Crystal structure of (diphenyl)(morpholino)phosphiniminocyclotrithiazene

The title compound (C₆H₅)₂(OC₄H₈N)P=N–S₃N₃ crystallizes in the space group with unit cell parametersa=9.3900(2),b=9.4747(1),c=11.3850(3) Å, =95.73(4), =96.85(6), =104.26(2)^o, and Z=2. The tricoordinated sulfur of the cyclotrithiazene ring deviates from the mean plane of other skeletal atoms by 0.683(4) Å. The angle at this atom is the smallest in the ring and is enclosed by the longest S–N bonds observed in the ring.     

Synthesis and absolute configuration of (+) α-hydroxymethyltyrosine by X-ray analysis of its N-benzoyl derivative

-Hydroxymethyltyrosine has been synthesized by a route involving-hydroxymethylation. Dextrorotatory N-benzoyl--hydroxymethyltyrosine4 crystallizes in space group P2₁2₁2₁ with cell parameters:a=13.2266(9),b=16.1099(9),c=7.4475(5) Å,V=15.86.9(2) ų,Z=4. The structure was solved by direct methods and refined toR=0.047 andR _w =0.066 with 1549 independent and 956 reflections. The absolute configuration of 1 was determined asR by the application of Hamilton test and by the estimation of the Bijvoet coefficientB. Just as in N-benzoyl--methylcysteine (Wieczorek et al., 1989), the-amino acid residue adopts the C⁵ ring conformation similar to the fully extended form. The two side chains also adopt an extended conformation around the C atom.     

Crystal and molecular structure of potassium 2-amino-6-sulfinato-purine monohydrate

The crystal and molecular structure of the title compound, K[C₅H₄N₅O₂S]H₂O, has been determined at room temperature. The structure determination reveals that the negative charge on the anion is localised on the sulfinate group which results in significant rearrangement of -electron density within the purine ring. The K⁺ cation exists in a N₃O₄ donor set which defines a distorted trigonal prismatic geometry. Crystals of K[C₅H₄N₅O₂S]H₂O are triclinic with space group and unit cell dimensionsa=8.248(2),b=8.710(2),c=6.988(6) Å, =99.87(4), =102.84(5), and =78.35(2)°,Z=2.     

Structure, thermal behavior, and IR investigations of (C6H9N2)H2PO4

Chemical preparation, X-ray single-crystal, thermal behavior, and IR spectroscopy studies of a new dihydrogenmonophosphate associated to an organic cation, the 3-(ammoniummethyl)pyridine dihydrogenmonophosphate (denoted as AMPP) are described. The AMPP crystallizes in the monoclinic system with P2₁/c space group. The unit cell dimensions are a = 5.8465(2) Å, b = 19.9776(9) Å, c = 7.3103(3) Å, = 90.848(3)° with V = 853.74(4) ų and Z = 4. The structure has been solved using direct method and refined to a reliability R factor of 0.0393. The structure of AMPP includes three types of hydrogen bonds. The first one, O H O, links the H₂PO₄ groups to form infinite inorganic chains [H₂PO₄]n ^n–, parallel to the c axis. The two other types, O H N and N H O assemble inorganic chains so as to build up a three-dimensional arrangement.     

Structure of bis(2-pyridine-N-oxide) diselenide and its formation from tetraphenylantimony(V)selenopyridine-N-oxide

The structure of bis(2-pyridine-N-oxide) diselenide was determined by single crystal X-ray diffraction. The compound crystallized in the triclinic system and the structure was solved in the space group . The lattice constants were determined to bea=7.174(2),b=7.176(2),c=11.070(2) , =87.67(2)°, =73.68(2)°, and =89.57(2)°;Z=2,D _x=1.906 Mg m^–3. The final least squares refinement based on 1942 independent observed reflections yieldedR=0.033,wR=0.044. The Se–Se bond length is 2.326(1) and each Se is coordinated to the O atom of the corresponding N-oxide moiety at a distance of about 2.6 .     

X-ray crystal structure oftrans-dichlorobis(2,6-lutidine)palladium(II)

The X-ray structure oftrans-(2,6-lutidine)₂PdCl₂ has been determined. Golden orange crystals of the complex crystallize in the triclinic space group , with cell dimensionsa=7.6950(8),b=7.9705(10),c=8.0485(8)Å, =116.967(9), =113.343(8), and =93.836(9)°;V=385.18(7)ų andZ=2. 1336 unique reflections withI _net>3 (I) on refinement afforded values ofR=0.018 andR _w=0.023.     

