HNCHNO). The most feasible channel is that the 1, 3-H shift with N2–H2 and C–N1 bonds cleavage associated with the N1–H2 bond formation of adduct a leads to the product P ₁ (HCN + HNO). Moreover, P ₂ (HNC + HNO) should be the competitive product. The other products, including P ₃ (NH₂ + NCO) and P ₄ (N₂H₂ + CO), are minor products. The product P ₁ can be obtained through two competitive channels Path 1: R → a → P ₁ and Path 3: R → b → d → P ₁ , whereas the product P ₂ can be formed through Path 2: R → b → d → P ₂ . At high temperatures, the nitrogen-to-nitrogen approach may become feasible. For the triplet potential energy surface of the NH (X³Σ^?) + HCNO reaction, the Path 10: R → ³ a → ³ a ₁ → P ₁ should be the most feasible pathway due to the less reaction steps and lower barriers. These conclusions will have impacts on further experimental investigations.     

Inclusion of Cl− or Br− anions within host framework formed by second-sphere interactions

In this study, we have deliberately utilized the second-sphere coordination approach into the construction of supramolecular inclusion solids Cl ? [H₂ L1]·[InCl₄] (Crystal I) and Br ? [H₂ L1]·[TeBr₆] (Crystal II). The chloride or bromine anions can be encapsulated inside the host assemblies formed by the diamine molecule (4,6-dimethyl-1,3-phenylene) bis(N,N-dibenzylmethane) (L1) and the metal complexes ([InCl₄]^? and [TeBr₆]^2?) via second-sphere interactions. The inclusion complexes have been structurally characterized by X-ray crystallography, indicating that weak C–H···Cl and C–H···Br hydrogen bonding synthons play a significant role in the construction of host framework. 2-D networks are formed in both complexes by the interconnection of 1-D networks through the multiple weak hydrogen bonding interactions with [InCl₄]^? or [TeBr₆]^2?. The guest Cl^? or Br^? anions are encapsulated inside the host cages through N–H···Cl hydrogen bonds. The inclusion selectively was studied for the two host assemblies.     

Triphenylamine-based simple chemosensor for selective fluorometric detection of fluoride, acetate and dihydrogenphosphate ions in different solvents

Triphenylamine-based new chemosensors 1 and 2 have been designed and synthesized for fluorometric detection of anions. The urea-amide conjugates in 1 and 2 are involved in binding of anions via hydrogen bonding. UV?Cvis and fluorescence titration experiments revealed that the sensor 1 has the selectivity for acetate (AcO^?), dihydrogenphosphate (H₂PO₄ ^?) and fluoride (F^?) over the other anions examined in the present study, in CHCl₃. In comparison, receptor 2 is non responsive for the same anions under similar conditions. In more polar solvent CH₃CN containing 0.1% DMSO, the receptor 1 shows a greater selectivity towards fluoride. The color of the solution of 1 is changed from colorless to light yellow and finally to yellowish brown only in the presence of fluoride in CH₃CN containing 10% DMSO. In pure DMSO and CH₃CN solvents, almost colorless solution of 1 is transformed into blood red and reddish brown in the presence of 30 equivalent amounts of F^?, respectively.     

Study by fluorescence of calix[4]arenes bearing heterocycles with anions: highly selective detection of iodide

The present work describes a study of complexation efficiency of calix[4]arenes bearing benzoimidazolyl, benzothiazolyl, and benzoxazolyl heterocycles (5–7) towards several anions. The binding ability of calixarene derivatives 5–7 towards selected anions of different molecular geometries such as: F^?, HSO₄ ^?, I^?, N₃ ^?, NO₃ ^?, NO₂ ^?, SCN^?, ClO₄ ^?, Br^?, CN^?, Cl^?, CH₃COO^? CF₃SO₃ ^? in methanol, has been investigated by fluorescence spectroscopic techniques, all anions were used as tetrabutylammonium salts to avoid possible complexation of cationic species by the derivative calix[4]arenes. Fluorescent chemosensor ability of these three calixarene derivatives was highly selective for iodide in contrast with other anions studied. The best chemosensor found, corresponds to compound 7, with an association constant of 2.01 × 10⁴ mol^?1 L and a detection limits of 0.22 ppm for iodide.     

