Triterpene Saponins from Four Species of the Polygalaceae Family

Twelve triterpene saponins were isolated by successive MPLC over silica gel from four species of Polygalaceae: From Polygala ruwenzoriensis, five new saponins 1 – 5 of which 1 – 4 as two pairs of (E)/(Z)‐isomers, together with the four known compounds tenuifoline, (E)‐ and (Z)‐senegasaponin b, (E)‐ and (Z)‐senegin II, and polygalasaponin XXVIII, from the genus Carpolobia, one new saponin 6 from C. alba and the known arilloside ( 11 ) from C. lutea, and another new triterpene glycoside 7 from Polygala arenaria. Their structures were established mainly by 600‐MHz 2D‐NMR techniques (¹H,¹H‐COSY, TOCSY, NOESY, HSQC, HMBC) as 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐α‐L ‐arabinopyranosyl‐(1 → 4)‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐O‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐4‐O‐[(E)‐4‐methoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 1 ) and its (Z)‐isomer 2 , 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐α‐L ‐arabinopyranosyl‐(1 → 4)‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐O‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 3 ) and its (Z)‐isomer 4 , 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐[O‐β‐D ‐galactopyranosyl‐(1 → 4)‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐O‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐fucopyranosyl] ester ( 5 ), 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐O‐[β‐D ‐galactopyranosyl‐(1 → 4)]‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐O‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐O‐[β‐D ‐apiofuranosyl‐(1 → 3)]‐4‐O‐acetyl‐β‐D ‐fucopyranosyl} ester ( 6 ), and 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐β‐D ‐galactopyranosyl‐(1 → 4)‐O‐[β‐D ‐glucopyranosyl‐(1 → 3)]‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐O‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐fucopyranosyl} ester ( 7 ) (presenegenin = (2β,3β,4α)‐2,3,27‐trihydroxyolean‐12‐ene‐23,28‐dioic acid).     

K2[Mo2O4(C2O4)2(H2O)2]·3H2O

The crystal and molecular structure of dipotassium di‐μ‐oxo‐bis[aqua(oxalato‐O¹,O²)oxomolybdenum(III)] trihydrate, K₂­[Mo₂O₄(C₂O₄)₂(H₂O)₂]·3H₂O, has been determined from X‐ray diffraction data. In the dimeric anion, which has approximate twofold symmetry, each Mo atom is in a distorted octahedral coordination, being bonded to one terminal oxo‐O atom, two bridging O atoms, two O atoms from the oxalato ligand and one from the water mol­ecule. Bond lengths trans to the multiple‐bonded terminal oxo ligand are larger than those in the cis position, confirming the trans influence as a generally valid rule.     

A novel two‐dimensional layered framework built of strontium(II) with 4‐nitrobenzene‐1,3‐dicarboxylic acid

In poly[[aquastrontium(II)]‐μ₆‐4‐nitrobenzene‐1,3‐dicarboxylato‐κ⁷O¹:O²:O²:O³:O³,O⁴:O⁴], [Sr(C₈H₃NO₆)(H₂O)]_n, the Sr^II ion displays a distorted bicapped triangular prismatic configuration, defined by seven carboxyl O atoms from six symmetry‐related ligands and one water molecule. The ligand molecules connect the Sr^II ions into a two‐dimensional layered framework in the ac plane, with close O...O contacts between the nitro groups and with each nitro group providing one acceptor O atom for a weak intermolecular C—H...O hydrogen bond.     

Thermal Studies of Copper(II) Squarate Complexes of Diamines in the Solid State

CuL₂C₄O₄ [L=ethane-1,2-diamine (en)], CuL₂C₄O₄⋅2H₂O [L=N-methylethane-1,2-diamine (meen), N-ethylethane-1,2-diamine (eten),N-propylethane-1,2-diamine (pren), N-methyl-N’-ethylethane- 1,2-diamine (meeten) andpropane-1,2-diamine (pn)], CuL₂C₄O₄⋅0.5H₂O [L=N,N’-dimethylethane- 1,2-diamine (dmeen)], CuL₂C₄O₄⋅4H₂O [L=propane-1,2-diamine (pn)]and CuL₂C₄O₄⋅H₂O[L=2-methylpropane-1,2-diamine (ibn)] have been synthesized by the addition of respective diamine to finely powdered CuC₄O₄⋅2H₂O and their thermal studies have been carried out in the solid state. Cu(en)₂C₄O₄ upon heating loses one molecule of diamine with shar pcolour change yielding Cu(en)C₄O₄ which upon further heating transforms to unidentified products. All aquated-bis-diamine species [CuL₂C₄O₄⋅2H₂O, CuL₂C₄O₄⋅0.5H₂O and CuL₂C₄O₄⋅H₂O] upon heating undergo deaquation–anation reaction in the solid state showing thermochromism and transform to CuL₂C⁴O₄, which revert on exposure to humid atmosphere (RH ∼90%). All the squarato bis-diamine species, CuL₂C₄O₄, on further heating transform to unidentified products through the formation of CuLC₄O₄ as intermediates. The mono diamine species, have been isolated pyrolytically in the solid state and can be stored in a desiccator as well as in open atmosphere. They are proposed to be polymeric. This revised version was published online in August 2006 with corrections to the Cover Date.     

