Crystal structures of a-cyclodextrin-3-iodopropionic acid (1: 1) complex pentahydrate ( I )and hexakis(2, 3, 6-tri-O-methyl)-α-cyclodextriniodoacetic acid (1: 1) complex monohydrate OD were investigated by the X-ray method. The crystal of I is orthorhombic, and the space group being P 2₁2₁2₁ with Z=4; the cell dimensions are a=13.808 ( 2 ), b 39.581 ( 4), and c=9.685 ( 1 ) Å, The crystal of II is monoclinic, and the space group being P 2, with Z=2; the cell dimensions are a=11.590 ( 2 ), b=23.285 ( 4 ), c=13.901 ( 2 ) Å, and 8 =106.98 ( 1 )°. The structures of both complexes were determined by the heavy atom method combined with the rigid-body least-squares technique, and refined by the block-diagonal least-squares method to the final R-values of O.096 for 4056 reflections ( I ) and 0.10 for 3634reflections On. In the complex I, α-cyclodextrin is in the shape of a distorted hexagon, within which 3-iodopropionic acid is included. The iodine atom is located at the secondary hydroxyl side of the cavity, while the carboxyl group located at the primary hydroxyl side forms the hydrogen bond with the secondary hydroxyl group of neighboring a-cyclodextrin. a-Cyclodextrin molecules are arranged in a zigzag mode, thus forming a typical “cage-type”structure. Five water molecules, which are located outside the cavity, form many hydrogen bonds among them and with hydroxyl groups of a-cyclodextrin. The hexakis(2, 3, 6-tri-Omethyl)a-cyclodextrin (methyl-α-CyD) molecule is in the shape of a distorted hexagonal cone. The cavity, which is wider than that of a-cyclodextrin, includes iodoacetic acid and water molecules. The methyl-α-CyD and iodoacetic acid molecules are linked by the hydrogen bonds via water molecule inside the cavity. The position of iodoacetic acid is disordered, and iodoacetic acid occupies two positions within the cavity with the same occupancy. Methyl-α-CyD molecules are stacked along the crystallographic a axis in a head-to-tail mode to form a “channel-type” structure.

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Inclusion complexes of β-cyclodextrin (β-CyD) with water, methanol, ethanol, 1-propanol, p-iodoaniline, p-ethylaniline and 3, 4-xylidine have been studied by differential thermal analysis and differential scanning calorimetry and the results are discussed in relation to their crystal structures. It is found that (1) the difference in the packing mode of host β-CyD is reflected in the different thermal behaviour of the complexes in the temperature region between 25 and 140°C (Fig.1), (2) there are different forms of 8-CyDwater complex, namely from I and II in Table 1, (3) the form I shows a strong endothermic peak at 46°C, whereas the form II and other β-CyD inclusion complexes exhibit a few small peaks. X-Ray structure analyses applied to the two forms of β-CyDwater complexes elucidate that the form I is the same structure as determined by Lindner et al., whereas the form II shows a new structure and the structural difference between the form I and JI is found mainly at the distribution of disordered water molecules in the host β-CyD cavity as shown in Table 3 and Fig.6.

