Chemistry of the phenoxathiins and isosterically related heterocycles. XI . The synthesis and 13C-NMR spectroscopy of 2-azaphenoxathiin

The synthesis of the 2-azaphenoxathiin ring system via the intermediary 2-azaphenoxathiin 2-oxide is described. Complete assignment of the ¹³C-nmr spectrum is reported, based on the observed heteronuclear ¹H-¹³C spin-couplings of the system and calculated chemical shifts as assignment criteria. The possible relation of the chemical shift of Cα to the dehidral angle of the system is also discussed.     

Chemistry of the phenoxathiins and isosterically related heterocycles. IX.N-oxidation on the 13C-nmr chemical shifts and coupling constants of the 1-azaphenoxathiin system

The synthesis of 1-azaphenoxathiin N-oxide is described. Total assignment of the ¹³C-nmr spectrum and the effects of the N-oxide moiety on the chemical shifts and ¹H-¹³C spin couplings constants are described and compared to the parent 1-azaphenoxathiin system. The potential for the use of N-oxidation induced changes in ¹³C-nmr chemical shifts and ¹H-¹³C coupling constants as an assignment criterion is also discussed.     

The crystal and molecular structure of tetrahydro-thiazole-2-thione

The crystal of tetrahydrothiazole-2-thione (TTT) belongs to monoclinic system. Space group P2₁/n. There are eight molecules in an unit cell with parameters a = 13.844(7)Å, b = 5.614 (2)Å, c = 13.516 (7)Å, β=95.08 (5)°, V =1046.3 (9)ų The three dimensional intensity data were obtained on a Syntex R3 four-circle diffractometer, and the number of the independent diffractions amounted to 1906. The structure was solved by direct method and refined by block-diagonal least-squares method. The final R is 0.082. In crystal, the molecular structure is between 1 and 2 in which S(1), S(2), N and C(1) are coplanar with conjugation. We use CNDO/2 programmes written by ourselves on Eclipse computer to compute the electronic energies, molecular total energies, dipole moments, the charge densities and net charges of each atom of TTT and its N-benzoylated derivative. The color of the acylated TTT and its properties for aminolysis are discussed.     

Novel Motif of Hydrogen Bonds in the Water-assisted Supramolecular Self-assembly of 2-acetylamino-6-methylpyridine-N-oxide and Hetero-assembly of 1:1 Co-crystal of o-Phenylenediamine with Catechol

Abstract

Water assisted supramolecular structures of 2-acetylamino-6-methylpyridine-1-oxide (1) and 1:1 complex of o-phenylenediamine with catechol (2) were determined. The crystal structure of 2-acetylamino-6-methylpyridine-1-oxide. H₂O (1), triclinic, a = 7.1276 (6), b = 7.8860 (6), c = 8.9938 (7) Å, α = 100. 143 (2), β = 91.493 (2), γ = 110.972 (1)°, V =462.47 (6) ų, Z = 2, D _calc = 1.323 mg.m^?3(293°K) reveals a novel centrosymmetric supramolecular assembly that is sustained by water molecules linking the dimers of pyridine-1-oxide through C—H…O, N—H…O, N⁺—O^? … H hydrogen bonds. The pyridine rings of the dimers are stacked at 3.473 Å apart, involving π- stacking interactions. Complex (2), C₆H₈N₂.—C₆ H₆O₂. 1/2H₂O crystallises in the monoclinic space group P2/c: a = 9.0498(2), b = 5.2275(1), c = 25.0771(2) A, β = 97.71°, V= 1175.62(4) ų, Z = 4. Refinement led to a final conventional R value of 0.041 for 2016 reflections. In these crystals (2), the water molecules lie on the twofold axis and they are linked to the pyrocatechol molecules through an O—H…O hydrogen bond.     

Synthesis,crystal structure and magnetic properties of Co(NIT4Py)(H2PDA)(H2O)3

A Co(II)-pyridyl substituted nitronyl nitroxide complex Co(NIT4Py)(H₂PDA)(H₂O)₃ has been synthesized and structurally characterized (NIT4Py: 2-(4′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and H₂PDA: 2,5-pyridine dicarboxylic acid). The compound is in the monoclinic space group P2(1)/c, a = 16.892(5) Å, b = 7.371(2) Å, c = 18.856(5) Å, β = 108.770(5)°, V = 2223.0(11) ų, Z = 4 and F(000) = 1064. The cobalt is in a distorted octahedral environment with one nitrogen from NIT4Py, one oxygen atom from H₂PDA, two oxygens from two water molecules in the basal plane and one nitrogen from H₂PDA and one water in the axial positions. The molecules are connected as a layered structure by intermolecular hydrogen bond interactions. Variable temperature magnetic susceptibility measurements reveal the occurrence of weak antiferromagnetic interactions in the compound.     

