Hollow nanoshell of layered double hydroxide

Hollow nanoshells of layered double hydroxide (LDH) have been fabricated using exfoliated LDH nanosheets as a shell building block and polystyrene beads as a sacrificial template.     

La@C72 having a non-IPR carbon cage

We show here that La@C72 has a non-IPR cage, unique electronic properties, and high reactivity by the spectroscopic and X-ray crystallographic analysis and the theoretical study. The isolation of La@C72 as a stable derivative might constitute an important stepping-stone on the way to isolation of these unknown metallofullerenes and open new material science of metallofullerenes.     

Silver technology for stabilization of simple (Z)-enethiols: stereoselective synthesis and reaction of silver (Z)-enethiolates

Reported here for the first time are the stereoselective synthesis and reaction of simple silver (Z)-enethiolates, which serve as stabilized (Z)-enethiol storage. In contrast to labile enethiols, silver (Z)-enethiolates are stable even in solutions, and their isolation and purification are very simple. The method for synthesis of silver (Z)-enethiolates involves an unusual vinylic SN2 reaction of (E)-vinyl-lambda3-iodanes with thiobenzamides yielding the inverted (Z)-S-vinylthioimidonium salts, followed by their regioselective C-S bond cleavage with silver acetate. Alkylation, arylation, and Michael addition of silver (Z)-enethiolates yielding (Z)-vinyl sulfides were dramatically accelerated by the addition of Bu4NI (LiI), which probably generates reactive ammonium (Z)-enethiolates with an increased nucleophilicity.     

Long-range exciton-coupled circular dichroism: application for determination of the absolute configuration of oligonaphthalenes

Hexadecanaphthalenes (S,S,S,S,S,S,S,S,S,S,S,S,S,S,S)-4b and (S,S,S,S,S,S,S,R,S,S,S,S,S,S,S)-4b that possess two tetraphenylporphyrins (TPP) on the upper and lower naphthalene rings were synthesized. Long-range exciton-coupled CD in the Soret region of TPP (about 66 A) was observed. [structure: see text]     

Thermally stable luminescent composites fabricated by confining rare earth complexes in the two-dimensional gallery of titania nanosheets and their photophysical properties

Fluorescent composite materials of exfoliated titania nanosheets, Ti(0.91)O(2), and rare earth (RE) complexes, Eu(phen)(2)Cl(3).2H(2)O and Tb(phen)(2)Cl(3).2H(2)O (phen = 1,10-phenanthroline), were synthesized via flocculation between them. X-ray diffraction measurements and transmission electron microscopy observations confirmed a restacked lamellar structure for the composites, and elemental analysis revealed a high RE complex content of 15 wt %. The decomposition temperature of the complexes trapped in the composites was improved to 420 degrees C from 250 degrees C for the free form. The restacked composite composed of Ti(0.91)O(2) nanosheets and Eu(phen)(2) exhibited characteristic red emission from the complex, while the composite with Tb(phen)(2) gave featureless emission originated from the ligand. This phenomenon can be explained by a shift of triplet state level of the ligand after encapsulation in the host titania nanosheets. The quantum yield of europium complex in the composite was enhanced 1.6 times more than that of the pure complex.     

Roles of adriamycin and adriamycin dimer in antitumor activity of the polymeric micelle carrier system

Adriamycin (ADR) dimer was prepared and its antitumor activity was evaluated with mouse colon adenocarcinoma 26 (C 26). As compared with original ADR, the dimer did not show significant antitumor activity, either in vitro or in vivo. Furthermore, polymeric micelles containing varied ratios of the dimer to the original ADR were prepared. Polymeric micelles with a higher dimer/ADR ratio (9.7) showed significant antitumor activity, but the effective dose shifted higher. Effective doses were found to largely depend on the concentration of the original ADR, rather than that of the dimer at the tumor sites. Therefore, it was presumed that the original ADR played a major role in antitumor activity, and the dimer played a supplementary role to contribute selective delivery of ADR to the tumor sites.     

Synthesis and recognition of amino acids by binaphthyl-crown receptors

Two binaphthyl crown receptors containing phenylboric acid 2 and 2,4-dinitrophenylurea 3 as lariat parts were prepared from the optically active binaphthyl crown alcohol 1 in two and four steps, respectively. Host 2 showed a 30% extraction efficiency for GABA by a solid-liquid extraction method in DMSO. Chromogenic Host 3 discriminated the guest linear amino acid by molecular length and the information was revealed through color changes.