Transformation of a ditopic Schiff base nickel(II) nitrate complex into an unsymmetrical Schiff base complex by partial hydrolytic degradation: structural and density functional theory studies

A new Schiff base complex [Ni(H₂L¹)(NO₃)](NO₃) (1) (H₂L¹ = 3-[N,N′-bis-2-(5-bromo-3-(morpholinomethyl) salicylideneamino) ethyl amine]) was synthesized from reaction of the ditopic ligand H₂L¹ with Ni(NO₃)₂ in anhydrous MeOH. Complex 1 is stable in the solid state, but prone to hydrolysis. Recrystallization of 1 from wet MeOH led to the isolation of a novel unsymmetrical complex [Ni(HL²)(NO₃)](NO₃) (2) (HL² = 2-[(2-(2-aminoethylamino) ethylimino) ethyl)-5-bromo-3-(morpholino methyl) salicylidene amine]). X-ray single-crystal analysis of complex 2 showed that complex 1 had undergone partial decomposition of one imine bond. In contrast, the Schiff base complex [Ni(HL³)](NO₃) (3) (H₂L³ = N,N′-bis(5-methyl-salicylidene) diethylenetriamine) was stable in wet methanol, and the single-crystal structure of 3 showed that the Ni(II) center was coordinated in an unsymmetrical square planar geometry. Density functional theory calculations were performed in order to obtain a geometry-optimized model of complex 1, in which the Ni(II) center was coordinated in a similar manner as that in complex 3. The thermodynamic parameters were calculated, in order to rationalize the difference in hydrolytic reactivity between complexes 1 and 3.     

Solvent extraction of europium trifluoromethanesulfonate into nitrobenzene by using three electroneutral receptors

From extraction experiments and $ \gamma $ -activity measurements, the extraction constants corresponding to the general equilibrium Eu³⁺(aq) + 3 A^?(aq) + L(nb) $ \Leftrightarrow $ EuL³⁺(nb) + 3A^?(nb) taking place in the two-phase water–nitrobenzene system ( $ {\text{A}}^{ - } = {\text{CF}}_{ 3} {\text{SO}}_{3}^{ - } $ ; L = electroneutral receptors denoted by 1, 2, and 3 – see Scheme 1; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the EuL³⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the series of 3 < 2 < 1.

Secondary interactions in the crystal structure of the iminate amine gold(III) complex [Au(C9H19N4)]I2

The acyclic iminate amine gold(III) complex iodide [Au(C₉H₁₉N₄)]I₂ (I) was obtained. The crystal structure of complex I is stabilized by weak secondary interactions N-H??I, C-H??Y (Y = I, Au, and ??), and Au??I forming an infinite 2D network. Double stacks of cations along the axis x are united through zigzag chains of H-bonds and of secondary contacts. Structure I contains 3?C14-membered cation-cation and cation-anion rings. The anions I(1)^? and I(2)^? act as bridges in structure I.     

Solubilization of cholesterol in aqueous solution by two β-cyclodextrin dimers and a negatively charged β-cyclodextrin derivative

Two βCD dimers (linked by succinic acid, 2, or ethylenediaminetetraacetic acid, EDTA, 3, bridges) and a negatively charged monomer derivative of βCD, 1, have been synthesized and their ability to solubilize cholesterol in aqueous solution was studied. The three compounds exhibit a great capacity in solubilizing cholesterol as, for instance, concentrations up to 6 mM of cholesterol were measured in the presence of 25 mM of 3. The phase-solubility diagrams of the two dimers exhibit A _L type profiles while the monomer 1 follows an A _P isotherm. The cholesterol/dimer complexes have 1:1 stoicheiometries while monomer 1 forms two complexes with molar ratios of 1:1 and 1:2 (cholesterol/1). The equilibrium constants are K _1:1 = (5.9 ± 0.3) × 10⁴ M^?1 and K _1:1 = (8.8 ± 0.2) × 10⁴ M^?1 for 2 and 3, respectively, and K _1:1 = 73 ± 19 M^?1 and K _1:2 = 204 ± 65 M^?1 for 1. The comparison of K _1:1(3) with the product K _1:1 × K _1:2 (1) reveals that a chelate effect in binding the cholesterol by 3 exists. The structure of the cholesterol/3 complex was studied by ROESY experiments and by molecular dynamics simulations.     

