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The enantioselective oxidation synthesis of chiral modafinil acid and its analogues with high enantiomeric excess has been developed by means of a chiral-at-metal strategy. Treatment of ruthenium complexes cis-[Ru(bpy)2Cl2] or Δ/Λ-[Ru(bpy)2(MeCN)2](PF6)2 (bpy is 2,2′-bipyridine) with the appropriate prochiral thioether ligands afforded thioether complexes rac-1, Δ/Λ-1, rac-2, Δ/Λ-2, rac-3, and Δ/Λ-3. Diastereoselective oxidation of the thioether complexes in situ produced the corresponding sulfoxide complexes rac-1a, Δ/Λ-1a, rac-2a, Δ/Λ-2a, rac-3a, and Δ/Λ-3a. The configuration at the metal center in each case is stable during the coordination and oxidation reactions, and dictates the chirality of the sulfoxide ligand in the oxidation process. The chiral modafinil acids were obtained with ee values greater than 98 % upon their removal from the corresponding sulfoxide complexes in the presence of TFA/MeCN. Moreover, the chiral ruthenium precursors Δ/Λ-[Ru(bpy)2(MeCN)2](PF6)2 are recyclable and reusable with complete retention of the configurations.

Treatment of cis-[Ru(bpy)2Cl2]⋅2 H2O or Δ/Λ-[Ru(bpy)2(py)2]2+ (bpy=2,2′-bipyridine, py=pyridine) with the prochiral thioether ligands 2-alkylthiobenzoic acid (HOSR) produces the corresponding thioether complexes rac-[Ru(bpy)2(OSR)](PF6) (R=Me (rac-1), iPr (rac-2), 2-benzylthiobenzonate (Bn) (rac-3)) and Δ/Λ-[Ru(bpy)2(OSR)](PF6) (R=Me (Δ-1/Λ-1), iPr (Δ-2/Λ-2), Bn (Δ-3/Λ-3)) with retention of the configurations at chiral metal centers. In situ oxidation of the thioether complexes by meta-chloroperoxybenzoic acid provides the corresponding sulfoxide complexes rac-[Ru(bpy)2(OSOR)](PF6) (OSOR is 2-alkylsulfinylbenzonate, R=Me (rac-1 a), iPr (rac-2 a), Bn (rac-3 a)), Δ-[Ru(bpy)2{(R)-OSOR}](PF6) (R=Me (Δ-1 a), iPr (Δ-2 a), Bn (Δ-3 a)), and Λ-[Ru(bpy)2{(S)-OSOR}](PF6) (R=Me (Λ-1 a), iPr (Λ-2 a), Bn (Λ-3 a)) in yields of 95 % with 98 % ee values. The absolute configurations at the metal centers and sulfur atoms were determined by means of X-ray crystallography. The results indicate that the configurations of the metal centers are retained and have the function of controlling sulfoxide chirality during the oxidation process. The Δ metal-centered configuration enantioselectively generates an R-configuration sulfoxide, and the Λ configuration enantioselectively forms an S-configuration sulfoxide in the course of the in situ oxidation reaction, thereby resulting in a predetermined chirality of the sulfoxide ligands. The predetermined chirality of sulfoxides (S)-HOSOR and (R)-HOSOR were obtained by the treatments of the corresponding sulfoxide complexes Δ-[Ru(bpy)2{(R)-OSOR}](PF6) and Λ-[Ru(bpy)2{(S)-OSOR}](PF6) with trifluoroacetic acid in yields of 90 % with 83.5–92.9 % ee values.

The complexes [Pd(phen)(aa)]Cl·3H2O, where phen is 1,10-phenanthroline and as is the anion of glycine (gly), DL-alanine (ala), DL-serine (ser) or DL-asparagine (asn), were synthesized and characterized by spectroscopies. The NMR signals were assigned completely on the basis of the double irradiation, 1H-1 H COSY and 1H-13C COSY techniques. In the 1H NMR spectra of phen in the complexes, the signals of 2-H and 9-H show upfield shifts 0.8–1 ppm, while the signals of 4-H and 3-H show downfield shifts or almost no shift, as compared to the free phen ligand, and the signal of 4-H appears in the lowest field. The signals of ring B which is trans to the carboxyl group show significant upfield shirts as compared to those of ring A. The probable structures were described on the basis of a metal-non-bonded hydrogen interaction, trans effect and ligand-ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl·3H2O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas in the α-CH part of the spectra.

