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The enantiomers, (R)-(-)-1 and (S)-(+)-1, of (+/-)-4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2,3- dihydro-2-methylbenzo[b]furan-7-carboxamide [(+/-)-1] were prepared from optically active benzyl 4-acetylamino-2,3-dihydro-2-methylbenzo[b]furan-7-carboxylate [(R)-(+)-6, (S)-(-)-6], respectively. The requisite (R)-(+)-6 and (S)-(-)-6 were prepared by large-scale preparative HPLC on chiral stationary phases (CSPs). The absolute configuration of (S)-(+)-1 was determined by single crystal X-ray analysis. The serotonin 5-HT4 receptor agonistic activity of (S)-(-)-1 hemifumarate (SK-951) which was hemifumarate of (S)-(+)-1 was about twice that of the other enantiomer (R)-(+)-1 hemifumarate which was hemifumarate of (R)-(-)-1.

Palladium(0)-catalyzed reactions of N-methanesulfonyl- or N-(arenesulfonyl)-3-alkyl-2-vinylaziridines reveal that 2,3-cis-isomers are more stable than the corresponding 2,3-trans-isomers in accord ...

Methyl methacrylate (MMA) was graft-copolymerized onto cellulose in an aq. FeCl3 solution by the irradiation of UV light. The copolymerization was found to proceed even after the interruption of the irradiation. The addition of the monomer into the polymerization system, which had been beforehand preirradiated in the absence of the monomer, was not followed by the copolymerization. The after effect also increased the molecular weight of the graft PMMA, being isolated from graft product by means of complete hydrolysis of trunk cellulose molecules. However, the increase was not always proportional to the weight increase observed after the interruption. On the other hand, the increase of kinetic chain length caused by the after effect in the AIBN-sensitized grafting systems was found to be nearly proportional to the weight increase of the graft PMMA, The chain lengths were calculated from the number-average molecular weight of the graft PMMA and the weight fraction of truly grafted PMMA chain in the graft PMMA which was determined by subjecting the graft PMMA to thin-layer chromatography. These results may imply that the propagating polymeric free radicals are long-lived ones. In the case of the graft copolymerization by chemical method initiated with AIBN, a linear relationship between the reciprocal of number-average molecular weights of graft PMMA and the first power of the AIBN concentrations shows that the termination mechanism of graft copolymerization is not bimolecular one.

Methyl methacrylate (MMA) was efficiently graft-copolymerized in aq. FeCl3 solution onto cellulose by the UV irradiation from a high-pressure mercury lamp. While the oxygen removal from the system by means of vigorous evacuation caused the drastic decrease of percent grafting. In this connection PMMA chains prepared in FeCl3-saccharide systems by the UV irradiation were found to scarcely contain saccharide residues at the chain ends, irrespective of the species of the saccharides used. The formation of both Fe2+ and hydrogen peroxide as a result of the irradiation on the reaction systems was confirmed by conducting model reactions. It was suggested from these results that the homopolymerization is initiated with free radicals resulted from the redox reaction between Fe2+ and H2O2, and followed by the grafting via the transfer reaction of the growing homopolymer radicals to cellulose molecules.

Several chiral 2-nitro-1-sulfinylalkenes were prepared and examined for their utility as dienophiles for asymmetric [4+2] cycloaddition. Trisu- bstituted dienophiles (3-6) undergo distereoselective cycloaddition with cyclopentadiene in the presence of Lewis acids. Even the tetrasubsti- tuted chiral sulfinyl dienophiles (1) and (2) could be coerced into un- dergoing [4+2] cycloaddition to afford the cycloadducts in high yield without concomitant elimination if the reaction was conducted under high pressure. Generally, the Z-sulfinyl dienophiles (1-4) showed higher diastereo- and exdo/exo-selectivity than the E-dienophiles (5) and (6)

In the graft copolymerization of styrene onto cellulose using benzoyl peroxide (BPO) as initiator graft copolymer was not formed and at the same time the phenomenon suggesting the consumption of BPO with cellulose was observed. Model reactions revealed that the degradation of BPO was accelerated with cellulose and that cellulose was readily oxidized with BPO. These results may imply that BPO/cellulose redox system lacks the ability to intiate graft copolymerization. On the other hand, α, α'-azobisisobutyronitrile was confirmed to bring about the graft copolymerization induced by the transfer reaction of propagating radicals. In this case, the initiator was not consumed with cellulose.