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Elucidating the role of asymmetric intermolecular interactions due to the stereospecific structure of a molecule is really important for understanding the mechanisms of reactions in chemisty and biochemistry. One of the present authors measured the enthalpies of mixing aqueous solutions of some optical isomers. Present authors report here the experimental results of microcalorimetry on enthalpy of dilution Q_d11 of aqueous solution of a-cyclodextrin (α-CyD), enthalpy of mixing Q_mix for aqueous ce-CyD solution with aqueous alcoholic solution, and enthalpy of transfer Δ H_tr of alcohol from aqueous to aqueous α-CyD solutions. They are listed in Tables 1 and 3. The equations and parameters used for the least-squares analysis are given in Eqs. (6 ), (7 ), and (10), and Tables 2 and 4 where the standard deviations are also given. Graphical illustrations of them are shown in Figs.1 and 2.
The calorimeter (RMC-II) and detailed procedures used were reported elsewhere 8). The measurements were carried out at 298.15±0.0005 K. The purities of alcohols obtained by GLC were 99.98, 99.95, and 99.84 mass per cent for methanol, 1-propanol, and 1-pentanol, respectively.
The theoretical procedure used for obtaining the enthalpy of transfer is given in Eqs. (1)- (4 ). From these values enthalpies of inclusion were determined as shown in Table 5. The ratio y of alcohols included by α-CyD, defined by Eq. (14), was estimated by the mathematical treatment presented by the authors in section 4.3, where n? n2, n8i and n, mean the amounts of water, α-CyD, alcohol, and 1: 1 complex in the solution, respectively. Since z was fixed to ca.1300 or 5000 in the experiment, Fig.3 was obtained through Eq. (21). Using the slopes of the curves in Fig.4 at f=0.55, we drew the curves in Fig.5. If the assumptions used in the treatment are valid approximately, (100/4Htr, ma. x) (d 4Htr/d f) would be equivalent to (100/Δ H_tr, max) (dΔ H_{tr, MAX}) is the limiting value of Δ H_tr at f→0 as shown in Fig.2. The assumptions involved are (1) all the activity coefficients are unity and (2) the inclusion complexes present in the solution are only of 1: 1 type. We used the values of (100/4Htr, max) (Δ H_tr/d f) to get the values of log₁₀ K and then to obtain Y_MAX through Eq. (20). The main results are summarized in Table 5.1-Pentanol molecules fit into the cavities of α-CyD best as expected. Methanol molecules, however, seem not to distinguish energetically between their circumstances in the cavities of α-CyD and bulk water, because they have the "structure-making" methyl groups only as hydrophobic radicals. Furthurmore we found that the enthalpy of dilution of aqueous α-CyD solution is positive which means that the interactions between α-CyD molecules are energetically more favorable than those between α-CyD and water molecules.

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The ⁵⁷Fe Mössbauer spectra of the title clathrates have been recorded at various temperatures in the range of 78-320 K. At low temperatures the spectrum consists of a simple quadrupole doublet, but upon heating it brings about an inward collapse into a single peak with of much reduced intensity(Fig.3). The variation of the spectrum with temperature has been interpreted by the model (Figs.1 and 2) that (η-formylcyclopentadienyl) (η-cyclopentadienyl)iron(II) (FFc) molecule reorientates in the cavity of α-cyclodextrin (α-CyD) with an activation energy of 14.3 kJ/mol (Figs.5 and 9). The reorientation of a FFc molecule became faster with increasing temperature and the isotropic relaxation time was 7.2 × 10^-8 s at 320 K (Fig.4). The variation of the Mössbauer spectra of α-CyD(η-methylcyclopentadienyl) (η-cyclopentadienyl) iron(II) (Fig.6) and β CyD-FFc clathrates (Fig.7) with temperature were recorded and the reorientation of the guest molecule was also observed. It has been concluded that the larger space in the cavity of CyD does not always give fast reorientation of a guest molecule.

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¹³C-NMR data have been obtained for piperidine, three kinds of hydroxypiperidines, six kinds of methylpiperidines and one methyl-substituted piperidinone in the presence or absence of α or β-cyclode xtrin. Larger inclusion shifts for these piperidines are observed in deuterium wade than in 50% dimethyl-d6 sulfoxide aqueous solution. It is suggested, based on the 'inclusion shifts, that the opposite end to nitrogen atom is preferentially included into cyclo, dextrin. Hydroxyl group is disadvantageous for inclusion and the substituent on the piperidine ring mars sclear orientation of inclusion. Methyl group is favorably included into the cyclodextrin cavity, however random orientations are still taking place in the case of N-methylpiperid.