Structure and IR spectroscopic properties of the anhydrous 4-N,N-dimethylaminopyridinium pentachlorophenolate

The structure of the anhydrous 4-N,N-dimethylaminopyridinium pentachlorophenolate has been determined by X-ray diffraction. The crystals are triclinic, space group witha=8.637(1),b=8.865(1),c=10.235(1) Å, =83.80(1), =86.88(1), =89.37(1)° andZ=2. The structure was solved by direct methods and refined to R=0.031 for 1874 non-zero reflections. The N⁺–H...O^– hydrogen bond length is 2.579(4) Å and bond angle 165(3)°. The pyridinium ring plane is almost perpendicular to the phenolate ring plane (83.9(5)°). The ionic character and strongly asymmetric proton position in the hydrogen bond has been confirmed by the IR spectrum.     

Schiff bases and their complexes with metal ions. Part II. Structures of N-n-butyl-2-hydroxy-1-naphthaldimine and bis[N-n-pentyl-2-hydroxy-1-naphthaldiminato]nickel(II)

The Schiff base ligand (1), [C₁₅H₁₇NO] crystallizes in the monoclinic space group P2₁/c witha=10.054(3),b=10.313(3), c=13.173(4)Å, =107.42(4)°,V=1303.2(7)ų,Z=4,Dx=1.159 g cm^–3, and (MoK)=0.674 cm^–1. The C2-O[1.23(1)Å] and C3–C4 [1.33(2)Å] bond lengths are short, due to its quinoidal structure. In the Schiff base nickel complex (2), [Ni(C₁₆H₁₈NO)₂] the asymmetric unit is comprised of two half-complexes. It crystallizes in the triclinic space group witha=5.124(3),b=16.227(3),c=16.886(4)Å, =95.47(8), =96.00(1), =90.71(4)°,V=1389.6(9) ų,Z=2,Dx=1.289 g cm^–3, and (MoK) =12.1 cm^–1. The coordination of the Ni(II) ions are square planar with bond angles between 87.9(1) and 92.1(1)°. The Ni–O and Ni–N distances are 1.819(2), 1.922(2) and 1.823(2), 1.914(3)Å in these two complexes.     

Reaction of trimethylaluminum and trimethylgallium with bifunctional amines: Syntheses and molecular structures of [Me2Al−N(CH2CH2)2−C−(OCH2)2]2 and [Me2Ga−N(Si(H)Me2)2]2

The crystalline products [Me₂Al–N(CH₂CH₂)₂–C–(OCH₂)₂]₂ (I) and [Me₂Ga–N(Si(H)Me₂)₂]₂ (II) were prepared from reactions of trimethylaluminum and trimethylgallium with 1,4-dioxa-8-azaspiro[4.5]-decane and 1,1,3,3-tetramethyldisilazane, respectively, in toluene. The organoaluminum dimer crystallizes in the monoclinic space groupP2₁/c with unit cell parametersa=8.970(2) ,b=9.683(2) ,c=12.833(3) , =103.18(2)°,V=1085.3(3) ³, andD _calcd=1.22 g cm^–3 forZ=2. Least-squares refinement based on 935 observed reflectionsI>3(I) in the range 3.5°<2<45.0° led to a finalR factor of 0.033 (R _w =0.041). The dimeric organosilazagallium crystallizes in the triclinic space group with unit cell parametersa=7.636(2) ,b=9.168(2) ,c=9.466(3), =72.81(2)°, =87.94(2)°, =69.90(2)°,V=593.0(3) ³, andD _calcd=1.30 g cm^–3 forZ=1. Least-squares refinement based on 1661 observed reflectionsI>3(I) in the range 3.5°<2<48.0° led to a finalR factor of 0.055 (R _w =0.070). Both compoundsI andII reside about a crystallographic center of symmetry and contain a planar M₂N₂ (M=Al forI, Ga forII) four-membered ring withI having an Al...Al contact of 2.801 .     