The reactions of protected serine- and threonine-derived γ-(mesyloxy) α,β-unsaturated esters with various magnesio organocyanocopper Lewis acid complexes have been investigated. The formation of syn-S N 2' products in addition to the normally expected anti-S N 2'products is taken as an indication that the reaction proceeds by a mechanism involving coordination of the magnesiocuprate with the C(δ)-N:C(γ)-O syn-γ-(mesyloxy) α,β-enoates

Alkylation of rac 3-substituted 4-acetoxyazetidin-2-one 4 with chiral tin(II) enolate 8 derived from 3-acetyl-(4S)-ethyl-1,3-thiazolidin-2-thione (7) proceeded in a highly diastereoselective manner to give alkylated products 9, 10, and 11 in 42%, 20%, and 9% yields, respectively, after chromatographic purification. Similar alkylation of rac-5 with 8 gave 16, 17, and 18 in 45%, 29%, and 5% yields, respectively. Compound 9 was readily converted to 33, a chiral key intermediate for the synthesis of carbapenems

Styrene (ST) and methyl methacrylate (MMA) were grafted onto cellulose gel, which had been prepared from cellulose solution in 85% phosphoric acid, by use of ceric ammonium nitrate as an initiator.The frequency of grafting for the ST/cellulose graft copolymer obtained as a toluene extract separated from the attendant unreacted cellulose was found to be unity. Intrinsic viscosities of the cellulose graft copolymers extracted from graft products with organic solvents implied that the copolymers were in a uniform molecular dispersion, forming monomolecular micell-like structures in the organic solvents. Cellulose crystallites were hardly found in the film prepared with the MMA/cellulose graft copolymer extracted from the MMA/cellulose graft product with 1, 2-dichloroethane.

A styrene/amylose graft copolymer prepared by using ceric ammonium nitrate as an initiator was first extracted with tetrahydrofuran at room temperature for removing homopolymer of styrene, and then after the destruction of amylose architecture, the product was subjected to toluene extraction. The toluene extract was found to be styrene/amylose graft copolymer, containing neither unchanged amylose molecules nor homopolymer of styrene chains. The graft copolymer sample was easily redissolved in organic solvents, such as toluene, benzene, chloroform or methyl ethyl ketone at room temperature. The resulting transparent solution did not yield any sediment after centrifugation at 4, 000rpm for 5min. Grafting frequencies in the graft copolymers calculated from the number average molecular weight of grafted polystyrene were slightly over unity. Intrinsic viscosities in various solvents and high resolution 1H NMR spectra were determined for the graft copolymer samples. These results suggested that the graft copolymer molecules were dispersed in the organic solvents to form a kind of polymer colloid system, in which polystyrene graft chains behaved like protective layers of backbone amylose chains.

Three tirucallane-type triterpenoids, niloticin, phellochin and melianone, were isolated from the fruits of Phellodendron chinense SCHNEID. (Rutaceae). The stereostructure of niloticin was determined based on spectroscopic and X-ray crystal structure analyses. Furthermore, a derivative of niloticin and two derivatives of melianone were also found. A possible biogenetic pathway in P. chinense is proposed : niloticin → melianone → limonoids, on the basis of isolation of the compounds in different oxidation states.

Rules relating the stereochemistry of N-Dnp (Dnp: 2,4-dinitrophenyl) derivatives of α-amino acids and peptides and the sign of the Cotton effects at the longest wavelength band (ca. 400 nm) are surveyed. Some new data and insights concerning the CD spectra of Dnp–α-amino acids are included: i.e., the spectra of Dnp derivatives as the composite of the corresponding o-nitrophenyl and p-nitrophenyl derivatives; the crystal structure of Dnp–I-phenylalanine and its solid-state CD spectra; the CD spectra of Dnp–α-amino acids containing sulfur atom on their side chains; and the theoretical approach to the CD spectra using molecular orbital method-based calculation. Conformational analyses of cyclic and linear peptides by the CD spectra of their Dnp derivatives are also discussed. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2005

A toluene solution of styrene/cellulose graft copolymer which had been prepared by using cellulose gel as an substrate was dispersed in an excess of water. Then the system was allowed to stand for hours at room temperature to be transformed into macroscopic two phases which consist of a transparent toluene phase and a clear water phase. The toluene of the former phase was evaporated with the intention of preparing the film containing toluene-water interface.Static contact angles of the films against deionized water revealed that the surface of the water phase side of the film was covered with cellulose.

