(Ethanol‐O)­tris­(nitrato‐O,O′)­bis­(triphenyl­phosphine oxide‐O)­cerium(III)

The title compound, [Ce(NO₃)₃(C₂H₆O)(C₁₈H₁₅OP)₂], contains discrete mol­ecules with nine‐coordinate Ce atoms having all nitrate groups bonded as symmetrical bidentate ligands [Ce—O(P) 2.369 (2) and 2.385 (2), Ce—O(N) 2.549 (3)–2.596 (3) and Ce—O(Et) 2.515 (3) Å].     

Disodium tetrakis(hexanoato‐O)zinc(II)

The structure of the title compound, Na₂[Zn(C₆H₁₁O₂)₄], consists of two‐dimensional polymeric sheets. The Zn²⁺ ions are approximately tetrahedrally coordinated by O atoms from different hexanoate anions. Both Na⁺ ions are six‐coordinated by carboxyl­ate O atoms. One of the hexanoate O atoms is attached to one Zn²⁺ ion and one Na⁺ ion, and the remaining O atom is attached to two Na⁺ ions.     

Tetraaquabis(3,5‐dicarboxybenzoato‐O)cobalt(II)

The hydro­thermal reaction of cobalt(II) chloride with trimesate (3,5‐di­carboxy­benzoate) ions in aqueous solution gives the novel title complex, [Co(C₉H₅O₆)₂(H₂O)₄]. The Co^II ion lies on an inversion centre and is octahedrally coordinated to two trimesate anions and four water mol­ecules. Hydro­gen bonds ensure the three‐dimensional architecture of the structure.     

Diamminebis(2,4,6‐tribromophenolato‐O)copper(II)

The title compound, [Cu(C₆H₂Br₃O)₂(NH₃)₂], a monomeric centrosymmetric Cu^II complex, crystallizes in the monoclinic system. The CuO₂N₂ coordination sphere is trans planar, [Cu—O 1.943 (5) Å and Cu—N 1.977 (6) Å], with the fifth and sixth coordination sites occupied by Br atoms from the phenoxide ions [Cu—Br 3.129 (1) Å], resulting in an elongated distorted octahedral structure for the CuO₂N₂Br₂ coordination. Each of the NH₃ groups forms two hydrogen bonds with the Br and O atoms of the CuO₂N₂Br₂ moiety of a neighbouring mol­ecule. This arrangement constitutes a one‐dimensional chain along the x axis of the unit cell.     

trans‐Bis(benzoato‐O)tetrakis(methanol‐O)iron(II): ligand bulk is not structure‐determining

The title compound, [Fe(C₇H₅O₂)₂(CH₄O)₄], is a centrosymmetric six‐coordinate Fe^II complex coordinated by two axial monodentate benzoate ligands and four methanol ligands in the equatorial plane [Fe—O_benzoate 2.0935 (7) Å, and Fe—O_methanol 2.1310 (7) and 2.1290 (7) Å]. The benzoate ligands adopt monodentate ligation, rather than a bridged polymeric structure, because of strong intra‐ and intermolecular hydrogen bonds to the methanol ligands. This structure is nearly identical to that obtained with a much bulkier carboxyl­ate ligand [Chavez, Que & Tolman (2001). Chem. Commun. pp. 111–112].     

Triaquatris(2,6‐dinitrophenolato‐κ2O1,O2)yttrium(III)

In the title compound, [Y(C₆H₃N₂O₅)₃(H₂O)₃], the Y atom is nine‐coordinate with a slightly distorted tricapped trigonal prismatic coordination geometry. The Y^III ion is coordinated to three bidentate 2,6‐di­nitro­phenolate ligands and three water mol­ecules. The Y—O bond distances are in the range 2.217 (3)–2.754 (4) Å, with the Y—O distances from the nitro groups being longer than those from the water mol­ecules and the phenol groups. The coordinated NO₂ groups are almost coplanar with the benzene rings.     

Bis(tetraphenylphosphonium) tris(oxalato‐O,O′)germanate(IV)

The synthesis and structure of the title compound, (C₂₄H₂₀P)₂[Ge(C₂O₄)₃], are reported. The PPh₄⁺ cations in the structure form infinite zigzag chains in which the P?P distances alternate between 6.229 (1) and 7.118 (1) Å, and the P?P?P angle is 131.4 (1) Å. The shorter P?P distance is associated with a sixfold phenyl embrace. However, the longer P?P distance is associated with both phenyl–phenyl interactions and interactions between the cations and a twofold symmetric [Ge(C₂O₄)₃]^2? anion. In the cation–anion interactions, the P?O distance is 4.444 (2) Å, the O?P—C_distal angle is 175.0 (1)° and the shortest H?O distances are 2.74 and 3.09 Å.     

