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Our previous EPR studies dealt with the contrasting behaviour of the lamellar C8OCu, as against the columnar C8Cu/C10Cu. X-ray and EPR studies of C n , Cu(n = 6–12) and CnOCu(n = 6–12) presented here, however, indicate that some members exhibit anomalous behaviour within each series. Thus C6Cu, C8Cu, C10Cu and C12Cu (even members) show a single exchange-narrowed strong asymmetric g⊥ along with a weak g‖ in pure solids. Interestingly, C7Cu and C9Cu (odd members) show hyperfine quartets in g‖, indicating weak or no exchange. C7Cu shows a single g⊥, conforming to the axial symmetry in CnCu. However, C9Cu is rather unique: gives three different mesophases and exhibits non-axial behaviour. Crystal structure for C9Cu and C7Cu reported here for the first time, indicate that the former has a structure similar to that of C7Cu. However, C7Cu, which also has z = 1 and belongs to the same triclinic space group, has a close interaction between two molecules at the opposite corners of the ab plane in the unit ...

Reactions of [Ni(tren)(H(2)O)(2)]X(2) (tren = tris(2-aminoethyl)amine; X = Cl (1a), Br (1b); X(2) = SO(4) (1c)) with mannose-type aldoses, having a 2,3-cis configuration (D-mannose and L-rhamnose), afforded {bis(N-aldosyl-2-aminoethyl)(2-aminoethyl)amine}nickel(II) complexes, [Ni(N,N'-(aldosyl)(2)-tren)]X(2) (aldosyl = D-mannosyl, X = Cl (2a), Br (2b), X(2) = SO(4) (2c); aldosyl = L-rhamnosyl, X(2) = SO(4) (3c)). The structure of 1c was confirmed by X-ray crystallography to be a mononuclear [Ni(II)N(4)O(2)] complex with the tren acting as a tetradentate ligand (1c.2H(2)O: orthorhombic, Pbca, a = 15.988(2) A, b = 18.826(4) A, c = 10.359(4) A, V = 3118 A(3), Z = 8, R = 0.047, and R(w) = 0.042). Complexes 2a,c and 3c were characterized by X-ray analyses to have a mononuclear octahedral Ni(II) structure ligated by a hexadentate N-glycoside ligand, bis(N-aldosyl-2-aminoethyl)(2-aminoethyl)amine (2a.CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 16.005(3) A, b = 20.095(4) A, c = 8.361(1) A, V = 2689 A(3), Z = 4, R = 0.040, and R(w) = 0.027. 2c.3CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 14.93(2) A, b = 21.823(8) A, c = 9.746(2) A, V = 3176 A(3), Z = 4, R = 0.075, and R(w) = 0.080. 3c.3CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 14.560(4) A, b = 21.694(5) A, c = 9.786(2) A, V = 3091 A(3), Z = 4, R = 0.072, and R(w) = 0.079). The sugar part of the complex involves novel intramolecular sugar-sugar hydrogen bondings around the metal center. The similar reaction with D-glucose, D-glucosamine, and D-galactosamine, having a 2,3-trans configuration, resulted in the formation of a mono(sugar) complex, [Ni(N-(aldosyl)-tren)(H(2)O)(2)]Cl(2) (aldosyl = D-glucosyl (4b), 2-amino-2-deoxy-D-glucosyl (5a), and 2-amino-2-deoxy-D-galactosyl (5b)), instead of a bis(sugar) complex. The hydrogen bondings between the sugar moieties as observed in 2 and 3 should be responsible for the assembly of two sugar molecules on the metal center. Reactions of tris(N-aldosyl-2-aminoethyl)amine with nickel(II) salts gave the tris(sugar) complexes, [Ni(N,N',N"-(aldosyl)(3)-tren)]X(2) (aldosyl = D-mannosyl, X = Cl (6a), Br (6b); L-rhamnosyl, X = Cl (7a), Br (7b); D-glucosyl, X = Cl (9); maltosyl, X = Br (10); and melibiosyl, X = Br (11)), which were assumed to have a shuttle-type C(3) symmetrical structure with Delta helical configuration for D-type aldoses on the basis of circular dichroism and (13)C NMR spectra. When tris(N-rhamnosyl)-tren was reacted with NiSO(4).6H(2)O at low temperature, a labile neutral complex, [Ni(N,N',N"-(L-rhamnosyl)(3)-tren)(SO(4))] (8), was successfully isolated and characterized by X-ray crystallography, in which three sugar moieties are anchored only at the N atom of the C-1 position (8.3CH(3)OH.H(2)O: orthorhombic, P2(1)2(1)2(1), a = 16.035(4) A, b = 16.670(7) A, c = 15.38(1) A, V = 4111 A(3), Z = 4, R = 0.084, and R(w) = 0.068). Complex 8 could be regarded as an intermediate species toward the C(3) symmetrical tris(sugar) complexes 7, and in fact, it was readily transformed to 7b by an action of BaBr(2).