This paper discusses the conformational changes in a single myosin molecule directly observed using atomic force microscopy (AFM). The myosin molecules were pretreated in rigor solutions without MgATP or in relaxed solutions with various concentrations of MgATP. The images of these molecules were obtained using a tapping mode AFM. The results indicate that the orientation of the myosin's heads and tail strongly depend on the MgATP concentration. Without using MgATP, almost all of the myosin molecules are in the extended form; however, when MgATP is used, the molecules bend according to the level of MgATP concentration. The mean-square end-to-end distance of the myosin molecules is significantly shorter with p[MgATP] = 4 than with p[MgATP] = 6. The rod region did not show the same level of intensity along their length in the extended form. The rods exhibited clusters of discontinuity, which were identified as substructures. The size of these substructures change at intervals that are multiples of 14.3-14.5 nm, which reflects the periodicity of the alpha-helical coiled coils. The substructure clusters also correspond to the myosin crossbridge spacing in muscles (14.3 or 43 nm). These results suggest that the myosin's head bends in conjunction with the bending or tilting in the helical substructures. Conformational changes of the myosin molecule induced by MgATP seem to mimic the molecular motions in a muscle's force generation process.

The stereospecific synthesis is described of the first member of a new class of C-nucleoside analogues in which the sugar ring is replaced with a 1, 3-thiazolidine ring. The 1, 3-thiazolidin-2-yl analogues (1) and (2) of pseudouridine were prepared stereospecifically via condensation of L or D-cysteine with a formylated nucleobase.

The stereochemical outcome of the 1,3- and 1,5-migration of an Fe(CO)3 group on (acyclic polyene)Fe(CO)3 complexes and their application to stereoselective construction of remote and contiguous stereogenic centers are described. Treatment of the [(eta(4)-4-7)triene]Fe(CO)3 complexes 1a-d bearing an electron-withdrawing group on the terminal position of an uncomplexed olefin with a base such as KN(SiMe3)2 (KHMDS) and LiCH2CN induced the 1,3-migration reaction of the Fe(CO)3 group, giving the [(eta4-2-5)triene]Fe(CO)3 complexes 2a-d in moderate to good yields, depending on the electron-withdrawing groups. From an experiment using the chiral (trienenitril)Fe(CO)3 complex 5, it is revealed that the 1,3-migration proceeds with inversion of configuration. Similarly, the 1,5-migration reaction of the[(eta4-6-9)tetraenone]Fe(CO)3 complexes 9 occurred with a catalytic amount of KHMDS, giving the [(eta4-2-5)tetraenone]Fe(CO)3 complexes 10 with retention of configuration. Furthermore, we have succeeded in the first regio- and stereoselective nucleophilic substitution of the (3,5-diene-1,2-diol) Fe(CO)3 complexes (15 --24a-h) with various nucleophiles via the ortho esters 21. By using iterative manipulation of the above two reactions, remote stereocontrol of the terminal substituents on acyclic polyene (9 --12) and construction of contiguous stereogenic centers (19, 28) have been achieved.

