Crystal and molecular structure of (exo)-1-carboxymethyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidmo-[2,3-a]-β-carboline,C18H20N2O5

The structure of the title compound C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, monoclinic, space groupP2₁/c,a=15.589(4),b=7.619(1),c=16.792(4) Å, =111.47(2)°,V=1856.1 ų,Z=4,D _x =1.23 Mg m^–3. CuK radiation (graphite crystal monochromator, =1.54178 Å),(CuK)=7.17 cm^–1,F(000)=728. Final conventionalR-factor=0.075,R _w =0.106 for 2266 observed reflections and 274 variables. The structure was solved usingMultan.     

Low-temperature,high-resolution crystal structure study of tricyclo[3.3.1.13,7]decan-2-ol (adamantanol-2)

The structure of the title compound (C₁₀H₁₅OH) was determined by X-ray diffraction at liquid nitrogen temperature. The crystals are triclinic, spacegroupP¯1 witha=11.3686(5),b=11.3990(5),c=11.4353(6) Å,=82.193(4),=70.211(4) and =62.279(4)°,V _c =1233.9(1) ų,Z=6,F(000)=504,D _x =1.229 g cm^–3; MoK radiation, =0.71073 Å,(MoK)=0.7 cm^–1. FinalR factor=0.046 andwR=0.062 for 8162 reflections withI>2.5(I). The asymmetric unit consists of three independent adamantanol-2 molecules which together with the three symmetry-related molecules form a cluster having pseudo ¯3 symmetry. The six molecules in the cluster are connected by six O-HO hydrogen bonds, the oxygens of which constitute an almost ideal chair conformation.     

On the organoaluminum chemistry of multidentate phosphine ligands. Reaction of trimethylaluminum with bis(diphenylphosphino)methane: Synthesis and molecular structure of [Al(CH3)3]2[(C6H5)2PCH2P(C6H5)2]

Reaction of an excess of trimethylaluminum with bis(diphenylphosphino)-methane in heptane affords the crystalline complex [A1(CH₃)₃]₂[(C₆H₅)₂PCH₂P(C₆H₅)₂]. The title compound crystallizes in the triclinic space group P¯1 with unit cell parametersa=10.053(6),b=11.017(6),c=15.908(8) Å,=85.58(4),=71.80(4), =77.49(4)°,V=1634(1) ų, andD _c=1.07 g cm^–3 forZ=2. Least-squares refinement based on 2924 observed reflection with intensitiesI3I) in the range 2.00245.0° converged atR=0.050 (R _w=0.067). The Al-P distances are 2.585(2) and 2.521(2) Å, and the P-C-P angle is 121.4(2)°.     

Crystal and molecular structure of (exo)-2-phenyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C22H22N2O3

The structure of the title compound, C₂₂H₂₂N₂O₃, was determined by X-rays atT=290 K.M _r =362.427, orthorombic, space groupPbca,a=11.666(4),b=15.691(1),c=20.931(1) Å,V=3831.4 ų,Z=8,D _x =1.257 Mgm^–3. CuK radiation (graphite crystal monochromator, =1.54178 Å),(CuK)=6.42 cm^–1. Final conventionalR-factor=0.050,R _w =0.062 for 2552 observed reflections and 301 variables. The structure was solved usingMultan.     

Crystal and molecular structure of (exo)-2-methoxycarbonyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C18H20N2O5

The structure of the title compound, C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, monoclinic, space groupP2₁/c,a=13.7850(8),b=8.8951(7),c=15.1603(11) Å, =111.410(6)°,V _c =1730.7 ų,Z=4,D _x =1.322 Mgm^–3. Cu K radiation (graphite crystal monochromator, =1.54178 Å),(Cu K)=7.69 cm^–1. Final conventionalR-factor=0.057,R _w =0.076 for 2160 observed reflections and 271 variables. The structure was solved usingMultan.     