Synthesis and Structure of ThTe2I2

The new ternary compound ThTe₂I₂, which crystallizes in the NbS₂Cl₂ structure type, was prepared from the elements and characterized by single‐crystal X‐ray diffraction. It adopts a monoclinic layer structure where binuclear [Th₂(Te₂)₂]⁴⁺ units with square‐antiprismatically coordinated thorium are linked together by I^– anions to form sheets parallel to the (001) plane. The space group is C2/m and the lattice constants are a = 7.642(1) Å, b = 14.336(4) Å, c = 7.727(2) Å, and β = 111.27(2)° for Z = 4. The final R1/wR2 for the crystal structure refinement was 0.029/0.073.     

Crystal Structure and Thermal Behaviour of K2[CrF5·H2O]

K₂[CrF₅·H₂O] is monoclinic: a = 9.6835(3) Å, b = 7.7359(2) Å, c = 7.9564(3) Å, β = 95.94(1)°, Z = 4, space group C2/c (n^o 15). Its crystal structure was solved from its X‐ray powder pattern recorded on a powder diffractometer, using for the refinement the Rietveld method. It is built up from isolated octahedral [CrF₅·OH₂]^2? anions separated by potassium cations. The dehydration of K₂[CrF₅·H₂O] leads to anhydrous orthorhombic K₂CrF₅: a = 7.334(2) Å, b = 12.804(4) Å, c = 20.151(5) Å, Z = 16, space group Pbcn (n^o 60), isostructural with K₂FeF₅.     

Crystal and molecular structure of caryophyllene α-oxide

An x-ray study (λMo K^α, 2θ/ω scanning for 2θ<30°, MLS in the anisotropic approximation) has been made of caryophyllene α-oxide (I) at ?(98–100)°C (1182 reflections, R=0.051); crystals of the orthorhombic system,a=8.975, b=10.160, c=14.882 Å, z=4, space group P2₁2₁2₁, mp 62–63°C. The crystalline and molecular structures of caryophyllene α-oxide (I) have been studied and the configuration of the oxide ring has been confirmed.     

Crystal and molecular structure of 2,3-benzo-1,4,7,13-tetraoxa-10-selenacyclopentadeca-2-ene

The crystal structure of 2,3-benzo-1,4,7,13-tetraoxa-10-selenacyclopentadeca-2-ene was de-termined,C_(14)H_(20)O_4Se,M_r:331.27,orthorhombic,Pbca,a=18.445(3),b=16.334(4),c9.232(2),V=2781.3 ~3,Z=8,Dx=1.582 Mg m~(-3),λ(Mo K_α)=0.71073 ,μ=26.77 cm~(-1),F(000)=1360,T=297 K,R=0.0329,R_w=0.0438 for 2192 reflections with I>3 σ(I).The crystal structure is closelyrelated to that of benzo-15-crown-5(at 123 K),whereas the molecular geometry of the two coronandsis different according to their torsion angles calculated and the shapes exhibited.     

Crystal structure and stereochemistry of (PS*, 2S*, 3aS*)-hexahydro-2-(tert-butylvinylthiophosphinyl)-6,6- dimethylpyrrolo[1,2-b]isoxazole

The structure of the major product of the cycloaddition of 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide to tert-butyldivinylphosphine sulfide was analyzed by means of single-crystal X-ray diffraction technique. The analysis revealed two crystallographically independent molecules that differed in conformation of the fused five-membered heterocyclic rings. These rings were found to be two envelopes in one molecule and two half-chairs in the other. The studied compound was identified as an exo adduct of the expected erythro configuration and was found to favor a conformation in which the PS and ring C–O bonds were anti and the CC–PS moiety was in the s-cis array. C₁₄H₂₆NOPS, space group P¯1, a = 10.6004(7) Å, b = 12.3225(6) Å, c = 13.4404(7) Å, α = 104.073(4)°, β = 92.758(4)°, γ = 95.968(5)°, V = 1688.802(4) ų, Z = 4.     

Chemistry of the phenoxathiins and isosterically related heterocycles. XXII. 6,7,9-trimethyl-4-azaphenoxathiin: First reported synthesis of an analog of the 4-azaphenoxathiin ring system

The reaction of 2-chloro-3-thiocyanatopyridine with a substituted spiroepoxycyclohexadienone, which served as a masked phenol with reversed polarity, led to the first reported synthesis of an analog of the 4-azaphenoxathiin ring system. Confirmation of the structure was obtained from the assignment of the ¹³C-nmr spectrum.     