The hydrochloride of the chiral cyclen ligand L3[(2R,5R,8R,11R)-1,7-dibenzyl-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane] reacted with Na3[CoIII(CO3)3] in acidic and alcoholic aqueous solution to give two crystalline complexes, [CoII(Cl)L3]Cl–[CoIII(CO3)L3]Cl and [CoII(Cl)L3]Cl, the crystal structures of which have been determined. The former contains an equimolar mixture of two markedly different crystallographically independent molecules in the unit cell, which have been crystallised independently as two salts variously hydrated. These differ from one another in the oxidation state of the metal, the co-ordination number, and the configurations of asymmetric nitrogens. The molecule [CoII(Cl)L3]Cl is distorted square pyramidal with the Cl– ion at the apex and RRRR configurations of the four asymmetric N atoms; the carbonato cobalt(III) complex is six-co-ordinated and the N atoms have RSRS configurations. The corresponding mixed-valence compound with bromide did not separate, although the analogue of the monomeric carbonate was isolated. The structure determinations of the carbonate and [CoII(Cl)L3]Cl show that the molecular geometries are essentially the same as those found in the double salt. The formation and stabilisation of the cobalt(II) species is probably due to the steric requirements of the macrocycle.

A series of five copper(II) complexes with four geometrically isomeric ligands of 1,4,7,10-tetrabenzyl-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane and with (2R,5R,8R,11R)-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane has been investigated by means of ESR, CD and MCD in solution. X-ray studies reported separately had shown that the [CuN4Cl] chromophores were distorted to varying extents from square pyramidal to trigonal bipyramidal geometry. The stability and rigidity of the molecular structure have enabled us to carry out a complementary study of the crystalline state and solution chemistry. The ground state Kramers doublets varied from 3dx2−y2 to 3dz2 type with increasing distortion around the copper ion. The orbital sequence of the 3d1 positive hole, dx2−y2

The chiral diamine (2R), (4R)-pentane-2,4-diamine (2R,4R-ptn) has been found efficiently to regulate the stereochemistry of the cobalt(III) complex [Co(edda)(2R,4R-ptn)]+(edda = ethylenediamine-N,N′-diacetate). The product ratio Λ-sym-cis:Δ-sym-cis is 3:97. The stereoselectivity is surprisingly high in comparison with that for the analogous complex involving (1R),(2R)-cyclohexane-1,2-diamine (R,R-chxn), Λ-sym-cis:Δ-sym-cis= 60:40. It is discussed on the basis of crystal structure determinations carried out for both diastereoisomers of sym-cis-[Co(edda)(2R,4R-ptn)]+. A notable difference was observed in the six-membered chelate ring of 2R,4R-ptn which adopts the chair conformation in Λ-sym-cis-[Co(edda)(2R,4R-ptn)]ClO4·H2O 1a but the λ skew-boat conformation in Δ-sym-cis-[Co(edda)(2R,4R-ptn)]ClO41b. The chair conformation in 1a is due to steric repulsions between the chelates, which is the important factor for the preferential formation of 1b over 1a. Such steric repulsions between the chelates are remarkably efficient for the chiral six-membered chelate compared with those for the five-membered one. N-Alkyl substitutions on the edda ligand caused preferential formation of the Λ-sym-cis form, as is the case for the [Co(R2edda)(R,R-chxn)]+ system.

The reactions of 2- and 8-(substituted amino)-1-azaazulenes with dimethyl acetylenedicarboxylate (DMAD) were investigated. Treatment of ethyl 2-acetylamino-1-azaazulene-3-carboxylate with DMAD in refluxing acetonitrile gave 9-ethyl 1,2,3-trimethyl 3a-azacyclopent[a]azulene-1,2,3,9-tetracarboxylate, 5-ethyl 1,2,2a,3-tetramethyl 4-acetyl-2a,3-dihydro-4H-4, 10b-diazapentaleno[1,6-aj]azulene-1,2,2a,3,5-pentacarboxylate (3a), and dimethyl (10-ethoxycarbonyl-4-methoxycarbonyl-2,4a-dihydro-2-oxo-2H-1,4a-diazabenz[a]azulen-3-yl)maleate. Compound 3a thermally rearranged to 9-ethyl 2,3,10,11-tetramethyl 1-acetyl-2,3,4,4a-tetrahydro-1H-1,4-diaza-3,4a-ethenofluorene-2,3,9,10,11-pentacarboxylate. The reaction of ethyl 2-alkylamino-1-azaazulene-3-carboxylate with DMAD gave the corresponding 4-alkyl-2a,3-dihydro-4H-4,10b-diazapentaleno[1,6-aj]azulene derivatives, and the etheno-bridged 1-azaheptalene derivative. The reaction of 8-ethylamino-3-phenyl-1-azaazulene with DMAD gave trimethyl 1-phenyl-2a-azabenz[cd]azulene-3,...