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Flexibly capped cyclodextrins 6-deoxy-6-(3-nitro-4-hydroxy-5-methylphenacylthio)-β-cyclodextrin, 6-deoxy-6-(4-pyridyldithio)-β-cyclodextrin, and 6-deoxy-6-(3-carboxy-4-nitrophenyldithio)β-cyclodextrin were prepared in order to detect any conformational change of the host upon guest binding. The changes in the electronic, circular dichroism and/or NMR spectra of there modified cyclodextrins upon binding of several guests indicate conformational changes around the chromophoric moieties of the cyclodextrins. These conformational changes were shown to dependent on the size of the guest molecules. The present modification of β-cyclodextrin enhanced the binding ability of the cyclodextrin.

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1-Substituted 2-methylimidazoles included in ce-cyclodextrin (CyD) were found to form stable penta-coordinate complexes with iron( II) protoporphyrin IX (Scheme 1). When an equivalent amount of CyD-included 1-phenethyl-2-methylimidazole (PMI) was added to a hexa-coordinate complex of (imidazole), -heme, they were selectively transfered to the pentacoordinate CyD-included PMI-heme complex (Scheme 2). The apparent formation constants (K) of the heme complexes with these CyD-included imidazoles were measured spectroscopically (Fig.1). The K values of the CyD-included imidazoles were 15-30 times larger than that of 2-methylimidazoleheme, due to the larger entropy change (Table I). The fluorescenece spectrum of the zinc(II) protoporphyrin N complex with CyD-included PMI suggested a hydrophobic interaction between CyD and the porphyrin. CyD-included PMI-heme complex formed a stable oxygen adduct in an aqueous N, N-dimethylformamide solution (1/9) at 30°C.

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The effects of three cyclodextrins (α-, β, and γ-CyDs) on the riboflavin (RF)-sensitized photooxidation of phenothiazine derivatives (PTZ) were examined in an acidic solution (pH 4.0). The photoirradiation (400 nm<) of PTZ in the presence of RF gave the corresponding sulfoxides under aerobic conditions. The RF-sensitized photooxidation of PTZ was inhibited by the addition of RF triplet quencher or singlet oxygen quenchers. Since the charge transfer interaction between RF and PTZ was of minor importance, singlet oxygen generated by the RF triplet could be primarily responsible for the RF-sensitized photooxidation of PTZ. Under these experimental conditions, the RF-sensitized photooxidation of PTZ was significantly retarded by β-CyD, while α- and γ-CyDs affected no noticeable changes in this reaction. The deceleration effect of β-CyD seems to be attributed to the decrease in the susceptibility to oxidation of PTZ rather than the reduction in the photoche mical reactivity of RF through inclusion complexation.

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Cavity size effects of three cyclodextrins (α-, (β-, and γ-CyDs) on the alkaline hydrolysis of seven 7-substituted coumarin derivatives were studied to elucidate the catalytic mechanism of CyDs for the fused-ring system. Inclusion complexations of the coumarins with three CyDs in aqueous solution were investigated by ultraviolet absorption, circular dichroism, and 'H-nuclear magnetic resonance spectroscopies. The results obtained were as follows: 1 )The spectroscopic studies suggested that the substitued benzene moiety of the coumarins was predominantly included within the cavity of CyDs; ( 2 ) The analysis of the cross-ring substituent effects by means of a modified Hammett equation indicated that the substituent effects were significantly magnified, and their transmission route was altered by the inclusion of coumarin molecule within hydrophobic CyD cavity; ( 3 ) The pH and D20 solvent isotope effects on the hydrolysis revealed that the secondary hydroxyl group of CyDs participated in the reaction as a general base catalyst. From these observations, it was concluded that CyDs may catalyze the hydrolysis of 7-substitued coumarins in cooperation with the microsolvent effect and general base catalysis through inclusion complexation.