Crystal and molecular structure of 1,6-dimethyl-3,6-dimethoxy-3-[(N-methylindol-3-yl)methyl] piperazine-2,5-dione,C18H23N3O4

The structure of the title compound, C₁₈H₂₃N₃O₄, was determined by X-rays.M _r =344.40, triclinic, space groupP¯1,a=8.163(4),b=9.230(2),c=13.297(2) Å,=102.70(2),=103.58(3)°,=102.50(3)°,V=911.3 ų,Z=2,D _c =1.26 Mg m^–3. CuK radiation (graphite crystal monochromator,=1.54178 Å),(CuK)=7.50 cm^–1,T=290 K. Final conventionalR-factor=0.068,R _w =0.079 for 1912 unique reflections and 295 variables. The structure was solved usingMultan andDirdif. The title compound is the first example of a 3,6-tetrasubstituted dioxopiperazine adopting a folded conformation, owing to a direct interaction between the dioxopiperazine ring and the aromatic side chain.     

Crystal and molecular structure of: 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octan-7-one and 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octane

X-ray crystallographic studies of the two title compounds have shown that the molecules crystallize in the same triclinic space group, , with very similar cell dimensions. For C₂₁H₂₁BrO₄,a=12.056(5),b=13.206(5),c=7.595(3)Å, =90.38(3), =106.07(3) and =124.42(3)° and for C₂₁H₂₃BrO₃,a=12.076(6),b=13.090(5),c=7.490(3)Å, =92.65(5), =104.90(5) and =124.55(5)°. Both compounds possess the oxabicyclo[3.2.1]octane bridged ring system and differ only at the carbon to the ring oxygen where the Csp³ in the ether is replaced by Csp²=O in the lactone. Both cyclohexane rings adopt distorted chair conformations and the lactone and ether rings approximate closely to the envelope conformation. The bromine substituent at C(4) results in distortion of the naphthalene ring. Both molecules pack with the naphthalene rings parallel to each other with interplanar spacings of 3.71 Å in the ether and 3.66Å in the lactone.     

Crystal and molecular structure of 5-ethoxy-4-methylene-exo-10-oxatricyclo[5.2.1.02,6]-deca-8-ene-3-ol,C12H16O3

The structure of the title compound, C₁₂H₁₆O₃, was determined by X-rays.M _r =208.26, triclinic, space groupP¯1,a=7.802(2),b=8.449(2),c=9.069(1) Å,=90.79(1)°,=105.57(1)°, =106.07(1)°,Z=2,D _x =1.26 Mg m^–3; MoK radiation (graphite crystal monochromator, =0.71069 Å),(MoK)=0.96 cm^–1,T=290 K. Final conventionalR-factor=0.046,R _w =0.067 for 3009 observed reflections and 184 variables. The structure was solved using Patterson methods andDirdif, and the resulting all cis-endo configuration of the alcohol group on C(3) and the ethoxy group on C(5) shows that the stereochemistry of the metal-mediated addition reaction involved is solely determined by steric factors.     

Crystal and molecular structure of 5-bromo-pentacyclo[4.3.0.02,5.03,8.04,7]nonane-4-carboxylic acid,C10H9BrO2

The structure of the title compound, C₁₀H₉BrO₂, was determined by X-rays.M _r =241.08, triclinic, space groupP¯1,a=5.800(1),b=6.441(1),c=12.030(1) Å,=92.90(1)°,=95.65(2)°, =95.69(2)°,V _c =444.2 ų,Z=2,D _x =1.80 Mg m^–3, MoK radiation (graphite crystal monochromator, =0.71069 Å),(MoK)=48.58 cm^–1,T=290 K. Final conventionalR-factor=0.037,R _w =0.044 for 1863 observed reflections and 145 variables. The structure was solved usingMultan andDirdif. The results show that the 5-bromo substituent has a marked effect on the geometry of the homocubane skeleton. Its presence prevents a complete release of geometrical strain and induces a shortening of the bond distances to the apex carbon atom.     

Synthesis and structure of (η5-C5H5)2Hf(η1-NC4H4)2

The crystal structure of (⁵-C₅H₅)₂Hf(¹-NC₄H₄)₂ has been determined from X-ray data measured by counter methods. The title compound is isostructural with (⁵-C₅H₅)₂Zr(¹-NC₄H₄)₂, and crystallizes in the monoclinic space groupP2₁/c (C _2h ⁵ , No. 14) with unit cell constantsa=9.605(3),b=8.174(3),c=19.487(4) Å, =90.85(3)°, andZ=4 forD _c=1.91 gcm^–3. Full-matrix least-squares refinement gave a finalR value of 0.068 for 2154 independent observed reflections. The two cyclopentadienyl rings are ⁵-coordinated to the hafnium atom at an average Hf-C(⁵–) distance of 2.51(1) Å. The Hf-N-centroid (-pyrrolyl) angles average 166°.     

