C-H⋯π(Ar)⋯Cl-C,C-Cl⋯π(Ar), Cl⋯Cl and other interactions in the crystal structure of 6-benzoyl-2,4-bis(trichloromethyl)-1,3-benzdioxin

The title compound is monoclinic,P2₁/n,Z=4,a=9.934(1),b=18.399(2),c=11.098(2)Å, =111.08(1)°. The molecule can conveniently be visualized as a benzophenone molecule with one of the aromatic rings fused to a 1,3-dioxin ring which adopts a distorted envelope conformation withcis-trichloromethyl groups substituted at positions 2 and 4. An interaction, observed for the first time, involves a hydrogen atom and a chlorine atom from opposite sides of the same aromatic ring to give C-H-(Ar)Cl-C. The parameters are Hring-centroid 2.63 A, Clring centroid 3.41 Å, Hring-centroidCl 167°, C-Hring centroid 159°, C-Clring centroid 150.2°. The (Ar) system is that of the unfused aromatic ring. A second (Ar) Cl-C interaction occurs but this time with the (Ar) system of the fused aromatic ring. The ClCl and ClO(=C) interactions form the familiar zig-zag pattern which has been noted for many chloroaromatic compounds.     

Crystal structure of a nucleoside analogue, 2′,3′-dideoxy-3′-fluoro-5-chlorocytidine

The title compound, 1-(2,3-dideoxy-3-fluoro--d-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallises in the orthorhombic space groupP2₁2₁2₁ witha=5.142(1),b=14.177(2),c=15.721(2) Å,Z=4. The crystal structure was solved by the heavy atom method and refined by full-matrix least-squares method to a finalR value of 0.031 for 1629 unique observed reflections. The N-glycosidic torsion angle is –156.1(2)° and the sugar moiety is anti to the cytosine base. The sugar pucker is ₂ ³ T withP=178.2(1)° and=31(1)°. The atom 05 is in a +sc conformation with respect to the furanose ring. The molecular packing in the crystal is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.     

Molecular structure and some reactivity aspects of 2,6-diamino-4(3H)-pyrimidinone monohydrate

Crystals of C₄H₆N₄O·H₂O are orthorhombic:Pbca,a=16.721(2),b=4.242(1),c=18.293(2)Å,Z=8. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.046 for 1252 unique reflections. The structure consists of approximately planar molecules of the 3(H)4-one tautomer. Delocalization of the ring and the C=O-electrons, and conjugation of the lone-pair electrons of the amine groups with the pyrimidinone nucleus are observed. The molecules are connected by O-HO, N-HN, and N-HO hydrogen bonds. The molecular structure clarifies the chemical properties of the compound.     

Two acetylamino derivatives of 2,4-bis(trichloromethyl)-1,3-benzdioxin showing different types of hydrogen bonding: (a) (C13C)CH⋯O=C and (b) N-H⋯O=C

8-Acetylamino-6-methyl-2,4-bis(trichloromethyl)-1,3-benzdioxin, (I), is monoclinic,P2₁/c,a=15.174(4),b=11.977(7),c=9.911(3)Å,=99.72(2)°. 6-Acetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin, (II), is monoclinic,P2₁/_n,a=5.927(4),b=40.623(1),c =7.120(3)Å,=91.39(4)°. In compound (I) the imino hydrogen atom is locked in an intramolecular hydrogen bond to the proximate oxygen atom of the heterocyclic ring and is not available for intermolecular hydrogen bonding. Instead the weakly acidic hydrogen atom [Cl₃C-C(2)]H takes part in a hydrogen bond to the carbonyl oxygen atom in another molecule. In compound (II) a normal intermolecular hydrogen bond of the type N-HO=C occurs. The 6-acetylam-ino group is twisted about the (C_Ar-N) bond such that the angles NHO=C, C_ArH_ArO=C, NHOH_ArC_Ar, at the carbonyl oxygen group total 360° (where NH is in the related molecule). The packing in both compounds takes the form of infinite chains and in compound (II) partial overlap of the aromatic ring and the acetylamino group, with very little offset, also occurs.     

Crystal and molecular structure of disarcosine hydrobromide

Disarcosine hydrobromide, C₆H₁₅N₂O₄ ⁺Br^–, crystallizes in the orthorhombic space groupPca2₁ with eight formula entities per unit cell of dimensionsa = 23.79,b = 6.18, andc = 15.40 Å, that is, two disarcosine molecules in the asymmetric unit. The structure was solved by the heavy-atom method using three-dimensional visually estimated X-ray data, and refined by the block-diagonal least-squares method to a finalR value of 0.11. The molecules are held together by a network of hydrogen bonds of the types N-H Br, N-H O, and O-H O.     

