Crystal structure of a silver(I) complex with the 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid)

The reaction between freshly precipitated silver oxide Ag₂O and an aqueous solution of tetrabenzenecarboxylic acid H₄L leads to the anhydrous Ag₂H₂L complex. It crystallizes in the space groupP2₁/c, witha=6.457(1),b=8.180(1),c=9.982(1) Å, β=97.83(1)°,V=522.3(1) ų,Z=2,d=2.976 g cm^?3. This structure is a three dimensional polymeric network polymer without any silver...silver interaction. The silver environment is a bipyramid trigonal polyhedron with three short bond distances in the equatorial plane (Ag?O=2.255(2), 2.295(2), and 2.499(2) Å) and two longer bond distances in axial positions (Ag?O=2.558(2) and 2.617(2) Å). Thus, the silver polyhedron involves five different ligands. It is noteworthy that the (H₂L₂)^2? ligand is located around an inversion centre.     

Structure of (N-(2-hydroxyphenyl)-salicylaldiminopiperidino) Ni(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂O₂Ni, has been determined by direct methods. The compound crystallizes in the monoclinic crystal system witha=22.973(1),b=5.212(1),c=27.076(1)Å, β=106.46(1)°, space groupC2/c,V=3109.1(6)ų, Z=8, andD _x=1.51g cm^?3. The nickel atom is in a slightly distorted square-planar environment of two oxygens [Ni(1)?O(1) 1.824(3) and Ni(1)?O(2) 1.856(3)Å] and two nitrogens [Ni(1)?N(1) 1.849(3) and Ni(1)?N(2) 1.932(3)Å] with O?Ni?N angles between 85.7(1) and 97.1(1)°. The nickel atom is 0.006 Å out of the plane of its ligands.     

1,3,5-trichlorotricyanobenzene complexes with mesitylene (1/1) and benzene (1/3)

Trichlorotricyanobenzene-mesitylene (1/1) is monoclinic, space group P2₁/n; at ?88°Ca=10.509(3),b=14.863(7),c=11.518(3) Å, β=99.38(2)⁰,V=1775(2) ų,D _x =1.409(2) g cm^?3,Z=4. Trichlorotricyanobenzene-benzene (1/3) is hexagonal, space group $P\bar 6$ ; at ?99°Ca=17.3914(3),c=7.2673(1) Å,V=1903.6(1) ų,D _x =1.2844(1) g cm^?3,Z=3. In both complexes there are stacks of alternating trichlorotricyanobenzene and hydrocarbon molecules. In both complexes there are sheets of molecules perpendicular to the stacks. In the mesitylene complex these sheets contain equal numbers of both kinds of molecules with the trichlorotricyanobenzene molecules arranged in tapes. In the benzene complex the sheets contain only one kind of molecule or the other. The sheets containing the trichlorotricyanobenzene molecules have approximately linear C?N...Cl?C intermolecular interactions with N...Cl distances about 3.02 å.     

Crystal structure of (2,2′-bipyrimidine)-dinitratopalladium(II) acetone solvate

(2,2′-bipyrimidine)dinitratopalladium(II) forms a triclinic crystal in space groupP?1 witha=7.605(5) Å,b=8.791(4) Å,c=12.632(5) Å, α=85.11(3)⁰, β=78.79(4)⁰, γ=77.45(4)⁰,V=807.7(7) ų, andZ=2. The Pd atom exhibits square planar coordination geometry with mean Pd?O=2.206(7) Å, Pd?N=1.990(5) Å, O?Pd?O=92.0(2)⁰, and N?Pd?N=81.0(2)⁰. The complexes associate across an inversion center with Pd...Pd=3.190(2) Å. The bipyrimidine ligand is bowed with a 5.9(2)⁰ dihedral angle between the C₄N₂ rings. The nitrate ions are on the same side of the N₂O₂ donor atoms plane and make 60.4(2)⁰ and 66.6(2)⁰ dihedral angles with that plane.     