The reactions of 2- and 8-(substituted amino)-1-azaazulenes with dimethyl acetylenedicarboxylate (DMAD) were investigated. Treatment of ethyl 2-acetylamino-1-azaazulene-3-carboxylate with DMAD in refluxing acetonitrile gave 9-ethyl 1,2,3-trimethyl 3a-azacyclopent[a]azulene-1,2,3,9-tetracarboxylate, 5-ethyl 1,2,2a,3-tetramethyl 4-acetyl-2a,3-dihydro-4H-4, 10b-diazapentaleno[1,6-aj]azulene-1,2,2a,3,5-pentacarboxylate (3a), and dimethyl (10-ethoxycarbonyl-4-methoxycarbonyl-2,4a-dihydro-2-oxo-2H-1,4a-diazabenz[a]azulen-3-yl)maleate. Compound 3a thermally rearranged to 9-ethyl 2,3,10,11-tetramethyl 1-acetyl-2,3,4,4a-tetrahydro-1H-1,4-diaza-3,4a-ethenofluorene-2,3,9,10,11-pentacarboxylate. The reaction of ethyl 2-alkylamino-1-azaazulene-3-carboxylate with DMAD gave the corresponding 4-alkyl-2a,3-dihydro-4H-4,10b-diazapentaleno[1,6-aj]azulene derivatives, and the etheno-bridged 1-azaheptalene derivative. The reaction of 8-ethylamino-3-phenyl-1-azaazulene with DMAD gave trimethyl 1-phenyl-2a-azabenz[cd]azulene-3,...

Branched alkyl chain-substituted complexes, bis(1-ethylpentoxydithiobenzoato)nickel(II), b, and bis(2-ethylhexyloxydithiobenzoato)nickel(II), c, have been synthesized and their liquid crystalline p...

The nickel(II) complex of N,N-dimethylethylenediamine (N,N-Me{sub 2}en), (Ni(N,N-Me{sub 2}en){sub 3})(ClO{sub 4}){sub 2} (1), in aqueous ethanol spontaneously adsorbed and fixed CO{sub 2} in air to give a trinuclear nickel(II) complex, (Ni{sub 3}(N,N-Me{sub 2}en){sub 6}(CO{sub 3})(H{sub 2}O){sub 4})(ClO{sub 4}){sub 4} (2). The complex 2 crystallizes in the hexagonal system 6. The structure was solved by direct methods and refined by least-squares techniques to a final R value of 0.065 for 2,940 independent reflections with F{sub o} > 3{sigma}(F{sub o}). The absolute configuration was determined by the Bijvoet method. The complex cation is trinuclear, which is made up of three octahedral nickel(II) complexes, {Lambda}-cis-(0,0)-(Ni(N,N-Me{sub 2}en){sub 2}(CO{sub 3})) and {Lambda}- and {Delta}-cis-(0,0)-(Ni(N,N-Me{sub 2}en)(H{sub 2}O){sub 2}){sup 2+}, joined by a novel hydrogen bonding network around the coordinating carbonate ligand. This planar hydrogen bonding system might stabilize the bidentate carbonate, resulting in the spontaneous fixation of CO{sub 2} in air. When analogous diamines (N,N{prime}-dimethylethylenediamine, N,N-diethylethylenediamine, N-methylethylenediamine, N-ethylethylenediamine) were used instead of N,N-Me{sub 2}en, no fixation of CO{sub 2} was observed. The N-substituent of diamines is an important factor in determining the occurrence of CO{sub 2} uptake.

Some α,β-unsaturated esters bearing an imidazolidine chiral controller at the β-position were employed in the asymmetric cycloaddition to nitrile oxides. Regio- and diastereoselectivities were both poor when the chiral controller was a perhydropyrrolo[1,2-c]imidazol-3-yl auxiliary, while the reaction of the esters bearing a C2-symmetric imidazolidine chiral controller was exclusively regioselective or diastereoselective depending upon the nature of N-substituent. The transition state was briefly discussed.

The title compounds were prepared smoothly in moderate yields by the reactions of 3-(mercaptomethylene)-2(3H)-indolizinones with various alkylating agents such as bromoacetonitrile, bromoacetates, and phenacyl bromides in the presence of base. The structural assignments of these products were accomplished by their spectral inspections, and the structure for one compound was distinctly proven by its X-ray crystallography. In order to explain the regioselectivity in this reaction, a molecular orbital calculation (CNDO/2) was also performed using a model compound.