The molecular structure of dibutylbis(2-pyridinethiolato-5-ethyl ester)tin(IV), [SnBu2(TNEE)2]

The crystal structure of [SnBu₂(TNEE)₂], (HTNEE=5-ethyl ester of 2-mercaptopyridine-5-carboxylic acid) has been determined by X-ray single crystal diffraction study. The crystal is triclinic, space groupP,a=10.042(1),b=18.421(2),c=7.979(1) Å, =98.7(1), =107.3(1), =87.7(1)^o,V=1393(1) ų, and Z=2 The tin center is coordinated to two butyl groups and to the nitrogen and the sulfur atoms of two ligand molecules in a very distorted trapezoidal bipyramid.     

Crystal and molecular structure of [rac-1S,2S,-3S,4R]methyl 2-benzoyl-3,4-dimethyl-4-phenylcyclobutane-1-carboxylate,C21H22O3

The structure of the title compound C₂₁H₂₂O₃, was determined by X-rays.Minr=322.4, monoclinic, space groupP2₁/a,a=11.960(2),b=14.275(3),c=10.858(2) Å,=103.20(2)°,V _c =1804.8 ų,Z=4,D _x =1.223 Mg m^–3. CuK radiation (graphite crystal monochromator,=1.54184 Å),(CuK)=6.53 cm^–1,F(000)=688, T=290 K. Final conventionalR factor=0.050,R _w =0.069 for 1679 unique reflections and 284 variables. The structure was solved usingMultan.     

Trimethylamine-N-oxide induced disproportionation of Re2(CO)10: Synthesis and X-ray crystal structure of [fac-Re(CO)3(ONMe3)3] [ReO4]

An attempted synthesis of [Re(CO₃) (-OH)]₄,1, by reacting Re₂(CO)₁₀ with an excess of NMe₃O in THF resulted instead in isolation of a disproportionation product, [fac-Re(CO)₃(ONMe₃)₃][ReO₄],2. The structure of2 was determined via X-ray crystallography: tri-clinic,P1^¯,a=9.499(5),b=9.841(2),c=13.448(2)Å,=109.92(2),=106.89(3), =93.15(4)°,D _calc=2.22 g^–3 andZ=2. Least-squares refinement based on 1606 observed (I>3(I)) reflections gave final values ofR=0.040 andR _w=0.047. The cation is a distorted octahedron that exhibits several structural manifestations of steric crowding among the bulky NMe₃O ligands.     

Pentacoordinated tin(II); crystal structure of dichloro-[2,2′∶6′,2″-terpyridyl]-tin(II)

The crystal structure of a well-defined 5-coordinate complex, dichloro-(2,26, 2-terpyridyl)-tin(II), is described. The stereochemistry of this complex is strongly influenced by the stereochemically active pair of electrons, illustrating clearly the potential donor capabilities of this molecule. The complex (C₁₅H₁₁Cl₂N₃Sn) crystallizes in the monoclinic space groupC2/c (No. 15) witha=15.770(5),b=9.450(2),c=10.482(2) Å,=97.53(2)°,Z=4. The finalR value is 0.029 for 1085 observed reflections.     

Crystal structure of bis-(rhodanine)copper(I) iodide,C6H6CuIN2O2S4

The structure of the polymeric rhodanine compound, C₆H₆CuIN₂O₂S₄, was determined by X-rays.M _r =456.8, monoclinic, space groupP2₁/c,a=4.1947(7),b=17.6999(12),c=17.1048(8) Å,=96.15(1)°,V _c =1262.6 ų,Z=4,D _c =2.40Mg m^–3, CuK radiation (graphite crystal monochromator, =1.54056 Å),(CuK)=278.9 cm^s-1,F(000)=872,T=290 K. Final conventionalR-factor=0.029, andR _w =0.044 for 2384 unique reflections and 153 variables. The structure was solved using Patterson methods andDirdif, and refined by full-matrix least-squares methods. The compound forms zigzag chains alonga. The copper atom is in trigonal pyramidal coordination, with two sulfur atoms of the thiocarbonyl group and two bridging iodine atoms. The copper-sulfur distances are 2.278(1) and 2.299(1) Å, and the copper-iodine distances are 2.657(1) and 2.814(1) Å.     