Triterpenoid Saponins from Schefflera arboricola

Four new triterpenoid saponins, named scheffarboside A – D ( 1 – 4 ), along with five known saponins were isolated from the stems of Schefflera arboricola. The structures of the four new saponins were determined as 3‐O‐(O‐β‐glucuronopyranosyl‐(1 → 3)‐O‐α‐rhamnopyranosyl‐(1 → 2)‐α‐arabinopyranosyl)oleanolic acid ( 1 ), 3‐O‐(O‐α‐arabinopyranosyl‐(1 → 4)‐O‐α‐arabinopyranosyl‐(1 → 3)‐O‐α‐rhamnopyranosyl‐(1 → 2)‐α‐arabinopyranosyl)oleanolic acid ( 2 ), 3‐O‐(O‐α‐arabinopyranosyl‐(1 → 4)‐O‐α‐arabinopyranosyl‐(1 → 3)‐O‐α‐rhamnopyranosyl‐(1 → 2)‐α‐arabinopyranosyl)hederagenin ( 3 ), 3‐O‐(O‐α‐arabinopyranosyl‐(1 → 4)‐O‐α‐arabinopyranosyl‐(1 → 3)‐O‐α‐rhamnopyranosyl‐(1 → 2)‐α‐arabinopyranosyl)oleanolic acid O‐α‐rhamnopyranosyl‐(1 → 4)‐O‐β‐glucopyranosyl‐(1 → 6)‐β‐glucopyranosylester ( 4 ), respectively, on the basis of spectroscopic and chemical degradation methods.     

Mechanochemical Synthesis and Characterization of Alkaline Earth Metal Terephthalates: M(C8H4O4)·nH2O (M = Ca,Sr, Ba)

The mechanochemical synthesis offers an easy access to obtain alkaline earth metal terephthalates M(C₈H₄O₄) · nH₂O (M = Ca, Sr, Ba). In the presented study we describe for the first time the mechanochemical synthesis of powders of Ca(C₈H₄O₄) · 3H₂O, Ca(C₈H₄O₄), Sr(C₈H₄O₄) · H₂O, and Ba(C₈H₄O₄), which so far were only synthesized as single crystals from aqueous solutions or by reactions in an autoclave. Furthermore, a new hydrate Ba(C₈H₄O₄) · 2(1.5)H₂O, not described so far in the literature, was prepared. All compounds were characterized by X‐ray powder diffraction, thermal analysis, elemental analysis, FT‐IR, and MAS NMR spectroscopic measurements.     

Conformational Control of Organocatalyst in Strongly Brønsted-Acidic Metal-Organic Frameworks for Enantioselective Catalysis

Chiral imidodiphosphates (IDPs) have emerged as strong Brønsted acid catalysts for many enantioselective processes. However, the dynamic transformation between O,O-syn and O,O-anti conformers typically results in low enantioselectivity. Here we demonstrate that topologies of metal-organic frameworks (MOFs) can be exploited to control IDP conformations and local chiral microenvironments for enantioselective catalysis. Two porous Dy-MOFs with different topologies are obtained from an enantiopure 1,1′-biphenol IDP-based tetracarboxylate ligand. While the ligand adopts a 4- or 3-connected (c) binding mode, all IDPs are rigidified to get only a single O,O-syn conformation and display greatly enhanced Brønsted acidity relative to the free IDP. The MOF with the 4-c IDP that has a relatively less compact shape than the 3-c IDP can be an efficient and recyclable heterogeneous Brønsted acid catalysing the challenging asymmetric O,O-acetalization reaction with up to 96 % enantiomeric excess.     

