Crystal and molecular structure of benzylidenemalononitrile

Benzylidenemalononitrile, C₁₀H₆N₂ crystallizes in the monoclinic space group,P2₁/c;a = 9·385,b = 3·976,c = 22·152 Å, = 93·53 °,V _c = 825·03 ų,D _m = 1·231,D _c = 1·242 g cm^–3,Z= 4. The structure was solved by fitting cojointly an assumed molecular shape to both the near-origin peaks of the sharpened vector map and the distribution in the Harker (U,1/2,W) section, followed by trial-and-error establishment of the coordinates. The structure was then refined by full-matrix least squares, reducingR to 0·090 for data comprising 1412 reflexions (0·086, omitting 373 unobserved) from room temperature CuK Weissenberg photographs. Steric hindrance of the malononitrile group and a hydrogen atom in theortho position of the phenyl ring causes simultaneous expansion of the bond angles between the malononitrile group and the benzylidene group and rotations of these groups relative to each other. These constraints cause the two groups to be non-planar, the dihedral angle between their least-squares planes being 11·0 °.     

Crystal and molecular structure of diphenylthiosulphodiimide

The crystal and molecular structure of diphenylthiosulphodiimide, C₁₂H₁₀N₂S₃, has been solved by the symbolic addition procedure using three-dimensional CuK diffractometer data. The system is monoclinic,a = 30·41(3),b = 5·601(5),c = 7·792(8) Å, = 108·77(1) °, space groupC2/c andZ = 4. The structure was refined by full-matrix least-squares methods toR = 0·096 for 926 observed reflexions. All hydrogen positions have been determined. The molecule possesses a crystallographic diad axis through the central sulphur atom. The planes of the phenyl rings make an angle of 30·8 ° with the closely coplanar central five atoms.     

Crystal structure of 5,5-dimethyl-2-p-bromophenylimino-Δ3-1,3,4-oxadiazoline

Oxidation of acetone-4-p-bromophenylsemicarbazone with lead tetraacetate yields only one isomer of 5,5-dimethyl-2-p-bromophenylimino-³-1,3,4-oxadiazoline, C₁₀H₁₀BrN₃O. Crystals of this compound are triclinic, space groupP¯1,a = 5·91(1),b = 9·52(1),c = 11·59(2) Å, =114·1(1) °, = 93·5(1) ° and = 108·8(1) °;z = 2 and the chemical composition is C₁₀H₁₀BrN₃O. Of 2306 independent reflexions examined, 877 were strong enough to be measured with integrated precession photographs using MoK radiation. The structure was refined using a full-matrix least-squares program to a finalR value of 0·064. The structure consists of planar phenyl and oxadiazoline rings, with a van der Waals interaction between a phenyl hydrogen atom and oxygen atom of the five member ring preventing the two rings from being co-planar; the H(13)-O(1) separation is 2·47 Å. TheZ-configuration of the product suggests a specific mechanism for the ring closure involving an organolead intermediate.     

Crystal structure of a 1:1 molecular adduct of hexamethylenetetramine with phenylacetic acid

A 11 crystalline adduct of hexamethylenetetramine with phenylacetic acid, (CH₂)₆N₄·C₆H₅CH₂COOH, has been isolated and characterized by X-ray analysis. The compound crystallizes in space groupI¯4 (No. 82), witha=20.576(3),c=6.907(1) Å, andZ=8. The crystal structure is composed of a packing of discrete molecular aggregates corresponding to the stoichiometric formula, each being consolidated by a NH-O hydrogen bond of length 2.643(8) Å, which has no significant effect on the regular geometry of the (CH₂)₆N₄ cage system. The C-CO₂ and phenyl groups in the C₆H₅CH₂COOH moiety make a dihedral angle of 74(1)°. The structure has been refined toR=0.071 for 1350 observed (F _o >2F _o ) MoK data.     

Crystal data,optics and vibrational spectra of potassium hydrogen squarate monohydrate,KHC4O4·H2O

Single crystals of potassium hydrogen squarate monohydrate have been prepared, and the unit cell, space group and crystal optics determined:a = 8·641(1),b = 10·909(1),c = 6·563(2)Å, = 99·807(5) °,Z = 4,P2₁/c,n = 1·411(1),n = 1·674(1),n = 1·793(2), 2V(–) = 59·1(8) °,n ¦¦_t,n :a = 2·3(2) ° in obtuse . Infrared and oriented Raman spectra have been obtained, and compared with the spectra of both the acid and the [C₄O₄]^2– ion. The squarate ring is itself very nearly orthorhombic, with symmetry axes parallel to the C-C bonds. The rings lie approximately in (001), with the C-C bonds aligned witha andb.     