Effect of chemical composition and heat treatment condition on microstructure and magnetic properties of nanocrystalline BaDyxFe12−xO19 (x = 0.1, 0.2, 0.3, 0.4) microfibres

A series of BaDy_xFe_12?xO₁₉ ferrite microfibres have been synthesized from metal nitrates and citric acid by the sol–gel method. TG-DSC, XRD, FTIR, FESEM, TEM and VSM were employed to characterize the thermal decomposition process, crystallite sizes, structure and magnetic properties of ferrite microfibres. The effect of calcined temperature, holding time, ion substitution on structure, magnetic properties of barium ferrite microfibres was investigated. The nanoparticle growth mechanism of ferrite microfibres was discussed. The results indicated that the hexaferrite phase was formed at 750 °C and Dy³⁺ ions entered the magnetoplumbite lattice. However, the reflections shift to a lower angle and the characteristic peaks of ferrite microfibres in FTIR shift to the lower wavenumber with the Dy content increasing. The VSM results shown that saturation magnetization (M _s ) gradually increased with calcined temperature increasing and holding time prolonging, while coercive force (H _c ) revealed an increase at first and then decreases. With the Dy content increasing, the M _s achieved values of M _s  = 50 emu?g^?1 (297 K) and 70 emu?g^?1 (77 K) and the H _c value shown a continuous reduction from 515 kA??m^?1 (297 K) and 435 kA?m^?1 (77 K) (x = 0.0) to 242 and 215 kA?m^?1 (x = 0.4).     

Naphthyridine-based receptors for flurometric detection of urea and biotin

Naphthyridine-based receptors 1–4 have been designed and synthesized for the recognition of urea in CHCl₃ containing 1% CH₃CN. Receptor 1 also binds biotin and its methyl ester with moderate binding constant values. In comparison, receptor 2 is less efficient in recognising biotin and its methyl ester analogue. Receptor 1 binds urea and biotin with binding constant values of 1.02 × 10⁴ and 1.08 × 10⁴ M^?1, respectively, in CHCl₃ containing 1% CH₃CN and shows significant change in emission of naphthyridine upon complexation. Characterization and sensing properties of the receptors were evaluated by ¹H NMR, UV–vis and fluorescence spectroscopic methods.     

Synthesis,characterization, and thermal behavior of palladium(II) complexes containing 4-iodopyrazole

The mononuclear pyrazolyl complexes [PdCl₂(HIPz)₂] (1), [PdBr₂(HIPz)₂] (2), [PdI₂(HIPz)₂] (3), [Pd(SCN)₂(HIPz)₂] (4), and [Pd(NHCOIPz)₂] (5) have been prepared. Compound 1 was obtained from the displacement of acetonitrile from [PdCl₂(CH₃CN)₂] precursor by the 4-iodopyrazole (HIPz) ligand, whereas 2–5 were synthesized by substitution of the chlorido in 1 by the respective anionic group. The compounds were characterized by elemental analysis, infrared spectroscopy, and ¹H NMR spectroscopy. The thermal behavior of 1–5 has been studied by TG and DTA. The thermal stability of [PdX₂(HIPz)₂] compounds varies according to the trends X = Cl^? < I^? ? SCN^?< Br^?. No stable intermediates were isolated during the thermal decompositions due to the overlap of the degradation processes. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.     