Structural diversity of polynuclear MgxOy cores in magnesium phenoxide complexes

The binuclear complex bis(2,6‐di‐tert‐butyl‐4‐methylphenolato)‐1κO ,2κO‐(1,2‐dimethoxyethane‐1κ²O ,O ′)bis(μ‐phenylmethanolato‐1:2κ²O :O )(tetrahydrofuran‐2κO )dimagnesium(II), [Mg₂(C₇H₇O)₂(C₁₅H₂₃O)₂(C₄H₈O)(C₄H₁₀O₂)] or [(BHT)(DME)Mg(μ‐OBn)₂Mg(THF)(BHT)], (I), was obtained from the complex [(BHT)Mg(μ‐OBn)(THF)]₂ by substitution of one tetrahydrofuran (THF) molecule with 1,2‐dimethoxyethane (DME) in toluene (BHT is O‐2,6‐^t Bu₂‐4‐MeC₆H₄ and Bn is benzyl). The trinuclear complex bis(2,6‐di‐tert‐butyl‐4‐methylphenolato)‐1κO ,3κO‐tetrakis(μ‐2‐methylphenolato)‐1:2κ⁴O :O ;2:3κ⁴O :O‐bis(tetrahydrofuran)‐1κO ,3κO‐trimagnesium(II), [Mg₃(C₇H₇O)₄(C₁₅H₂₃O)₂(C₄H₈O)₂] or [(BHT)₂(μ‐O‐2‐MeC₆H₄)₄(THF)₂Mg₃], (II), was formed from a mixture of Bu₂Mg, [(BHT)Mg(ⁿ Bu)(THF)₂] and 2‐methylphenol. An unusual tetranuclear complex, bis(μ₃‐2‐aminoethanolato‐κ⁴O :O :O ,N )tetrakis(μ₂‐2‐aminoethanolato‐κ³O :O ,N )bis(2,6‐di‐tert‐butyl‐4‐methylphenolato‐κO )tetramagnesium(II), [Mg₄(C₂H₆NO)₆(C₁₅H₂₃O)₂] or Mg₄(BHT)₂(OCH₂CH₂NH₂)₆, (III), resulted from the reaction between (BHT)₂Mg(THF)₂ and 2‐aminoethanol. A polymerization test demonstrated the ability of (III) to catalyse the ring‐opening polymerization of ϵ‐caprolactone without activation by alcohol. In all three complexes (I)–(III), the BHT ligand demonstrates the terminal κO‐coordination mode. Complexes (I), (II) and (III) have binuclear rhomboid Mg₂O₂, trinuclear chain‐like Mg₃O₄ and bicubic Mg₄O₆ cores, respectively. A survey of the literature on known polynuclear Mg_x O_y core types for ArO–Mg complexes is also presented.     

The structures of the isomorphous potassium and rubidium salts of 4‐nitrobenzoic acid and an overview of the metal complex stereochemistries of the alkali metal salt series with this ligand

4‐Nitrobenzoic acid (PNBA) has proved to be a useful ligand for the preparation of metal complexes but the known structures of the alkali metal salts of PNBA do not include the rubidium salt. The structures of the isomorphous potassium and rubidium polymeric coordination complexes with PNBA, namely poly[μ₂‐aqua‐aqua‐μ₃‐(4‐nitrobenzoato)‐potassium], [K(C₇H₄N₂O₂)(H₂O)₂]_n, (I), and poly[μ₃‐aqua‐aqua‐μ₅‐(4‐nitrobenzoato)‐rubidium], [Rb(C₇H₄N₂O₂)(H₂O)₂]_n, (II), have been determined. In (I), the very distorted KO₆ coordination sphere about the K⁺ centres in the repeat unit comprise two bridging nitro O‐atom donors, a single bridging carboxylate O‐atom donor and two water molecules, one of which is bridging. In Rb complex (II), the same basic MO₆ coordination is found in the repeat unit, but it is expanded to RbO₉ through a slight increase in the accepted Rb—O bond‐length range and includes an additional Rb—O_carboxylate bond, completing a bidentate O,O′‐chelate interaction, and additional bridging Rb—O_nitro and Rb—O_water bonds. The comparative K—O and Rb—O bond‐length ranges are 2.7352 (14)–3.0051 (14) and 2.884 (2)–3.182 (2) Å, respectively. The structure of (II) is also isomorphous, as well as isostructural, with the known structure of the nine‐coordinate caesium 4‐nitrobenzoate analogue, (III), in which the Cs—O bond‐length range is 3.047 (4)–3.338 (4) Å. In all three complexes, common basic polymeric extensions are found, including two different centrosymmetric bridging interactions through both water and nitro groups, as well as extensions along c through the para‐related carboxylate group, giving a two‐dimensional structure in (I). In (II) and (III), three‐dimensional structures are generated through additional bridges involving the nitro and water O atoms. In all three structures, the two water molecules are involved in similar intra‐polymer O—H...O hydrogen‐bonding interactions to both carboxylate and water O‐atom acceptors. A comparison of the varied coordination behaviour of the full set of Li–Cs salts with 4‐nitrobenzoic acid is also made.     

