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The title compound, [Fe(C3H7NO)6][Cd2Cl7], crystallizes in the trigonal space group R3̅ and is assembled from discrete [Fe(DMF)6] 3+ cations (DMF = N,Ndimethylformamide) and [Cd2Cl7] 3- anions. In the cation, the iron(III) atom, located on a special position of 3̅ site symmetry, is coordinated by six oxygen atoms from DMF ligands with all Fe—O distances being equal [2.0072 (16) A˚ ]. A slight distortion of the octahedral environment of the metal comes from the cis O—Fe—O angles deviating from the ideal value of 90 [86.85 (7) and 93.16 (7)] whilst all the trans angles are strictly 180. The central Cl atom of the [Cd2Cl7] 3- anion is also located on a special position of 3̅ site symmetry and bridges two corner sharing, tetrahedrally coordinated CdII atoms. The two Cd atoms and the central Cl atom are colinear. The two sets of terminal chloride ligands on either side of the dumbbell-like anion are rotated relative to each other by 30. In the crystal, the cations and anions, stacked one above the other along the c-axis direction, are held in place principally by electrostatic interactions. There are also C—H...Cl and C—H...O interactions, but these are rather weak. Of the six crystal structures reported to date for ionic salts of [Fe(DMF)6] n+ cations (n = 2, 3), five contain FeII ions. The title compound is the second example of a stable compound containing the [Fe(DMF)6] 3+ cation. The existence of both [Fe(DMF)6] 2+ and [Fe(DMF)6] 3+ cations shows that the DMF ligand coordination sphere can accommodate changes in the charge and spin states of the metal centre. [ABSTRACT FROM AUTHOR]

Four multi-component complexes based on p-sulfonatocalix[4]arene anion, the methyltriphenylphosphonium cation, lanthanide ions (Gd(III)) and different ionic liquid-based cations (1-methyl-3-butylimidazolium, 1-methyl-3-octylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene) were synthesised and structurally characterised. Common bilayer arrangements are formed in the extended structures of all four complexes, though the bilayer thicknesses varies depending on the components involved. Molecular capsule formation is facilitated by the inclusion of methyltriphenylphosphonium, 1-methyl-3-butylimidazolium and 1,4-bis((3-methylimidazolidinyl)methyl)benzene cations, but not in the case of the 1-methyl-3-octylimidazolium cation. Molecular capsule size depends on the nature of the included guest cation, and methyltriphenylphosphonium cations fill compact spaces between calixarenes in these new bilayer arrays. [ABSTRACT FROM AUTHOR]

Structural studies on p-sulfonatocalix[4]arene coordination compounds involving diverse metal ions with respect to their size and charge, caesium(I), copper(II) and neodymium(III) are reported. The metal coordination-driven self-assembly forms metallosupramolecules, either as a two-dimensional (2 D) or a three-dimensional (3D) network while retaining the commonly established bilayer array for p-sulfonatocalix[4]arene. The complex (Cs5-p-sulfonatocalix[4]arene-H+)·6H2O has five crystallographically independent caesium(I) ions with high coordination numbers. In the divalent complex {[Cu3(H2O)12-2(p-sulfonatocalix[4]arene)]2-}·2([Cu(H2O)5])2+·2NO3-·7H2O, two different copper(II) coordination environments are present, one with octahedral stereochemistry while bridging two opposing calixarenes with the other having a square pyramidal geometry involving one sulfonate group. Eight-coordinate neodymium(III) metal ions prevail in Nd0.25(H2O)1.25(p-sulfonatocalix[4]arene + H+)0.25, involving four sulfonate groups from four different calixarenes. [ABSTRACT FROM AUTHOR]

Two multi-component crystal structures comprising a carboxylic acid-functionalized imidazolium zwitterion, a p-sulfonatocalix[4]arene anion and aquated metal ion (Na+ or Y3+) with or without an auxiliary component (the 3-methoxyphenyl-triphenylphosphonium cation) are reported. The carboxylic acid-functionalized imidazolium ion binds either as a monodentate or a bidentate ligand depending on the nature of the metal ions, and a bi-layer arrangement prevails in the extended structure regardless of the type of metal ion employed or presence/lack of auxiliary component. [ABSTRACT FROM AUTHOR]