Recent studies have indicated that there are many barriers to successful systemic gene delivery via cationic lipid vectors using the intravenous route. The purpose of this study was to investigate the effect of binding and interaction between erythrocytes, a major constituent of blood cells, and the complexes, in relation to the role of the helper lipid, on the in vivo gene delivery to the lung following intravenous injection. We used three types of cationic lipid vectors, DNA-DOTMA/Chol liposome complexes, DNA-DOTMA liposome complexes, and DNA-DOTMA/DOPE liposome complexes. Although the three types of vectors bind to murine blood cells in vivo and in vitro, DOTMA/Chol and DOTMA complexes with a higher in vivo transfection activity do not induce fusion between erythrocytes, whereas DOTMA/DOPE complexes, a less efficient vector in vivo, induce fusion between the erythrocytes after a short incubation period. Pre-incubation of DOTMA/DOPE complexes with erythrocytes significantly reduced the transfection efficiency while DOTMA/Chol- and DOTMA complexes were more resistant to such treatment. The differences in the physicochemical and structural properties of these complexes could explain the differences in interaction with erythrocytes and subsequent gene expression. Lipids in DOTMA/Chol and DOTMA complexes have a stable lamellar structure. However, lipids in DOTMA/DOPE complexes have a highly curved structure with high fluidity. These results indicate that the interaction with erythrocytes depends on the properties of the cationic lipid vectors and this is an important factor for intravenous gene delivery using cationic lipid vectors.

C26H40N4O7, Mr = 520.6, tetragonal, P4(3)2(1)2, a = 10.433 (1), c = 54.476 (7) A, V = 5930 (1) A3, Z = 8, Dm = 1.155 (3), Dx = 1.166 Mg m-3, lambda (Cu K alpha) = 1.54178 A, mu = 0.665 mm-1, F(000) = 2240, T = 295 K, R = 0.057 for 2037 observed reflections. The tetrapeptide adopts a type II beta-turn conformation with an extremely weak 4----1 intramolecular hydrogen bond [3.479 (7) A]. The molecules are held together in the crystal by three kinds of N-H---O intermolecular hydrogen bonds.

C 12 H 10 N 2 O cristallise dans C2/c dans a=16,246, b=8,423, c=17,383 A, β=122,34 o , Z=8; affinement jusqu'a R=0,045. Les molecules forment un dimere centrosymetrique unique, dans lequel le groupement OH forme une liaison hydrogene qui se dedouble vers l'atome N de la pyridine et l'atome N de l'oxime. Les 2 atomes N de l'oxime ont un contact non liant court de 2,837 A

C 18 H 40 N + •Br − •H 2 O cristalline dans P1 avec a=8,164, b=8,486 et c=17,531 A, α=74,72, β=86,28 et γ=71,57°, Z=2; affinement jusqu'a R=0,061. Les molecules sont empilees en bicouches paralleles au plan (001). Les ions Br − et les molecules H 2 O forment un groupe anionique. Les liaisons hydrogenes Br...O sont de 3,410 et 3,414 A

The crystal of bovine trypsin complexed with a potent inhibitor, 4-[4-(N,N- dimethylcarbamoylmethoxycarbonylmethyl)phenoxycarbonylphenyl ]guanidinium (FOY-305) in the novel orthorhombic from with a low molecular packing density was studied by the X-ray diffraction method. Using synchrotron radiation, the intensity data were collected to 1.8 A resolution. The structure was solved by molecular replacement methods, and refined to an R-factor = 18.0% for 14364 reflections by the restrained least-squares method. The final difference Fourier maps revealed that hydrolyzed inhibitor fragments bind with the protein at multiple sites around the active center of trypsin. The structural feature in the crystalline state probably corresponds to a statistical average of several complexes which would be formed between the inhibitor and trypsin during the binding and releasing process in solution.

The 600 MHz 1H-nuclear magnetic resonance spectra of a mixed aqueous solution of typsin and a synthesized trypsin inhibitor, 4-[4-(N, N-dimethylcarbamoylmethoxycarbonylmethyl)phenoxycarbonylphenyl]-guanidinium methanesulfonate(FOY-305) were measured. Signals assigned to the inhibitor protons indicated that the hydrated fragment of the inhibitor formed a complex with trypsin. The signal change during 4 h of incubation at 37°C was interpreted as reflecting a successive process of the partial release of the fragment and its weak recombination with the enzyme around the active site. The result is consistent with the disorder of the fragment in the crystal structure of the inhibitor : trypsin complex.

The structure and stereochemistry of scopadulin, a novel aphidicolane-type diterpene isolated from Scoparia dulcis L. have been established from spectral data and single-crystal X-ray analysis of its acetone solvate.

