Stereoselective Synthesis and X-Ray Structure Determination of Labeled [1, 2, 3-<Superscript>13</Superscript>C<Subscript>3</Subscript>]-1-(Phenylsulfinyl)-3-Benzyloxyacetone

[1,2,3-¹³C₃]-1-(Phenylsulfinyl)-3-benzyloxyacetone, C₁₆H₁₆O₃S, (3) has been synthesized and its crystal structure has been determined by a single-crystal X-ray diffraction analysis. The X-ray diffraction study revealed that compound 3 crystallizes in the monoclinic crystal system in the acentric space group Pc, with cell constants at T = 100 K: a = 16.073(5), b = 5.5079(16), c = 7.949(2) Å, β = 100.221(4)^°, V = 692.6(3) ų, Z = 2, d _calc = 1.383 g/cm³. Compound 3 contains the chiral tetravalent three-coordinated sulfur atom, which has a distorted tetrahedral configuration with a lone electron pair occupying one of the tetrahedron vertices. In the crystal, the molecules are packed in stacks along the b axis; the stacks consist of the molecules of the same chirality. Furthermore, the stacks of the molecules of the opposite chirality alternate along the c axis. The molecules in neighboring stacks are arranged by head-to-tail orientations. There are no short intermolecular contacts in the crystal of 3.     

Synthesis,structural characterization,and DFT calculations of 3-buthyl-4-(3-methyl-3-mesitylcyclobut-1-yl)-1,3-thiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

The title compound, C₂₁H₂₉NS₂, has been synthesized and its crystal structure has been determined from single crystal X-ray diffraction data. Crystals are monoclinic, a = 11.4923(8), b = 13.1842(7), c = 14.6583(8) Å, β = 109.983(6)°, sp. gr. P2₁/c, Z = 4. Mesityl and thiazole groups are in cis positions with respect to the cyclobutane ring. The cyclobutane ring is puckered, with a dihedral angle of 26.6(2)° between the two three-atom planes. The crystal structure involves one weak intermolecular C–H···S hydrogen-bond. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d, p) basis set in ground state. Geometric parameters (bond lengths, bond angles and torsion angles) and vibrational assignments have been calculated theoretically and compared with the experimental data.     

Quantitative Phase Analysis of Mixtures Containing α-, β-Tungsten and WO2

For incandescent lamp wire fabrication various powder metallurgical steps are necessary. The stepwise reduction of WO₃ to the tungsten metal powder is one of these. During reduction chemical reactions take place under participation of doping elements (K, Si and Al) causing the structure of non-sag wires. The origin of secondary β-W like an indicator for the activity of dopings has been attributed importance. Therefore it has been developed a method for quantitative phase analysis of α-W, β-W, WO₂ mixtures consisting of oxidation value determination to establish the WO₂ content and X-ray phase analysis for a quantitative separation of the α-W and β-W content. The influence of extinction effects caused by particle size has been investigated and it is proposed a correction method of the measured integral intensities as a function of half-width of the (110) α-W reflex. In regard of the obtained results the formation of the tungsten suboxide W₃O has been excluded.     

Structures of 2-, 3-, and 4-methyl-9-oxothioxanthenes

The structures of 2-, 3-, and 4-methyl-9-oxothioxanthenes (2-, 3-, and 4-TX, respectively) were determined by single crystal x-ray methods. The molecules are folded by 2–3° about their SC=O lines. Bond distances and angles vary only slightly as a function of the methyl substitution position, and reveal no inherent structural reason for the long-range nmr couplings observed between the ring and methyl protons. The molecular packings exhibit interesting similarities as well as subtle differences that result from variation of the methyl position. Crystals of 2-TX are orthorhombic, space groupPn2₁ a,a=10.807(1),b=4.024(2),c=24.827(3) Å,Z=4,R=0.059 for 715 observed reflections. Crystals of 3-TX are orthorhombic, space groupPbc2₁,a=3.999(1),b=25.051(2),c=10.758(1)Å,Z=4,R=0.041 for 1382 observed reflections. Crystals of 4-TX are triclinic, space groupP¯1,a=7.118(1),b=7.907(2),c=10.415(2) Å,=77.74(1),=74.35(1), =73.96(1)°,Z=2,R=0.043 for 1542 observed reflections.Deceased.