(Solid+Liquid) Equilibria in the Quaternary System Na2B4O7-MgB4O7-K2B4O7-H2O at 288 K

(Solid+Liquid) phase equilibria in the quaternary system Na₂B₄O₇‐MgB₄O₇‐K₂B₄O₇‐H₂O at 288 K were studied experimentally using the method of isothermal solution saturation. Solubility of any single salt in the solution of the quaternary system was determined experimentally. Based on the experimental data achieved, the phase diagram and water content diagram of the quaternary system were constructed, respectively. In the phase equilibrium diagram of the quaternary system Na₂B₄O₇‐MgB₄O₇‐K₂B₄O₇‐H₂O at 288 K, there are one invariant point E, three univariant curves E1E, E2E and E3E, and three fields of crystallization corresponding to Na₂B₄O₇·10H₂O, K₂B₄O₇·4H₂O and MgB₄O₇·9H₂O. The experimental results show that potassium borate (K₂B₄O₇·4H₂O) have higher solubilities than the magnesium borate and sodium borate in the quaternary system Na₂B₄O₇‐MgB₄O₇‐K₂B₄O₇‐H₂O at 288 K.     

Comparison of two polymeric transition metal complexes with 1,4‐benzenedicarboxylate ions as bridging ligands, [Co(C8H4O4)(C12H8N2)(H2O)] and [Cu(C8H4O4)(C10H9N3)]·H2O

The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ²N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₈N₂)(H₂O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ⁴O¹,O^1′:O⁴,O^4′] hydrate], [Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The Co^II ion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The Cu^II ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O—Cu—O bonds and with a trans O—Cu—O angle of only 137.22 (8)°.     

A novel Na–O–Ni–O–Ni bridging complex of Cl‐HXTA,where Cl‐HXTA is 2,6‐bis{[bis­(carboxyl­ato­methyl)­amino]­methyl}‐4‐chloro­phenolate

In the structure of the title compound, hepta­aqua‐1κ³O,2κ²O,3κ²O‐(μ₃‐2,6‐bis{[bis­(carboxyl­ato­methyl)­amino]methyl}‐4‐chloro­phenolato‐1κO;2κ⁴O,O′,N,O¹;3κ⁴O¹N′,O′′,O′′′)dinickel(II)­sodium(I) pentahydrate, [NaNi₂(C₁₆H₁₄ClN₂O₉)(H₂O)₇]·5H₂O or [Ni₂(Cl‐HXTA)(H₂O)₄{Na(H₂O)₃}]·5H₂O, the trinuclear complex unit consists of two distorted NiNO₅ octahedra bridged by a phenolate O atom and an NaO₄ tetrahedron bridged to one of the Ni octahedra by a carboxylate O atom. There are four intramolecular hydrogen bonds forming four six‐membered rings in the complex and the complex mol­ecules are connected to each other by a very complicated hydrogen‐bond network.     

Adsorption properties of crystalline silicas: (II) Adsorption of anionic surfactants and delamination

Lamellar crystalline silicas (crystalline silicic acids, chemical composition SiO₂·xH₂O; examples: H₄Si₁₄O₃₀·xH₂O, H₄Si₂₀O₄₂·xH₂O) are distinguished from the amorphous forms by their layered structure and exceptional adsorption properties. One outstanding example is the reaction with anionic surfactants. Several types of crystalline silicas (typical H₄Si₂₀O₄₂·xH₂O) can intercalate ionic pairs consisting of surfactant anion and gegen ion into the interlayer space. The saturation value of SDS adsorption is 0.475 mmol SDS/g H₄Si₂₀O₄₂·3H₂O. The acid H₄Si₁₄O₃₀·xH₂O adsorbs anionic surfactants at the external surfaces only (saturation value 0.04 mmol/g H₄Si₁₄O₃₀·0.8 H₂O). When anionic surfactants are adsorbed in the interlayer space, the layer separation increases to such an extent that the crystals disarticulate in a fan-like manner or delaminate into thinner packets of layers or smaller aggregates. Washing-out the SDS ionic pairs or drying reconstitutes the parallel layer orientation and leads to re-aggregation of the packets and fragments.     