The accurate crystal structure of nicotinamide, 3-pyridinecarboxamide, was determined from X-ray and neutron diffraction experiments: C6H6N2O, Mr = 122.13, monoclinic, P21/c, Z = 4. The electron distribution at 150 K was determined by the maximum entropy method and the electrostatic potential in the crystal was calculated by Fourier convolution of the electron distribution. The electrostatic properties of the nicotinamide molecule depend on the molecular conformation. The asymmetric electrostatic potential field observed above and below the pyridine-ring plane is related to the rotation of the carboxamide group with respect to the pyridine plane. The positive potential peak at the C4 atom of the pyridine ring extends to the C=O-group side of the plane. The asymmetry of the potential on the C4 atom is consistent with the stereospecificity of hydride transfer in NAD+/NADH oxidoreduction.

Palladium(0)-catalyzed reactions of five sets of four stereoisomeric 4,5-epimino-N-(methanesulfonyl) or -N-(arylsulfonyl) 2-enoates reveal that 4,5-cis-(2E)-isomers are thermodynamically more stable than other isomers, in accord with calculations. A highly stereoselective synthesis of (E)-alkene dipeptide isosteres having the desired stereochemistries from unwanted stereoisomeric 4,5-epimino-N-(arylsulfonyl) 2-enoates is also presented.

The structures of taxchinins D and G and taxchin A have been determined by means of NMR spectroscopy and confirmed by X-ray analyses. The fomer two possess a rearranged taxane skeleton found in taxchinin A, while the latter has a taxane skeleton.

Lanthanoid-induced 1H NMR shifts of glyceric acid, gluconic acid, and lactobionic acid were observed in D2O. Stoichiometric analysis using the shift data at various pH values indicated that the concentration of a 1 : 1 complex between substrates and lanthanoid ions was higher than that of a 2 : 1 complex at a low pH. The structure of an axially symmetric 1 : 1 complex was obtained on the assumption of a predominant pseudo-contact interaction between a europium ion and the ligand nuclei. All the title glycosidic acids were found to chelate the cation with α-carboxy, α-hydroxy, and β-hydroxy oxygens. The relative position of β-hydroxy oxygen is particularly important for the complex formation between β-hydroxy carboxylic acids and metal ions.

The crystal structure of the calcium salt of D-glycero-D-gulo-heptonic acid has been determined by the X-ray method. The crystal is monoclinic of space group P21 with unit-cell dimensions of a=10.064(1), b=10.540(2), c=11.340(2) A, and β=108.92(1)°. The intensity data for 1754 unique reflections were measured with an automatic diffractometer. A trial structure, obtained by the direct method, was refined by the full-matrix least-squares method to R=0.030. The two independent heptonate anions have different conformations, and they chelate a calcium ion in different ways. The calcium ion is surrounded by eight oxygen atoms in a deformed dodecahedral form, the Ca···O distances ranging from 2.40 A to 2.48 A. The distortion of the moleular strcuture of the heptonate anions due to the calcium chelation was discussed in relation to the calcium-binding sites on a linear carbohydrate chain.

A crystal of 1,3-dimethyl-5-fluorouracil can be used to solve large amounts of 1,3-dimethyluracil as a solid–solution crystal. The crystal structure has been determined by an X-ray method. The planar molecules are arranged in a parallel sheet, and the molecules within the same sheet interact with each other through short CH···O and CH···F contacts. The short intermolecular C···F distance is 2.999(6) A. The stability of a mixed crystal could be explained in terms of intermolecular interactions around the fluorine atom.

The crystal structure of potassium D-glucarate was determined by X-ray analysis. The conformation of the glucaric anion in the potassium salt differs from that of the dianion in the crystal of the calcium salt. The proton magnetic resonance spectra of the solutions of the potassium salt and the calcium salt show that the glucarate solution is an equilibrium mixture of the two conformers observed in the crystals. Studies on the induced shifts by adding europium nitrate to the acidic solution indicate that the europium ions are selectively bound to the potassium type conformer. Calcium sequestant by the glucaric acid in alkaline solutions should occur when calcium ions bind the calcium type conformers in a dianionic state.