Crystal structure ofcis-[Ru(bpy)2(PPh3)Cl+][ClO 4 − ]·(toluene)·∼0.5(CH2Cl2), a species with two different disordered solvent molecules of crystallization

The complexcis-[Ru(bpy)₂(PPh₃)Cl⁺][ClO ₄ ^– ] (where bpy=2,2-bipyridyl) crystallizes from a solution in toluene/dichloromethane as the toluene-hemi(dichloromethane) solvate in the centrosymmetric space group witha=10.343(2)Å,b=11.823(3)Å,c=18.469(4)Å, =98.90(2)^o, =93.32(2)^o, =101.46(2)^o,V=2177.8(8)ų andZ=2. The structure was refined toR(F)=4.6% for those 4248 reflections above 6(F _o ). The octahedral Ru(II) cation is associated with the bond lengths Ru–Cl=2.424(2)Å, Ru–PPh₃=2.328(1) Å and Ru–N=2.045(5)–2.109(4)Å. Both the cation and the perchlorate anion are ordered. However, the unit cell also contains two disordered toluene molecules (centered about inversion centers at 1, 1/2, 0 and 1/2, 0, 1/2), and a disordered dichloromethane molecule of a partial occupancy (centered about 1/2, 0, 1).     

Synthesis and crystal structure of the two-dimensional coordination polymer catena(bis(μ3-iodo)-(μ 2-pyrazine)-di-copper(I))

The two-dimensional coordination polymer [Cu₂ i ₂(pyz)]_n (where pyz = pyrazine) has been synthesized hydrothermally and structurally characterized by single crystal X-ray diffraction analysis. [Cu₂ i ₂(pyz)]_n crystallizes in the space group P with a = 4.1759(4) Å, b = 7.1281(7) Å, c = 8.1279(8) Å, = 109.607(2), = 101.769(2), = 96.676(2), and Z = 1. The sheet-like polymer is characterized by infinite stair step [Cu₂ i ₂]_n double chains connected in two dimensions through bridging pyrazine ligands. The coordination environment about each copper is approximately tetrahedral having three Cu–I bonds and a single Cu–N bond.     

Molecular structure of isopropyl 1-phenyl-4-phenylhydrazono-5-oxo-3-pyrazolecarboxylate

The new azopyrazolone dye has been synthesized and its crystal structure has been investigated. Crystals of C₁₉H₁₈N₄O₃ are triclinic: ,a=7.484(1),b=10.646 (1),c=11.897(1) Å, =82.28(1), =72.86(1), =86.83(1)°,Z=2. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.050 for 2622 unique reflections. The tautomeric form of the molecules has been determined as a hydrazo form. Delocalization of the C5=O3 and C4=N3 -electrons and delocalization of the lone-pair electrons of N1, N3, and N4 atoms has been observed. The intramolecular N–H...O hydrogen bond forms the six-membered ring C₂N₂H...O condensed with the pyrazolone ring. The molecules are connected by intramolecular C–H...O hydrogen bonds.     

Crystal and molecular structure of: 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octan-7-one and 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octane

X-ray crystallographic studies of the two title compounds have shown that the molecules crystallize in the same triclinic space group, , with very similar cell dimensions. For C₂₁H₂₁BrO₄,a=12.056(5),b=13.206(5),c=7.595(3)Å, =90.38(3), =106.07(3) and =124.42(3)° and for C₂₁H₂₃BrO₃,a=12.076(6),b=13.090(5),c=7.490(3)Å, =92.65(5), =104.90(5) and =124.55(5)°. Both compounds possess the oxabicyclo[3.2.1]octane bridged ring system and differ only at the carbon to the ring oxygen where the Csp³ in the ether is replaced by Csp²=O in the lactone. Both cyclohexane rings adopt distorted chair conformations and the lactone and ether rings approximate closely to the envelope conformation. The bromine substituent at C(4) results in distortion of the naphthalene ring. Both molecules pack with the naphthalene rings parallel to each other with interplanar spacings of 3.71 Å in the ether and 3.66Å in the lactone.     

Crystal structures of 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione and 1-(1,3-benzodioxol-5-yl)-3-(2,4-dimethoxyphenyl)-1,3-propanedione

1-(2-Hydroxyphenyl)-3-phenyl-1,3-propanedione crystallizes in the triclinic space group (a=5.4233(5),b=13.910(1),c=17.036(1) Å, =68.311(6), =80.854(7), =78.760(8)°) as two independent enolic tautomers in which the hydroxyl and phenolic protons are hydrogen bonded to the ketonic oxygen atom. The structure was refined toR=0.039 for 2085I3(I) reflections. 1-(1,3-Benzodioxol-5-yl)-3-(2,4-dimethoxyphenyl)-1,3-propanedione, which belongs to the triclinic space group (a=7.3990(7),b=8.1239(5),c=14.004(1) Å, =86.673(6). =88.574(7), =64.885(7)°) also exists in the enolic form. The structure was refined toR=0.040 for 1564I3(I) reflections.     