Two manganese(II) coordination polymers, [Mn2(bpt)(pa)2(N3)]n [1; Hpa = picolinic acid, Hbpt = 3,5-bis(2-pyridyl)-4H1,2,4-triazole] and [Mn3(ina)2(pa)2(N3)2]n (2; Hina = isonicotinic acid), have been synthesized by solvothermal treatment, in which the ligands bpt and pa were generated in situ by cyclocondensation and hydrolysis of 2-pyridylamidrazone, respectively. In 1, each binuclear subunit [Mn2(bpt)(N3)] bridged by bpt and N3 – ligands is interlinked to four adjacent subunits via four tridentate pa ligands into a diamondoid 3D network, which shows spin-canting magnetism arising from

The new complex [Cd2(bpa)2Cl4]·6 H2O [bpa = N,N'-bis(picolinamide)azine] has been synthesized in which each bpa ligand is twisted into a spiral-like conformation and the two CdII ions are ligated by two bpa ligands to form a double-stranded binuclear helicate. Unprecedented water chains featuring cyclic water tetramers composed of three independent water molecules are trapped by [Cd2(bpa)2Cl4] double helicates by hydrogen bonds. The binuclear chiral helicates are interlinked into homochiral layers by hydrogen bonds with the water tapes. The layers are alternately stacked in a heterochiral fashion to yield the final racemic structure. The complex shows an endotherm at 65.7 °C in the DSC due to loss of water molecules, giving an enthalpy value of 47 kJ mol–1 per water molecule. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Two new coordination polymers [Cd(tdc)(bpy)(H2O)]n (1) and [Cd(tdc)(phen)]n (2) (H2tdc = thiophene-2,5-dicarboxylic acid, bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline) have been synthesized under hydrothermal condition. Their crystal structures have been established by X-ray single-crystal diffraction. Complex 1 crystallizes in the orthorhombic space group Fdd2 with a = 14.757(7), b = 45.38(2), c = 10.518(5) A, V = 7044(6) A3, Z = 16; 2 in the monoclinic space group P21/c with a = 7.262(1), b = 21.970(2), c = 10.051(1) A, β = 105.01(1)°, V = 1548.8(2) A3, Z = 4. Both of them are double-stranded chains and further assembled into three-dimensional networks by π-π stacking interactions. 1 and 2 are stable in air, and show blue photoluminescence at 415 nm and 410 nm, respectively.

A new one-dimensionally neutral coordination polymer, namely {[Pb(phen)2(ox)]·5H20}n (phen = 1, 10-phenanthroline, ox = oxalate) (1), has been synthesized under hydrothermal condition and characterized by X-ray crystallography. Complex 1 crystallizes in the orthorhombic space group Pban (No. 50) with a = 19.358(2), b = 6.8135(6), c = 9.7015(8)A, V = 1279.6(2)A3, and Z = 2. Each Pb(II) atom is eight-coordinated in a square-antiprismatic D4d geometry by four nitrogen atoms from two phen groups and four oxygen atoms from two ox ligands. The polymeric chains further constructed into a three-dimensional network via strong π—π stacking interactions and hydrogen bonds. The complex exhibits intense blue photoluminescence with an emission maximum at 403 nm at room temperature. Hydrothermale Synthese und Kristallstruktur eines neuen polymeren oxalatverbruckten Blei(II)-Komplexes {[Pb(phen)2(ox)]·5H20}n (phen = 1, 10-Phenanthrolin, ox = Oxalat) Eine neue eindimensional-polymere, neutrale Koordinationsverbindung, {[Pb(phen)2(ox)]·5H20}n (phen = 1, 10-Phenanthrolin, ox = Oxalat) (1), wurde unter hydrothermalen Bedingungen synthetisiert und durch Rontgen-Kristallstrukturanalyse charakterisiert. 1 kristallisiert orthorhombisch, Raumgruppe Pban (No. 50) mit a = 19.358(2), b = 6.8135(6), c = 9.7015(8)A, V = 1279.6(2)A3, Z = 2. Jedes Blei(II)-Atom ist achtfach koordiniert in quadratisch-antiprismatischer D4d-Geometrie von vier Stickstoffatomen der zwei Phen-Gruppen und vier Sauerstoffatomen der zwei Oxalat-Liganden. Die polymeren Ketten bilden durch starke π—π-Wechselwirkungen und Wasserstoffbruckenbindungen ein dreidimensionales Gerust. Der Komplex zeigt intensiv-blaue Photolumineszens mit einem Emissionsmaximum von 403 nm bei Zimmertemperatur.

