Crystal and molecular structure of <Emphasis Type="Italic">tris</Emphasis>(<Emphasis Type="Italic">m</Emphasis>-chlorophenyl)phosphine selenide

The crystal and molecular structure of tris(m-chlorophenyl)phosphine selenide, C₁₈H₁₂Cl₃PSe (I), was investigated by X-ray diffraction (XRD) analysis. The trigonal rhombohedral structure of I (space group \(R\overline 3 c\), a = 14.110(2) Å, c = 32.360(4) Å, Z = 12) was solved by direct methods and refined by least squares in an anisotropic approximation (R = 0.029) for 1319 averaged measured reflections (CAD-4 automatic diffractometer, λCuK_α).     

Crystal structure of methylbis(chloromethyl)phosphine oxide

In the crystal structure of (CH₂C1)₂P(O)CH₃ and the isomorphous crystal structures of (CH₂Br)₂P(O)CH₃ and (CH₂I)₂P(O)CH₃, the molecules of the methylbis(halomethyl)phosphine oxide have an identical trans, gauche conformation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1526–1528, July, 1991.     

Second crystal modification of 1,10-diazonia-18-crown-6 dichloride

The second crystal modification (II) of 1,10-diazonia-18-crown-6 dichloride [H₂DA18C6]²⁺·2Cl^?, where [H₂DA18C6]²⁺ is the 1,10-diaza-18-crown-6 dication (DA18C6) with two protonated nitrogen atoms, was investigated by XRD. The monoclinic modification (II) (space group P2₁/n, a = 9.600 Å, b = 5.689 Å, c = 15.749 Å, β = 91.03°, Z = 2) was solved by direct methods and refined by full-matrix least squares analysis in an anisotropic approximation to R = 0.032 for all 2494 independent reflections collected (CAD-4 automatic diffractometer, λMoK _α). In modification II, the conformation of the DA18C6 dication and the ion packing differ from those in triclinic modification I investigated previously.     

Synthesis and the reactions of trifluoromethylated 1,2,3-triketones 2-(het)arylhydrazones and 4,7-dihydroazolo[5,1-c]triazines

The coupling of trifluoromethylated 1,3-diketones with (het)aryldiazonium chlorides results mainly in the formation of 1,2,3-triketones 2-(het)arylhydrazones while using hetarylamine with a NH-group at the α-position of the heterocycle as the diazonium component gives 4,7-dihydroazolo[5,1-c]triazines due to cyclization at the trifluoroacetyl fragment. Trifluoromethylated 1,2,3-triketones 2-(het)arylhydrazones and 7-hydroxy-4,7-dihydroazolo[5,1-c]triazines react regio-selectively with methyl hydrazine and phenyl hydrazine to form 3-CF₃-pyrazoles. The long-range coupling constants (J_F-H) of 1-methylpyrazoles and the chemical shifts of trifluoromethyl groups in the ¹⁹F NMR spectra can be used for the determination of regio-isomeric structures of mono(trifluoromethyl)-substituted pyrazoles. 2-(Het)arylhydrazones and 4,7-dihydroazolo[5,1-c]triazines with two trifluoromethyl substituents afford the mixtures of cis- and trans-azopyrazoles in the reactions with hydrazines.     

Crystal and molecular structure of 1-ferrocenyl-r-3,t-5-diphenyl-c-4-(1-ferrocenylvinyl)-1-cyclohexene

X-ray diffraction has been used to establish the crystal and molecular structure of one diastereoisomer of 1-ferrocenyl-3,5-diphenyl-4-(1-ferrocenylvinyl)-1-cyclohexene. This diastereoisomer, formed in the greatest amounts in the protoncatalyzed cyclodimerization of 1-phenyl-3-ferrocenyl-1,3-butadiene, is shown to have the r-3, c-4, t-5 configuration of the exocyclic substituents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1216–1220, May, 1991.     

Crystal structure of 1H+,10H+-1,10-diazonia-18-crown-6 diethyldithiophosphate

An x-ray diffraction structural analysis was carried out on 1H⁺,10H⁺-1,10-diazonia-18-crown-6 diethyldithiophosphate, which exists in the crystal as isolated ionic hydrogen-bonded complexes [H₂DA18C6]²⁺·2(EtO)₂PS₂ ^– with strong inter-ion N-HS hydrogen bonds. The centrosymmetric DA18C6 dication has an unusual two-cornered conformation stabilized by a pair of weak intra-ring furcated OH(N)O hydrogen bonds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 190–192, January, 1991.     

Crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane monohydrate picrate

The crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane monohydrate picrate, [H(Crypt-222) H₂O]⁺·Pic^? (I), has been studied by X-ray crystallography. The structure of I (space group P2₁/c, a = 9.336 Å, b = 19.497 Å, c = 16.420 Å; β = 94,84°, Z = 4) was solved by direct methods and refined by full-matrix least squares in an anisotropic approximation to R = 0.056 for all 3877 independent reflections collected (CAD-4 automatic diffractometer, λMoK _α). This compound is one of the few representatives of the class of crystal salts containing a 2.2.2-cryptand cation with a protonated nitrogen atom that have been synthesized and studied by X-ray crystallography. The void of the cation contains a water molecule held by three H bonds. Crystal I also has unusual H bonds of C-H…O type that link the neighboring 2.2.2-cryptand cation and the picrate anion.     

Crystal Structure of Diaqua(2.2.2-cryptand)strontium Bis(thiocyanate)

The crystal structure of the title compound, [Sr(C₁₈H₃₆N₂O₈)(H₂O)₂]²⁺·2SCN^– (I), was investigated by X-ray diffractometry: space group , a = 10.724(3), b = 15.512(3), c = 16.826(4) , = 97.96(3)°, Z = 4. The structure was solved by direct methods. The full-matrix least-squares anisotropic refinement converged to R = 0.038 for all 3837 independent measured reflections (CAD-4 automatic diffractometer, ). In the structure of I, the Sr²⁺ cation (c.n. 10) lies in the cavity of the cryptand ligand and is coordinated by all of its eight heteroatoms (6O+2N) and two O atoms of the two water molecules; its coordination polyhedron is a distorted two-base-centered bicapped trigonal prism. The cryptand ligand in I has an asymmetric conformation. The crystal structure of I has interionic hydrogen bonds (formed by the H atoms of the ligand water molecules) linking the complex cations and the SCN^– anions into complex infinite chains.     

Crystal Structure of the Complex of 1,2-Bis[2-(o-hydroxyphenoxy)ethoxy]ethane with Ammonium Thiocyanate

The complex of the podand 1'2-bis[2-(o-hydroxyphenoxy)ethoxy]ethane (L) with ammoniumthiocyanate, [NH₄(SCN)L], was prepared, studied by single crystal X-ray diffraction. This is a host-guestcomplex; in its molecule the podand L is wrapped around the NH ₄ ⁺ cation, which forms hydrogen bondswith all the six oxygen atoms of the podand and one hydrogen bond with the sulfur atom of the SCN^- anion. The geometric parameters (bond lengths, bond angles, torsion angles, etc.) of the molecule of [NH₄(SCN)L] and packing of the molecules in the crystal were determined. The molecules are linked into infinite polymeric chains by intermolecular hydrogen bonds O-H···NCS.