The structure of {[Co(pht)(bpy)(H2O)]·3H2O}n (pht is phthalate and bpy is 4,4′‐bipyridine) and the role of solvent water clusters in structure stability

The Co^II cation in poly[[aqua(μ‐benzene‐1,2‐dicarboxylato‐κ³O¹,O²:O¹)(μ‐4,4′‐bipyridine‐κ²N:N′)cobalt(II)] trihydrate], {[Co(C₈H₄O₄)(C₁₀H₈N₂)(H₂O)]·3H₂O}_n, is octahedrally coordinated by two N atoms of two 4,4′‐bipyridine ligands, three O atoms from phthalate anions and a fourth O atom from a coordinated water molecule. The packing consists of planes of coordination polymers linked by hydrogen bonds mediated by three solvent water molecules; the linkage is achieved by the water molecules forming intricate oligomeric clusters which also involve the O atoms of the phthalate ligands.     

A new two‐dimensional cadmium coordination polymer with 1H‐imidazole‐4‐carboxylate and oxalate

The title compound, poly[aqua(μ₂‐1H‐imidazole‐4‐carboxylato‐κ³N³,O:O′)hemi(μ₂‐oxalato‐κ⁴O¹,O²:O^1′,O^2′)cadmium(II)], [Cd(C₄H₃N₂O₂)(C₂O₄)_0.5(H₂O)]_n, exhibits a two‐dimensional network. The Cd^II cation is coordinated to one N atom and two carboxylate O atoms from two 1H‐imidazole‐4‐carboxylate (Himc) ligands, two carboxylate O atoms from the bridging oxalate anion and one ligated water molecule; these six donor atoms form a distorted octahedral configuration. The oxalate anion lies on a centre of inversion. The Himc ligands connect the Cd^II cations to form –Cd–Himc–Cd–Himc–Cd– zigzag chains, with a Cd...Cd separation of 5.8206 (6) Å along the b direction, which are further linked by tetradentate oxalate anions to generate a two‐dimensional herringbone architecture in the ab plane. These layers are extended to form a three‐dimensional supramolecular framework via O—H...O and N—H...O hydrogen bonds and π–π stacking interactions. The solid‐state photoluminscent behaviour of the title compound has been investigated at room temperature.     

3‐O‐Methylquercetin Glucosides from Ophioglossum pedunculosum and Inhibition of Lipopolysaccharide‐Induced Nitric Oxide Production in RAW 264.7 Macrophages

The three new 3‐O‐methylquercetin glucosides 1 – 3 , together with three known congeners and 3‐O‐methylquercetin, were isolated from the fern Ophioglossum pedunculosum (quercetin=2‐(3,4‐dihydroxyphenyl)‐3,5,7‐trihydroxy‐4H‐1‐benzopyran‐4‐one). The new compounds were identified on the basis of spectroscopic analysis as 5′‐isoprenyl‐3‐O‐methylquercetin 4′,7‐di‐β‐D ‐glucopyranoside ( 1 ), 3‐O‐methylquercetin 4′‐β‐D ‐glucopyranoside 7‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside] ( 2 ), and 3‐O‐methylquercetin 7‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside] ( 3 ). The effect of the isolated compounds on lipopolysaccharide (LPS)‐induced NO production was evaluated. The inhibitory activity of 3‐O‐methylquercetin derivatives decreased markedly with the increasing number of glucosyl groups in the structures.     