The 1:1 crystal complex of salicylic acid and urea

The 1∶1 crystal complex of salicylic acid (C₇H₆O₃) and urea (CH₄N₂O), mp 121° C, is monoclinic, with space groupC2/c (C ₂ ⁶ h, No. 15) and unit cell dimensionsa=22.206(3),b=5.108(1),c=17.177(2) Å,β=106.18(1)°.d _calc=1.407 g cm^?3,d _meas=1.41 g cm^?3 forZ=8. The structure was determined by direct methods and refined by a full-matrix least-squares procedure to giveR=0.057 andR _w =0.050 for 1652 integrated intensities above 2σ(I). The structure contains a strong OH?O hydrogen bond with O?O distance 2.54 Å in which the carboxyl OH group is donor and urea oxygen atom is acceptor. There are two NH?O intermolecular hydrogen bonds with N?O distances of 2.90 and 2.96 Å. Additionally, the salicyclic acid contains an intramolecular OH?O hydrogen bond of 2.56 Å.     

Structure of 1,4-bis(diiodophenylstannyl)butane

The molecule of I₂PhSnCH₂CH₂CH₂CH₂SnPhI₂ (1) in the solid state, is centrosymmetric with the molecular center-of-symmetry coincident with a crystallographic center-of-symmetry. It crystallizes in the monoclinic space group,P2₁/c (Z=2), witha=13.495(1) Å,b=6.844(1) Å,c=14.732(1) Å, and β=116.12(2)^o. The compounds consist of essentially individual molecules, separated by I(2)---I(2ⁱ) and I(2)---I(2ⁱⁱ) distances [4.258(12) Å], close to the sum of the van der Waals radii. There are no interactions between the two diiodophenylstannyl moieties. The tin atoms have slightly distorted tetrahedral geometries, with the bond angles at tin varying from 103.40(3) [I(1)?Sn?I(2)] to 117.0(3)⁰ [C(1)?Sn?C(7)] and with Sn?I(1) and Sn?I(2) bond lengths of 2.6980(9) and 2.7106(10) Å, respectively.¹H-,¹³C- and¹¹⁹Sn-NMR spectra in CDCl₃ solution have also been obtained.     

Crystal structures of two platinum-bipyrimidine complexes: Pt(bpm)Cl2·dmf and Pt(bpm)(dmso)(SO4)·H2O

Red Pt(bpm)Cl₂·dmf forms a stacked structure which has Pt…Pt separations of 3.423(2) A and 3.447(2) Å with Pt…Pt…Pt angles of 155.39(3)^o. The unit cell isP-1, witha=6.712(4) A,b=10.0765(6) Å,c=11.551(3) Å, α=106.732(12)^o, β=103.65(4)^o, γ=90.46(3)^o, andZ=2. The structure refined to anR(F) of 0.046 using 181 parameter and 2165 reflections withI>1σ(I). The yellow complex Pt(bpm)(dmso)(SO₄)·H₂O does not stack in the solid state: the shortest Pt…Pt separation is 4.638(2) Å. The unit cell is alsoP-1, witha=8.060(3) A,b=9.560(3) A,c=9.7534(18) Å, α=90.62(2)^o, β=99.43(3)^o, γ=90.66(3)^o, andZ=2. The structure refined to anR(F) of 0.039 using 208 parameters and 3689 reflections withI>1σ(l).     

The structure of 2R-(3′S-benzyloxy-5′S-hydroxy-2′R-hydroxymethyl-1′-oxacyclohexan-6′S-yl)-propionic acid-1,5′-lactone,C16H20O5

The title compound is C₁₆H₂₀O₅, MW=292.3, orthorhombic,P2₁2₁2₁,a=9.741(2),b=29.391(7),c=5.354(1) Å from diffractometer measurements,V=1532.8 ų,Z=4,D _c =1.267 g cm^?3,D _o =1.271 g cm^?3 (ether/1,1,2,2-tetrabromoethane), λ(Mo Kα)=0.71069 Å,F(000)=624,μ=1.02 cm^?1, crystal dimensions 0.23×0.23×0.40 mm,R=0.049 for 1164 observed reflections. The molecule contains a possibly significant asymmetric ether linkage between the oxacyclohexane ring and the highly anisotropic benzyl ring. The packing consists of zigzagged chains parallel to thea-axis formed by hydrogen bonds. The chains are separated by van der Waals contacts.     

