The structures of three trimethylarsine-boron trihalide adducts: (CH3)3AsBCl3, (CH3)3AsBBr3, and (CH3)3AsBI3

An X-ray structure analysis of three trimethylarsine-boron trihalide adducts has been undertaken. Crystals of (CH₃)₃AsBCl₃ and (CH₃)₃AsBBr₃ are monoclinic with space groupP2₁/m (No. 11) withZ=2 while those of (CH₃)₃AsBI₃ are orthorhombic with space groupPnma (No. 62) withZ=4. For (CH₃)₃AsBCl₃,a=6.497(3) Å,b=10.735(3) Å,c=7.070(2) Å,=111.8(3)°,V=458.4(3) ų,R=0.0343. For (CH₃)₃AsBBr₃,a=6.672(4) Å,b=11.135(7) Å,c=7.199(4) Å,=111.5(1)°,V=497.7(5) ų,R=0.0434. For (CH₃)₃ÅsBI₃,a=13.113(7) Å,b=11.733(5) Å,c=7.387(3) Å,V=1136.5(5) ų,R=0.0329. The As-B bond lengths are 2.065(6), 2.04(1), and 2.03(1) Å, respectively, for the chloride, bromide, and iodide. These and other structural parameters are discussed with reference to previous predictions based on vibrational spectra and previous structural studies on the trimethyl-phosphine and trimethylamine adducts.     

Study on the crystal and molecular structure of triphenyl tin methacrylate: (C6H5)3SnOCOCCH2CH3

The crystal and molecular structure of (C₆H₅)₃SnOCOCCH₂CH₃ has been determined by a single crystal X-ray diffraction study. The crystal is monoclinic with space group P2₁/c,a=11.902(3),b=10.104(4),c=16.721(2) Å,=97.56(1)°,V=1930.4 ų,Z=4 andD _c =1.495 g/ cm³,F(0,0,0)=872,(CuK)=1.5418 Å. The structure was solved by the heavy-atom method and refined by full-matrix least-squares procedures to anR factor of 0.060 based on 2157 independent reflections. The results showed that the Sn-O bond distance is 2.064(4) Å. The average Sn-C bond distance is 2.126 Å. There is a weak coordination through the O of the CO group of the methacrylate residue (Sn-O(2) 2.774(5) Å) except for four normal coordinations. The coordination number at the Sn⁴⁺ is 5.     

Crystal structure of (E)-5-hydroxypyrrolizidin-3-one and (Z)-5-thioketalpyrrolizidin-3-one

The crystal structures of (E)-5-hydroxypyrrolizidin-3-one (2) and (Z)-5-thioketalpyrrolizidin-3-one (3) have been determined by single-crystal x-ray diffraction techniques and refined by full-matrix least squares. Molecule2 crystallizes in the monoclinic space groupP2₁/a(No. 14) witha=7.887(3) Å,b=9.788(5) Å,c=9.316(4) Å,=100.6(1), andZ=4. Molecule 3 crystallizes in the monoclinic space groupP2₁/c witha=12.947(14) Å,b=10.553(14) Å,c=9.629(14) Å,=101.4(1), andZ=4. The calculated density for both molecules is 1.33 g cm^–1. FinalR-factors were 5.1% for2 and 8.59% for3. The x-ray results showed that a change in configuration occurred in the reaction going from2 to3.     

Crystal and molecular structure of 1-phenyl-3-(2-hydroxyphenylamino)-2-buten-1-one,C16H15NO2

Orange, yellow, and colorless crystals were obtained for the title compound. The orange crystals are triclinic, space groupP¯1,a=9.181(2),b=10.734(2),c=15.245(3) Å,=73.06(2),=79.21(2), =67.83(2)°,V=1325.9(5) ų,Z=4. Two different symmetry-independent molecules (moleculeA andB) were determined in the crystal unit. The conformation ofA is stabilized by an intramolecular H bond from the amino NH to the keto and phenolic O atoms [1.89(2) and 2.38(2) Å, respectively]. The conformation ofB is stabilized by only one intramolecular H bond, from the amino NH to the keto O atom [1.925(2) Å]. The colorless crystals (moleculeC) are monoclinic, space groupP2₁/n,a=11.883(3),b=11.004(3),c=10.053(3) Å,=95.93(3)°,V=1307.5(6) ų,Z=4. This conformation is stabilized by one intramolecular H bond, the same as in B, with N-HO, 1.84(3) Å. An intermolecular H bond is observed forA,B, and C, O-HO, 2.634(2), 2.640(2), and 2.697(2) Å, respectively. The yellow crystals are adducts with ethanol (¹H NMR, infrared and GC measurements).     