Preparation and Crystal Structure of the Strontium Aluminium Fluoride Sr5Al2F16

Single crystals of Sr₅Al₂F₁₆ crystallize in colourless translucent plates and have been prepared by solid state synthesis, starting from stoichiometric mixtures of the binary fluorides. The crystal structure has been determined and refined from single crystal diffractometer data (orthorhombic, space group Ccca (no. 68), a = 7.4488(4) Å, b = 12.4714(7) Å, c = 14.1411(8) Å, V = 1313.67(13) ų, Z = 4, R[F ² > 2σ(F ²)] = 0.025; wR2(F ² all) = 0.056, 971 structure factors, 56 parameters) and can be derived from a slightly distorted c.c.p. arrangement where 7/8 of the c.c.p. positions are occupied by the metal atoms. The main features of the structure are AlF₆ octahedra and SrF₈ polyhedra with mean distances d(Al–F) = 1.791 Å and d(Sr–F) = 2.531 Å, respectively.     

The crystal and molecular structure of phenothiazine-10-propionitrile. The effect of crystal packing on the dihedral angle of phenothiazine heterocycles

Phenothiazine-10-propionitrile, C₁₂H₈SNC₂H₄CN, crystallizes in the centrosymmetric monoclinic space group P2₁/n, with a = 5.785(1)Å, b = 15.427(3)Å, c = 14.497(4)Å, β = 92.50(1)°, Z = 4, D_meas = 1.29(1) g cm³ and D_calc = 1.28 g cm³ at 23°. Three dimensional X-ray data were collected with a manual diffractometer using MoKα (λ 0.71069Å) radiation and by multiple film Weissenberg techniques using CuKα (λ 1.5418Å) radiation. The structure was determined by Patterson and Fourier methods and refined with 519 observed reflections by full matrix least-squares methods to an R of 0.077. The dihedral angle between the two planes of the o-phenylene rings is 135.4(3)°. In the folded heterocyclic ring the C-S-C angle is 97.8(7)° and the average C? S bond is 1.76(1)Å. A comparison of this structure to that of phenothiazine-10-propionic acid shows the two chemically similar molecules have the same dihedral angles in spite of completely different solid state packing patterns.     

Synthesis and Structure of the New Compound La2O(CN2)2 Possessing an Interchanged Anion Proportion Compared to the Parent La2O2(CN2). Synthese und Kristallstruktur der neuen Verbindung La2O(CN2)2 mit einem vertauschten Anionenverhältnis gegenüber der Bezugsverbindung La2O2(CN2)

La₂O(CN₂)₂ was synthesized from a 1:1:2 molar reaction mixture of LaCl₃, LaOCl, and Li₂(CN₂) at 650 °C. Well developed single crystals were grown from a LiCl‐KCl flux. The crystal structure was refined as monoclinic (space group C2/c, Z = 2, a = 13.530(2) Å, b = 6.250(1) Å, c = 6.1017(9) Å, β = 104.81(2)°) from single crystal X‐ray diffraction data. The La³⁺ and (CN₂)^2— ions in the crystal structure of La₂O(CN₂)₂ can be compared to Fe³⁺ and S₂^2— ions in the cubic pyrite structure, being arranged like in a distorted NaCl type structure with their centers of gravity. In addition, the O^2— ions in La₂O(CN₂)₂ are occupying 1/4 of the tetrahedral voids formed by the arrangement of metal ions.     

Crystalline and molecular structure of diaminoguanidinium tetrachlorozincate

A single-crystal X-ray diffraction study of a single crystal of the composition (AgunH)₂[ZnCl₄], where AgunH = (NH₂)₂C-NH-NH₂)⁺, has been performed. Crystals are monoclinic, space group P2₁/c, Z = 4, a = 7.642(2) Å, b = 24.123(4) Å, c = 7.496(2) Å, β = 81.77(2)°, V = 1368.0(2) ų, T = 293 K. The finite value R = 0.045 was obtained for 1878 independent reflections with I > 3σ(I). The structure was built from cations of aminoguanidinium and tetrahedral complex anions [ZnCl₄]^2?.     

Synthesis,crystal and molecular structure of [Na(B15C5)+]2[Hg3Cl8]2-·H2O

A crystal complex with the formula [Na(B15C5)⁺]₂ [Hg₃Cl₈]^2-·H₂O was synthesized by the reaction of benzo-15-crown-5 with sodium chloride and mercuric chloride. Its crystal and molecular structures were determined by X-ray diffraction. Crystal data: monoclinic, space group P2/n with cell dimensions of a= 17.809(4) Å, b= 13.938(4) Å, c= 17.984(4) Å, β=107.14°, Z=4, V= 4266.2 Ų. R and R_w are 0.043 and 0.053, respectively. The results obtained by spectral analysis are consistent with those of the structural analysis.     