Synthesis and oxoanions (dichromate/arsenate) sorption study of N-methylglucamine derivative of calix[4]arene immobilized onto poly[(phenyl glycidyl ether)-co-formaldehyde]

The article describes synthesis as well as the evaluation of sorption properties of new N-methylglucamine substituted calix[4]arene and its poly[(phenyl glycidyl ether)-co-formaldehyde] immobilized product. Firstly, 5,17-bis-[(N-methylglucamine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene (3) was synthesized by the treatment of calix[4]arene with a secondary amine N-methylglucamine and formaldehyde via Mannich reaction. The immobilization of 3 onto poly[(phenyl glycidyl ether)-co-formaldehyde] to form calixarene based polymer (4) was carried out under suitable reaction conditions via nucleophilic substitution reaction. All the new compounds were characterized by a combination of FT-IR, ¹H-NMR spectroscopic and elemental analysis techniques. The sorption studies of 4 reveal that it is an excellent material for the removal of toxic oxoanions especially arsenate from aqueous environment. To understand the selectivity of 4, we also examined the retention of dichromate anions in the presence of Cl^?, NO₃ ^? and SO₄ ^2? anions at pH 1.5.     

Extraction and theoretical study on the complexation of the strontium cation with beauvericin

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr²⁺(aq) + 2A^?(aq) +1(nb) ? 1·Sr²⁺(nb) + 2A^?(nb) taking place in the two-phase water–nitrobenzene system (A^? = picrate, 1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex(1·Sr²⁺,2A^?) = ?0.6 ± 0.1. Further, the stability constant of the 1·Sr²⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb(1·Sr²⁺) = 8.5 ± 0.1. Finally, by using quantum-mechanical DFT calculations, the most probable structure of the resulting cationic complex 1·Sr²⁺ was derived.     

Synthesis of lanthanide(III) complexes appended with a diphenylphosphinamide and their interaction with human serum albumin

Two DOTA-based proligands bearing a pendant diphenylphosphinamide 4a and 4b were synthesised. Their Eu(III) complexes exhibit sensitised emission when excited at 270 nm via the diphenylphosphinamide chromophore. Hydration states of q = 1.5 were determined from excited state lifetime measurements (Eu.4a $ k_{{{\text{H}}_{ 2} {\text{O}}}} = 2. 1 4 \,{\text{ms}}^{ - 1} ,\;k_{{{\text{D}}_{ 2} {\text{O}}}} = 0. 6 4 \,{\text{ms}}^{ - 1} $ ; Eu.4b $ k_{{{\text{H}}_{ 2} {\text{O}}}} = 2. 6 7\, {\text{ms}}^{ - 1} ,\;k_{{{\text{D}}_{ 2} {\text{O}}}} = 1. 1 8 \,{\text{ms}}^{ - 1} $ ). In the presence of human serum albumin (HSA) (0.1 mM Eu.4a/b, 0.67 mM HSA, pH 7.4) q = 0.4 for Eu.4a ( $ k_{{{\text{H}}_{ 2} {\text{O}}}} = 1. 3 4\, {\text{ms}}^{ - 1} ,\;k_{{{\text{D}}_{ 2} {\text{O}}}} = 0. 7 5\, {\text{ms}}^{ - 1} $ ) and q = 0.6 for Eu.4b ( $ k_{{{\text{H}}_{ 2} {\text{O}}}} = 1. 8 3\, {\text{ms}}^{ - 1} ,\;k_{{{\text{D}}_{ 2} {\text{O}}}} = 1.0 5 \,{\text{ms}}^{ - 1} $ ). Relaxivites (pH 7.4, 298 K, 20 MHz) of the Gd(III) complexes in the absence and presence of HSA (0.1 mM Gd.4a/b, 0.67 mM HSA) were: Gd.4a (r ₁ = 7.6 mM^?1s^?1 and r ₁ = 11.7 mM^?1s^?1) and Gd.4b. (r ₁ = 7.3 mM^?1s^?1 and r ₁ = 16.0 mM^?1s^?1). These relatively modest increases in r ₁ are consistent with the change in inner-sphere hydration on binding to HSA shown by luminescence measurements on Eu.4a/b. Binding constants for HSA determined by the quenching of luminescence (Eu) and enhancement of relaxivity (Gd) were Eu.4a (27,000 M^?1 ± 12%), Eu.4b (32,000 M^?1 ± 14%), Gd.4a (21,000 M^?1 ± 15%) and Gd.4b (26,000 M^?1 ± 15%).     