Crystal structure of a nucleoside analog: 2′,3′-dideoxy-3′-fluoro-5-bromocytidine

The title compound crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=5.084(1),b=14.322(3),c=16.065(2)Å,Z=4. The structure was solved by the heavy atom method and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1106 unique observed reflections. The N-glycosidic torsion anglex has a value of –153.7(4)°, in the anti-range. The sugar pucker is²T₃ withP=175(1)° and=30(1)°. The C4-C5 conformation is + sc with =46.7(7)°. The structure is stabilized by N-HN, N-HO and O-HO hydrogen bonds and C-HO close contacts.     

Cl⋯π(Ar), Cl⋯Cl,and other intermolecular interactions in the crystal structure of 8-nitro-6-methyl-2-trichloromethyl-4-dichloromethylene-1,3-benzodioxin

Crystals of the title compound are monoclinic,P2₁,a=9.791(4),b=7.129(3),c=10.428(3)Å,=91.84(3)°,V=727.50ų,Z=2. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by full matrix least squares to a finalR value of 0.045 using 2466 reflections. The molecules form stacks along theb axis of the formA, B, A, B(A=dichloromethylene group; B=aromatic ring in the molecule at –x, 1/2+y, –z to the molecule atx, y, z containing A). Cl(Ar),, ClCl, ClO(N), (Cl₃C)HO intermolecular interactions are also present. An inverse correlation between the (C)ClCl(C) distance and the difference in the corresponding pairs of C-ClCl angles is observed and is interpreted in terms of incipient nucleophile: electrophile attack.     

Hydrogen-bonded coordination network in crystal structures of [Cu(3-PM)4Cl2] and [Cu(4-PM)4Cl]Cl, (PM = pyridylmethanol)

The crystal and molecular structures of [Cu(3-PM)₄Cl₂] (1) and [Cu(4-PM)₄Cl]Cl (2) have been determinated by X-ray crystallography. Complex 1 crystallizes in the triclinic system, space group P–1, with lattice parameters a = 7.972(2) Å, b = 8.293(2) Å, c = 10.707(2) Å, = 105.73(3)°, = 90.04(3)°, = 110.38(3)°, and Z = 1 at 100 K. The coordination geometry of each Cu atom is approximately octahedral formed by four nitrogen atoms of pyridine rings of 3-pyridylmethanol molecules in the equatorial plane and two chlorine atoms occupying the axial positions. The O—HsO, C—HsCl, and O—HsCl intermolecular hydrogen bonds and s stacking link the molecules in 3-D hydrogen-bonded coordination network. Complex 2 crystallizes in the tetragonal system, space group P4/n, with lattice parameters a = 10.464(1) Å, c = 11.339(2) Å, and Z = 2 at 217 K and a = 10.352(1) Å, c = 11.201(2) Å, and Z = 2 at 293 K. The coordination geometry of Cu atom in the [Cu(4-PM)₄Cl]⁺ ion is approximately square pyramidal formed by four nitrogen atoms of pyridine rings of 4-pyridylmethanol molecules in equatorial plane and one chlorine atom in axial position. The O—HsCl and C—HsCl intermolecular hydrogen bonds link the molecules in 2-D hydrogen-bonded coordination network.     

Crystal structures of two therapeutically active 2-imidazolines: naphazoline nitrate and tymazoline hydrochloride monohydrate

Naphazoline·HNO₃ (1): C₁₄H₁₅N₃O₃,M _r =273.3, crystallizes in the orthorhombic space group Pbca(Z=8) witha=12.028(1),b=14.408(2) andc=15.894(2) Å,V=2754.4 ų,D _x =1.318 g cm^–3,=0.70 mm^–1, (CuK)=1.54178 Å,F(000)=1152. FinalR=0.092 andwR=0.088 for 1348 observed reflections collected on a diffractometer. The structure was solved with direct methods, it shows two distinct positions of the naphthyl group with populations about 0.5, which differ by a 180 rotation. As in other arylmethyl-2-imidazolines, the imidazoline ring is approximately perpendicular to the aromatic ring. The molecules are linked by two hydrogen bonds N(3)-HO (nitrate anion)H-N(1) into infinite chains running along the 2₁ axis in the [100] direction. Tymazoline·HC1·H₂O (2): C₁₄H₂₃ClN₂O₂,M _r =286.8, crystallizes in the monoclinic space groupP2₁/n (Z=4) witha=8.136(1),b=10.015(1),c=18.601(1) Å and,=97.20(1)°,V=1503.7 ų D _x =1.266 g cm^–3,=2.27 mm^–1, (CuK)=1.54178 Å,F(000)=636. FinalR=0.115 andwR=0.119 for 3073 observed reflections collected on a diffractometer. The structure was solved with direct methods. Unlike other aryloxymethyl-2-imidazolines, the molecule is almost planar with an angle of 12.8(2)° between the two rings. Hydrogen bonding networks consist of N(1)-HO (water)Cl^–H-N(3) chains joined by an additional link O(water)-HCl^– between chains running in opposite directions.     