Preparation,X-ray crystal structure and 13C- and 1H-NMR study of 1-methyl-2-(N-methyl-N-phenylglycyl)-3-(N-methylanilino)indole

Reaction of N-methylaniline with 40% glyoxal yields 1-methyl-2-(N-methyl-N-phenylglycyl)-3-(N-methylanilino)indole ( 1a ) as the main product together with 1-methyl-3-(N-methylanilino)indole ( 1b ). The reaction appears to be general for aromatic secondary amines since N-ethylaniline and N-phenylbenzylamine yield the corresponding indoles. The structure of 1a has been verified by single crystal X-ray diffraction. Compound 1a (C₂₅H₂₅N₃O) crystallized in the triclinic space group Pl? with cell dimensions a = 10.085(3)Å, b = 10.371(3)Å, c = 11.908(5)Å, α = 74.2(3)°, β = 74.7(3)° and γ = 60.7(2)° with Z = 2. The complete ¹H and ¹³C nmr assignment of indoles 1a and 1b was achieved from two-dimensional HETCOR and COSY spectra with the aid of homonuclear and heteronuclear double resonance experiments.     

Determination of structure and 13C chemical shift assignments of the nitration products of 2-chloro-10-methylphenothiazine. X-Ray molecular structure of 2-chloro-7-nitro-10-methylphenothiazine 5-oxide

Nitration of 2-chloro-10-methylphenothiazine, 1 , yields two mono-nitro compounds identified as sulfoxide 2 and sulfone 3 . The nmr analyses of the ¹³C spectra of 2 and 3 establish unequivocally that in both compounds substitution has occurred at the seven position. This is supported by the X-ray crystal structure of one of the compounds 2-chloro-7-nitro-10-methylphenothiazine 5-oxide, 2 , which also shows that the sulfoxide group is in the “pseudo-axial” configuration. Crystals of 2 are monoclinic, space group P2₁/n, a = 11.606(4), b = 13.970(4)Å, c = 9.837(2), β = 127.49(2)° and Z = 4. The structure has been refined by full-matrix least-squares to R = 0.033 and R_w = 0.035, using 1704 observed reflections.     

Synthesis and Crystal Structure of SrFe[BP2O8(OH)2]

SrFe[BP₂O₈(OH)₂] was synthesised under mild hydrothermal conditions. The crystal structure was determined from single–crystal X–ray diffraction data: triclinic, space group P (No. 2), a = 6.6704(12) Å, b = 6.6927(13) Å, c = 9.3891(19) Å, α = 109.829(5)°, β = 102.068(6)°, γ = 103.151(3)°, V = 364.74(12) ų and Z = 2. The crystal structure of SrFe[BP₂O₈(OH)₂] contains isolated borophosphate oligomers, [BP₂O₈(OH)₂]^5–, which are interconnected by Fe^IIIO₄(OH)₂ coordination octahedra. The resulting three–dimensional framework is characterised by elliptical channels running along [011]. Strontium takes positions inside the channels.     

Structural Investigations and Thermal Behavior of (NH4)[Cr(C2O4)2]·2H2O

Single crystals of ammonium chromium(III) dioxalate dihydrate (or ammonium diaquo bis(μ‐oxalato)chromate(III)) have been obtained from aqueous solution of oxalic acid and ammonium dichromate. A pale violet crystal of good optical quality was used for the structure determination at ?100(2) and 25(2) °C, respectively. The basic crystallographic data for the low temperature data set are as follows: monoclinic, space group C2/m, a = 6.597(2) Å, b = 7.301(2) Å, c = 9.983(3) Å, β = 92.32(2)°, V = 480.5(2) ų. The structure was solved by direct methods and refined (using anisotropic displacement parameters for all non‐hydrogen atoms) to a final residual of R1 = 0.032 for 503 independent observed reflections (I>2σ(I)). The compound is isotypic with the corresponding rubidium salt. The structure is built up from alternating layers parallel to (001) containing (NH₄)⁺ ions or Cr(C₂O₄)₂(H₂O)₂ octahedra, respectively. The corners of the octahedra consist of four O atoms from two oxalate groups and two additional water molecules. The ammonium cations (occupying Wyckoff‐site 2a) are disordered among two possible orientations. They provide linkage between different octahedral layers by hydrogen bridging. The water molecules in turn form hydrogen bridges with adjacent octahedra within the same layer. Further structural characterization included infrared spectroscopy. According to DTA/TG experiments the present compound shows several thermal processes in the range between room temperature and 900 °C.