Structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline from oxidative cyclization of a thiosemicarbazone

1987 ◽  
Vol 65 (6) ◽  
pp. 1154-1157 ◽  
Author(s):  
R. Faggiani ◽  
M. Kaminski ◽  
C. J. L. Lock ◽  
J. Warkentin

The X-ray crystal structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline, C10H11N3S, has been determined. The compound is monoclinic, P21/c (No. 14), with a = 13.200(5), b = 6.340(4), and c = 13.823(4) Å, β = 113.50(4)°, and Z = 4. The structure was determined by direct methods and refined to R = 0.061, Rw = 0.067 for 1277 unique reflections. The molecule has the Z configuration. The thiadiazoline ring is planar. C—N and N=N bond lengths are within the normal range. The C—S bond lengths are similar to those we have observed previously in thiazolidines. Angles differ markedly from an expected average 108°. The small C—S—C angle (90.6(2)°) is accompanied by larger C—N=N angles (114.9(3), 117.8(3)°). The phenyl ring is not coplanar with the thiadiazoline ring (dihedral angle 38.6(4)°) because of repulsive interaction of the phenyl o-hydrogen atom with the sulphur atom.

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.


1983 ◽  
Vol 36 (11) ◽  
pp. 2333 ◽  
Author(s):  
B Kamenar ◽  
RA Pauptit ◽  
JM Waters

The X-ray crystal structure of 3α,4α:5β,6β-diepoxyandrostan-17-one has been determined. Crystals of the title compound (C19H26O3)are monoclinic, space group P21, with a 9.208(2), b 9.620(4), c 9.312(3) �, β 99.14(2)�, V 814.5 Ǻ3 and Z 2. The structure was solved by direct methods and refined to R 0.039 for 887 observed reflexions. The 3α,4α:5β,6β configuration of the epoxide rings confirms the assignment based on proton n.m.r. studies.


2011 ◽  
Vol 75 (6) ◽  
pp. 2823-2832
Author(s):  
P. Elliott ◽  
A. Pring

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space group P212121, a = 17.9733(18), b = 5.6916(11), c = 9.130(4) Å, V= 933.9(4) Å3, Z = 4, has been solved by direct methods and refined from single-crystal X-ray diffraction data (T = 293 K) to an R index of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6 octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6 octahedra coupled by PO4 tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.


1999 ◽  
Vol 54 (11) ◽  
pp. 1375-1378 ◽  
Author(s):  
Michael Becker ◽  
Martin Jansen

The synthesis of RbHCN2 was carried out by reaction of cyanamide with rubidium amide in liquid ammonia. The crystal structure has been determinedo by x-ray powder methods (orthorhombic, P21,21,21, a = 7.299(1), b = 9.435(1), c = 9.420(1) Å; Z = 8). The anion is slightly bent (174°) and exhibits two different bond lengths (C-N: 1.17, HN-C: 1.31 Å).


1991 ◽  
Vol 46 (12) ◽  
pp. 1625-1628 ◽  
Author(s):  
Stefan Vogler ◽  
Werner Massa ◽  
Kurt Dehnicke

The reaction of tungsten hexachloride with Se4N2 leads to [WCl4(NSeCl)]2, which reacts with pyridine to form [WCl4(NSeCl)Py], and with tetraphenylphosphonium chloride to form PPh4[WCl5(NSeCl)], which was characterized by an X-ray structure determination. Space group P21, Z = 2, 1657 observed unique reflections, R = 0.074, wR = 0.061. Lattice dimensions at —80 C: a = 710.7(1), b = 2217.9(4), c = 953.6(2) pm; β = 111.93(3) . The [WCl5(NSeCl)]- ion possesses an almost linear WNSe group with bond lengths WN = 188 pm, corresponding to a double bond, and NSe = 200 pm.


Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 359-364
Author(s):  
Hans-Joachim Knölker ◽  
Valerie Lösle ◽  
Olga Kataeva

AbstractWe describe the first total synthesis of the recently discovered pyrano[3,2-a]carbazole alkaloid clausenalansine A. The synthetic strategy for the construction of this formylpyrano[3,2-a]carbazole is based on a sequence of Buchwald–Hartwig coupling, palladium(II)-catalyzed oxidative cyclization, Lewis acid promoted annulation of the pyran ring, and chemoselective oxidation of a methyl to a formyl group.


1985 ◽  
Vol 40 (12) ◽  
pp. 1631-1637 ◽  
Author(s):  
Ruth Christophersen ◽  
Paul Klingelhöfer ◽  
Ulrich Müller ◽  
Kurt Dehnicke

Abstract The pyridine complexes of cyclo-thiazeno vanadium dichloride, [VCl2(N3S2)py] and [VCl2(N3S2)(py)2] were synthesized by reactions of polymeric VCl2(N3S2) with varying amounts of pyridine in CH2Cl2. The compounds were characterized by their IR spectra as well as by their 51V NM R spectra. The crystal structure of [VCl2(N3S2)(C5H5N)] was determined by means of X-ray diffraction (1582 independent observed reflexions, R = 0.031). Crystal data: orthorhombic, space group Pnma, a = 1372, b - 2261, c - 1068 pm, Z = 12. In the lattice there are two monomeric, crystallographically independent molecules [VCl2(N3S2)(C5H5N)], which differ only slightly. The vanadium atoms have a trigonal bipyramidal coordination with the N atom of the pyridine molecule and one chlorine atom in apical positions, and with one chlorine atom and the N atoms of the cyclo-thiazeno ligand in equatorial positions. The VN bond lengths of the planar VN3S2 ring of 174 pm correspond to double bonds


1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.


2014 ◽  
Vol 78 (7) ◽  
pp. 1687-1698 ◽  
Author(s):  
Oleg I. Siidra ◽  
Lidiya P. Vergasova ◽  
Sergey V. Krivovichev ◽  
Yuri L. Kretser ◽  
Anatoly N. Zaitsev ◽  
...  

AbstractMarkhininite, ideally TlBi(SO4)2, was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. Markhininite occurs as white pseudohexagonal plates associated with shcherbinaite, pauflerite, bobjonesite, karpovite, evdokimovite and microcrystalline Mg, Al, Fe and Na sulfates. Markhininite is triclinic, P1̄ , a = 7.378(3), b = 10.657(3), c = 10.657(3) Å , α = 61.31(3), β = 70.964(7), γ = 70.964(7)º, V = 680.2(4) Å3, Z = 4 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are (I/d/hkl): 68/4.264/111, 100/3.441/113, 35/3.350/222, 24/3.125/122, 23/3.054/202, 45/2.717/022, 20/2.217/331, 34/2.114/204. Chemical composition determined by electron microprobe analysis is (wt.%): Tl2O 35.41, Bi2O3 38.91, SO3 25.19, total 99.51. The empirical formula based on 8 O a.p.f.u. is Tl1.04Bi1.05S1.97O8. The simplified formula is TlBi(SO4)2, which requires Tl2O 35.08, Bi2O3 38.48, SO3 26.44, total 100.00 wt.%. The crystal structure was solved by direct methods and refined to R1 = 0.055 on the basis of 1425 independent observed reflections. The structure contains four Tl+ and two Bi3+ sites in holodirected symmetrical coordination. BiO8 tetragonal antiprisms and SO4 tetrahedra in markhininite share common O atoms to produce [Bi(SO4)2]– layers of the yavapaiite type. The layers are parallel to (111) and linked together through interlayer Tl+ cations. The mineral is named in honour of Professor Yevgeniy Konstantinovich Markhinin (b. 1926), Institute of Volcanology, Russian Academy of Sciences, Kamchatka peninsula, Russia, in recognition of his contributions to volcanology. Markhininite is the first oxysalt compound that contains both Tl and Bi in an ordered crystal structure.


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