[Study on the Technology of the 4.4 μm Mid-Infrared Laser Heterodyne Spectrum].

In this paper, first time as our knowledge, we describe the development and performance evaluation of a 4.4 μm external cavity quantum cascade laser based laser heterodyne radiometer. Laser heterodyne spectroscopy is a high sensitive laser spectroscopy technique which offers the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy.

Catalytic asymmetric sulfenylation to structurally diverse dithioketals.

We report the first example of the highly enantioselective synthesis of structurally diverse chiral dithioketals via asymmetric sulfenylation of various types of S-based nucleophiles, catalyzed by a cheap cinchona alkaloid derivative, dihydroquinine.

[Yearly Changes of Phytoplankton Community in the Ecology-monitoring Area of Changli, Hebei in Summer].

Based on the investigation of phytoplankton and water body nutrient concentration in the ecology-monitoring area of Changli in summer from 2005 to 2013, the phytoplankton community structure was analyzed. The result showed that in recent 9 years, 3 phyla including 23 families, 39 genera and 105 species of phytoplankton were identified, in which 85.7% were diatoms and 13.

Michael Addition Catalyzed by Chiral Secondary Amine Phosphoramide Using Fluorinated Silyl Enol Ethers: Formation of Quaternary Carbon Stereocenters.

A chiral secondary amine phosphoramide was developed and identified as a powerful catalyst for the Mukaiyama-Michael addition of fluorinated enol silyl ethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternary carbon stereocenter bearing either a difluoroalkyl or monofluoroalkyl group.

Highly enantioselective Michael addition of 3-arylthio- and 3-alkylthiooxindoles to nitroolefins catalyzed by a simple cinchona alkaloid derived phosphoramide.

A new cinchona alkaloid derived bifunctional tertiary amine-phosphoramide is identified as a highly enantioselective catalyst for Michael addition of both unprotected 3-arylthio- and 3-alkylthiooxindoles to nitroolefins. The phosphoramide moiety of plays an indispensable role in this reaction.

Asymmetric copper(I)-catalyzed azide-alkyne cycloaddition to quaternary oxindoles.

We report a highly enantioselective Cu(I)-catalyzed azide-alkyne cycloaddition via asymmetric desymmetrization of oxindole-based 1,6-heptadiynes, which furnishes quaternary oxindoles bearing a 1,2,3-triazole-containing moiety with 84-98% ee.

Decacarbon-yl[μ(4)-(ethane-1,2-diyl-dinitrilo)-tetra-kis-(methane-thiol-ato)]bis(triphenyl-phosphane)tetra-iron(2 Fe-Fe).

In the title compound, [Fe(4)(C(6)H(12)N(2)S(4))(C(18)H(15)P)(2)(CO)(10)], the unit cell contains one mol-ecule, which exhibits a crystallographically imposed center of symmetry. The independent Fe(2)S(2) fragment [Fe-Fe = 2.527 (1) Å] is in a butterfly conformation, and each Fe atom displays a pseudo-square-pyramidal coordination geometry.