2D hexagonal grids assembled into 3D nets via Ag···Ag interactions

A three-dimensional coordination polymer [Ni(en)₂Ag₃(CN)₅]_n (en = 1,2-diaminoethane) was synthesized and characterized by X-ray crystallography. It crystallizes in the triclinic space group ,a = 7.520(2) Å, b = 8.194(2) Å, c = 8.426(2) Å, = 65.35(3)°, = 69.57(3)°, = 68.91(3)°, V = 428.0(2), ų Z = 1. The 2D hexagonal grids are constructed using cyanides as bridges, and the Ag···Ag interactions between layers lead to a three-dimensional network.     

Synthesis and crystal structure of two vanadium(V) hydroxylamido complexes with amino acid ligands

Two vanadium(V) hydroxylamido complexes with amino acid ligands including Alanine, [VO(NH₂O)₂(Ala)]·2H₂O, and Threonine, VO(NH₂O)₂(Thr), were synthesized and characterized by elemental analyses, IR spectrum, and single crystal X-ray diffraction. The two complexes are seven-coordinated with four nitrogen atoms and three oxygen atoms in pentagonal bipyramidal geometry. The different hydrogen bonds (N–H···O, O–H···O) observed in the two complexes result in the two-dimensional network structure. [VO(NH₂O)₂(Ala)]·2H₂O belongs to monoclinic: space group P2(1)/c, with a = 21.874(13) Å, b = 8.874(5) Å, c = 15.865(9) Å, = 100.423(8)°, V = 3029(3) ų, Z = 12, D _c = 1.678 g/cm³, (MoK) = 1.002 mm^–1, F (000) = 1584, and final R ₁ = 0.0375, wR ₂ = 0.0886 for observed reflections 1189 (IT > I> 2(I)). VO(NH₂O)₂(Thr) is rhombohedral: space group R-3, with a = 21.460(16) Å, b = 21.460(16) Å, c = 11.184(12) Å, = 120°, V = 4461(7) ų, Z = 18, D _c = 1.669 g/cm³, (MoK) = 1.012 mm^–1, F(000) = 2304, and final R ₁ = 0.0356, wR ₂ = 0.0924 for observed reflections 1306 (I > 2(I)).     

Crystal and molecular structures of three trimethylamine-boron halide adducts: (CH3)3NBCl3, (CH3)3NBBr3, and (CH3)3NBI3

X-ray diffraction data from single crystals of the trimethylamine complexes of the three boron halides, BCl₃, BBr₃, and BI₃, lead to aP2₁/m monoclinic cell containing two molecules for each complex. The unit cell dimensions area = 6·68(1),b = 10·247(3),c = 6·502(6) Å, =116·2(1)° (chloro);a = 6·86(1),b = 10·612(4),c = 6·737(6) Å, = 115·8(1)° (bromo);a = 6·92(2),b = 10·86(1),c = 7·147(6) Å, = 93·9(1)° (iodo). The structures were solved by three-dimensional sharpened Patterson functions and show only the chloro and bromo compounds to be isomorphous. Refinement of 662,718 and 954 observed reflexions for the chloro, bromo and iodo complexes, respectively, using anisotropic thermal parameters yielded conventionalR factors of 0·045, 0·087 and 0·054.The molecules are shown to possess a B—N dative bond, a staggered conformation, and effective 3m (C _3v) symmetry. Average C—N bond lengths are 1·52(1) Å for all three complexes. Boronhalogen bond lengths average 1·864(4), 2·04(2) and 2·28(2) Å, while B—N bond distances are 1·609(6), 1·60(2) and 1·58(3) Å, respectively, for the chloro through iodo compounds. Bond angles are approximately tetrahedral with the C—N—C angle decreasing by several degrees in the Cl Br I series.Based in part on a dissertation submitted by Patty H. Clippard to the Rackham School of Graduate Studies of the University of Michigan, January 1969 in partial fulfillment of the requirements of the Ph.D. Degree.     