Structure oftrans-difluorobis(1,3-propanediamine)chromium(III) perchlorate,trans-[Cr(N2C3H10)2F2](C104)

The title compound is monoclinic,M _r =337.8,P2₁/c-C _2h ⁵ (No. 14),a=5.508(2),b=13.944(6),c=18.238(5) Å,=95.99(3)°,V=1393.1(9) ų,Z=4,D _x =1.61 g cm^–3, (MoK)=0.71073 Å,F(000)=660.0,=10.3 cm^–1, finalR=0.051 for 2122 observed [I>3(I)] reflections. The two six-membered rings resulting from the coordination of the 1,3-propanediamine ligands to the chromium atom are in the chair conformation. The Cr-N and Cr-F distances average 2.085(4) and 1.876(3) Å, respectively.     

Crystal structures of difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]boron(III), [BF2(C16H13O3)], and bis[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II), [Cu(C16H13O3)2]

The crystal structures of difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]boron(III), [BF₂(C₁₆H₁₃O₃)], and bis[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II), [Cu(C₁₆H₁₃O₃)₂], have been determined by single-crystal X-ray diffraction methods. The structures were solved by direct methods and electron density calculations and were refined by the full-matrix least-squares method. Difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]-boron(III) crystallizes as yellow rhombs in the monoclinic space groupP2₁/c witha=11.429(3),b=11.364(4),c=11.412(4) Å,=92.19(2)°,V=1481.0(8) ų andZ=4. A total of 2754 unique reflections were collected. Of these 1342 were considered observed [I>3(I)] leading to a finalR-value of 0.045. Boron is tetrahedrally coordinated to the two fluorine atoms and to two oxygen atoms of the bidentate 2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato ligand, C₁₆H₁₃O ₃ ^– . Average bond distances: C-C (aromatic) 1.378(10) Å, B-O 1.473(7) Å and B-F 1.343(4) Å. bis[2-(4-Methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II) crystallizes as dark yellow-green plates in the monoclinic space groupC2/c witha=23.410(7),b=13.856(3),c=8.039(3) Å,=101.79(2)°,V=2553(1) ų andZ=4. Of the unique set of 3076 scanned reflections 2401 hadI>3(I) for whichR became 0.040. Copper is coordinated to four oxygen atoms, two from each of the two bidentate 2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato ligands, in a distorted square planar manner. The molecule hasC ₂ symmetry. Average bond distances: C-C (aromatic) 1.383(6) Å and Cu-O 1.896(8) Å. The crystals of both compounds consist of monomeric molecular complexes held together by van der Waals forces.     

Crystal structures of (η5-C5H4COMe)M(CO)3Me (M=Mo,W)

The crystal structures of ( ⁵-C₅H₄COMe)M(CO)₃Me (M=Mo,W) have been determined. They are not isostructural. M=Mo isP2₁/c,a=10.205(6),b=14.192(8),c=8.135(6) Å,=93.43(4)° andD(calc)=1.71 g cm^–3 forZ=4. M=WisP2₁/c,a=12.580(7),b=6.830(5),c=13.750(7) Å,=93.72(4)° andD(calc)=2.20 g cm^–3 forZ=4. Both have a four-legged piano stool geometry with the substituted carbon making the closest M-C( ⁵) approach. The methyl group in the M=W derivative is disordered between twotrans-ligand positions. The average bonding parameters for the more accurately determined Mo analog are: Mo-C()⁵)=2.34(3) Å, Mo-CO=1.98(2) Å, Mo-Me=2.304(4) Å.     

Studies of systemic acylanilide fungicides. Part I. Crystal structure and molecular conformation ofdl-methyl-N-(2,6-dimethylphenyl)-N-(2-methoxyacetyl) alaninate

The crystal structure of metalaxyl (C₁₅H₂₁NO₄) was determined by three-dimensional X-ray analysis from diffractometer data. The crystals are monoclinic,P2₁/c,a=7.851(3) Å,b=13.119(10) Å,c=15.107(7) Å,=101.71(6)°,Z=4,D _x=1.218 g cm^–3, (MoKa)=0.095 mm^–1. FinalR=0.079 for 1203 observed reflections. The dimethylphenyl ring is almost perpendicular to the amidic plane of the molecule.     