Adducts of the form Ln(pic)3(tmp)3 (Ln = lanthanide(iii); pic = picrate = 2,4,6-trinitrophenoxide; tmp = trimethylphosphate, (MeO)3PO) have been prepared for extremal Ln = La, Lu and some intermediate members, also Y, and characterised by single crystal X-ray structure determinations as unsolvated, mononuclear, molecular species. The lanthanide atom has nine-coordinate, tri-capped trigonal prismatic stereochemistry in all cases, the picrate components behaving as O , O ′-bidentate ligands chelating through the phenoxy- and an adjacent O -nitro oxygen atom, thus: [Ln(tmp- O)3(pic- O , O ′)3]. Two isomeric forms are found, one mer in which the three unidentate tmp- O ligands coordinate in cis -sites spanning the upper and lower triangles and a capping site of the coordination sphere, and fac , in which all three unidentate ligands occupy the mutually cis -sites of one triangular face. The mer isomer has been described as an isomorphous series in a monoclinic P 21/ c , Z 4, form, for Ln = La, Ce, Pr, Nd, Sm, Gd, Lu, and Y, presumptively accessible for the full gamut of Ln. The fac -isomer also crystallises in a monoclinic P 21/ c form, Z 8, two independent molecules of similar stereochemistry here comprising the asymmetric unit and described for Ln = Eu, Lu(isomorphous); it has also been described in a triclinic P CH19176_IE1.gif , Z 2 form for Ln = La. Trimethylphosphate (tmp) is the first of a series of related O-donor solvates of lanthanide(III) picrates to give isomeric mer- and fac- [Ln(pic)3(tmp)3] complexes. [ABSTRACT FROM AUTHOR]

Single crystal X-ray structure determinations have been executed for several title compounds of the mononuclear form [LMX2], namely [(bpy)ZnX2], X = Cl, Br; [(phen)ZnX2], X = Cl, Br, I (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline). Also reported are the crystal structures of ZnSO4/bpy/H2O (1 : 1 : 5) (≡ [(bpy)Zn(OH2)4](SO4)·H2O) and Zn(NO3)2/bpy/H2O (1 : 1 : 3) (≡ [(bpy)Zn(OH2)3(O NO2)](NO3)). The sulfate complex completes the array [LM(OH2)4]2+, L = bpy, phen, M = Zn, Cd, while the nitrate is the first nitrate example for [LM(OH2)3(O X)](+) (O X = O NO2, O SO3). In all examples of the sulfate and nitrate forms here and previously defined, the metal atoms are six-coordinate, with any anionic donors lying in axial coordination sites (i.e. M–O (quasi-) normal to the LM plane). The structures of [LHg(SCN)2] (L = phen, tpy) (tpy = 2,2′:6′,2′-terpyridine), [(tpy)(CdBr2], and [Zn(tpy)2](NO3)2·2H2O are also recorded. Single crystal X-ray structure determinations have been executed for several mononuclear Zn halide, sulphate, and nitrate complexes with 2,2′-bipyridyl and 1,10-phenanthroline ligands. [ABSTRACT FROM AUTHOR]

Addition of various oxygen-donor ligands (L, all dipolar, aprotic solvents), to a solution of hydrated scandium picrate in weakly coordinating solvents (S), has yielded several crystalline adducts of the form Sc(pic)3(L) m (· n S) in which all ligands L are coordinated, subsequently characterised by a series of single crystal X-ray studies. For L = dmso, m = 3 and the picrate anions are all bound as phenoxide-O donor units, while for nmp, dma, tmp, and hmpa, m = 2 and one of the bound picrates becomes bidentate through phenoxide- and nitro-O donation. For L = ompa, m = 2 and two picrate ligands are bound through phenoxide-O while one is displaced from the primary coordination sphere. All complexes contain six-coordinate ScIII, confirming that this coordination number is a consequence of ligand bulk. Six-coordination of ScIII is observed throughout in crystalline adducts of scandium picrate with dmso, dma, nmp, tmp, hmpa, and ompa, although with variations in the adduct stoichiometry and the coordination mode of picrate. [ABSTRACT FROM AUTHOR]

Single crystal X-ray structural characterisations are reported for adducts of the form [(L- O)Eu(O , O ′-dpm)3] obtained by the crystallisation of tris(dipivaloylmethanato)europium(iii) (dpm = [HC(C(tBu).CO)2]−) from an array of dipolar aprotic oxygen-donor solvents L (L = N -methylpyrrolidinone (nmp), trimethylphosphate, (MeO)3PO, (tmp), hexamethylphosphoramide (hmpa), dimethylacetamide (dma), dimethyl sulfoxide (dmso), and the bidentate octamethylpyrophosphoramide (ompa). In all adducts, the resulting arrays contain seven-coordinate metal atoms, which adopt two different isomeric forms of the mono-capped trigonal prismatic stereochemistry, the L = dma and dmso adducts corresponding to one type, nmp and tmp the other. The adduct formed with ompa behaves as a pair of discrete metal environments bridged by the O -ompa- O ′ ligand, thus; [(dpm- O , O ′)3Eu(O -ompa- O ′)Eu(O , O ′-dpm)3], and is found in two forms, one in which both Eu environments is of the tmp type, the other of the dmso/dma type. In the hmpa adduct, the asymmetric unit of the structure is a disordered composite of both types. In none of the adducts is there any further solvation beyond coordination of a single L. Structural studies of crystalline adducts of [Eu(dipivaloylmethanato)3] with dmso, dma, tmp, hmpa, and ompa have shown all to contain seven-coordinate EuIII. This low coordination number appears to be a consequence of partial coordination sphere interpenetration in the solid state. [ABSTRACT FROM AUTHOR]