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The Institute of Physical and Chemical Research; Wako-shi, Hirosawa 351 Japan (2R, 5R, 8R, 11R)-1, 4, 7, 10-Tetrabenzy1-2, 5, 8, 11-tetraethyl-1, 4, 7, 10-tetraazacyclododecane [2] has been found to form various inclusion compounds with guest molecules as listed in Table 1. The title compound [1] p-bromo derivertive of [2], is also found to form a toluene clathrate crystal with 1: 1 molecular ratio. The crystal is orthorhombic, space group P 212121, with a=12.860(5), b=13.699(2), c =28.496(6) A, Z=4. An X-ray study has shown that the new host has a very similar crown type conformation of [2] as shown in Figs.1 and 2, but the inclusion form is quite different from that found in [2]. The host molecules are arranged in a layer parallel to ab plane (Figs.7 and 8). The neighboring layers are related by a two fold screw axis parallel to a axis. Therefore, the molecules in the neighboring layers have opposite directions with their ethyl groups facing each other. A zigzag channel is formed between these layers, and the guest molecules occupy this channel in head-to-tail arrangement along the a direction (Fig.3).

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We found that 1, 1, 4, 4-tetraphenyl-2-butyne-1, 4-diol and 1, 1, 6, 6-tetraphenyl-2, 4 hexadiyne-1, 6-dial[2] include various kinds of guest molecule such as aromatic hydrocarbon, halogeno compound, ketone, aldehyde, carboxylic acid, ether, amine, amide, sulfoxide, and alkaloid, and form stable clathrate compounds. In most cases, [1] and [2] form 1: 1 and 1: 2 complex with guest molecule, respectively. In order to know the structure of the clathrate compound, X-ray structural analysis of acetone complex [1] and [2] was carried out. It was found that guest molecule is included in a definite ratio in the channel which is formed by arranging host molecule regularly. It was also disclosed that hydrogen bond between hydroxyl group of acetylenic alcohol and guest molecule plays an important role to include the guest molecule in the channel.

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Sodium or potassium ion complexation of homogeneous oligo(oxyethylene) derivatives(oxyethylene units 4 to 10) with hydroxyl, methoxyl or dimethylamino groups on the chain was investigated on the basis of the stability constants determined by potentiometry in methanol and the comparison of ¹H-NMR shifts in acetone-4As is shown in the Table 2 and 3, and Fig.1, their stability constants increase with an increase in the number of oxyethylene units, and generally the effects of the terminal groups were significant in the shorter POE derivatives with 4 to 6 oxyethlene units. In the complexation with Nat, the specific interaction with hexaethylene glycol (EO 6) was confirmed by the steep rise in the stability constant and the high stability constant per oxygen atom (Fig.1). The terminal hydroxyl groups were favorable for the complexation with Nat, which led to the successful isolation of the following crystalline complexes; (EO 2)₂·NaBPH₄, (EO 3)₂·NaBPh₄· H₂O, EO 4·NaBPh₄·1/2, EO 5·NaBPh₄·2/3H₂O. The substitution of dimethylamino groups for the oxygen atoms of the oxyethylene decreased their interaction both in methanol and in acetone.
As for the complexation with K+, heptaethylene glycol (EO 7) showed the spceific interaction. However, the terminal methoxyl groups were more effective than the hydroxyl groups except for EO 4 series, and 1, 23-dimethoxy-3, 6, 9, 12, 15, 18, 21-heptaoxatricosane (Octaglyme)showed the most efficient and selective complexation with K+ (Fig.1). The effect of the terminal methoxyl group was also supported by the downfield shift and the marked splitting of the signal caused by the presence of K+ in the ¹H-NMR (Fig.2). The replacement of oxygen atoms by dimethylamino groups enhanced the stability constants of EO 4 series, which is in contrast to the reverse influence on EO 6 series. These facts suggest that the oxyethyelne units and the terminal groups should complement each other and play an important role in the fulfilment of the coordination geometry of metal ion.