Tricaesium tris(oxalato‐κ2O1,O2)chromate(III) dihydrate

The title compound, Cs₃[Cr(C₂O₄)₃]·2H₂O, has been synthesized for the first time and the spatial arrangement of the cations and anions is compared with those of the other members of the alkali metal series. The structure is built up of alternating layers of either the d or l enantiomers of [Cr(oxalate)₃]³⁻. Of note is that the distribution of the [Cr(oxalate)₃]³⁻ enantiomers in the Li⁺, K⁺ and Rb⁺ tris(oxalato)chromates differs from those of the Na⁺ and Cs⁺ tris(oxalato)chromates, and also differs within the corresponding BEDT‐TTF [bis(ethylenedithio)tetrathiafulvalene] conducting salts. The use of tris(oxalato)chromate anions in the crystal engineering of BEDT‐TTF salts is discussed, wherein the salts can be paramagnetic superconductors, semiconductors or metallic proton conductors, depending on whether the counter‐cation is NH₄⁺, H₃O⁺, Li⁺, Na⁺, K⁺, Rb⁺ or Cs⁺. These materials can also be superconducting or semiconducting, depending on the spatial distribution of the d and l enantiomers of [Cr(oxalate)₃]³⁻.     

Triaqua(oxalato‐O,O′)oxovanadium(IV) dihydrate

In the structure of the title compound, [VO(C₂O₄)(H₂O)₃]·2H₂O, the V atom of the oxovanadium(IV) cation is coordinated to one bidentate oxalate anion and three water mol­ecules, resulting in a neutral complex. Two more water mol­ecules are not coordinated to the V atoms but are involved in the hydrogen‐bonding network, which consists of ten different hydrogen bonds.     

Dichlorobis(dl‐proline‐κO)zinc(II)

The title compound, [ZnCl₂(C₅H₉NO₂)₂], crystallizes in the centrosymmetric space group C2/c with the Zn atom on a twofold axis. The two proline residues in any one complex thus have the same absolute configuration. Hydrogen bonding links the mol­ecules into linear chains, which run in the crystallographic b direction. The proline residues within any one chain also have an identical absolute configuration.     

Kristallstrukturen des Sr(BrO3)2 · H2O,Ba(BrO3)2 · H2O,Ba(IO3)2 · H2O,Pb(CIO3)2 · H2O und Pb(BrO3)2 · H2O

Crystal Structure of Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O The crystall structures of the isostructural halates Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O were determined using X-ray single crystal data (monoclinic space group C2/c? C, Z = 4), The mean bond lengths and bond angles of the halate ions in the Ba(ClO₃)₂ · 1 H₂O-type compounds, which correspond to those of other halates, are Cl? O, 149.0, Br? O, 165.9, I? O, 180.2 pm, ClO₃^?, 106.4, BrO₃^?, 104.0, and IO₃^?, 99.6°. The structure data obtained are discussed in terms of possible orientational disorder of the water molecules, strengths of the hydrogen bonds, influence of the lead ions on the structure, and site group distortion of the halate ions.     

Hexakis­(antipyrine‐O)­terbium(III) triperchlorate

In the title compound, hexakis(1,2‐di­hydro‐1,5‐di­methyl‐2‐phenyl‐3H‐pyrazol‐3‐one‐O)­terbium(III) triperchlorate, [Tb(C₁₁H₁₂N₂O)₆](ClO₄)₃, the Tb atom lies on a site of crystallographic symmetry and the unique Tb—O distance is 2.278 (2) Å. One of the perchlorate anions has threefold crystallographic symmetry, while the other is disordered about a site.     