Poly[hexaaquabis(μ4‐4‐carboxybenzenesulfonato)bis(μ3‐4‐carboxybenzenesulfonato)calcium(II)dipotassium(I)]

This study presents the coordination modes and crystal organization of a calcium–potassium coordination polymer, poly[hexaaquabis(μ₄‐4‐carboxybenzenesulfonato‐κ⁴O¹:O^1′:O^1′′:O⁴)bis(μ₃‐4‐carboxybenzenesulfonato‐κ²O¹:O^1′)calcium(II)dipotassium(I)], [CaK₂(C₇H₅O₅S)₄(H₂O)₆]_n, displaying a novel two‐dimensional framework. The potassium ion is seven‐coordinated by four sulfonate and one carboxyl O atom located on five different acid ligands, two of which are unique, and by two symmetry‐independent water O atoms. A pair of close potassium ions share two inversion‐related sulfonate O‐atom sites to form a dimeric K₂O₁₂ unit, which is extended into a one‐dimensional array along the a‐axis direction. The six‐coordinate Ca²⁺ ion occupies a special position () at (0, , ) and is surrounded by four sulfonate O atoms from two inversion‐related pairs of unique acid monoanions and by two O atoms from aqua ligands. The compound displays a layered structure, with K₂O₁₂ and CaO₆ polyhedra in the layers and aromatic linkers between the layers. The three‐dimensional scaffold is open, with nano‐sized channels along the c axis.     

Lanthankomplexe mit 2,2′-Bipyridin-N,N′-dioxid

Compounds of the composition La(bpyO₂ ^*)₄Cl₃·4H₂O, La(bpyO₂)₃Cl₃·5H₂O, La(bpyO₂)₂Cl₃·3H₂O, La(bpyO₂)Cl₃·3H₂O, La(bpyO₂)₄Br₃·4H₂O, La(bpyO₂)₃Br₃·8H₂O, La(bpyO₂)₂Br₃·7H₂O, La(bpyO₂)Br₃·4H₂O, La(bpyO₂)₄I₃·3H₂O, La(bpyO₂)₃(NO₃)₃·2H₂O, La(bpyO₂)₂(NO₃)₃·2H₂O, La(bpyO₂)₄(SCN)₃·3H₂O, La(bpyO₂)₃(SCN)₃·2H₂O, La(bpyO₂)₂(SCN)₃·2H₂O were isolated. They were investigated by means of thermoanalysis, I.R. spectroscopy, X-ray diffraction and molar conductivity.     

A ternary complex of aqua(18‐crown‐6)bis(o‐nitrophenolato)barium(II), the triaqua(18‐crown‐6)(o‐nitrophenolato)barium(II) cation and the o‐nitrophenolate anion

In the title compound [systematic name: tri­aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)(2‐nitro­phenolato‐κO)­barium(II)–aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)‐ bis(2‐nitro­phenolato‐κ²O,O′)­barium(II)–2‐nitro­phenolate (1/1/1)], [Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)(H₂O)₃][Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)₂(H₂O)](C₆H₄NO₃), the two Ba^II atoms encapsulated by the 18‐crown‐6 rings have different coordinations. Although both Ba^II atoms are coordinated to the six O atoms of the crowns, in the neutral moiety, the Ba^II atom is coordinated to one terminal O atom from a water mol­ecule, two phenolate O atoms and two nitro‐group O atoms, while in the cationic moiety, the Ba^II atom is coordinated to three terminal O atoms from water mol­ecules and one phenolate O atom. Both the crowns are eclipsed and translated along the b direction. In the asymmetric unit, the three components are interconnected by four O—H?O interactions. The packing is stabilized by two intermolecular C—H?O interactions and by one O—H?O interaction.     

CdII and CoII coordination polymers constructed from benzene‐1,4‐dicarboxylic acid and 2‐(pyridin‐3‐yl)‐1H‐benzimidazole ligands

In poly[aqua(μ₃‐benzene‐1,4‐dicarboxylato‐κ⁵O¹,O^1′:O¹:O⁴,O^4′)[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cadmium(II)], [Cd(C₈H₄O₄)(C₁₂H₉N₃)(H₂O)]_n, (I), each Cd^II ion is seven‐coordinated by the pyridine N atom from a 2‐(pyridin‐3‐yl)benzimidazole (3‐PyBIm) ligand, five O atoms from three benzene‐1,4‐dicarboxylate (1,4‐bdc) ligands and one O atom from a coordinated water molecule. The complex forms an extended two‐dimensional carboxylate layer structure, which is further extended into a three‐dimensional network by hydrogen‐bonding interactions. In catena‐poly[[diaquabis[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cobalt(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₉N₃)₂(H₂O)₂]_n, (II), each Co^II ion is six‐coordinated by two pyridine N atoms from two 3‐PyBIm ligands, two O atoms from two 1,4‐bdc ligands and two O atoms from two coordinated water molecules. The complex forms a one‐dimensional chain‐like coordination polymer and is further assembled by hydrogen‐bonding interactions to form a three‐dimensional network.