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 (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.     

The structure of 9-methyladenine salicylate

Crystals of 9-methyladenine salicylate (C₆H₈N ₅ ⁺ ·C₇H₅O ₃ ^? ), mp 126°C, are orthorhombic, space groupPbcn (D _2h ¹⁴ , No. 60) witha=25.305(3),b=8.066(1),c=12.928(2) Å,d _c=1.446 g cm^?3,d _m=1.43 g cm^?3 (CCl₄/ cyclohexane) forZ=8. The 9-methyladenine, protonated at N(1), and salicylate form a pair of strong hydrogen bonds with N?O distances of 2.617 and 2.858 Å. In addition, a hydrogen bond is formed between two adenine moieties using the amino group and imidazole nitrogen, N(7), with N?N separation of 3.114 Å. As in salicylic acid, an intermolecular hydrogen bond of 2.560 Å is formed between the hydroxyl and a carboxyl oxygen atoms.     

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.     

Crystal structures of 1,1′-di(2-propanone)-2,2′-biimidazole dihydrazone and 2,6-diacetylpyridine dihydrazone

The nucleophilic addition reactions between 1,1′-di(2-propanone)-2,2′-biimidazole or 2,6-diacetylpyridine and hydrazine hydrate afford 1,1′-di(2-propanone)-2,2′-biimidazole dihydrazone (1) and 2,6-diacetylpyridine dihydrazone (2), respectively. Compound1 crystallizes in the orthorhombic space groupP2₁2₁2₁, witha=9.042(2),b=9.731(3),c=15.683(4)Å, V = 1379.9(6)Å^? andZ=4. Compound2 crystallizes in the orthorhombic space groupPnma, witha=10.948(2),b=19.742(6),c=4.566(1)Å, V=986.9(4)Å^? andZ=8. A pseudo center of inversion is present at the midpoint of the C?C bond joining the imidazole rings of1, whose substituents crystallize in atrans configuration. The imidazole rings are rotated 2.5(3)° about the C?C bond. In contrast to the essentially planar structure of2, the hydrazone substituent groups of1 are at angles of 89.9(1)° and 88.4(1)° with respect to the plane of the adjacent imidazole moiety.     

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.     

(Imidazole)(3,3′-trimethylenedinitrilo bis (2-butanone oximate)) copper(II) perchlorate: Synthesis and crystal structure of a five-coordinate copper-protein model complex

The synthesis and crystal structure of the novel pentacoordinated complex [Cu(DOHPN)(IMI-DAZOLE)] (ClO4), (DOHPN=(3,3′-trimethylenedinitrilo bis 2-butanone oxime) are reported. The X-ray crystal structure (space groupP2₁/n, a=11.349(2) Å,b=14.241(3) Å,c= 12.635(3) Å; α=90°, β=100.21 (3)°, γ=90°) shows that the copper(II) ion occupies a distorted square-pyramidal geometry with the imidazole ligand occupying the axial position. The copper(II)-(N)imidazole distance is 2.125(3) Å and the copper(II)-tetraaza plane distance is 0.385/Å. The tetraaza ligand DOHPN adopts a “butterfly-like” geometry with a dihedral angle of 149.69°. The title complex is the first structurally characterized compound of the series [Cu(DOHPN)(axial ligand)]ⁿ⁺ where the axial ligand is a neutral N-heterocycle with known biological relevance. A comparison of the structural parameters with those observed when the axial ligand is H₂O or NCS^? (N-bonded) gives the following series with increasing metal-ligand interaction: H₂O>IMIDAZOLE>NCS^? (N-bonded).     

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.     

The crystal and molecular structure of SnBr[N(SiMe3)2]3

The crystal structure of SnBr[N(SiMe₃)₂]₃ has been determined from three-dimensional X-ray diffraction data collected by counter methods. This compound crystallizes in the rhombohedral space groupR3c witha=11.970(3) Å, α=99.06(3)°, andZ=2forD _c> =1.37 g cm^?3. The finalR value was 0.027 based on 608 independent observed reflections. The molecule lies on a crystallographic three-fold axis which contains the Sn and Br atoms. The bromine atom is covalently coordinated to the tin atom at a Sn-Br separation of 2.519(2) Å. The three nitrogen atoms complete the bonding to tin with an Sn-N bond length of 2.056(7) Å.     