Crystal structure of tris(triphenylsiloxy)borane·triphenylsilanol (1:1) adduct

The title compound crystallizes in the triclinic space group , with a = 14.458(6), b = 14.630(5), c = 14.721(8) Å, = 79.75(2), = 80.11(3), = 80.50(3)°, and Z = 2. The crystal structure consists of molecules of (Ph₃SiO)₃B and Ph₃SiOH linked by an weak B···(silanol) acceptor-donor bond, additionally stabilized by OH(silanol)···O(siloxy) hydrogen bonds. The average B–O, Si–O distances and B–O–Si angle are 1.369, 1.649 Å and 137.2°, respectively.     

Crystallographic studies of dihalogeno-tetramethylethylenediamine complexes of zinc,cadmium and mercury. I: crystal and molecular structure of dichloro-(N,N,N′,N′-tetramethylethylenediamine)zinc(II)

The crystal structure of dichloro-(N,N,N,N-tetramethylethylenediamine)zinc(II), C₆H₁₆Cl₂N₂Zn, has been determined from 1684 reflexions measured on a Siemens four-circle diffractometer (A.E.D.) using the /2-scan technique and CuK radiation. The crystals are monoclinic, space groupP2₁/c,a = 7·716(3),b = 13·335(9),c =11·545(5) Å, = 105·59(6) ° andZ = 4. The structure was solved by Fourier methods, and refined by full-matrix least squares to a finalR (conventional) of 6·7 %. Anisotropic thermal parameters were evaluated for the non-hydrogen atoms, but the hydrogen atoms were assigned the equivalent isotropic thermal parameters of the carbon atoms to which they were bonded. The geometry around the zinc atom is distorted tetrahedral, with the Zn-Cl and Zn-N average bond lengths of 2·207(4) and 2·08(1) Å respectively.     

N-Arylmaleimide derivatives

Nine phenyl substituted N-phenylmaleimide monomers for photopolymerization studies have been characterized by x-ray crystallography. Structures for N-(2-t-butylphenyl)maleimide (1), P2₁/n, a = 10.197(3) Å, b = 11.904(4) Å, c = 10.496(5) Å, = 100.61(3)° N-(2-trifluoromethylphenyl)maleimide (2), P2₁/c, a = 11.763(8) Å, b = 10.699(9) Å, c = 8.284(5) Å, = 90.02(5)° N-(2,6-diisopropylphenyl)maleimide hemibenzene solvate (3), Pc, a = 16.747(6) Å, b = 8.552(3) Å, c = 12.899(4) Å, = 105.08(3)° N-(2,6-diisopropylphenyl) maleimide (unsolvated) (4), C2/c, a = 28.146(10) Å, b = 8.434(4) Å, c = 12.881(4) Å, = 92.20(4)° N-(2-bromo-3,5-bis(trifluoromethyl)phenyl) maleimide (5), P2₁/n, a = 8.7115(16) Å, b = 16.125(3) Å, c = 9.6707(19) Å, = 99.757(15)° N-(2-phenylphenyl)maleimide (6), P2₁/n, a = 8.519(4) Å, b = 13.742(5) Å, c = 11.147(4) Å, = 92.25(3)° N-(4-methoxyphenyl)maleimide (7), P2₁/n, a = 9.320(3) Å, b = 6.621(2) Å, c = 16.059(6) Å, = 99.58(3)° N-(2-trifluoromethylphenyl)-2-methylmaleimide (8), Fdd2, a = 43.362(12) Å, b = 8.202(2) Å, c = 12.720(4) Å and N-(2-trifluoromethylphenyl)-2-methanosuccinimide (9), Cc, a = 7.708(2) Å, b = 22.191(9) Å, c = 7.137(2) Å, = 115.76(2)° are described. Molecules with bulky 2-substituents show larger rotations between the mean phenyl and maleimide ring planes, and varying degrees of distortion to the imide group.     

Crystal structure and conformational analysis of N-formyl and N-nitroso derivatives of piperidinone

Single crystal X-ray studies for N-formyl-2,6-diortho chlorophenyl-3,5-dimethyl piperidin-4-one (FOCDMPO) and N-nitroso-2,6-di(3,4,5-trimethoxyphenyl)-3,5-dimethyl piperidin-4-one (NTMPO) are reported. Crystals of FOCDMPO and NTMPO belong to the monoclinic space groups P2₁/n and C2/c, respectively. FOCDMPO: a = 9.147(2), b = 14.586(3), c = 13.665(5) Å and = 101.68(2)° NTMPO: a = 38.52(2), b = 13.727(5), c = 9.564(3) Å and = 98.60(1)°. In both the structures, the piperidine ring adopts a boat conformation with slight distortion. In FOCDMPO, one of the phenyl and methyl groups are in axial positions while the other phenyl and methyl groups are in equatorial orientations. In NTMPO, the situation is reversed. The molecules are stabilized by weak intermolecular C—H ··· O interactions in addition to van der Waals forces.     

