Chiral anionic layers in tartramide spiroborate salts and variable solvation for [NR 4][B(TarNH2)2] (R = Et, Pr or Bu)

The spiroborate anion, namely, 2,3,7,8-tetracarboxamido-1,4,6,9-tetraoxa-5λ4-boraspiro[4.4]nonane, [B(TarNH2)2]−, derived from the diol L-tartramide TarNH2, [CH(O)(CONH2)]2, shows a novel self-assembly into two-dimensional (2D) layer structures in its salts with alkylammonium cations, [NR 4]+ (R = Et, Pr and Bu), and sparteinium, [HSpa]+, in which the cations and anions are segregated. The structures of four such salts are reported, namely, the tetrapropylazanium salt, C12H28N+·C8H12BN4O8 −, the tetraethylazanium salt hydrate, C8H20N+·C8H12BN4O8 −·6.375H2O, the tetrabutylazanium salt as the ethanol monosolvate hemihydrate, C16H36N+·C8H12BN4O8 −·C2H5OH·0.5H2O, and the sparteinium (7-aza-15-azoniatetracyclo[7.7.1.02,7.010,15]heptadecane) salt as the ethanol monosolvate, C15H27N2 +·C8H12BN4O8 −·C2H5OH. The 2D anion layers have preserved intermolecular hydrogen bonding between the amide groups and a typical metric repeat of around 10 × 15 Å. The constraint of matching the interfacial area organizes the cations into quite different solvated arrangements, i.e. the [NEt4] salt is highly hydrated with around 6.5H2O per cation, the [NPr4] salt apparently has a good metric match to the anion layer and is unsolvated, whilst the [NBu4] salt is intermediate and has EtOH and H2O in its cation layer, which is similar to the arrangement for the chiral [HSpa]+ cation. This family of salts shows highly organized chiral space and offers potential for the resolution of both chiral cations and neutral chiral solvent molecules.

Investigation on the effect of an anion layer on photocatalytic activity: carbonate vs. oxalate

The separate [Bi2O2]2+ and CO32− layers can greatly improve the charge separation efficiency.

Design of Organic Superconductors Based on Bedt-TTF

ABSTRACTA close examination of the relation between Tc and structural characteristics of BEDT-TTF superconductors has revealed that there is a good correlation between the effective volume (VeffαVc-Vanion and Tc but no such correlation between the unit cell volume (Vc) and Tc. In order to increase Veff, it is favorable to use big but thin anion which can form a thin two-dimensional anion layer. Three-dimensional donor interactions are critical to have sizable Tc. According to the designing, two new superconductors; K-(BEDT-TTF)2CuCN[N(CN)2] (Tc=11.2K) and K'-(BEDT-TTF)2Cu2(CN)3 (Tc=3.8K), are prepared and their physical and structural properties are described. Their Tc's are discussed in terms of veff.

Synthese und Kristallstruktur von Triphenylmethylphosphoniumtriiodid [P(C6H5)3CH3]I3 / Synthesis and Crystal Structure of [P(C6H5)3CH3]I3

Triphenylmethylphosphonium triiodide [P(C6H5)3CH3]I3 has been prepared by the reaction of [P(C6H5)3CH3]I with iodine in ethanol. Deep violet crystals were obtained by recrystallization from dichloromethane.The crystal and molecular structure of the compound has been determined. The crystals are orthorhombic, space group Pbca, Z = 8, a = 1182.2(2), b = 1987.6(3), c = 1798.8(3) pm.Least squares refinement of the structure yielded R = 0.038 (Rw = 0.030, RG = 0.030) for 2433 independent reflections.The triodide ion I3- is slightly asymmetrical and slightly bent. The distances are 293.7(1) pm (I(1)—I(2)) and 291.7(1) pm (I(2)—I(3)), the angle I(1)—I(2)—I(3) is 179.3(1)°.The structure contains layers perpendicular to the c axis, which follow each other with a period of c/2 and are built up by I3- anions and [P(C6H5)3CH3]+ cations. They are stacked to give layers of cations and layers of anions perpendicular to the b axis. The shortest I ··· I distance between I3- ions in the anion layer occurs in the c direction. It amounts to 414 pm, thus indicating that there are only very weak I ··· I interactions between the I3- ions. Further I ··· I contacts in the layer lie between 510 and 746 pm.