Molecular structure of (tBu)3AlP(nPr)3

The crystal and molecular structure of (^tBu)₃AlP(ⁿPr)₃ has been determined. The Al(1)?P(1) bond distance [2.594(3) Å] is slightly longer than other aluminum-phosphine complexes; however, the geometry about aluminum is similar to that of the [AlCl(^tBu)₃]^? anion, suggesting that the geometry about the aluminum in tri-tert-butylaluminum complexes is defined by the size of thetert-butyl ligands and not as a consequence of the steric bulk of the Lewis base. Crystal data: Monoclinic,P2_t,a=8.932(2),b=16.832(3),c=9.328(2), Å, β=114.36(3)°,V=1277.6(6) ų,Z=4,R.=0.055,R _w =0.053.     

Synthesis and Crystal Structure of μ-oxo-bis[(octaethyloxoporphinato)iron(III)] Tetrafluoroborate

Exposure of dichloromethane solution of [OEOPFe(BF₄)], where OEOP is the monoanion of octaethyloxoporphyrin, to dioxygen results in its transformation into the μ-oxo bridged compound, [(OEOPFe)₂O)](BF₄)₂. The molecular structure of the title compound, [(OEOPFe)₂O](BF₄)₂, was determined by single-crystal X-ray diffraction. It contains a binuclear centrosymmetric [(OEOPFe)₂O]²⁺ cation (the bridging O atom lies on an inversion centre) and two tetrafluoroborate anions. The Fe atom is five-coordinate to four N atoms of the porphyrin ring and to one bridging O atom. The compound is characterized by an average Fe–N bond length of 2.064 Å. The Fe–O bond distance is 1.7665(11) Å and the Fe–O–Fe bond angle is 180.0° and the two porphyrin rings are parallel. Crystal data: crystal system, monoclinic, a = 8.867(3), b = 26.104(9), c = 15.748(6) Å, β = 105.40(3)°, space group, P2₁/c, V = 3514(2) Å³, Z = 2.     

Intra- vs intermolecular hydrogen bonding. The crystal structure of 5-methyl-2-hydroxyacetophenone thiosemicarbazone monohydrate and salicylaldehyde-2-methylthiosemicarbazone monohydrate

The crystal structure of 5-methyl-acetophenonethiosemicarbazone monohydrate,A, and salicylaldehyde-2-methylthiosemicarbazone monohydrate,B, were determined using single crystal X-ray diffraction.A crystallizes in the monoclinic space groupC2/c, with lattice parametersa=14.161(2),b=15.753(1) Å,c=11.084(1) Å, β=112.59(1)° andZ=4, yielding a calculated density ofD _calc=1.352 mg/m³.B crystallizes in the triclinic space groupP1, witha=7.233(2) Å,b=7.371(2) Å,c=11.841(2) Å, α=82.77(2)°, β=78.33(2)°, γ=63.06(2)° andD _calc=1.371 mg/m³ forZ=2,. In bothA andB the immine nitrogen and the sulfur atom areanti with respect to N2-C8. WhileA presents the usual intramolecular six membered hydrogen bond ring,B has instead an intermolecular hydrogen bond between the hydroxy moiety of the salicyladehyde and a water molecule. AM1 calculations agree with the experimental conformations observed in both compounds.     

N,N-Dimethylglycine hydrochloride

Crystals of C₄H₁₀NO₂Cl, M _r =139.58 are monoclinic,P2₁/c, witha=7.061(2),b=7.194(2),c=13.932(3) Å,β=98.88(2)°,V=699.2(5) ų,Z=4,D _x=1.326(1) g cm^?3. The structure was solved by hand application of direct methods and refined to a goodness of fit of 1.7 for 1212 reflections and 114 parameters (R=0.028 for 1202 reflections withF ²>0).     

Stereochemical studies of oligomers. IV: structure of bis-3,3,5-trimethylcyclohexyl phthalate

C₂₆H₃₈O₄,Mr=414.6, is monoclinic,P2₁/c, witha=15.059(2),b=7.348(2),c=23.164(3) Å,β=90.35(16)°,V _c =2563.13(85) ų,D _x =1.07(4) g cm^?3,μ(CuKα)=5.28 cm^?1. The structure was determined by direct methods and refined by full-matrix least squares toR=0.074 for 2479 observed reflections. The two cyclohexane rings both adopt a chair conformation.     

Synthesis and crystal structure of bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl)copper(II)

The title compound, bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl) copper(II), [Cu(C₁₇H₁₁NOCl)₂] (1) was synthesized and its crystal structure was determined. The Compound 1 is monoclinic, space group P2 ₁/c with a = 9.146(3) Å, b = 18.724(3) Å, c = 16.230(2) Å, β = 96.46(1)°, V = 2761.8(11) ų, Z = 4, D _c = 1.503 g cm^?3, μ(Mo Kα) = 1.020 mm^?1, R = 0.0606 for 2361 reflections [I > 2σ(I)]. In the title compound, the Cu atom is coordinated by an N₂O₂ donor set from the imine-phenol ligand in a slightly distorted square planar coordination geometry, with the two phenolate O atoms being deprotonated. The Cu–O bond lengths are 1.878(4) and 1.889(4) Å, the Cu–N bond lengths are 1.980(5) and 1.985(5) Å. The angles O1–Cu–N1 and O2–Cu–N2 are 90.96(19) and 90.72(19)°, respectively.     

