Xuejiao Tang’s research while affiliated with University of Puerto Rico at Río Piedras and other places

Tetraethylammoniumtribromo[2-(3.4-dimethoxy)styrylbenzothiazole]platinate(II), [(C2H5)4N]-[PtBr3(C17H15NO2S)], monoclinic,P21/c,a=13.454(7),b=11.991(3),c=19.004(5) , = 108.92(3),V=2900(4) 3,Z=4,D r=1.975 g cm–3, (MoK)=0.71073 , =95.59 cm–1,F(000)=1656,T=303 K, finalR=0.051 for 2262 unique observed reflections. The structure was solved by heavy atom and Fourier methods. The molecule is nearly planar, with a dihedral angle of only 3.57(7) between the benzothiazole and phenyl rings. The C–S–C angle in the thiazole ring is 91(1).

Tetraethylammonium tribromo[2-(2-chloro-5-nitrostyryl)benzoselenazole] platinate (II), [(C2H5)4N][PtBr3(C15H9ClN2O2Se)], is monoclinic, in space groupP21/c, witha=9.496(2),b=20.321(7),c=15.166(3)Å,β=100.18(1)°,V=2880(2)Å3,M r =928.72,Z=4,D x =2.141 g cm−3, λ(MoKα)=0.71073 Å,μ=104.1 cm−1,F(000)=1752,T=298 K. The structure was solved by direct methods and refined toR=0.032 for 2626 unique observed reflections withI>3σ(I). The [Pt(nsbse)Br3)] unit has square-planar geometry about the Pt atom, with the nsbse coordinated to the Pt through the N of the selenazole ring. The ligand molecule is non-planar, with a dihedral angle of 61.6(2)° between the benzoselenazole and phenyl rings. The dihedral angles between the PtBr3 plane and the benzoselenazole and phenyl planes are 105.2(1) and 80.7(1)°, respectively.

The crystal structure of 11-acetoxy-4-deoxyasbestinin B (C22H34O4, Mr=362.49) crystallized in the orthorhombic space group P212121 with a=10.923(5)Å, b=11.127(5)Å, c=17.047(5)Å, V=2072(3)Å3, Z=4, Dx=1.163g/cm-3. Mo Kα radiation was used for data collection at room temperature. The final R=0.042 for 2464 observed reflections. The stereochemical assignments of the molecule from the 2-D NMR data are verified totally by the overall geometry of the molecule obtained from the X-ray diffraction analysis.