α,β-Unsaturated esters bearing a chiral oxazolidine or perhydropyrrolo[1,2-c]imidazole auxiliary at the β-position have been prepared and applied to the cycloadditions with N-metalated azomethine ylides derived from α-(benzylideneamino) esters. These reactions are found to proceed with an exclusively high diastereofacial selectivity to give 2,4-pyrrolidinedicarboxylates with four consecutive chiral centers after the removal of chiral auxiliary. Detailed stereochemistry in the transition state is discussed.

The syntheses, structures, spectroscopic properties, and antitumor activities of a series of platinum(II) diamino sugar complexes, [PtCl 2 (diamino sugar)], have been studied. The molecular structure of one of these is described. Crystal data for [PtCl 2 (Me-ManNN)]•H 2 O (Me-ManNN=methyl 2,3-diamino-2,3-dideoxy-α-D-mannopyranoside) are as follows: monoclinic, P2 1 . Antitumor activity was investigated against S180 and L1210 tumors

Various 2-(acylmethylthio)-, 2-(benzylthio)-, and 2-(propargylthio)pyrazolo[1, 5-a]pyridine derivatives (4a-n' and 7a-n') were prepared in moderate to good yields by the reactions of potassium pyrazolo[1, 5-a]pyridine-2-thiolates (2 and 6), readily available by the treatment of 2-[(2-ethoxycarbonylethyl)thio]- and 2-[(2-cyanoethyl)thio]pyrazolo[1, 5-a]pyridines (1a-h and 5a-h) with potassium tert-butoxide in N, N-dimethylformamide (DMF), with alkylating agents such as chloroacetone (3a), phenacyl bromides (3b-d), ethyl bromoacetate (3e), benzyl bromides (3f-k), and propargyl bromide (31). Of these S-functionalied pyrazolo[1, 5-a]pyridines only 2-(acetonylthio)- and 2-(phenacylthio)pyrazolo[1, 5-a]pyridine-3-carbonitriles (4a-t) were converted to new heterocyles, thieno[2', 3' : 3, 4]pyrazolo[1, 5-a]pyridines (8a-t) by heating them with 1, 8-diazabicyclo[5.4.0]undec-7-ene (DBU); the other compounds did not provide any tricyclic heterocycles under various alkaline conditions. The structures of thieno[2', 3' : 3, 4]pyrazolo[1, 5-a]pyridines (8a-t) were determined mainly by elemental analyses and spectral inspections, and the structural assignment was confirmed by the X-ray analysis of compound 8d.

Single crystal X-ray analyses of thieno[3, 2-a]- and thieno[2, 3-b]indolizine derivatives were carried out and their structures were definitively established. The tricyclic ring systems in both molecules were nearly planar and their deviations from the least-squares planes were less than 6.26°. The structural factors for their indolizine moieties were very similar to those for known aromatic indolizines, but those for the thiophene rings were somewhat different. The deviation from co-planarity and the deformation of the thiophene ring in thieno[3, 2-a]indolizine were greater than those in thieno[2, 3-b]indolizine.

Reactions of [Ni(tren)(H(2)O)(2)]X(2) (tren = tris(2-aminoethyl)amine; X = Cl (1a), Br (1b); X(2) = SO(4) (1c)) with mannose-type aldoses, having a 2,3-cis configuration (D-mannose and L-rhamnose), afforded {bis(N-aldosyl-2-aminoethyl)(2-aminoethyl)amine}nickel(II) complexes, [Ni(N,N'-(aldosyl)(2)-tren)]X(2) (aldosyl = D-mannosyl, X = Cl (2a), Br (2b), X(2) = SO(4) (2c); aldosyl = L-rhamnosyl, X(2) = SO(4) (3c)). The structure of 1c was confirmed by X-ray crystallography to be a mononuclear [Ni(II)N(4)O(2)] complex with the tren acting as a tetradentate ligand (1c.2H(2)O: orthorhombic, Pbca, a = 15.988(2) Å, b = 18.826(4) Å, c = 10.359(4) Å, V = 3118 Å(3), Z = 8, R = 0.047, and R(w) = 0.042). Complexes 2a,c and 3c were characterized by X-ray analyses to have a mononuclear octahedral Ni(II) structure ligated by a hexadentate N-glycoside ligand, bis(N-aldosyl-2-aminoethyl)(2-aminoethyl)amine (2a.CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 16.005(3) Å, b = 20.095(4) Å, c = 8.361(1) Å, V = 2689 Å(3), Z = 4, R = 0.040, and R(w) = 0.027. 2c.3CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 14.93(2) Å, b = 21.823(8) Å, c = 9.746(2) Å, V = 3176 Å(3), Z = 4, R = 0.075, and R(w) = 0.080. 3c.3CH(3)OH: orthorhombic, P2(1)2(1)2(1), a = 14.560(4) Å, b = 21.694(5) Å, c = 9.786(2) Å, V = 3091 Å(3), Z = 4, R = 0.072, and R(w) = 0.079). The sugar part of the complex involves novel intramolecular sugar-sugar hydrogen bondings around the metal center. The similar reaction with D-glucose, D-glucosamine, and D-galactosamine, having a 2,3-trans configuration, resulted in the formation of a mono(sugar) complex, [Ni(N-(aldosyl)-tren)(H(2)O)(2)]Cl(2) (aldosyl = D-glucosyl (4b), 2-amino-2-deoxy-D-glucosyl (5a), and 2-amino-2-deoxy-D-galactosyl (5b)), instead of a bis(sugar) complex. The hydrogen bondings between the sugar moieties as observed in 2 and 3 should be responsible for the assembly of two sugar molecules on the metal center. Reactions of tris(N-aldosyl-2-aminoethyl)amine with nickel(II) salts gave the tris(sugar) complexes, [Ni(N,N',N"-(aldosyl)(3)-tren)]X(2) (aldosyl = D-mannosyl, X = Cl (6a), Br (6b); L-rhamnosyl, X = Cl (7a), Br (7b); D-glucosyl, X = Cl (9); maltosyl, X = Br (10); and melibiosyl, X = Br (11)), which were assumed to have a shuttle-type C(3) symmetrical structure with Delta helical configuration for D-type aldoses on the basis of circular dichroism and (13)C NMR spectra. When tris(N-rhamnosyl)-tren was reacted with NiSO(4).6H(2)O at low temperature, a labile neutral complex, [Ni(N,N',N"-(L-rhamnosyl)(3)-tren)(SO(4))] (8), was successfully isolated and characterized by X-ray crystallography, in which three sugar moieties are anchored only at the N atom of the C-1 position (8.3CH(3)OH.H(2)O: orthorhombic, P2(1)2(1)2(1), a = 16.035(4) Å, b = 16.670(7) Å, c = 15.38(1) Å, V = 4111 Å(3), Z = 4, R = 0.084, and R(w) = 0.068). Complex 8 could be regarded as an intermediate species toward the C(3) symmetrical tris(sugar) complexes 7, and in fact, it was readily transformed to 7b by an action of BaBr(2).