Anion-directed organized assemblies of protonated pyrazole-based ionic salts

The reactions of 3(5)-(4-methoxyphenyl)-5(3)-phenyl-1H-pyrazole (L ¹ ) with nitric acid and 5-(4-benzyloxyphenyl)-3-(furan-2-yl)-1H-pyrazole(L ² ) with hydrochloric acid produced [HL ¹ · NO₃] (Salt-1) and [HL ² · Cl] (Salt-2). The structures of Salt-1 and Salt-2 were determined by single crystal X-diffraction. In Salt-1, HL ¹ showed [2 + 2] binding of NO₃ ^? ions in the solid state to form dimer architecture with R ₁ ² (4) and R ₄ ⁴ (14) graph sets. An anion directed one-dimensional anion-assisted helical chain with active participation of the chloride ion and protonated pyrazole via N–H···Cl hydrogen bonding in Salt-2. In addition, the protonated HL ² molecules interacted with each other through weak C–H···π interactions resulting in the formation of another one-dimensional helical chain.     

Complexation of the cesium cation with nonactin: extraction and DFT study

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺(aq) + A^?(aq) + 1(nb) ? 1·Cs⁺(nb) + A^?(nb) taking place in the two-phase water–nitrobenzene system (A^? = picrate, 1 = nonactin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (1·Cs⁺,A^?) = 2.8 ± 0.1. Further, the stability constant of the 1·Cs⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Cs⁺) = 4.7 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic complex species 1·Cs⁺ was derived.     

Synthesis, crystal structures and electrochemical properties of CoIII complexes with hexadentate ligand containing thioether-amidopyridyl donor set

Two new cobalt(III) complexes of the hexadentate ligand [1,4-bis[o-(pyridine-2-carboxamidophenyl)]-1,4-dithiobutane] (H₂bpctb) with N₄S₂ donor set atoms have been synthesized. A reaction of Co(CH₃COO)₂·4H₂O with (H₂bpctb) leads to the formation of [Co^III(bpctb)]PF₆ (1) having a CoN₂(pyridine)N′₂(amide)S₂(thioether) coordination by symmetric bpctb^2? ligand. A similar reaction under slightly different conditions, however, gives [Co^III(L ^a )(L ^b )] (2), resulting from a C–S bond cleavage reaction triggered by an acetate ion as a base, having CoN₂(pyridine)N′₂(amide)S(thioether)S′(thiolate) coordination. These two Co(III) complexes have been characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structures of [Co^III(bpctb)]PF₆ (1) in the form of the solvate (1·MeOH·H₂O) and of [Co^III(L ^a )(L ^b )] (2) have been determined by X-ray crystallography. The Co atoms of both complexes exhibit distorted octahedral geometry. The electrochemical investigation of [Co(bpctb)]PF₆·MeOH·H₂O (1·MeOH·H₂O) and [Co^III(L ^a )(L ^b )] (2) by cyclic voltammetry reveals a reversible Co^III–Co^II redox process at E _1/2 = ?0.32 V (ΔE _p = 80 mV); for 1, and E _1/2 = ?0. 87 V (ΔE _p = 70 mV) for 2.     