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N-[co-(Long-chain alkyl)oligo(oxyethylene)] monoaza crown ethers (Cx⋅E(m+1)-N(15, 18), x: 8 and 12, m: 0-2) were prepared from alkyl oligo(oxyethylene) chlorides and N-unsubstituted monoaza crown ethers (Scheme 1). From the measurements of cloud points, it was found that the introduction of oxyethylene units between monoaza crown ring and alkyl moiety increased the hydrophilicities compared with those in the N-alkyl monoaza crown ethers (Cs-N(15, 18), x: 8 and 12) (Table 2). Most of the changes in the cloud points (ΔTcp) of Cx⋅E(m+1)-N(15, 18) and Cs-N(15, 18) between the absence and the presence of metal chlorides showed "positive" values (Fig.1, 2 and Table 3), and it was found that z1T0p of these compounds as well as alkyl crown ethers depended on such factors as the size of the crown ring, the number of oxygen atoms in the side chain and the kind of metal cations. On the other hand, complexing stability constants log 1(11) for these monoaza crown compounds with Na + and K+ in methanol and in water/methanol (10: 90 v/v) mixture at 25°C were measured by Frensdorff's method. It was observed that the stability constants for CsE(m+1)-N(15, 18) having oxygen atoms in the side chain were much higher than those for Cs-N(15, 18) with both cations (Table 4). These results show that the oxygen atoms in the side chain make a remarkable contribution to the complexation with metal cations. Besides, a good correlation between 4 TO and log K, ' was observed (Fig.3) and it was indicated that 4Tcp was able to be an index of complexing abilities for these monoaza crown compounds with metal cations in water.

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Dneso-Tetrakis[α, α, α, α-o-(pivalamido)phenyl]porphinatoliron( II) ([Fe(pfp)]) complex with 1-dodecyl-2-methylimidazole (DMI) was incorated into the hydrophobic region of liposome of dimyristoylphosphatidylcholine (DMPC). The incoporporation was confirmed by 11NMR (Fig.2), ³¹P-NMR, differential scanning calorimetry (Fig.4), gel permeation chromatogrAphy (Fig.1), ESR (Fig.3), and fluorescence (Fig.5) measurements. The liposomeincorporated [Fe(PfP)] complex formed in the pH 7 aqueous medium at 37°C an oxygen adduct with a life-time of 3 h reversibly.

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Two preparation methods, "substitutional method" and "direct method" for obtaining ureapolyethylene complex are presented, and then the crystallization mechanism in these methods has been clarified. In the former method, a large crystal of urea-polyethylene complex was prepared by using a starting single crystal of urea-tetracosane complex. X-ray diffraction patterns of these complexes were interpreted in terms of the disordered lattices of the guest molecules. Effects of molecular weight of the guest components on the morphologies of ureapolyethylene complexes prepared by the latter method were studied by the scanning electron microscopy. It was indicated that the formation of shish-kebab crystals of polyethylene on the surfaces of the complex and morphology of polyethylene crystals obtained by the decomposition of the complex with methanol are attributed to the extended chain conformation of polyethylene molecules in the urea tunnels.

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A new method of separation and/or concentration of a specific anion present in an aqueous solution has been investigated. The method is based on the combination of the formation of clathrate hydrate of quaternary ammonium salts with an ordinary distribution equilibrium between. an aqueous solution and an organic phase. One of the most important features of the clathrate is its ability of forming a mixed hydrate: by cooling an aqueous solution containing several guest species which can form the same type of clathrate hydrate, we can obtain a clathrate hydrate solid in which a large amount of a specific guest species is present. In this study, as a model system, we chose an aqueous mixture of (n-C₄H₉)₄NF and (n-C₄H₉)₄NCl d examined to what extent the fluoride could be concentrated within the aqueous media (including clathrate hydrate phase) by both the formation of mixed clathrate hydrate and extraction of the chloride with chloroform. It was found that, when an equimolar mixture of (nC₄H₉)₄NF and (n-C₄H₉)₄NCl (0.62mol/kg each) was cooled down to around 18°C to form a clathrate hydrate solid and then equilibrated with a half volume of CHCl, the amount of the fluoride extracted by CHC13 was only 0.7 percent, while that of the chloride was nearly 60 percent. This indicates that highly selective separation of the fluoride can be attained because more than 99 percent of the fluoride remains in the aqueous media (aqueous solution clathrate hydrate solid), whereas in ordinary aqueous solution/chloroform distribution equilibrium for the same system at 25°C (at which clathrate hydrate solid is no longer present), the proportion of the fluoride which is transfered to the chloroform phase goes up to about 18 percent. The applicability of this new method for separating another kind of anion is also discussed.