Polymorphs of nitrofurantoin. I. Preparation and X-ray crystal structures of two monohydrated forms of nitrofurantoin

The preparation and X-ray crystal structures of two monohydrates of the antibacterial drug nitro furantoin are reported. MonohydrateI crystallizes in the monoclinic space groupP2₁ n and monohydrateII in the orthorhombic space group Pbca. The nitrofurantoin molecule maintains the same, planar conformation in both crystals. The molecular packing arrangements inI andII are distinctly different,I possessing a layer structure while inII the packing is based on a herring bone motif. Hydrogen bonds of the type O-HO, N-HO, O-HN and C-HO stabilize the crystal structures.     

Crystal structure of a nucleoside analog, 2′,3′-dideoxy-3′-azido-5-chlorocytidine

The title compound, l-(2,3-dideoxy-3-azido--D-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=5.840(1),b=13.780(1),c=15.396(2)Å,Z=4. The structure was solved by direct methods and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1688 unique observed reflections. The N-glycosidic torsion angle has a value of –160.8(1)°, in the and range. The sugar pucker is ₂ ³ T withP=180(1)° and=34(1)°. The C4–C5 conformation is +sc with =50.8(2)°. The azido group is nonlinear and oriented trans to the C3–C4 bond. The molecular packing in the crystalline space is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.     

Crystal and molecular structure of glycinehydroxamic acid

Glycinehydroxamic acid, C₂H₆N₂O₂ (NH₂CH₂C(O)NHOH), was synthesized and its crystal and molecular structure determined by single-crystal X-ray diffraction methods. The crystals are monoclinic:P2 ₁/c C _2h ⁵ , No. 14),a=5.682(2),b=7.133(2),c=9.540(3) Å,=104.38(4)°,Z=4. The structure has been solved by direct phase determination methods, and refined to anR value of 0.042 for 633 nonzero independent amplitudes. The molecule of the title compound exists in the structure as a zwitterion, NH ₃ ⁺ -CH₂-C(O)-N-OH. The hydroxamate group is planar and the N (amino) atom, from the glycine part of the molecule, deviates by 1.43 Å from the best molecular plane defined by O(1), N(1), C(1), and O(2) atoms, respectively.The molecules are held together by a network of N⁺-HO, N⁺-H¯N, and O-HO hydrogen bonds.     

Crystal structure of 5-fluoro-1-(2,3,6-trideoxy-α-l-glycero-hex-2-enopyranos-4-ulosyl)uracil

The present compound crystallizes in the space groupP2₁2₁2₁ withZ=4 and cell parametersa=21.687(2),b=8.155(3),c=5.883(2)Å. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.045 for 1153 observed reflections. The N-glycosidic torsion angle _CN is in the anti-range and the pyranosyl ring adopts a distorted half-chair conformation with ₂=142.7(4)°, ₂=124.4(3)° andQ=0.456(2)Å. In the crystal packing the molecules are linked together by N-HO hydrogen bonds and C-HO contacts.     

Hydrogen bonding in 2-hydroxy((di)thio)benzoates. III. IR and NMR spectra of 2,6-dimethylpiperidinium and tetraethylammonium salts

Solid state ir and solution ir and nmr data are reported for 2,6-dimethylpiperidinium and tetraethylammonium salts of 2-hydroxybenzoic, 2-hydroxythiobenzoic and 2-hydroxydithiobenzoic acid. The solid state ¯v(OH) frequencies, range from 2800 to 2300 cm^–1 and decrease within the series thiocarboxylate (O-HO)>dithiocarboxylate (O-HS)>carboxylate (O-HO)>thiocarboxylate (O-HS), reflect the different kinds of intramolecular O-HY association. The solution ¯v(OH) frequencies range from 2830 to 2560 cm^–1 and decrease within the series thiocarboxylate>dithiocarboxylate>carboxylate; the (OH) proton shifts range from 12.8 to 16.0 ppm and correspondingly increase within the same series. IR and NMR data give confident evidence for an O-HO intramolecular association of the thiocarboxylate anions in solution.     