Crystal and molecular structure of (exo)-1-methoxycarbonyl-5-ethoxycarbonyl-4, 5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C18H20N2O5

The structure of the title compound, C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, orthprombic, space groupP2₁2₁2₁,a=9.350(5),b=11.954(2),c=15.455(3) Å,V _c =1727.3 ų,Z=4,D _c =1.324 Mg m^–3. CuK. radiation (graphite crystal monochromator, =1.54178 Å),(CuK)=7.70 cm^–1. Final conventionalR-factor=0.065,R _w =0.086 for 2887 observed reflections and 265 variables. The structure was solved usingMultan.     

Crystal and molecular structure of (endo)-1-methoxycarbonyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C18H20N205

The structure of the title compound, C₁₈H₂₀N₂O₅, was determined by X-rays atT=290 K.M _r =344.366, monoclinic, space groupP2₁/c,a=11.4266(5),b=7.9563(15),c=18.9075(7) Å, =101.851(3)°,V=1682.3 ų,Z=4,D _x =1.360 Mg m^–3. CuK radiation (graphite crystal monochromator, X=1.54178 Å),(CuK)=7.91 cm^–1. Final conventionalR-factor=0.054,R _w =0.073 for 2787 observed reflections and 286 variables. The structure was solved usingMultan.     

Crystal structure and conformation of N-(t-butoxycarbonyl)-L-isoleucyl-L-alanine benzylester

C₂₂N₂O₅H₃₂,M _r =404.5, monoclinic,C2,a=21.781(5),b=5.065(1),c=22.333(4)Å,=112.81(2)°,V=2271.1(9)ų,D _calc=1.148 g cm³, (CuK )=1.5418 Å,=5.89 cm^–1,F(000)=848, room temperature,R=0.058 for 2178 unique reflections [I2.5(I)]. The peptide linkage is in thetrans conformation. The molecule adopts the-sheet structure. The crystal structure is stabilized by a three-dimensional network of N-HO and C-HO hydrogen bonds.DCB Contribution No. 813.     

Crystal and molecular structure ofN-methylphenazinium bis(benzene-1,2-dithiolato)nickelate(III). Structure of (C13H11N2)[Ni(S2C6H4)2]

The crystal and molecular structure of the title compound, (C₁₃H₁₁N₂)[Ni(S₂C₆H₄)₂], is reported. Crystals are triclinic, space groupP¯1(No.2) withZ=2 in a unit cell of dimensionsa=9.363(1),b=10.148(1),c=13.623(1) Å,=85.64(1),=107.33(1), and =113.10(1)°. The structure was solved by the heavy-atom method and refined by the method of full-matrix least squares toR=0.036 for 2874 unique reflections. The metal atom of the anion has an approximate square-planar configuration. The metal atoms occupy the origins and A-face centers of the lattice. The anions with the metal atoms in the origins stack along thec-axis, the interplanar separation being thec-axis lattice repeat of 13.623(1) Å. The anions with the metal atoms in theA-face centers and the cations form a mixed stack along the short diagonal of theab-plane. The short interplanar distances (C–A=A–C=3.43 Å and C-C=3.91 Å) in the mixed stack (CAC-CAC) show the possibility of unusual electrical behavior. There is no evidence of direct or indirect metal-metal interaction.This work was supported by the Department of Science and Technology, Government of India, New Delhi, for which we are grateful. One of the authors (PK) also expresses his thanks to the U.G.C., New Delhi and Pachaiyappas College, Madras, for the award of FIP Fellowship.     

Crystal and molecular structure ofcis-dibenzobicyclo[3.3.0]octa-2,7-diene,C16H14

The structure of the title compound, C₁₆H₁₄, was determined by X-rays:M _r =206.29, monoclinic, space groupP2₁/n,a=5.002(1),b=23.972(5),c=9.505(2) Å,=102.56(2)°,V _c =1112.4 ų,Z=4,D _x =1.23 Mg m^–3, MoK radiation (graphite crystal monochromator, Å),(MoK)=0.75 cm^–1,T=290 K. Final conventionalR-factor=0.028,R _w =0.030 for 742 unique reflections and 187 variables. The structure was solved usingMultan.