Synthesis and structure of 2-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalene)]-5-benzimidazole ethylcarboxylate monohydrate

As part of a program investigating the conformations of potential anticarcinogens and antioxidants, the structure of the title compound C₂₄H₂₈N₂O₂·H₂O is reported. The monohydrate crystallizes in the monoclinic space group P2/c with unit cell parameters a = 16.184(1),b = 7.937(1), c = 16.968(1), = 92.788(7)°, and Z = 4. The benzimidazole and tetrahydrotetramethylnaphthalene ring systems are inclined to one another by approximately 26°. The water molecule plays an important role in the crystal structure by hydrogen bonding to different functional groups of three organic moieties. Additional crystal stabilization is dueto – stacking of benzimidazole rings.     

Crystal structure of γ-2-trans-2,6-diphenylthian-1,1-dioxide-4-one oxime, C17H17NO3S

The X-ray crystal structure of -2-trans-2,6-diphenylthian-1,1-dioxide-4-one oxime is determined [C₁₇H₁₇NO₃S, space group P2₁ n, a = 8.177(1) b = 9.574(1)c = 19.730(5) Å, = 97.35(5)°]. The oxime group does not form an oxime dimer, but is involved in an O-H···O=S hydrogen bond.     

Crystal structure of tris(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedionato) aquolutetium(III)—Lu(fod)3. H2O

The crystal structure of Lu(fod)₃. H₂O has been solved by three-dimensional X-ray methods at room temperature. The space group isP and the cell dimensions area = 16·392,b = 22·492,c = 13·366 Å, = 91·83 °, = 119·93 °, = 90·00 °. There are four formula-units per unit cell;D _m = 1·66,D _c = 1·667 g cm^–3. Least-squares refinement of atomic and individual isotropic thermal parameters terminated withR = 0·128. This relatively highR factor is due to crystal decomposition, to the prohibitively large asymmetric unit which necessitated refinement in parts and also to the high vapour pressure of the compound and consequently large thermal vibrations in the structure. These factors caused large uncertainties especially in the positions of the atoms at the ends of the long side chains, but the more important geometry of the coordination polyhedra at the cores of the roughly spherical molecules have been firmly established. Except for orientation differences, the two crystallographically independent formula-units are very similar and both are dimerized through water molecules with hydrogen bonds across centres of symmetry. In each case the coordination of lutetium is seven-fold, with the geometry of a monocapped trigonal prism.     

Structure of 2-{2-[3-methyl-3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl}isoindole-1,3-dione

2-{2-[3-Methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]-2-oxoethyl}isoindole-1,3-dione (C₂₄ H₂₅NO₃) was synthesized, and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 14.109(9) Å, b = 14.130(8) Å, c = 12.152(6) Å, = 105.62(5)°, = 113.75(4)°, = 98.78(5)°, V = 2039.8(19) ų, D _c= 1.223 g/cm³, and Z = 4. The crystal structure has two crystallographically independent molecules, I and II. These molecules are held together by weak intermolecular C—H···O interactions, forming a continuous chain. The dihedral angles between the N-substituted phthalimide moiety and cyclobutane ring in molecules I and II are 60.37(14) and 68.18(18)°, respectively.     

Precision neutron diffraction structure determination of protein and nucleic acid components. VIII: the crystal and molecular structure of the β-form of the amino acidl-glutamic acid