Dinuclear nickel(II) complexes with Schiff base ligands: syntheses, structures and bio-relevant catalytic activities

Three Ni(II) complexes of cresol-based Schiff-base ligands, namely [Ni₂(L¹)(NCS)₃(H₂O)₂], (1) [Ni₂(L²)(CH₃COO)(NCS)₂(H₂O)] (2) and [Ni₂(L³)(NCS)₃] (3), (where L¹ = 2,6-bis(N-ethylpyrrolidineiminomethyl)-4-methylphenolato, L² = 2,6-bis(N-ethylpiperidineiminomethyl)-4-methylphenolato and L³ = 2,6-bis{N-ethyl-N-(3-hydroxypropyl iminomethyl)}-4-methylphenolato), have been synthesized and structurally characterized by X-ray single-crystal diffraction in addition to routine physicochemical techniques. Density functional theory calculations have been performed to understand the nature of the electronic spectra of the complexes. Complexes 1?C3 when reacted with 4-nitrophenyl phosphate in 50:50 acetonitrile?Cwater medium promote the cleavage of the O?CP bond to form p-nitrophenol and smoothly convert 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) either in MeOH or in MeCN medium. Phosphatase- and catecholase-like activities were monitored by UV?Cvis spectrophotometry and the Michaelis?CMenten equation was applied to rationalize all the kinetic parameters. Upon treatment with urea, complexes 1 and 2 give rise to [Ni₂(L¹)(NCS)₂(NCO)(H₂O)₂] (1??) and [Ni₂(L²)(CH₃COO)(NCO)(NCS)(H₂O)] (2??) derivatives, respectively, whereas 3 remains unaltered under same reaction conditions.     

Excited state intramolecular hydrogen atom transfer of phenylethynyl-substituted 2′-hydroxychalcones

(E)-1-[2-Hydroxy-4-(phenylethynyl)phenyl]-3-[4-(phenylethynyl)phenyl]prop-2-en-1-one (1), (E)-1-[2-hydroxy-4-(phenylethynyl)phenyl]-3-phenylprop-2-en-1-one (2), and (E)-1-(2-hydroxyphenyl)-3-[4-(phenylethynyl)phenyl]prop-2-en-1-one (3), which belong to a new class of 2′-hydroxychalcones with phenylethynyl group(s) at the para position of the phenyl ring, were synthesized, and their photochemical properties were investigated. The lowest energy absorption band of 1 peaks at a longer wavelength (383 nm) with a much larger molar extinction coefficient (5.0 × 10⁴ M ^?1 cm^?1) than that of the parent 2′-hydroxychalcone (2′HC) (2.0 × 10⁴ M ^?1 cm^?1 at 318 nm). Upon photoexcitation, all three compounds underwent excited-state intramolecular hydrogen atom transfer (ESIHT) to produce an excited tautomer that emitted fluorescence with a large Stokes shift in the longer wavelength region at 600–700 nm. The quantum yield of the tautomer fluorescence of 1 was not high at 298 K (Φ _f = 9.1 × 10^?5), but was highest among 2′HC and its analogues. The Φ _f values of 1–3 increased 10–30 fold upon reducing the temperature from 298 to 77 K.     

Simplified bicyclic cage-type molecule as a C 3 -symmetric host: X-ray and FTIR characterization of encapsulation of a nitrile molecule

We synthesized a new amine-type host molecule 2 by 2 steps, using 1,3,5-tris(aminomethyl)-2,4,6-trimethylbenzene and 2,6-pyridinedicarboxaldehyde as starting materials. Recrystallization of 2·6H₂O from hot acetonitrile, hot propionitrile and hexane/benzonitrile solutions gave colorless crystals of MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN. In the former two crystals, the nitrile compounds were captured inside of the cavity of 2. On the other hand, in the latter one, the benzonitrile was laid outside 2. Infrared spectral measurements of MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN showed that absorption bands assignable to the C ≡ N stretching vibrations of nitrile compounds were observed at 2240, 2241, and 2226 cm^?1 for MeCN@2·MeCN·2H₂O, EtCN@2·EtCN, and 8H₂O@2·PhCN, respectively. The former two peaks shifted to a lower energy region by 6–13 and 21–26 cm^?1 than those of liquid and gas phases of MeCN and EtCN, respectively. That for 8H₂O@2·PhCN shifted to a slightly lower region by 2 and 12 cm^?1 those of liquid and gas states of PhCN, respectively, indicating that the outer benzonitrile molecule dose not so much interact with 2 in the crystal.