Structural and spectroscopic study of a five-coordinate rhodium(I) complex (η-1,5-cyclooctadiene)(η-2, 6-diallylpyridine,N)rhodium (1+) with two different and unusual di-μ-chloro-bis[dichlorodimethylstannate](2−) anions. Crystal structures of [Rh(C8H12)-(C11H13N)]2[{SnCl3(CH3)2}2] · 2CH2C12 and [Rh(C8H12)-(C11H13N)]2[{SnCl3(CH3)2}2]

The preparation and structures of a five-coordinate rhodium(I) complex with 2,6-diallylpyridine (DAP) and cyclooctadiene (COD) ligands with two different [{SnCl₃(CH₃)₂}₂]^2? anions are described, including IR and¹H NMR data. The crystals of the title compounds are both triclinic P¯1: C₄₂H₆₂Cl₆N₂Rh₂Sn₂·2CH₂Cl₂ (1)a=12.200(4),b=13.016(4),c=9.402(2) Å,α=93.92(1),β=100.67(1), γ=115.03(2)°,V _c =1311.2(7) ų,Z= 1,R=0.0312 for 3321 independent observed reflections; C₄₂H₆₂Cl₆N₂Rh₂Sn₂ (2)a=12.187(3),b=12.851(3),c=7.752(2) Å,α=90.15(1),β=101.22(1), γ=73.29(1)°,V _c =1138.8(5) ų,Z=1,R=0.0429 for 4117 independent observed reflections. In both structures the cationic rhodium has a trigonal-bipyramidal environment with theN-pyridine and one double bond of the COD ligand in axial positions and the two allylic double bonds together with the other double COD bond in equatorial positions. Much more interesting are the structures of the anionic parts, which show a different unsymmetrical dimerization through two chlorine bridges. The tin coordination polyhedra, which assume a distorted trigonal-bipyramidal geometry in the monomeric units, achieve an octahedral shape. There is a simple correlation between the Me-Sn-Me angle value and the longest Sn-Cl bond distance.     

The molecular structures of two furanoheliangolides

The heliangolide-class sesquiterpene lactone 8β-angeloyloxy-9α-acetoxycalyculatolide, C₂₂H₂₆O₈,1, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=12.455(3),b=12.601(3),c=14.023(5) Å,V=2200(1)Å,³ Z=4.R=0.059 for 1735 observed data. The 11,13-dihydro-11α, 13-epoxyatripliciolide-8β-angelate, C₂₀H₂₂O₇. 1/2 H₂O,2, crystallizes as the hemihydrate with two molecules in the asymmetric unit in triclinic space groupP1 witha=9.422(1),b=9.559(1),c=12.358(3) Å, α=101.62(2)°, β=91.30(2)°, γ=117.80(1)°,V=955.6(7)ų,Z=2.R=0.046 for 3607 observed data. In both, the 10-membered rings adopt approximate chair-boat conformations. Their conformations are typical for heliangolides. The methyl group C14 is α, while the C-15 has a β-orientation. The α-methylene-γ-lactone istrans-fused at C6 and C7 with H6 β and H7 α. In compound2, the epoxide at C11–C13 has an α orientation.     

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.     

Crystal and molecular structures of di-µ-azido-bis-[N,N,N′,N′-tetramethylethylenediamine azido copper(II)]

The title compound has been synthesized and its structure at room temperature has been solved. It crystallizes in the space groupP2₁/c, witha=9.581(5),b=13.746(4),c=8.869(1) Å, β=101.000(5)°, andZ=2. The structure was refined toR=0.029 from 1738 reflections. It consists of centrosymmetric dimeric units with two asymmetric end-to-end azido bridges. Each copper(II) ion is fivefold coordinated in the form of a slightly distorted square-based pyramid CuN₅. The apical position is occuped by a nitrogen atom of the azido bridge with a Cu-N apical bond of 2.456(6) Å. The Cu-N bond with the azido bridge in the basal plane is 1.979(5) Å. The intradimer Cu?Cu distance is 5.004(2) Å. The magnetic properties and the X-band EPR spectrum are interpreted in the light of these structural data.