Crystal and molecular structure ofp-aminobenzene sulfonacetamide sodium [sulfacetamide sodium] monohydrate

The crystal and molecular structure ofp-aminobenzene sulfonacetamide sodium, C₈H₉N₂NaO₃S·H₂O, an important substituted sulfa drug, has been determined from diffractometric data using MoK radiation. The crystals are monoclinic, witha=6.614(2),b=23.788(6),c=7.012(2) Å,=103.13(2)°, and space groupP2₁/c. The structure was solved by the heavyatom method, and refined by full-matrix least squares to a finalR value of 0.040 with 1435 unique reflections. In packing, the molecules form dimers through pairs of N-HN and N-HO hydrogen bonds. The molecules are further stabilized by O-HO and O-HN hydrogen bonds.     

Crystal and molecular structure of tetra-n-butylammoniumbis(stilbenedithiolato)-nickelate(III)

The crystal and molecular structure of the title compound, C₄₄H₅₆NS₄Ni, are reported. Crystals are triclinic, space groupP¯1 (No. 2) withZ=2 in a unit cell of dimensionsa=8.874(2) Å,b=9.549(5) Å,c=26.025(7) Å,=97.22(3)°,=95.06(2)°, and=98.75(3)°. The structure was solved by Patterson and Fourier methods and refined by full-matrix least squares toR=0.062 for 2910 unique diffractometer data. The metal atom of the anion has an approximate square-planar configuration and the nitrogen atom of the cation an approximate tetrahedral configuration. The anions as well as the cations are well separated, the closest NiNi and NN approaches being the lattice repeat of 8.874(2) Å.     

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.     

Crystal structure of μ-adeninatobis (methylmercury (II)) perchlorate monohydrate

The title compound belongs to the triclinic space groupP¯1,a= 8.189 Å,b = 9.863 Å,c = 10.726 Å, = 69.93 °, = 68.62 °, = 73.66 °, andZ = 2. The structure was refined on 1337 observed reflections to anR factor of 0.042. The crystals contain [adeninato(CH₃Hg)₂]⁺ complex cations in which mercury is linearly bonded to N(7) and N(9) of a deprotonated adenine ring. Centrosymmetrically related complex cations are paired via two N(6)-H(6) N(l) hydrogen bonds. Those planar units are stacked in the crystal with a distance of 3.4 Å between rings. The water molecule and the ClO₄ ^-ion are involved in hydrogen bonding and HgO contacts. This structure identifies N(7) as the best residual coordination site after H(9) has been substituted by CH₃Hg.     

Structure of 5-benzoylamino-5-methyl-4-oxo-1,3-dioxane

The crystals of the title compound (C₁₂H₁₃NO₄) are orthorhombic,P2₁2₁2₁ witha=8.541(3),b=10.988(1), andc=11.912(1) Å.M _r =235.24, mp 427 K,Z=4,D _x =1.348 Mg m^–3, (MoK=0.71069 Å, =0.11 mm^–1,T=293 K. The structure was solved by direct methods and refined by full-matrixs least squares to a finalR=0.028 for 1180 observed reflections. The molecules are connected by N-HO (ring carbonyl) intermolecular HO hydrogen bonds of 2.24(2) Å. The 4-oxo-1,3-dioxane ring is in a slightly distorted sofa conformation with a C _s ¹ asymmetry parameter of 3.6(2)° and the 5-methyl substituent in a pseudoaxial position. The benzoyl oxygen is turned toward the ring, resulting in a close OH(C6) contact of 2.45(2) Å.     

Structure and spectroscopic properties of 2-(N,N-dimethylaminomethyl)-4-nitrophenol

The crystal structure of 2-(N,N-dimethylaminomethyl)-4-nitrophenol, C₉H₁₂N₂O₃ has been determined by X-ray diffraction methods. The crystals are monoclinic;C2/c (No. 15),a=23.437(6),b=5.334(2),c=17.444(4) Å,=119.90(5)°,Z=8. The structure was solved by direct methods, and refined to anR value of 0.032 for 1095 nonzero independent amplitudes. Molecules of the title compound are found to exist in a zwitterionic form. Differences in hydrogen bonding in solution and in the solid phase are discussed. In nonpolar and weakly polar solvents, intramolecular O-HN hydrogen bonding is predominating. In the solid state, two N⁺-HO^– bonds related through an inversion center form a cyclic dimer.