The crystal structures of NaAlR4, R=methyl,ethyl, and n-propyl

The crystal structures of the title compounds have been determined from diffractometer data and refined by full-matrix least squares. NaAlMe₄ is orthorhombic,Cmcm,a=9.234(3),b=9.221(3),c=8.303(2) Å,Z=4,D _c=1.03 g cm^–3,R=0.029 for 278 data. NaAlEt₄ is monoclinic,P2₁/c (No. 14),a=13.900(2),b=13.207(2),c=14.443(1) Å,=117.43(1)°,Z=8,D _c=0.94 g cm^–3,R=0.056 for 2747 data. NaAl(n-Pr)₄ is monoclinic,C2/c,a=9.802(5),b=15.336(4),c=21.611(10) A,=98.34(4)°,Z=8,D _c=0.92 g cm^–3,R=0.072 for 899 data. Coordination of Al is essentially tetrahedral in all structures, and closest contacts to Na⁺ involve-carbon atoms of alkyl groups.     

Crystal structure of bis(2,3,5-trimethylpyridine N-oxide) 2,4,6-trinitrophenolate: Cation complex tied by the extremely strong OHO hydrogen bonding

The salt of bis(2,3,5-trimethylpyridine N-oxide) 2,4,6-trinitrophenolate, C₂₂H₂₅N₅O₉, crystallizes in monoclinic space group C2/c with a=12.411(2)Å, b=15.326(3)Å, c=13.559(3)Å, =113.13(1)°, V=2371.8(8)ų, Z=4, D _c=1.410 mg/m³, F(000)=1056. The molecule of 2,3,5-trimethylpyridine N-oxide is protonated. Two pyridine N-oxide molecules are linked by extremely strong OHO hydrogen bonding (2.378(4)Å) to form a cation complex. CHO hydrogen bonding and – interactions also play important role in stablizing the structure of the salt.     

Crystal and molecular structure of [CpRu(PPh3)2(t-C4H9SH)]BF4

The structure of the [CpRu(PPh₃)₂(t-C₄H₉SH)]BF₄ complex was determined by X-ray diffraction techniques: monoclinic space groupP2₁/c,a=14.662(9),b=18.515(7),c=15.368(6)Å,=101.88(5)°,V=4082(6)ų,Z=4,R=0.049,R _w=0.057. The Ru is attached to two triphenylphosphine ligands, a cyclopentadienyl and thet-butylmercaptan. The Ru-S distance is 2.396(2)Å and the S-H distance is 1.289(2)Å.     

Crystal and molecular structures of 5,7-dimethyl-1,8-naphthyridine-2-ol (=LH) and of its mercury (II) complex HgL2 and synthesis of some lanthanide/HgL2 heterometallic complexes

The crystal structures of the title compounds have been determined by single crystal diffraction methods. Crystals of 5,7-dimethyl-1,8-naphthyridine-2-ol (1) are monoclinic, space groupP2₁/n witha=7.336(2),b=8.989(2),c=13.125(3)Å,=95.72(3)°,V=861.2(4)ų,Z=4,D _c =1.34 g cm^–3, finalR=0.052. The molecules are linked in pairs by two N-HO hydrogen bonds, and these dimers are stacked in a discontinuous, stepped fashion. Crystals of HgL₂ (2) are monoclinic space groupP2₁,/c witha=4.044(2),b=12.147(2),c=18.093(5)Å,=93.32(2)°,V=887.3(4)ų,Z=2,D _c =2.05 g cm^–3, finalR=0.051. In2 the mercury binds to N(1) to form a linear N-Hg-N coordination geometry, and the HgL₂ molecules form a continuous stacked structure. The syntheses of the compounds ML₄(NO₃)₃·H₂O (M=Nd, Gd, and Er), PrHg₂L₄(NO₃)₃, andM ₂Hg₃L₆(NO₃)₆ (M=Gd, Er) are also reported.     

Crystal and molecular structures of the 4-(1H)-pyridone (=L) lanthanide complexes {[GdL(NO3)3(H2O)]·CH3OH}2 and [DyL4(NO3)2](NO3) and of L2HNO3

The crystal structures of the title compounds have been determined by single crystal diffraction methods. Crystals of the dysprosium compound are monoclinic, space groupP2₁/c witha=14.133(4),b=13.438(5),c=14.401 (4)Å,=103.98(2)°,V=2654(1)ų,Z=4,D _c =1.82 g cm^–3, finalR=0.035. The Dy atom is eight-coordinate with a distorted dodecahedral coordination geometry involving two bidentate nitrate groups and four pyridone oxygen atoms. An erbium complex with analogous stoichiometry was also prepared but not structurally characterized. Crystals of the Gd compound are monoclinic, space groupP2₁/n, witha=11.226(2),b=9.075(2),c=16.737(3)Å,=93.88(3)°,V=1701(1)ų,Z=2,D _c =1.91 g cm^–3, finalR=0.042. Each Gd atom is bonded to one pyridone oxygen atom, a water molecule and three bidentate nitrate groups. An oxygen atom of one of the bidentate nitrates additionally serves to bridge pairs of Gd atoms so as to form a dinuclear complex in which each Gd atom is nine-coordinate with a tricapped trigonal prismatic geometry. Crystals of L₂HNO₃ are monoclinic, space groupI2/a witha=12.479(4),b=6.535(2),c=14.297(6)Å,=96.07(3)°,V=1159(1)ų,Z=4,D _c =1.45 g cm^–3, finalR=0.057. The pyridones are linked in pairs by very short (2.44 Å) symmetrical OHO hydrogen bonds. Each pair is further linked via a nitrate ion by means of N-HO(nitrate)H-N hydrogen bonds, so as to form an extended chevron-like pyridone-pyridone-nitrate-pyridone-pyridone array. Adjacent chains are linked via weak C-HO(NO₃) interactions.     