The chiral 12-membered cyclic tetramine (2R,5R,8R,11R)-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane (L) reacts with CoBr2 to give mainly cis-SSSR-[CoIIIBr(H2O)L]Br21. Another isomeric complex 2 has recently been isolated from the reaction mixture obtained under mild alkaline conditions. In order to clarify the geometry, the structures of cis-(RSRS)-[Co{(S)-alaO}L][ClO4]24(alaO = alaninate) and cis-(RSRS)-[Co{(S)-thrO}L][ClO4]2·3H2O 6(thrO = threoninate) derived from 2 have been determined by X-ray analysis. All complexes prepared are cis-octahedral, each CoIII is surrounded by four N from L and by N and O of the amino acid, and the configurations of the four asymmetric nitrogen atoms are RSRS. This means that the cobalt ion in 2 co-ordinates to the crowded face of the N4 plane of L, and the ligations of the metal to L in 1 and 2 occur from opposite directions. The absorption band maxima of the respective visible spectra of all the RSRS complexes shift approximately 400 cm–1 to higher energy than those of the corresponding SSSR ones. A slow exchange reaction between the fifth and sixth ligands is observed for 1, and release of the amino acid from a SSSR-amino acidato complex takes place in Na2CO3 solution. No such reactions occur in 2 and in RSRS-amino acidato complexes. These results are probably related to the ligand-field strength.

The crystal and molecular structure of the title compound, [Rh(NH3)6]3[Rh(SnCl3)4(SnCl4)] [SnCl6] · 4H2O, has been determined by the single-crystal X-ray diffraction method. The compound crystallizes in the monoclinic system, space group P2 n with a = 16.581(2), b = 11.010(4), c = 16.024(2)A, β = 90.76(1), and two molecules per unit cell. The structure was solved by Patterson's method and refined by the least-squares technique to give a final R factor of 0.031. The three cations, [Rh(NH3)6]3+, are a regular octahedron with an average RhN bond length of 2.07 A. The rhodium anion, [Rh(SnCl3)4(SnCl4)]5−, is a trigonal bipyramid with the two axial RhSn bonds, 2.493 A in length, and the three equatorial bonds, 2.546, 2.540, and 2.540 A. One of the three tin atoms in the equatorial trigonal plane forms a distorted trigonal bipyramid with two short SnCl bonds 2.384 A in length and two long bonds, 2.733 A. The other four tin atoms have a distorted tetrahedral arrangement with an average SnCl bond length of 2.42 A. The tin anion, [SnCl6]4−, which is not coordinated to rhodium, forms extremely long SnCl bonds of 2.763, 2.800, and 2.893 A in a distorted octahedral arrangement.