Two new neutral polymeric layer compounds, [Cu3(bpy)2(Hip)2(ip)2] (1) and [Cu3(phen)2(Hip)2(ip)2] (2) (bpy = 2, 2′-bipyridine, phen = 1, 10-phenanthroline, ip = isophthalate), have been synthesized under hydrothermal conditions and characterized by X-ray crystallography. Complex 1 crystallizes triclinic, P1¯ (No. 2), a = 10.352(5), b = 10.859(6), c = 11.602(6)A, α = 83.25(1), β = 84.71(1), γ = 66.19(1)°, V = 1183.5(11)A3, Z = 1; 2 triclinic, P1¯ (No. 2), a = 10.375(1), b = 10.668(1), c = 11.758(1)A, α = 83.179(2), β = 86.228(2), γ = 71.187(2)°, V = 1222.7(2)A3, Z = 1. The complexes consist of trinuclcear copper units that are bridged via two ip ligands forming zigzag polymeric chains. These chains are further extended into layers via aromatic π-π interactions as well as hydrogen bonds between the free carboxyl groups and carboxylates. Synthese und strukturelle Charakterisierung von zwei neuen 2D-Isophthalatverbruckten Kupfer(II)-Polymeren mit Cu3-Einheiten Zwei neue polymere Schichtverbindungen, [Cu3(bpy)2(Hip)2(ip)2] (1) und [Cu3(phen)2(Hip)2(ip)2] (2) (bpy = 2, 2′-bipyridin, phen = 1, 10-phenanthrolin, ip = isophthalat), wurden unter hydrothermalen Bedingungen synthetisiert und mittels Rontgen-Kristallstrukturanalyse charakterisiert. Complex 1 kristallisiert triklin, P1¯ (No. 2), a = 10.352(5), b = 10.859(6), c = 11.602(6)A, α = 83.25(1), β = 84.71(1), γ = 66.19(1)°, V = 1183.5(11)A3, Z = 1; 2 triklin, P1¯ (No. 2), a = 10.375(1), b = 10.668(1), c = 11.758(1)A, α = 83.179(2), β = 86.228(2), γ = 71.187(2)°, V = 1222.7(2)A3, Z = 1. Die Komplexe bestehen aus dreikernigen Kupfer-Einheiten, die uber zwei ip-Liganden unter Bildung von polymeren zick-zack-Ketten verbruckt sind. Diese Ketten bilden Schichten uber aromatische π-π-Wechselwirkungen und Wasserstoffbruckenbindungen zwischen den freien Carboxyl-Gruppen und Carboxylaten.

A staggered arrangement like that of the hydrogen atoms in ethane is exhibited by the six phenol groups about each pair of silver atoms in the self-assembled three-dimensional coordination networks [Ag(2)(H(2)L)(3)](n)X(2n) (H(2)L=N,N'-bis(salicylidene)-1,4-diaminobutane; X(-)=NO(3)(-) or ClO(4)(-)); the former is depicted (for clarity the H(2)L ligands are represented by long rods and the Ag atoms by hatched circles). These solids contain short ligand-unsupported metal-metal bonds and display intense blue photoluminescence at room temperature.