Synthesis and molecular structure of {[Se(CH3)3][(CH3)AlCl3]}n: A novel two-dimensional layered organoaluminum-selenium polymer

The crystalline product {[Se(CH₃)₃][(CH₃)AlCl₃]}_n was prepared from reaction of SeCl₄ with A1(CH₃)₃ in heptane. The organo-main group polymer crystallizes in the monoclinic space group P2₁/c with unit cell parametersa=11.218(3) Å,b=11.119(3) Å,c=9.915(2) Å,=107.82(2)°,V=1177.4(5) ų, andD ^calcd=1.54 g cm^–3 forZ=4. Least-squares refinement based on 1195 observed reflections I>3(I) in the range 3.50°<2<45.0° led to a finalR factor of 0.036 (R ^w=0.047). The asymmetric unit contains one selenonium ion, Se(CH₃) ₃ ⁺ , and one organoaluminum anionic species, (CH₃)AlCl ₃ ^– . Secondary interactions (SeCl) serve to link the ions along two dimensions to form infinite layers. Thus, {[Se(CH₃)₃] [(CH₃)A1C1₃]}_n may be regarded as a layered organoaluminum-selenium polymer. The mean Se-C bond distance is 1.921(5) Å while the mean C-Se-C bond angle is 99.1(4)°. The independent Al-C bond distance is 1.927(8) Å while the mean Al-Cl bond distance is 2.166(7) Å.     

Structure of a styrylbenzoselenazole platinum(II) complex: [NEt4][Pt(nsbse)Br3]

Tetraethylammonium tribromo[2-(2-chloro-5-nitrostyryl)benzoselenazole] platinate (II), [(C₂H₅)₄N][PtBr₃(C₁₅H₉ClN₂O₂Se)], is monoclinic, in space groupP2₁/c, witha=9.496(2),b=20.321(7),c=15.166(3)Å,=100.18(1)°,V=2880(2)ų,M _r =928.72,Z=4,D _x =2.141 g cm^–3, (MoK)=0.71073 Å,=104.1 cm^–1,F(000)=1752,T=298 K. The structure was solved by direct methods and refined toR=0.032 for 2626 unique observed reflections withI>3(I). The [Pt(nsbse)Br₃)] unit has square-planar geometry about the Pt atom, with the nsbse coordinated to the Pt through the N of the selenazole ring. The ligand molecule is non-planar, with a dihedral angle of 61.6(2)° between the benzoselenazole and phenyl rings. The dihedral angles between the PtBr₃ plane and the benzoselenazole and phenyl planes are 105.2(1) and 80.7(1)°, respectively.     

Molecular structure of 3-(3-oxo-bicyclo[2.2.1]hept-5-en-2-yl)-oxirane-2-carboxylic acid methyl ester

The crystal and molecular structure of an epoxy ester is described. The structure has been solved by vector search methods and refined by least squares methods toR ₁=0.0372 [I>2(I)]. The structure consists of two independent molecules in the asymmetric unit. These molecules are chemically the same. Crystal data: C₁₁H₁₂O₄, triclinic, space group ,a=10.324(3),b=10.553(7),c=10.869(5)Å, =61.77(4), =88.64(4), =88.16(6)°,V=1042.7(9)ų,Z=4.     