The complex [CoIIIBr(H2O)L] Br2[L = optically-active (2R,5R,8R,11R)-2,5,8,11-tetraethyl-1,4,7,10-tetra-azacyclododecane] reacts with amino acids under mild reaction conditions, at room temperature and at pH 8.0, to give the corresponding amino acidato complexes. The crystal structures of two such complexes, [Co{(R)alaO}L]Br[ClO4]·H2O (2) and [Co{(S)-alaO}L]Br[ClO4]·H2O (3), were determined by X-ray analyses. Crystal data for (2): tetragonal, space group P43, a=14.320(6), c= 13.377(2)A, and Z= 4; for (3): tetragonal, space group P43, a= 14.319(3), c= 13.325(7)A, and Z= 4. Least-squares refinement converged at R= 0.044 and 0.042 for 2 618 and 2 413 unique reflections respectively. Both complexes show a cis-octahedral geometry, with the macrocycle co-ordinated in a folded manner, and the chiralities of the four nitrogen atoms of the macrocycle are SSSR as found in the starting complex, In both alaninato complexes, each amino acid co-ordinates in the β form with Iµ and δ conformations, respectively. The release of alanine from complex (3) is also discussed.

Preparation and property of Co(III) complex of an optically active 12-membered macrocyclic lignad (tecyclen) are reported.

The electron-spin-resonance (ESR) spectra of three paramagnetic species trapped in single crystals of chloro(tetraphenylporphyrinato)cobalt(III) have been observed at 77 K. Using the ESR parameters obtained, one of them has been identified as the [CoIII(tpp)]2+·(Cl−)2 π cation radical, and the other two species, as [CoII(tpp)] which are influenced by axial ligation. From the angular variations in the hfcc due to the 59Co, 14N, and 35Cl in the π cation radical, it has been found that the unpaired electron resides on the a2u porphyrin π orbital and polarizes the Co and Cl atomic orbitals through a spin-polarization mechanism. Finally, the radical formation mechanisms in solution are briefly discussed, based on the results obtained from the single-crystalline measurements.

The crystal structure of the title compound was determined by X-ray diffraction. The crystals have monoclinic symmetry with a=13.481(5), b=8.285(5), c=l3.092(3) A. β=96.24(3)°, and space group P21⁄n with Z=4. The final R-factor was 0.065 for 2191 independent reflections. The torsion angles of the C–Ph bonds are 47.4(4) and 44.4(4)°. The cyclohexene rings have approximate twist-boat conformations. The molecular structure in the crystal is compared with that in the solution phase, that of (E)-stilbenes, and the results of the molecular mechanics calculations. It is also discussed in relation to the molecular packing.

The complex [CoBr(H2O)L] Br2(1)[L =(2R,5R,8R,11R)-2,5,8,11-tetraethyl-1,4,7,10-tetra-azacyclododecane] reacts with a racemic neutral amino acid having a hydroxymethyl group to give a pair of diastereomeric complexes. One of these crystallized preferentially as its appropriate salt. The less-soluble complex co-ordinated its (R)-amino acid. Structure determinations of (R)- or (S)-serinato (serO) and (R)-α-methylserinato (mseO) complexes, (3)–(5), showed that each hydroxyl group in the amino acid forms a hydrogen bond. The OH group of (R)-amino acids takes part in an intramolecular hydrogen bond to one of the secondary nitrogen atoms in L, and that of (S)-serO in (4) interacts with a cocrystallized water molecule and with an anion. Such different hydrogen-bonding formation results in different solubility between the diastereomers, and allows them to be isolated. Only a powdery solid was obtained for the complex co-ordinating (S)-mseO. Slightly racemized (R)- and (S)-ser and optically pure mse were obtained upon release from the corresponding complexes. Further, complex (1) was regenerated in good yield. The resolution expressed as the different solubilities between two salts in this series is ascribed to the effect of a three-point attachment.

The synthesis and crystal structure of the nickel(II) complex, [Ni(N,N′-(D-Man)2-tren]Cl2·CH3OH containing two N-glycosides derived from the reaction of D-mannose (D-Man) and N,N-di(2-aminoethyl)ethylenediamine (tren) are reported. The suagr part in the complex involves novel intramolecular sugar–sugar hydrogen bondings around the metal center.

The structure of the title compound, C44H28N4CoCl, has been determined by single-crystal X-ray diffraction. The crystals are body-centered tetragonal, with a=b=13.693(2), c=9.701(2) A, and Z=2. The space group was determined to be I4 from the measurement of the anomalous dispersion effect. The structure was predicted prior to the X-ray analysis from the calculation of the intermolecular van der Waals energy; the result agreed quite well with the experimentally determined structure. A tetragonal pyramidal five coordination with the chlorine atom at the apex was found for the cobalt atom. The cobalt-chlorine distance is 2.149 (6) A, about 0.1 A shorter than those found in ordinary octahedral coordinations.