Crystal structures of thecis andtrans isomers of dithiahexahydro[3.3]metacyclophane

Structures of both thecis andtrans isomers of dithiahexahydro[3.3]metacyclophane, ?C₆H₄?CH₂SCH₂?C₆H₁₀?CH₂SCH₂?, have been determined, wherecis andtrans refer to the attachments to the cyclohexane ring. Thecis form crystallizes in the monoclinic space groupP2₁/c witha=8.4299(11)Å,b=21.772(2)Å,c=8.9724(13)Å, β=116.574(11)^o, andZ=4. Thetrans isomer packs into the monoclinic space groupP2₁ witha=8.159(16)Å,b=10.185(5)Å,c=9.558(2)Å, β=112.435(18)^o, andZ=2. The cyclohexane ring of thecis isomer is in the chair conformation, while the cyclohexane of thetrans isomer is found in a twisted boat conformation.     

Synthesis and characterization of 9-(4-nitrophenyl)3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H) acridinedione and its methoxyphenyl derivative

9-(4-Nitrophenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H) acridinedione (NTHA) crystallizes in orthorhombic space group P2₁2₁2₁ with a = 5.9716(1) Å, b = 18.0476(3) Å, c = 19.2445(2) Å, V = 2074.04(5) ų, Z = 4, D_cal = 1.263 Mg m^?3 and R = 0.0521 (wR = 0.1326) for 4078 observed reflections. 9-(4-Nitrophenyl)-10-(4-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydro-1,8(2H,5H) acridinedione NMTHA, crystallizes in monoclinic space group P2₁/c with a = 15.669(5) Å, b = 10.652(4) Å, c = 18.337(6) Å, β = 108.25(1)^°, V = 2906.66(2) ų, Z = 4, D_cal = 1.245 Mg m^?3 and R = 0.0725 (wR = 0.1847) for 5105 observed reflections. The experimental values are compared with the theoretical values calculated based on the semiemperical methods. The structures are stabilized by N–H?sO and C–H?sO types of intermolecular interactions in addition to van der Waals forces.     

Synthesis of spinacine and spinacine derivatives: crystal and molecular structures of Nπ-hydroxymethyl spinacine and Nα-methyl spinaceamine

The natural amino acid L-Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid) has been synthesized following a new pathway which gives a chemically and optically pure product with an excellent yield. The crystal structures of a synthetic intermediate, N^π-hydroxymethyl-spinacine, and a spinacine derivative, N^α-methyl-spinaceamine, have been investigated through X-ray diffraction: Spi(πMeOH)·H₂O, monoclinicP2 _i,a=8.571(1),b=6.682(1),c=8.588(1) Å, and β=94.67(1)^o. Spm(αMe)·2HCl·H₂O, triclinicP l,a=7.492(4),b=10.799(3),c=7.040(2) Å, α=91.88(2), β=98.36(3) and γ=73.34(3)^o. Spi(πMeOH) crystallizes with a water molecule and displays a zwitterionic character. The carboxylate group is in equatorial position and forms a short electrostatic interaction of 2.618(2) Å between one of its oxygens and the protonated nitrogen of the tetrahydropyridine ring. The crystal packing is assured by strong O?H???O, O?H???N, N?H???N intermolecular hydrogen bonds and C?H???O close contacts. The biprotonated compounds Spm(αMe) crystallizes with two Cl^? anions and a water molecule. The positive charge on the imidazole ring is delocalized on the conjugated moiety N=C?N. The crystal is built up by clusters formed by two biprotonated Spm(αMe) molecules, four Cl^? anions and two water molecules linked together by hydrogen bonds.     

