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.     

4- and 5-nitroindane

Mononitration of indane produces a mixture of 4- and 5- nitroindanes. Crystallization from mixtures occurs after distillation improves composition of a major component to above 80%. 4-Nitroindane: triclinic, space group (#2),a=7.332(4) Å,b=8.304(4) Å,c=8.358(4) Å, =61.43(4)°, =67.60(4)°, =70.15(4)°,V=405.4(4) ų,Z=2. Non-H-atoms are nearly planar, aliphatic H's are eclipsed. 5-Nitroindane: monoclinic, space groupP2₁/c (#14),a=10.946(8) Å,b=15.643(10) Å,c=9.415(6) Å, =92.34(5)°,V=1611(2) ų,Z=8. Non-H-atoms in the two molecules differ in torsion of the nitro group with respect to indane and fold of the nonbenzylic methylene group. Semiempirical calculations (PM3) suggest that distorsion from planarity may be associated with the two lowest energy vibrational modes. Uv, ir, ms, proton, and¹³C-nmr spectra are correlated with the solid state structures.     

X-ray crystal structures ofcis-bis(diphenylphosphinamide)tetracarbonylmolybdenum(0) andtrans-bis(N-methyl diphenylphosphinamide)tetracarbonylmolybdenum(0)

The X-ray crystal structures ofcis-Mo(CO)₄(Ph₂PNH₂)₂,I, andtrans-Mo(CO)₄(Ph₂PNHMe)₂,II, are presented. ComplexI crystallizes in the monoclinic space groupP2₁/c(a=13.433(1),b=12.2719(8),c=17.318(2)Å;=109.79(1)°;V=2686.1(8)ų;Z=4). ComplexII crystallizes in the triclinic space groupP¯1 (a=6.9986(8),b=10.328(1),c=11.241(2)Å,=107.58(1)°,=91.76(1)°, =101.28(1)°,V=756.1(4)ų,Z=1). The molybdenum coordination geometry in each complex is a slightly distorted octahedron. The molybdenum-carbon bond lengths for the carbonyls trans to phosphorus in complexI are shorter than those the carbonyls trans to other carbonyls. The average molybdenum-phosphorus distance inI (2.525(5)Å) is similar to those in other diphenylphosphinamide complexes and longer than the molybdenum-phosphorus distance inII in 2.4585(7)Å). The distance between two nitrogen atoms incis Mo(CO)₄(Ph₂PNH₂)₂ (3.74(3)Å) is significantly larger than the sum of their van der Waals radii (3.10 Å) indicating that the two nitrogens are not hydrogen bonded.     

Crystal structure of 751-1751-1751-1751-2751-2751-2

The title compound crystallizes in the centrosymmetric triclinic space group (No. 2) witha=10.818(1)Å,b=10.876(1)Å,c=11.072(2)Å, =98.74(1)°, =98.83(1)°, =96.61(1)°,V=125906(3)ų andZ=2. Interatomic distances include Fe–P=2.243(2)Å, Fe–CO=1.771(6)–1.781(5)Å, Fe–C(C₅H₅)=2.074(6)–2.103(5)Å and P–F=1.511(6)–1.571(4)Å.     

Structures of 2-, 3-, and 4-methyl-9-oxothioxanthenes

The structures of 2-, 3-, and 4-methyl-9-oxothioxanthenes (2-, 3-, and 4-TX, respectively) were determined by single crystal x-ray methods. The molecules are folded by 2–3° about their SC=O lines. Bond distances and angles vary only slightly as a function of the methyl substitution position, and reveal no inherent structural reason for the long-range nmr couplings observed between the ring and methyl protons. The molecular packings exhibit interesting similarities as well as subtle differences that result from variation of the methyl position. Crystals of 2-TX are orthorhombic, space groupPn2₁ a,a=10.807(1),b=4.024(2),c=24.827(3) Å,Z=4,R=0.059 for 715 observed reflections. Crystals of 3-TX are orthorhombic, space groupPbc2₁,a=3.999(1),b=25.051(2),c=10.758(1)Å,Z=4,R=0.041 for 1382 observed reflections. Crystals of 4-TX are triclinic, space groupP¯1,a=7.118(1),b=7.907(2),c=10.415(2) Å,=77.74(1),=74.35(1), =73.96(1)°,Z=2,R=0.043 for 1542 observed reflections.Deceased.     