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Intercalates of the anionic molybdenum( V, VI) oxide host MoMoO₃^0.5- originally reported by Sch011horn et al. (1976) were prepared for several hydrated metal cations and metal complex cations as the guest. The expansion of basal spacings and the chemical compositions of the products are listed in Table 1. The starting material, Nat-form, which was prepared by suspending MoO, crystalline powder in an aqueous solution of 1 moldm-3 Na2S204 for 1 h at room temperature, was partly protonated to give the apparent composition (Na+)_0.25(H+)_0.25 (H₂O)(MoO₃^0.5-); the protons were inert in the cation-exchange reactions applied to prepare the intercalates of other cations. The "guest-poor" compositions of the products for the other cations can be interpreted in terms of the partial neutralization of the negative host charge by the inert protons. The values of the basal spacings can also be interpreted in terms of the orientations of the respective hydrated or complex guest cations between the host layers.

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The layer compounds of nickel cyanide with alkylamines, Ni(CN)₄Ni(C_nH_2n+1NH₂)₂, where n=12, 14, 16, and 18, exhibit two phase transitions respectively above room temperature. Although the endothermic peaks recorded on a differential scanning calorimeter are broad, the basal spacing rapidly increases upon the transition (see Fig.1). The packing coefficients of the amine molecules are estimated to be 0.66-0.68 in the room temperature phase, 0.59-0.62 in the intermediate temperature phase, and 0.56-0.58 in the high temperature phase. The second moment of the broad-line'H-NMR spectrum is about 12 to 14 G just below the lower transition temperature, about 3 G in the intermediate temperature phase, and in the order of 0.1 G2 above the higher transition temperature, indicating liquid-like characteristics of the alkyl chains in the last phase (see Figs.3 and 4). Two more step-wise changes in the second moment are noted in the range from 100 to 0°C. The addition of the alcohol with the same chain length as that of the amine or an excess of the amine results in the disappearance of one of the phase transitions. On the basis of the basal spacing, the room temperature phase is found to include up to about 0.4 moles of the alcohol or the amine per the above-mentioned formula regardless of the number of carbon atoms in the alkylamine molecule (see Figs.5 and 6). Above the transition temperature, the amount of the alcohol taken by the layer compound is dependent on the chain length; about 1.1 moles when n=14, about 0.9 moles when n =16, and about 0.7 moles when n=18. On the other hand, saturation is not observed up to two moles per formula when the alcohol is replaced with amine. From the viewpoint of motional behavior of the alkyl chains, the phase lost by the addition of alcohols or amines corresponds to the intermediate temperature phase of the parent layer compound.

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The 1 st stage graphite intercalation compounds of fluorine and copper(II) fluoride, C_xF(CuF₂), (x=5-13, y=0.01-0.07) were prepared at temperatures between 20 and 343°C; their identity periods were in the range of 9.3, -9.4Å, which was almost the same as those for the intercalation compounds containing A1F3 or MgF2. ESCA spectra showed that the chemical bond similar to that of graphite fluoride increased around the surface of the compounds with increasing reaction temperature. On the basis of F-NMR measurement, it was found that fluorine atoms in the bulk of the intercalation compound existed in pseudo-liquid state.

