Theoretical Investigations of the Chiral Transition of α-Amino Acid Confined in Various Sized Armchair Boron-Nitride Nanotubes.

We computationally study the chiral transition process of the α-Ala molecule under confined different sizes of armchair SWBNNTs to explore the confinement effect. We find that the influence of a confinement environment (in armchair SWBNNTs) on the α-Ala molecule would lead to different reaction pathways. Meanwhile, the preferred reaction pathway is also different in various sizes of armchair SWBNNTs, and their energy barriers for the rate-limiting step decrease rapidly with the decreasing of the diameters of the nanotubes. It is obvious that significant decrease of the chiral transition energy barrier occurs compared with the isolated α-Ala molecule chirality conversion mechanism, by ∼15.6 kcal mol-1, highlighting the improvement in the activity the enantiomers of α-Ala molecule. We concluded that the confinement environment has a significant impact at the nanoscale on the enantiomer transformation process of the chiral molecule.

catena-Poly[[[triaqua-(4,5-diaza-fluorene-9-one)cadmium]-µ-benzene-1,3-dicarboxyl-ato] dihydrate].

In the title compound, {[Cd(C(8)H(4)O(4))(C(11)H(6)N(2)O)(H(2)O)(3)]·2H(2)O}(n), the Cd(II) atom is seven-coordinated by two N atoms from the phenanthroline-derived 4,5-diaza-fluorene-9-one ligand, two O atoms from one bidentate benzene-1,3-dicarboxyl-ate ligand and three O atoms from the three water mol-ecules in a distorted penta-gonal-bipyramidal arrangement. Moreover, there are two dissociative water mol-ecules in each unit. Neighbouring units inter-act through π-π inter-actions [centroid-centroid distances = 3.325 (3) and 3.358 (4) Å] and O-H⋯O hydrogen-bonding, resulting in a two-dimensional network extending parallel to (001).

[2-(1,3-Dithio-lan-2-yl-idene)-5-(4-methyl-phen-yl)-3-oxopent-4-enoato-κO]tri-phenyl-tin(IV).

In the title compound, [Sn(C(6)H(5))(3)(C(17)H(17)O(3)S(2))], the Sn(IV) atom adopts a distorted tetra-hedral SnC(3)O geometry. A short intra-molecular Sn⋯O contact of 2.793 (2) Šalso occurs.

catena-Poly[[(dipyrido[3,2-a:2',3'-c]phenazine)cobalt(II)]-µ-biphenyl-2,2'-dicarboxyl-ato].

In the title compound, [Co(C(14)H(8)O(4))(C(18)H(10)N(4))](n), the Co(II) atom is six-coordinated by four O atoms from two different biphenyl-2,2'-dicarboxyl-ate ligands and two N atoms from the bidentate dipyrido[3,2-a:2',3'-c]phenazine ligand in a distorted octa-hedral geometry. The Co(II) atoms are bridged by the biphenyl-2,2'-dicarboxyl-ate ligands to form a one-dimensional chain structure. π-π inter-actions between neighbouring chains result in a two-dimensional supra-molecular network (centroid-to-centroid separation = 3.381 Å).

A novel macrocyclic organotin carboxylate containing a nona-nuclear long ladder.

A novel macrocyclic organotin(iv) carboxylate {[n-Bu2Sn(O)]9(CH2CH3)2L}·3CH2CH3OH (complex 1) (L = (9-carboxymethyl-1,3,8,10-tetraoxo-3,8,9,10-tetrahydro-1H-anthra[2,1,9-def;6,5,10-d'e'f']diisoquinolin-2-yl)-acetic acid) was generated by the reaction of dibutyltin oxide with amide dicarboxylic acid L and characterized by elemental analysis, IR, (1)H and (13)C NMR spectroscopy. X-ray crystallography diffraction analysis reveals that 1 is a centrosymmetric macrocycle and contains a nona-nuclear eight-fold-ladder-like organo-oxotin cluster. The preliminary luminescent properties of complex have also been studied.