Crystal structure of 2,4′-biflavonoid

The X-ray crystal structure of 2,4′-biflavonoid has been determined. Colorless regular prism shaped crystals of C₃₀H₂₂O₄ crystallize in the space group $P\bar 1$ with cell dimensionsa=11.574(1) Å,b=12.235(1) Å,c=17.428(1) Å, α=108.46(3)^o, β=80.08(1)^o, γ=103.34(2)^o,V=2264.7(4) ų, andZ=4.     

Crystal structures of 1,1′-di(methylacetato)- and 1,1′-di(chloroethoxyethyl)-2,2′-biimidazole

1,1′-Di(methylacetato)-2,2′-biimidazole, C₁₂H₁₄N₄O₄, crystallizes from methanol in the space groupP2 ₁/c, wherea=9.535(2),b=13.385(2),c=5.1208(8) Å,V=652.2(2) ų, andZ=4.1,1′-Di(chloroethoxyethyl)-2,2′-biimidazole, C₁₄H₂₀Cl₂N₄O₂, crystallizes from cyclohexane in the space groupPbca, wherea=12.372(2),b=8.959(2),c=14.840(2) Å,V=1644.9(5) ų, andZ=8. The structures were refined toR=0.041 (1380 observed reflections) andR=0.043 (3243 observed reflections), respectively. Both molecules crystallize with coplanar rings and the substituents assume atrans configuration with a center of inversion between the bridging carbon atoms.     

N-isopropyl-2-(isopropylamino)troponiminate complexes of lithium and calcium

The synthesis and structures of [(i-Pr)₂ATI]Li₂(thf)(I)(1) and [(i-Pr)₂ATI]Ca(thf)₂(I)₂Li₂(thf)₂-[(i-Pr)₂ATI] (2) (where [(i-Pr)₂ATI]=N-isopropyl-2-(isopropylamino)troponiminate) have been described. The lithium atoms in compounds1 and2 occupy positions above and below the plane of the aminotroponiminate ligand. The calcium atom in2 adopts a pseudo-octahedral geometry with two tetrahydrofurans occupying thetrans-positions. Compound1 crystallizes as dimeric units. Crystal data with MoKα at 193 K:1, C₁₇H₂₇ILi₂N₂O,a=13.217(2)Å,b=9.875(2)Å,c=16.410(4)Å, B=111.41(1)^o,V=1993.4(6)ų, a monoclinic space groupP2₁/n,Z=4,R=0.029;2, C₄₂H₇₀CaI₂Li₂N₄O₄,a=911.390(2)Å,b=30.880(4)Å,c=13,465(2)Å, B=93.85(1)^o,V=4724(1)ų, monoclinic space groupC2/c,Z=4,R=0.027.     

Crystal Structures of 6-methyl-3-phenylsulfonylchroman-4-one andtrans-6-methyl-3-phenylsulfonylchroman-4-ol

The crystal structures of (i) CH₃(C₉H₆O₂)SO₂C₆H₅ and (ii) CH₃(C₈H₈O₂)SO₂?C₆H₅ have been determined by X-ray diffraction. (i) crystallizes in the monoclinic space groupP2₁/c with unit cell parametersa=8.814(1)Å,b=10.310(1)Å,c=15.841(4)Å, β=98.17(1)^o, andZ=4, and (ii) crystallizes in the orthorhombic space groupP2₁2₁2₁ with unit cell parametersa=6.206(1)Å,b=11.752(5)Å,c=19.865(3)Å, andZ=4. The pyran ring in both of them is in the distorted half-chair conformation with differeing degrees of distortion from the ideal.     