Primary to secondary sphere coordination of 18-crown-6 to lanthanide (III) nitrates: Structural analysis of [Pr(NO3)3-(18-crown-6)] and [M(NO3)3(OH2)3]·18-crown-6 (M=Y,Eu, Tb−Lu)

The direct reaction of hydrated lanthanide nitrate salts with 18-crown-6 in 31 CH₃CNCH₃OH has resulted in the isolation and structural characterization of [Pr(NO₃)₃(18-crown-6)] and [M(NO₃)₃(OH₂)₃]·18-crown-6 (M=Y, Eu, Tb–Lu). (The Eu and Yb analogs were confirmed with preliminary cell data only.) [Pr(NO₃)₃(18-crown-6)] is 12-coordinate icosahedral and crystallizes in the orthorhombic space group Pbca with (at 20°C)a=12.230(2),b=15.598(4),c=21.777(9)Å andD _calc=1.89 g cm^–3 forZ=8. The seven isostructural [Pr(NO₃)₃(18-crown-6)] complexes all contain 9-coordinate capped square antiprismatic metal centers hydrogen bonded via the bound water molecules to D_3d 18-crown-6 within the lattice to form hydrogen bonded polymeric chains. Each complex is orthorhombic Pnma with cell parameters as follows: M=Tb (20°C):a=15.242(6),b=14.253(11),c=11.070(6)Å,D _calc=1.83 g cm^–3 forZ=4; M=Dy (20°C):a=15.248(3),b=14.239(5),c=11.058(3)Å,D _calc=1.84 g cm^–3 forZ=4; M=Y (19°C):a=15.260(2),b=14.238(2),c=11.048(3) Å,D _calc=1.64 g cm^–3 for Z=4; M=Ho (20°C):a=15.226(4),b=14.208(15),c=11.028(3)Å,D _calc=1.86 g cm^–3 forZ=4; M=Er (20°C):a=15.250(3),b=14.208(7),c=11.028(3)Å,D _calc=1.87 g cm^–3 forZ=4; M=Tm (20°C):a=15.246(6),b=14.190(16),c=11.013(6) Å,D _calc=1.88 g cm^–3 forZ=4; M=Lu (21°C):a=15.244(9),b=14.158(6),c=10.980(7)Å,D _calc=1.90 g cm^–3 forZ=4.     

The crystal and molecule structure of tetraphenylphthalic anhydride,C32H20O3

Tetraphenylphthalic anhydride has been structurally characterized by X-ray crystallography: triclinic,P¯1,a=13.386(4),b=13.563(4),c=16.185(6) Å,=71.70(3),=109.32(3), =116.17(3)°,V=2439(1) ų,Z=4,D _x=1.23 g cm^–3,=0.73 cm^–1,T=295 K, andR=0.065 for 3910 observed reflections. The asymmetric unit consists of two crystallographically independent molecules of tetraphenylphthalic anhydride (TPPA). Crowding from four adjacent phenyl substituents produces large average displacements of the substituents from the central ring (av. ~0.08 Å, max. 0.17 Å) and distortions in the central aromatic ring. The torsion angles relating the plane of the substituent phenyl rings to the central ring plane (av. 62°) is consistent with other polyphenylated aromatic structures.     

Crystal structure of the 1:1 complex formed by 4-nitropyridine N-oxide and 4-nitrophenol

The title complex (C₆H₅NO₃·C₅H₄N₂O₃,M _r =279.21) crystallizes in the orthorhombic space groupPna2₁ witha=18.862(2),b=5.876(1),c=10.803(2) Å,V=1197.3(6) ų,D _c =1.549 g cm^–3 forZ=4,F(000)=576, (MoK)=0.71073 Å,=0.84 mm^–1,T=297 K. The structure was solved by direct methods and refined by block matrix least-squares. FinalR=0.032, wR=0.037 for 904 observed reflections. The complex is held together by an intermediate hydrogen bond between the hydroxyl and the N-oxide group with an OO distance equal to 2.618(3) Å. The stacking of thea glide related complex molecules by translation in theb direction results in a herringbone structure with an overlap of the nitrophenol and 4-nitropyridine N-oxide rings and a mean interplanar distance of 3.4(1) Å between those rings.On leave from Universidad del Valle, Departamento de Quimica, Cali, Colombia.     

The crystal structure of LiBr·(CH3OCH2CH2OCH3)2

The crystal structure of LiBr·(CH₃OCH₂CH₂OCH₃)₂ has been determined from counter data and refined by full-matrix least-squares techniques. The crystals belong to the monoclinic space groupC2/c (C _2h ⁶ , No. 15) witha=13.518(4),b=8.007(3),c=12.252(4) Å,=98.08(2)°, andD _calc=1.35 gcm^–3 forZ=4. The finalR value for 489 observed reflections is 0.033. The lithium and bromine atoms lie on a crystallographic two-fold axis. The structure consists of discrete LiBr·(CH₃OCH₂CH₂OCH₃)₂ units. The Li-Br separation is 2.57(1) Å. The two DME molecules are coordinated to the lithium atom through the four oxygen atoms at an average LiO separation of 2.09(3) Å.