The crystal structure of 2-nitroresorcinol

2-Nitroresorcinol is triclinic, space group P; at –100°Ca=7.083(2),b=7.696(2),c=6.607(2) Å, =74.61(2), =77.81(2), =68.64(2)°,V=320.8(2) ų,D _x=1.606(1) g cm^–3,Z=2. The two hydroxyl groups form symmetric intramolecular hydrogen bonds to the nitro group. The molecules pack in stacks held together by - interaction with adjacent molecules in a head-to-tail arrangement.     

Crystal structure of 4,6-dinitro-1-(5-tetrazolyl)-1H-indazole trihydrate

The title compound, C₈H₄N₈O₄·3H₂O, crystallizes in space groupP¯1 with cell constantsa=7.022(1),b=9.507(2),c=10.906(2) Å,=84.99(1),=71.89(1),=72.56(1)°,Z=2, andV _c =660.2 ų. The structure was solved by direct methods using diffractometer data and was refined by full-matrix least-squares methods to anR value of 0.060 for 2112 observed reflections. The molecule, consisting of a phenyl ring fused to a pyrazole ring with a tetrazole ring connected to it equatorially, is planar except for the N(7) nitro-group oxygen atoms. The structure is stabilized by a three-dimensional network of O-HO, O-HN, and N-HO hydrogen bonds through the water molecules.     

Structural characterization of oxidized lumiflavin hydrochloride hydrate: Comparison with the hydrogen bonding at the cofactor of flavoproteins

In order to examine the possibility of hydrogen bonding around the flavin ring, an X-ray diffraction study of the title compound was undertaken. Crystals of lumiflavin hydrochloride hydrate [2(C₁₃H₁₂N₄O₂) 4 HCl 7 H₂O] are triclinic, space group ,Z=2,a=11.064(1),b=17.903(1),c=9.891(1)Å, =111.9(6), -96.4(8), =91.6(7)°. We present the crystal structure of this compound and compare it with other flavin derivatives and with the structure of the active site of some flavoproteins.     

Synthesis and structure of the adduct dichlorodiaquobis(ethylpropionate)magnesium(II)

The crystal and molecular structure of MgCl₂(H₂O)₂(ethylpropionate)₂ has been determined by single crystal X-ray diffraction analysis. The complex crystallizes in the triclinic system, space group (No. 2);a=5.912 (2),b=5.931 (3),c=12.792 (4) Å, =77.15°(3), =86.21°(3), =88.31°(3);Z=1. The metal lies at the center of a slightly distorted octahedron formed by two chlorine atoms and four oxygens, two from water molecules and two from the carbonyl groups of the ethylpropionate ligands in atrans configuration.     

Crystal structures of 3-(4-pyridinyl)-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyrimidine and its 6-hydroxy derivative

(1): C₁₀H₁₁N₅,M _r=201.23, from water, P ,a=6.913(1),b=8.198(2),c=9.212(2) Å, =72.36(2), =109.03(2) and =88.13(1)^o,D _x=1.436 g/cm³,Z=2. FinalR=0.043 for 1477 observed reflections. (2): C₁₀H₁₁N₅O,M _r=217.23, from methanol/water solution. P2₁/c,a=9.291(2),b=11.263(3),c=10.454(3) Å, and =114.05(1)^o,D _x=1.444, g/cm³,Z=4. FinalR 0.056 for 1587 observed reflections. The data were collected on a diffractometer at room temperature. Structures were solved by direct methods and refined by anisotropic full-matrix least-squares method. In the solid state both molecules have the same conformation and are packed in similar manner. The planarity of the condensed triazole ring and its electrons conjugation with a lone pair at N8 impose C6 sofa conformation of the saturated diazine rings. Hydroxy group in2 is in an energetically unfavorable axial position. Both in1 and2, N8–H ... N34 hydrogen bonds join molecules into infinite chains, and O6–H ... N1 hydrogen bonds in2 span the chains into two-dimensional net. The molecules in hydrogen bonded chains and sheets have the same chirality.