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The behavior of metal-ammonia-graphite intercalation compounds subjected to deammoniation process was studied. Structures and chemical compositions were determined from the results of X-ray diffraction measurement and chemical analysis. The behavior of the cornpounds under deammoniation is classified to three groups as follows: ( 1 ) Caesium and rubidium compounds; which release all ammonia included in the compounds. ( 2 ) Potassium and sodium compounds; which release a greater part of ammonia included and change into new compounds. ( 3 ) Lithium and alkaline-earth metals compounds; which have a tendency to form amides and the decomposition processes are relatively complex. Na-NH3-graphite intercalation compounds synthesized from natural graphite, Grafoil, and an artificial graphite (petroleum eokes; HTT.2000°C) showed the same behavior regardless the graphite materials as for the deammoniation process. When the deammoniated samples are allowed to react with sodium, a sodium rich, secondary. intercalation compound was formed at 350°C. The identity period of the compound was 10.7A and the chemical composition was found to be Na₄(NE13)C₂₈. Using HOPG as a starting material, it was shown that a mixture of the graphite phase containing slight amount of sodium and a compound with the identity period of 9.1A was formed by the same treatment. The chemical analysis of the mixture showed that the composition was Na₁₆(NH₃)C₂₆₀. It should be noted that the compound with the identity period of 9.1A, as well as that with the identity period of 10.7A, has the chemical composition relatively rich in sodium, and that the compound Na4(N113)C28 is rather stable in air and it decomposed to Na, NHOC, in dilute HC1. The behavior of K-NH3-graphite intercalation compounds subjected to the deammoniation process is similar to that of the Na-NH₃-graphite compounds.

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Libration, constrained translation, and effects on them of the translation-orientation coupling U^RT(γ, ω) are studied quantum-mechanically on the basis of empirical host-guest potentials, whose parameters given in Table 1 are fitted to electron spin resonance and far-infrared absorption experiments. As is seen from Table 2, the libration due to U^R (ω) and the constrained translation due to U^T (γ)+U^RT (γ, ω_c) should be regarded as the modes of motion in the cavity, where ω_c, is the equilibrium orientation of the molecular axis. The higher order coupling U^RT (γ, ω)-U^RT(γ, ω_c) is more effective for O2 than for N, , since the rotational motion of 02 is freer. It is also discussed that the charge distribution of the host molecule may be different for different guest molecules.

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The induced circular dichroism and electronic spectra of β-cyclodextrin complex with 1, 4naphthoquinone in aqueous solutions were measured. The linear dichroism spectra in a stretched polyethylene sheet were also measured. On the basis of the theoretical conclusions obtained by Harata and Uedaira for β-cyclodextrin complexes with naphthalene derivatives, the electronic absorption bands of 1, 4-naphthoquinone were assigned from the signs of the induced circular dichroism spectra. The assignment determined from the signs of the induced circular dichroism spectra agreed well with that determined from the linear dichroism spectra. From these results, it was concluded that the structure of β-cyclodextrin complex with 1, 4naphthoquinone was an axial inclusion.

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The 270MHz H-NMR spectra and the spin-lattice relaxation times, T, , have been measured for aqueous solutions of β-cyclodextrin incubated with various concentrations of both nitroxide spin label 2, 2, 6, 6-tetramethyl-l-piperidinyloxyl (TEMPO) and paramagnetic metal ion gadolinium(III). Remarkable spectral perturbations and paramagnetic nuclear relaxation effects were induced for some s. β-cyclodextrin protons by the addition of TEMPO. In contrast, the effect of the added gadolinium(III) on the spectra of β-cyclodextrin was small, probably because of too weak binding of this metal ion toβ-cyclodextrin to from the inclusion complexes.

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The effect of β-cyclodextrin (β-CyD) on the electron-transfer rates between glassy carbon and ferrocenecarboxylic acid (FCA) has been investigated. The induced circular-dichroism spectrum shows that FCA can be included in β-CyD and the Fe atom in FCA is located in the cavity. Although the complexation retards the electron-transfer rate, the retardation effect of β-CyD is small, indicating that electrons can easily penetrate into the molecular wall of fl-CyD. This result may be extended to other systems. Thus the retardation effect by addition of CyD is concluded not to be responsible for relatively large potential shifts, which are observed, for example, in the electroreduction of p-nitrophenol.