Tetraammine(selenito‐O,O′)cobaltate(III) nitrate monohydrate

The title compound crystallizes as the mono­hydrate, [Co(SeO₃)(NH₃)₄]NO₃·H₂O. The crystallographic mirror symmetry coincides with the molecular symmetry; the mirror plane passes through the cation, anion and water mol­ecule. The CoN₄O₂ octahedron is distorted, with the selenito group acting as a bidentate ligand through two bridging O atoms to the cobalt. The coordinated Se—O distance is 1.742 (2) Å, whereas the uncoordinated Se—O distance is 1.646 (3) Å. A three‐dimensional hydrogen‐bonded network exists between [Co(SeO₃)(NH₃)₄]NO₃ and the water mol­ecule. The nitrate anion and water mol­ecule form open pores in the structure when hydrogen bonded to two neighboring [Co(SeO₃)(NH₃)₄]⁺ cations. Selenium participates in two types of relatively close intermolecular interactions with neighboring charged species (Se?N1 and Se?O3), but does not participate in an interaction with a neighboring O2 atom, the nearest contact distance being 4.638 (3) Å.     

Electro‐Optic (E‐O) Molecular Glasses

This Focus Review describes molecular glasses as a new class of materials for nonlinear optical (NLO) applications, especially for electro‐optic (E‐O) devices. Examples of E‐O molecular glasses are reviewed with a focus on the molecular design of NLO chromophores and solid‐state engineering of molecular glasses. Molecular glasses based on dendrimers of multiple chromophores, molecular glass blends of chromophores, and molecular glasses based on reversible self‐assembly of chromophores are introduced as promising architectures to prepare morphologically stable molecular glasses with large E‐O activities and improved material properties for device applications. Future directions to fully exploit the potential of molecular glasses for NLO materials are presented.     

trans‐Bis(diethanolamine‐N,O)bis(saccharinato‐N)cadmium(II)

The structure of the title complex consists of isolated [Cd(C₇H₄NO₃S)₂(C₄H₁₁NO₂)₂] units. The Cd²⁺ cation lies on an inversion centre and is octahedrally coordinated by two N,O‐bidentate diethanol­amine (dea) and two N‐bonded saccharinate (sac) ligands [saccharin is 1,2‐benziso­thia­zol‐3(2H)‐one 1,1‐dioxide]. The dea ligands constitute the equatorial plane of the octahedron, forming two five‐membered chelate rings around the Cd^II ion, while the sac ligands are localized at the axial positions. The Cd—N_sac, Cd—N_dea and Cd—O_dea bond distances are 2.3879 (12), 2.3544 (14) and 2.3702 (13) Å, respectively. The H atoms of the free and coordinated hydroxyl groups of the dea ligands are involved in hydrogen bonding with the carbonyl and sulfonyl O atoms of the neighbouring sac ions, while the amine H atom forms a hydrogen bond with the free hydroxyl O atom. The individual mol­ecules are held together by strong hydrogen bonds, forming an infinite three‐dimensional network.     

(μ‐Oxalato‐O1,O2:O1′,O2′)bis[aqua(diethyl­enetri­amine)nickel(II)] bis(hexafluorophosphate) dihydrate

The title compound, [Ni₂(C₂O₄)(C₄H₁₃N₃)₂(H₂O)₂](PF₆)₂·‐2H₂O, contains a dinuclear oxalato‐bridged nickel(II) complex cation. The structure determination reveals the presence of a centrosymmetric binuclear complex where the oxalate ligand is coordinated in a bis­‐bidentate mode to the Ni atoms. The distorted octahedral environment of each Ni atom is completed by the three N atoms of the diethyl­enetri­amine ligand in a fac arrangement and by one O atom from a water mol­ecule. PF₆^? acts as counter‐anion. A two‐dimensional network of hydrogen bonds links the cations and anions and stabilizes the structure.     

Crystal Structures of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O

Reactions of 1,10‐phenanthroline monohydrate, Na₂C₄H₄O₄ · 6 H₂O and MnSO₄ · H₂O in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] · 2 H₂O ( 1 ) and [Mn(phen)₂(H₂O)₂][Mn(phen)₂(C₄H₄O₄)](C₄H₄O₄) · 7 H₂O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) ų, Z = 1) consists of the dinuclear [Mn₂(H₂O)₄(phen)₂(C₄H₄O₄)₂] molecules and hydrogen bonded H₂O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H₂O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) ų, Z = 2) is composed of the [Mn(phen)₂(H₂O)₂]²⁺ cations, [Mn(phen)₂(C₄H₄O₄)] complex molecules, (C₄H₄O₄)^2– anions, and H₂O molecules. The (C₄H₄O₄)^2– anions and H₂O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.