Crystalline products of the reactions of lanthanide picrates, Ln(pic)3 (pic = 2,4,6-trinitrophenoxide), with hexamethylphosphoramide (hmpa) and octamethylpyrophosphoramide (ompa) have been characterised by single-crystal X-ray diffraction studies. With hmpa and lighter lanthanides (La, Sm, Eu), isomorphous species (monoclinic, P 21/ c , Z 4) of stoichiometry [Ln(pic)3(hmpa)3]·0.5H2O, have been defined where the molecular units in the lattice contain 9-coordinate Ln with tricapped trigonal-prismatic coordination geometry. The picrate ligands are bidentate through phenoxide-O and 2-nitro-O, with the latter occupying the capping positions, while the hmpa ligands are singly O-bound to one trigonal face. Heavier lanthanides (Gd, Lu) and Y have been found to give isomorphous (monoclinic, P 21/ n , Z 4) species of stoichiometry [Ln(pic)3(hmpa)2], with 8-coordinate Ln of an irregular geometry best considered as close to that of a bicapped trigonal-prism. The picrate ligands chelate in the same manner as in the lighter Ln complexes but with one spanning a trigonal edge, and the hmpa-O donors occuping two apices of the other trigonal face. The ligand ompa has been found to act as a bidentate chelate in all isolated species, displacing one picrate from the metal ion coordination sphere to give ionic complexes. For La, Nd, and Gd, isomorphous (monoclinic, P 21/ n , Z 4) complexes of stoichiometry [Ln(pic)2(ompa)2(OH2)](pic)·0.5H2O containing 9-coordinate, tricapped trigonal-prismatic Ln with a single aqua ligand have been defined, while for Er, Yb, Lu, and Y, both the coordinated and lattice water molecules are lost in isomorphous (monoclininc, P 21/ c , Z 8) 8-coordinate, square-antiprismatic species of stoichiometry [Ln(pic)2(ompa)2](pic). For Er, further polymorphs, one monoclinic, P 21/ c , and the other triclinic, CH19251_IE1.gif , have also been characterised. Structural studies of adducts of the lanthanide picrates with hexamethylphosphoramide (hmpa) and octamethylpyrophosphoramide (ompa) provide significant contrasts with those of analogous adducts with dimethylsulfoxide and trimethylphosphate. Adducts of hmpa show a transition from 9-coordinate (hmpa)3 to 8-coordinate (hmpa)2 species, while ompa displaces one picrate from the primary coordination sphere. [ABSTRACT FROM AUTHOR]

Adducts of dimethylsulfoxide, dmso = Me2SO, with lanthanide(iii) picrates (picrate = 2,4,6-trinitrophenoxide, pic) of stoichiometry Ln(pic)3·3dmso have been prepared and characterised by single-crystal X-ray structure determinations as discrete, neutral, mononuclear molecular species. Such complexes have been obtained across the gamut of Ln, specifically for Ln = La, Pr, Nd, Sm, Gd, Dy, Yb, Lu, and Y, presumably also accessible for other intermediate members, the series being isomorphous (monoclinic, C 2/ c , Z = 8); a second triclinic P CH19169_IE1.gif form has also been identified for Ln = La, Pr. In both forms, the metal atom coordination environments are nine-coordinate, tricapped trigonal prismatic, [Ln(dmso- O)3(pic- O,O′)3], two of the three unidentate ligands lying in one of the trigonal planes and one in the other (an isomer we have termed meridional, mer). A hydrated form of Ln(pic)3·2dmso·H2O stoichiometry has also been defined for Ln = Sm, Gd, Lu, the metal atom environment again nine-coordinate, [Ln(dmso- O)2(H2 O)(pic- O,O′)3], but now fac , with the three unidentate ligands occupying one triangular face of the tricapped trigonal prism and involved in a centrosymmetric H-bonding array with the three similar ligands of an adjacent complex; the three capping atoms are nitro-oxygen atoms, the phenoxy- O triad occupying the other face. Structural characterisation of adducts of lanthanide picrates with dimethylsulfoxide has provided evidence that the 9-coordinate, tricapped trigonal-prismatic, mer -[Ln(pic)3(dmso)3] form with chelating picrate ligands may extend through the full series. Partial aquation of the tris(dmso) complexes to [Ln(pic)3(dmso)2(OH2)] provides three examples of an otherwise similar but facial isomer. [ABSTRACT FROM AUTHOR]

Bioactive natural products underpin the intriguing pollination strategy used by sexually deceptive orchids. These compounds, which mimic the sex pheromones of the female insect, are emitted in particular blends to lure male insect pollinators of specific species. By combining methods from field biology, analytical chemistry, electrophysiology, crystallography, and organic synthesis, we report that an undescribed β‐hydroxylactone, in combination with two specific hydroxymethylpyrazines, act as pollinator attractants in the rare hammer orchid Drakaea micrantha. This discovery represents an unusual case of chemically unrelated compounds being used together as a sexual attractant. Furthermore, this is the first example of the identification of pollinator attractants in an endangered orchid, enabling the use of chemistry in orchid conservation. Our synthetic blend is now available to be used in pollinator surveys to locate suitable sites for plant conservation translocations. [ABSTRACT FROM AUTHOR]