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Charge and discharge properties were investigated on Li/TiS₂ and Na/TiS₂ intercalation batteries in relation to the structual changes of TiS₂ during the charge and discharge processes. More than 2V of the cell emf were maintained until the cell utilization of about 40% for the above two batteries as shown in Fig.1. Then abrupt drop of the cell emf to about 1V was observed. Cointercalation of water molecule with alkali metals were observed in the discharged products of Li/Ti₂ and of Na/TiS₂. It was also found that the presence of excess amount of Ti in TiS₂ seriously hindered the discharge process.

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Materials Science, Toyohashi University of Technology; Tempaku-cho, Toyohashi-shi 440 Japan Carbon fibers and/or platinum electrodes and nitric acid electrolyte were used for a cell with the temperature difference between cathode (the higher temperature) and anode (the lower temperature). The open circuit voltage increased linearly with an increase in the temperature difference, and depended strongly on the presence of carbon fibers at the anode. The formation reaction of the intercalation compounds of nitric acid with carbon fibers may occur in the anodic process. By keeping the anode (carbon fibers) and the cathode (platinum) at 20°C and 85°C respectively, the open circuit voltage of 150mV was obtained.

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The reaction of the first-stage potassium-graphite intercalation compound, KC8, with aromatic hydrocarbon molecules of benzene, phenanthrene, anthracene and benzophenone in tetra. hydrofuran (THF) and formation of ternary intercalation compound of potassium-graphiteTHF were examined. Starting material, KC₈, was prepared from the powder of Ceylon natural graphite. The formation reaction is divided into three steps, as shown in Table 1 in the case of phenanthrene. The first step is electron transfer from KC8 to phenanthrene and closely related with the electron affinity of aromatic hydrocarbon used. The second step is the formation of stable ion pair by the coordination of THF. The third step is the penetration of THF molecules into graphite interlayers to result in ternary compound such as KC₂₄(THF)₂.

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The crystals of MPS₃ (M=Mg, Zn, Mn, Fe, Mn_1-xFe_x) produced pyridine intercalates with a basal spacing of 12.4 Å. One-dimensional electron distribution map of the intercalate showed that pyridine molecules were arranged between the phosphorus-sulfur layers with the molecular planes perpendicular to the layers. The reactivity of the MPS₃ crystals decreased in the following orders, MgPS₃≈, ZnPS₃>MnPS₃>FePS₃>NiPS₃. The NiPS₃ crystal and the solid solution of Mn_1-xNi_xPS₃ (x O.67) did not form the intercalate with pyridine. The order is reversed in comparison with the order for lithium intercalation into MPS₃, indicating that the intercalation mechanism is different between these two kinds of electron donors.

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The conformation of nitrocyclohexane in its thiourea adduct was investigated by the measurement of infrared absorption spectra in the region of 4000-30cm^-1. For the purpose of making an assignment of infrared absorption bands of nitrocyclohexane in the adduct, calculation of normal vibration of equatorial and axial conformers of nitrocyclohexane was carried out. In the spctrum of the adduct, the bands at 841cm^-1 and 325cm-' assigned to the axial conformer based on the calculation are strong, while those at 215cm^-1 and 505cm^-1 assigned to the equatrial conformer are very weak. On the contrary, in the spectrum of liquid nitrocyclohexane, the bands assigned to the equatorial conformer are stronger than those of the axial conformer. Therefore, the abundance ratio of both conformers in the adduct is different from that in the liquid. Although it was found that the predominant conformer in the adduct is the axial conformer, it is noteworthy that the equatorial conformer was also found to coexist. The cavity shape of the host lattice of the adduct seems to fit for packing the axial conformers. However, it is not the only factor to determine the species of the guest in the host lattice.

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The fractional desorption of tritiated water adsorbed on molecular sieve (MS) 4 A and 5 A and its tritium concentration have been measured in the temperature range 26-300°C. A peak at 200°C has been found on tritium concentration of desorbed water on the MS 4 A, while not on the MS 5 A. Some difference in the fractional desorption curves of adsorbed water between the two molecular sieves has also been observed.

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