The crystal structure of α-AlB12 (tetragonal; a = 10.158(2) A, c = 14.270(5) A, space group P41212 or P43212) has been determined by the single-crystal X-ray diffraction method. It was solved by the Fourier technique initially based on a partial B12 icosahedral structure, which was inferred from crystal chemical considerations. Refinement was made with the aid of a full-matrix least-squares program leading to a final R value of 3.0%. The structure is based on a three-dimensional framework consisting of B12 icosahedra, B19 units, and single B atoms; the B19 unit is a twinned icosahedron with a triangular composition plane and a vacant apex on each side. The chemical unit is Al3.2·2B12·B·B19 and its number in the unit cell is 4. The Al atoms are distributed statistically over five sites in the boron framework. The occupancies of the sites are 72, 49, 24, 15, and 2%, respectively.

The ESR spectra of three paramagnetic species trapped in single crystals of chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III) (CoIIICl(tpp)), have been observed at 4.2 K to room temperature. Based on the ESR parameters obtained, the paramagnetic species have been identified as two CoII(tpp) with different axial ligand effects and a previously reported cation radical, [CoIII(tpp)]2+·(Cl−)2. A correlation diagram among g, A, and axial ligation made from published data of cobalt(II) complexes has been successfully used for identification of the two trapped CoII(tpp) species: one is four-coordinate CoII(tpp) and the other five-coordinate CoIIX(tpp) in which X is presumably Cl−. Their electronic and molecular structures are discussed according to McGarvey’s theory. Finally, the formation mechanism of the three paramagnetic species in CoIIICl(tpp) is discussed, based on the results obtained from the single crystalline ESR measurements.

A binuclear complex of bis(μ-N,N′-dipicolinoyl-1,3-propanediamine)-bis(sulfato)dicopper(II) has been isolated as a blue single crystal tridecahydrate, [{Cu(SO4)(ppda)}2]·13H2O, from an aqueous solution. The crystals are orthorhombic, C2221, with a=15.42(1), b=24.92(2), c=25.73(2) A, and Z=8. Each copper(II) ion is in a square-pyramidal coordination with two pyridine nitrogen atoms, two carbonyl oxygen atoms, and a sulfate oxygen atom at the apex. The two equivalent copper(II) ions, about 3.9 A apart from each other, are aligned coaxially. The eight Cu–Cu vectors are approximately parallel to one another along the c axis. The most important feature of the crystal structure is the presence of the bulky ligands and of many water molecules, which magnetically isolate the Cu–Cu coupled pair from one another. This facilitates the ESR study of the molecular anisotropies by using the single crystal, even at room temperature. The ESR parameters determined are as follows: g⁄⁄=2.280(2), g⊥=2.067(1), |D|=422.4(8), |A...

X-ray difference electron densities in α-AlB12 were examined. Broad peaks presumably characteristic of highly delocalized three-center bonds were observed at the centers of the triangular faces of the B12 icosahedron. Another kind of prominent peak on the external BB bonds of the icosahedron indicated that the inter-icosahedral BB bonds are two-center bonds. An averaging over the icosahedral symmetry significantly reduced the random noises in the difference densities. Theoretical difference electron densities for a B12H−212 molecular ion, calculated by the CNDO 2 molecular orbital method, were qualitatively in good agreement with the observed densities mentioned above. Residual peaks were observed on all the five edges of the open pentagonal face of the B19 unit; they had broad tails extending toward the aluminum triplet sites. The observed difference densities around the “single” B(23) atom suggested that the atom belongs to the B19 unit rather than being single.

(−)546-trans-[Co(NO2)2(R,R-dmchxn)2]+ and (+)546-Λ-Co(CO3)(R,R-dmchxn)2]+, which had been newly prepared, reacted with concentrated HCl to give, respectively, (−)435-trans-(SSSS)-[CoCl2(R,R-dmchxn)2]+ and (+)435-trans-(SRRS)-[CoCl2(R,R-dmchxn)2]+ stereospecifically, where R,R-dmchxn=(1R,2R)-N,N′-dimethyl-1,2-cyclohexanediamine. The stereospecific formation of (+)546-Λ-[Co(CO3)(R,R-dmchxn)2]+ has been observed. The trans-dichloro complexes and their precursors have been characterized by elemental analysis and by electronic absorption, circular dichroism, 1H NMR, and 13C NMR spectroscopies. An X-ray crystal-structure determination was undertaken on one of the trans-dichloro isomers, (+)435-[CoCl2(R,R-dmchxn)2]Cl·HCl·2H2O, whose structure could not be characterized by usual spectroscopies. This complex forms triclinic crystals with a=11.395(10) A, b=11.674(8) A, c=11.031(8) A, α=98.62(6)°, β=102.48(8)°, γ=118.24(5)°, and Z=2, in the space group P1. Least-squares refinements converged at an R value of 0.041 f...