The crystal structure of the title complex has been determined by the X-ray method. The complex crystallizes in the monoclinic space group P2/c with a=24.171(9), b=14.037(3), c=24.401(9) A, β=119.68(9)°, and Z=4. The structure was solved by the heavy-atom method and refined to R=0.094 for 3838 reflections. Two independent dimers exist with a crystallographically imposed two-fold axis in the unit cell. The two dimers are in an approximately orthogonal arrangement, and they take very similar conformations. The noticeable structural parameters are the average distances of 2.033(28) A for OsIV–N, 1.808(3) A for OsIV–O2−, and 1.997(29) A for OsIV–OCH3. The two porphinato cores bridged by a μ-oxo oxygen atom rotate around the approximately linear Os–O–Os bond (the average valence angle=178°) by 23(1)° from the eclipsed form. The porphine ring is planar within 0.10 A, and deviation of the Os atom from the porphinato plane of the four nitrogen atoms is 0.06 A. These results were compared, in the relation of the s...

A highly stereoselective synthesis of (6S*, 7S*, 8S*)-7-butyl-8-hydroxy-1-azaspiro [5.5]-undecan-2-one (6), a key intermediate for (±)-perhydrohistrionicotoxin synthesis, from the Diels-Alder cycloadduct of 1, 3-bis (trimethylsiloxy)-2-methyl-1, 3-butadiene (15) and ethyl 3-acetoxy-1-cyclohexene-1-carboxylate is described. This key intermediate and its stereoisomer, (6R*, 7S*, 8S*)-7-butyl-8-hydroxy-1-azaspiro [5.5] undecan-2-one (7), were stereoselectively synthesized by means of a conjugate addition reaction using 1-(3-tert-butyldimethylsiloxy-1-cyclohexen-1-yl)-ethanone and BuCu·AlCl3 as the key step.

Title compound has been found to form a 2:2 crystalline inclusion complex with ethanol, and X-ray crystal structure of the complex was determined. In the structure of the complex, four intermolecular hydrogen bonds are involved between the two host and two guest molecules. By using the complexation, extraction of ethanol from aqueous solution is demonstrated.

Oxydations des dimethyl-1,3 thymine(A) et -uracile, de la di-O-acetyl-3',5' thymidine, de la tri-O-acetyl-2',3',5' uridine et du dimethyl-1,3 fluoro-5 uracile. Mecanisme des reactions. Structures cristalline de la chloro-3' benzoyloxy-6 dimethyl-1,3 hydroxy-5 perhydro thymine (produit d'oxydation de A)

Two host-specific phytotoxic metabolites, AK-toxin I and II, were isolated from a culture broth of Alternaria alternata Japanese pear pathotype, the fungus causing black spot disease of susceptible Japanese pear cultivars. From chemical, spectral and X-ray crystallographic data, AK-toxin I was characterized as 8-(2′S, 3′S)-2′-acetylamino-3′-methyl-3′-phenyl-propionyloxy]-(8R,9S)-9,10-epoxy-9-methyl-deca-(2E,4Z,6E)-trienoic acid. The structure of AK-toxin II was also assigned to be 3′-demethyl derivative of AK-toxin I by comparing the spectral data with those of AK-toxin I.

Treatment of 8, 8-dibromobicyclo [5.1.0] octanes (A) with a higher order organocuprate prepared from cuprous thiocyanate (method A) or cuprous cyanide (method B) and methyllithium, followed by the addition of methyl iodide in situ, readily afforded 8, 8-dimethylbicyclo [5.1.0] octanes (B) in good yields. The results are summarized in Table I. Interestingly, reaction of the cisdibromides (4 and 19) under the present conditions gave tricyclic compounds (15 and 16, and 20, respectively)