A neutron diffraction study of the -form of L-glutamic acid, C₅H₉NO₄, has been carried out. The structure is orthorhombic: space groupP2₁2₁2₁,a= 5·159(5),b= 17·30(2),c= 6·948(7) Å andz = 4. Least-squares refinements based on 803 reflexions led to a final conventionalR value of 0·026, and bond lengths involving hydrogen atoms have been determined with an average precision of 0·004 Å. The molecule is in the zwitterion form, and no intramolecular hydrogen bonds have been found. The hydrogen atom involved in a strong hydrogen bond between two carboxyl groups in adjacent molecules (0 ... 0 distance 2·519(2) Å) is covalently bonded to the carboxyl group belonging to the side chain of the amino acid. This side chain is buckled with C gauche to C with respect to the C —C bond. The bond angles involving carbon atoms in the side chain are accordingly strained.Research performed under the auspices of the U.S. Atomic Energy Commission. Part VII is the crystal and molecular structure of the amino acid L-lysine monohydrochloride dihydrate bt T. F. Koetzle, M. S. Lehmann, J. J. Verbist & W. C. Hamilton (Acta Crystallogr, in Press).On leave from Kemisk Institut, Århus Universitet, Denmark, and supported in part by a grant from Statens Naturvidenskabelige Forskningsråd, Denmark.U.S. National Institutes of Health Postdoctoral Fellow.We are indebted to Drs. A. Sequeira, H. Rajagopal and R. Chidambaram for communicating their results for L-glutamicacid hydrochloride prior to publication.     

Synthesis and crystal structure of [Cu(azpy)(H2O)4][Cu2(nta)2(azpy)]····6H2O: A two-dimensional network solid

The copper(II) complex [Cu(azpy)(H₂O)₄][Cu₂(nta)₂(azpy)]····6H₂O (nta = nitrilotriacetate, azpy = 4,4-azobispyridine) has been synthesized and structurally characterized. It crystallizes in the triclinic space group P , a = 8.6985(3) Å, b = 9.4776(3) Å, c = 14.6544(5) Å, = 71.5360(10)°, = 85.7600(10)°, = 88.1420(10)°, V = 1142.74(7) ų, Z = 1. The crystal structure consists of one-dimensional linear chain cations and dimeric anions. The copper centers in the anion possess distorted trigonal bipyramidal geometry, while Cu(2) has a distorted octahedral geometry in the cation. Coordinated water molecules in the one-dimensional chain form interionic hydrogen bonds with the oxygen atoms of the carboxylate of nta of the dimmer anion. These hydrogen bonds result in the formation of a two-dimensional network.     

Crystal structure of 2-N,N-diethylamino-1-carbomethoxy-2a,8a-dihydro-2a-methoxycyclobuta [b]naphthalene-3,8-dione,C19H21NO5

Crystals of the title compound, C₁₉H₂₁NO₅, are monoclinic, space groupP2₁/c,a = 7·706,b = 14·470,c = 16·836 Å, = 106·45°,Z = 4. The structure was determined with CuK diffractometer data by symbolic addition procedures and Fourier syntheses, and was refined by full-matrix least-squares methods toR = 0·079 for 2192 observed reflexions. All non-methyl hydrogen atom positions were determined. The non-aromatic six-membered ring has aboat conformation. The four-membered ring, which iscis-fused to the six-membered ring, is slightly folded, and the planar amino and carboxyl groups lie almost in the four-membered ring plane. This geometry, and the detailed bond distances suggest electron delocalization, which may make the compound a useful intermediate in the synthesis of a stable cyclobutadiene system.We thank Dr M. E. Kuehne for suggesting the problem and for crystals, the National Research Council of Canada for financial support, and the University of British Columbia Computing Centre for assistance.     

Short H· · ·H distances in norbornene derivatives

A short H···H intramolecular interaction was reported previously for an anhydride of syn-sesquinorbornene. The synthesis and structure of a such an anhydride with an additional five-membered dithiole ring has been investigated. While hydrogen atom positions are not accurately located, the 1.62 Å separation indicates this molecule is a candidate for the shortest H···H interaction. Two cycloadducts of norbornadiene, which literature suggests might exhibit additional short interactions, are reported also; however, the isomers with minimal intramolecular interactions are the isolated products. C₂₂H₂₀O₃S₂, 3, crystallizes in P with a = 10.881(4), b = 13.712(8), C = 6.548(8) Å, = 101.32(6), = 107.49(5), = 90.49(4)°, D _calc = 1.445 g cm^–3, and Z = 2, C₂₁H₂₀O₄Cl₈, 5, in P2₁/n with a = 8.168(2), b = 13.488(4), c = 23.500(6) Å, = 94.72(2)°, D _calc = 1.597 g cm^–3, and Z = 4, C₂₁H₂₈O₄, 6, in P> with a = 12.667(2), b = 12.792(2), c = 12.540(2) Å, = 113.51(1), = 98.18(1), = 74.39(1)°, D _calc = 1.276 g cm^–3, and Z = 4.