A phytotoxin, isopimarane diterpene γ-lactol, 6α,7β,9α-trihydroxy-8 (14),15-isopimaradiene- 20,6-γ-lactone, was isolated from the culture filtrate of the fungus Phomopsis sp., which was obtained from the interior part of the trunk of most wilting Japanese red pines, Pinus densiflora I Sieb, et Zucc. The stereostructure was established by X-ray crystal analysis and spectroanalysis. This γ-lactol was identical with LL-S491, a fermentation product of the fungus Aspergillus chevalieri. The cytotoxic activity of the γ-lactol isopimarane was the same as pentachlorophenol at 150 ppm on cell cultures from Japanese red pine buds.

The title compound was prepared by the reaction of L-tartaric acid with [CoCO3(en)2]Br. It contains a dimer cation in which two cobalt atoms are bridged through a tridentate tartrate anion. The configuration about one cobalt atom is Δ-cis, and about another is trans(O,O).

The molecular structure of naematolin 3-p-bromobenzoate has been determined by X-ray diffraction analysis. Unlike known caryophyllene derivatives isolated so far, the stereochemistry of the ring juncture is cis (1S,9S) form. The absolute configurations of five chiral centers of this compound are 1S,2S,3R,6R, and 9S, and the geometry of endocyclic double bond is E mode. This is the first example of a cis-fused 1S,9S-caryophyllane sesquiterpenoids confirmed by X-ray structure determination. Crystal data and the final R factor are: Mr=491.36, orthorhombic, space group P212121, a=10.650(2), b=20.650(6), c=10.526(2) A, U=2315(1) A3, Z=4, Dc=1.410 Mg m−3, μ=1.791 mm−1, R=0.084 for 1666 observed unique reflections.

Photooxidation of thiiranoradialene sulfoxide afforded a new thiirene sulfoxide fused with an endoperoxide ring, which gave the [2+4]cycloadduct with furan.

The crystal and molecular structure of the title compounds, [CoIIICl(tpp)(H2O)], has been determined by means of X-ray diffraction techniques. The compound crystallizes in the monoclinic system; space group P21⁄c. The unit cell has a=13.542(2), b=25.760(2), c=10.423(1) A, β=99.33(2)°, and Z=4. The cobalt atom is coordinated by four porphyrinato nitrogen atoms, one chlorine atom, and one oxygen atom of water, and is displaced by 0.039(2) A from the mean plane defined by the four porphyrinato nitrogen atoms towards the axial chlorine atom. The average Co–N(tpp) distance is 1.955(2) A. The Co–Cl distance is 2.216(1), and the Co–O(water) distance, 1.979(3) A. The porphyrinato core is significantly ruffled and has an approximate \bar4 symmetry. The [CoIIICl(tpp)(H2O)] molecules are stacked along the c axis by O–H···Cl hydrogen bonds.

The Wittig-type reactions of N-sulfinyl-p-toluenesulfonamide with (1) O=C–, (2) C=C–, and (3) N=C-conjugated phosphorus ylides were investigated. In the reaction with (1), N-sulfinyl-p-toluenesulfonamide reacted at both the ylide and the carbonyl moiety to form TsN=C-conjugated thione S-imide, which underwent intramolecular 1,3-dipolar cycloaddition of the CSN group with the aromatic C=C bond of the tosyl group giving a structurally unique spiro-fused tricyclic adduct. The structure of the adduct was determined by means of X-ray diffraction. In the reactions with (2) and (3), 1-azadiene and sulfobetaines were obtained instead of the expected conjugated thione S-imides.

A series of copper(II) complexes of (S)-3-aminohexahydroazepine (abbreviated as S-ahaz) were prepared. The molecular structure of bromobis[(S)-3-aminohexahydroazepine]copper(II) perchlorate, [CuBr(S-ahaz)2]ClO4, was determined using single-crystal X-ray diffraction method. The complex crystallizes is space group P212121 with a=13.449(6), b=17.411(11), c=7.937(2) A, and Z=4. The structure was solved by the direct method and refined by the least squares to R value of 0.068 for 1853 unique reflections. The Cu2+ ion has the square-pyramidal five-coordination geometry with four nitrogen atoms as basal donors and a bromide as an apical donor. The structures of other copper(II) complexes of S-ahaz were assigned on the basis of the above X-ray analysis result, together with electronic spectral and conductivity measurements. The complexes having the formula Cu(S-ahaz)2X(ClO4) (X−=CI−, I−, NCS−, ONO−) were assigned to have square-pyramidal five-coordinated structures. The S-ahaz complexes Cu(S-ahaz)2X2 (X−=Cl−, Br−...

It is well known that naturally occurring caryophyllane sesquiterpenoids possess in general 1R,9S(trans)-ring juncture. However, it has been clarified that both of naematolin and naematolin B, microbial products, have 1S,9S(cis)-ring juncture in the caryophyllane skeleton.