We first analyze why most of the photonic crystals produced by two-photon photopolymerization technique exhibit no photonic band gap effect. And then subdiffraction-limited resolution-enabled finely quantified pixel writing, a scheme that has been used in micromachine fabrication, is adopted as the solution. As a result, higher accuracy in depicting and better reproducibility in both fabrication and photonic band gap effect observation are obtained. More important, the method allows for precise precompensation of the structure shrinkage induced by photochemical reactions of polymerization, which may pave the way to high-fidelity fabrication of polymer photonic and optoelectronic devices that require strictly the structural parameters.

Reductive amination of various aldehydes and ketones has been performed effectively by pentacoordinate chloro-substituted tin hydride complex, Bu 2 SnClH-HMPA. The tin reagent worked particularly well for the case using weakly basic aromatic amines as starting substrates. Stoichiometric amounts of a substrate and a reducing agent were adequate for the reaction. The Sn-Cl bond in the complex plays an important role for both steps of imine formation and subsequent reduction. Highly chemoselective reduction of carbonyls could be achieved regardless of other functionalities such as halogen, carbon-carbon double bond and hydroxyl groups in the starting carbonyls and amines.

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A novel ate tin hydride complex, Li+[n-Bu2SnI2H]- (I), was synthesized and characterized on the basis of its 119Sn NMR spectrum as a trigonal bipyramid (TBP) structure, in which two iodine atoms and one hydrogen atom occupy the apical and the equatorial positions, respectively. The apical iodine has much greater nucleophilicity than the hydrogen, so that the attack by iodide precedes the reduction by hydrogen, achieving regioselective 1,4-reduction of α,β-unsaturated aldehydes.