The crystal structures of the complexes [Cu(2,2′-bipyridine)(ethylene)]ClO4 (I) and [Cu(1,10-phenanthroline)(ethylene)]ClO4 (II) have been determined from X-ray diffraction studies. Complex I crystallizes in the triclinic space group, P 1 , with four molecules in a unit cell of dimensions a 10.657(1), b 6.998(1), c 18.251(2) A, α 91.05(1), β 93.35(1), and γ 84.97(1)°. Complex II crystallizes in the monoclinic space group, P21/a, with four molecules in a unit cell of dimensions a 19.981(5), b 10.904(2), c 6.955(1) A, and β 103.90(2)°. Both structures were solved by heavy-atom methods, and refined by block-diagonal least-squares methods. The final R-values for I and II were 0.044 for 2225 observed reflections for I and 0.066 for 2005 observed reflections for II. In both crystals, the CuI ion is coordinated to two nitrogen atoms of 2,2′-bipyridine or 1,10-phenanthroline, and two carbon atoms of ethylene in an approximately planar form. The CC bond distances of the coordinated ethylene molecules, 1.360(13) and 1.346(18) A for I and 1.361(22) A for II, do not show marked lengthening compared with that for free ethylene, and may be explained by dπ(Cu) → dπ (ethylene) back-bonding between the Cu 3dπ orbital and the Rydberg 3dπ orbital of the ethylene molecule.

Mixed crystals of formates, with the general formula of (Cu,MII)(HCOO)2·2H2O, were found to show non-uniform changes in lattice constants with the change in the chemical constitution. The reason for this unusual change was sought in relation to a possible non-uniform distribution of the cations over the two non-equivalent sites for metal ions. A simple model based merely on the difference in the radii of metallic ions did not agree with the results of IR measurements nor with those of an ESR study by Wagner et al. Another model, incorporating the change in the direction of the longest axis of the octahedron coordinating to the Cu2+ ion at the Ml-site, as suggested from the results of a related work (Part II), was found not only to explain the changes in lattice constants, but also to conform with other evidences; it seems to be an essentially correct interpretation.

The crystal structure of bis[tetracarbonyldiphenylphosphidomanganese(0)] has been determined by an X-ray diffraction study. The complex crystallizes in the monoclinic space group P 2 1 / n with four molecules in a unit cell of dimensions, a 15.714(4), b 16.446(5), c 12.016(4) A, and β 101.25(2)°. The molecule has approximately centrosymmetric bi-octahedral D 2 h structure. Each manganese atom is bonded to two phosphorus atoms of μ-diphenylphosphide groups and four carbonyl carbon atoms. The separation of the manganese atoms is 3.690(1) A.

Drugs with a primary aromatic amino moiety such as procaine, procainamide, and p-aminobenzoic acid (PABA) are capable of reacting with various reducing sugars containing hexoaldoses and pentoaldoses. The amine-carbohydrate reaction products can be separated from the parent drugs by high performance liquid chromatography (HPLC) analysis. The formation and dissociation profiles of the products were followed by HPLC and ultraviolet spectroscopy. The reaction products formed in aqueous solution were not association complexes, but chemical reaction products, which were identified as glycosylamines or N-glycosides, by comparison with authentic samples obtained by the condensation of amines with carbohydrates in methanol. An X-ray analysis of one of the glycosylamines, 2-deoxy-N-p-carboxyphenyl-D-ribosylamine, was carried out, and the absolute conformation and configuration in the crystalline state were determined.

The crystal structure of (octaethylporphinato)bis(tetrahydrofuran)iron(III) perchlorate was determined by the X-ray method. The complex crystallizes in the monoclinic space group C2/m, a=13.916(3) A, b=16.509(3) A, c=10.659(5) A, β=118.18(1)°, and Z=2. The structure was solved by the direct method and refined by the full-matrix least-squares method. The final R value was 0.079 for 597 reflections. The complex has a crystallo-graphically imposed twofold axis and a mirror of symmetry. The porphinato core is planar within 0.06 A. The iron(III) ion lies at the center of the octahedron formed by the four porphinato nitrogen atoms and the two tetrahydrofuran oxygen atoms. The axial Fe–O distance, 2.187(11) A, is considerably longer than the reported distances for high-spin porphinatoiron(III) complexes, while the equatorial Fe–N distance, 1.978(12) A, is comparable to those for low-spin and intermediate-spin porphinatoiron(III) complexes. The Fe–O and Fe–N bond distances are well explained in terms of an interm...