X-ray crystal structure of dichloropicric acid

Dichloropicric acid is orthorhombic, space groupP2₁2₁2₁; at 24°a=5.672(3),b=8.044(3),c=22.491(7) Å,D _x=1.929(2) g-cm^?3,V=1026(1) ų,Z=4. The phenolic OH group is intramolecularly hydrogen bonded to one of theortho nitro groups with an O...O distance of 2.524(5) Å. As a consequence, this nitro group is twisted out of the plane of the benzene ring by only 20.1° in spite of crowding by the adjacent chlorine atom which is only 2.764(3) Å from the O atom in the nitro group. The two non-hydrogen bonded nitro groups have twist angles of 73.9 and 84.1°. There is no evidence of intermolecular hydrogen bonding with any adjacent dichloropicric acid molecule.     

Structural investigation of 1-amino-2,4,6-trinitrobenzenes in the solid state and in solution

The crystal structure of 1-pyrrolidino-2,4,6-trinitrobenzene3, 1-morpholino-2,4,6-trinitrobenzene4 and 1-piperidino-2,4,6-trinitrobenzene5 have been determined by single-crystal X-ray diffraction data and the structure in solution was investigated by UV-visible spectrophotometry and¹³C nmr. The three compounds are monoclinic, space groupP2_i/n. Unit cell dimensions area=6.6660(1),b=8.612(1),c=20.696(3) Å, β=90.73(1)^o, andD _c =1.58 g cm^?3 for compound3;a=7.090(2),b=21.493(9),c=8.298(3) Å, β=101.27(1)^o, andD _c 1.60 g cm^?3 for compound4 anda=10.426(1),b=10.038(1),c=12.291(1) Å, β=90.04(1)^o withD _c =1.53 g cm^?3 for compound5 forZ=4. In the solid state, differences regarding the planarity of the aromatic ring in the three substrates were found. Rotation of theortho-nitro groups and of the amino group out of the aromatic plane was observed both in the solid state and in the solution. Greater coplanarity of the two rings was found in3 than in4 and5.     

Ether cleavage of [2.2.2]cryptand: synthesis and X-ray crystal structure of [NH(CH2CH2I)3][I5]

Treatment of [2.2.2]cryptand1 in toluene with HI(g) has resulted in the formation of a twophase liquid clathrate solution from which the complex [NH(CH₂CH₂I)₃][I₅]2 has been isolated and crystallographically characterized. Crystal data for2: triclinic, space group $P\bar 1$ ,a=9.301(3) Å,b=10.419(3) Å,c=11.078(3) Å, α=90.20(2)^o, β=103.28(2)^o γ=96.50(2)^o,D _c =3.57g/cm³,Z=2,R _f =0.054,R _w =0.054. The salt is a product of an ether cleavage of the macrobicycle. The crystal structure of2 contains [NH(CH₂CH₂I)₃]⁺ ions and zigzag chains of [I₅]^? ions which self-assemble to form alternating layers, of cations and anions.     

The structures of N-(t-butoxycarbonyl)-3-methylbenz[f]indole and N-benzenesulfonyl-4-bromo-3-methylbenz[f]indole

N-(t-butoxycarbonyl)-3-methylbenz[f]indole,1, C₁₈H₁₉NO₂, crystallizes in orthorhombic space groupPna2₁ witha=6.0338(2),b=24.839(4),c=10.2481(7) Å,V=1535.9(3) ų,Z=4. The structure was refined toR=0.051 for 2007 observed reflections. The benz[f]indole ring system is nearly planar, exhibiting mean deviation of 0.048 Å. The ester plane of thet-butoxycarbonyl substituent is nearly coplanar with the benz[f]indole ring system, forming a C?N?C=O torsion angle with magnitude 10.6(5)⁰.N-benzenesulfonyl-4-bromo-3-methyl-benz[f]indole,2, C₁₉H₁₄BrNO₂S crystallizes in triclinic space groupP?1 witha=8.1400(5),b=10.0587(8),c=10.8863(7) Å, α=89.927(7), β=110.495(5), γ=96.846(6)⁰,V=828.2(3) ų,Z=2. The structure was refined toR=0.050 for 2653 observed reflections. The benz[f]indole ring system is nearly planar, with mean deviation 0.016 Å, and forms a dihedral angle of 80.93(9)⁰ with the phenyl plane.