2-(1-Methyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2] octan-3-one: Acid-catalyzed isomerization of the Z isomer to the E isomer

Crystals of (Z)-2-(1-methyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2]octan-3-one (I) were obtained from a condensation reaction of 1-methyl-1H-indole-3-carboxaldehyde with 1-aza-bicyclo[2.2.2]octan-3-one and subsequent crystallization of the product from methanol. The isomeric (E)-2-(1-methyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2] octan-3-one hydrochloride (II) was obtained by treating a methanolic solution of I with a 1M solution of hydrogen chloride diethyl ether, followed by crystallization of resultant product from methanol. Crystal data: I, is monoclinic, P2₁, a = 5.7440(10), b = 11.102(2), c = 10.708(2) Å, = 91.751(10)°, and V = 682.5(2) ų with Z = 2, for D _cal= 1.296 mg/m³ and II, is monoclinic, P2₁/c, a = 8.8510(2), b = 17.4990(5), c = 20.4300(5) Å, = 101.3620(12)°, V = 3102.26(14) with Z = 8, for D _cal= 1.316 mg/m³.     

Crystallographic characterization of N,N′-diarylformamidines bearing an alkoxy substituent at either the meta- or ortho-position

Crystal structures of four diphenylformamidines bearing phenyl substituents ortho-CH₃O (1), ortho-C₂H₅O (2), meta-CH₃O (3), and meta- ⁿ BuO (4) are reported. In each of the structures, formamidine exists as an unsymmetrical cyclic hydrogen bond dimer, and the geometry of the amidine unit is consistent with the localized C–N and C=N bonds. Interesting conformations due to the orientation of aryl groups were also observed. Crystal Data: 1, orthorhombic, Pbca, a = 11.297(1) Å, b = 15.092(1) Å, c = 16.380(2) Å, V = 2792.6(4) ų, Z = 8; 2, triclinic, P , a = 9.651(1) Å, b = 11.974(1) Å, c = 14.583(2) Å, = 101.789(2)°, = 99.320(2)°, = 99.048(2)°, V = 1595.9(3) ų, Z = 4; 3, orthorhombic, Pbca, a = 15.562(2) Å, b = 8.626(1) Å, c = 20.110(2) Å, V = 2699.4(5) ų, Z = 8; 4, monoclinic, P2₁/c, a = 14.525(2) Å, b = 15.534(2) Å, c = 8.818(1) Å, = 93.113(2)°, V = 1986.6(4) ų, Z = 4.     

Crystal and molecular structures of 1-phenyl-4,6-dimethylpyrimidine-2-thionetetraaquacobalt(II) dinitrate complex and of two pyrimidine thiones

The crystal structures of 1-phenyl-4,6-dimethylpyrimidine-2-thionetetraaquacobalt(II) dinitrate (I)a=9.032(2),b=12.458(2),c=18.067(3)Å,=103.25(3)°,Z=4;P2₁/c,R=0.049; 1-phenyl-4,6-dimethylpyrimidine-2-thione (II)a=12.005(3),b=10.090(2),c=9.649(2)Å,=104.4(1)°,Z=4;P2₁/n,R=0.038; and 4,6-dimethylpyrimidine-2-thione (III)a=15.485(3),b=13.255(3),c=7.127(2)Å,=104.3(1)°,Z=8,C2/c,R=0.041 are reported. In (I) the coordination around the cobalt(II) is distorted octahedral involving one ligand moleculevia sulphur and nitrogen atoms and four water molecules. It is relevant that the parameters in the complexed ligand are not different from those found in the uncomplexed one (II), excepting the distances on the nitrogen atom directly involved in the coordination. Bond distances and angles in compound (III) agree with those found in (II).     

The crystal and molecular structures of 2-hydroxy-1-naphthalenecarboxaldehyde and 3-hydroxy-2-naphthalenecarboxaldehyde

The crystal and molecular structures of 2-Hydroxy-1-naphthalenecarboxaldehyde (I) and 3-Hydroxy-2-naphthalenecarboxaldehyde (II) were determined. Compound (I) crystallizes in the space groupP2 ₁/n witha+5.589(2),b+9.352(2), andc+15.490(3) Å, =98.14(3)°, andZ+4. Compound (II) crystallizes inP2 ₁/n witha+16.831(11),b+5.936(3), andc+8.295(3) Å =97.24(5)°. andZ+4. The structures were solved by direct methods, and refined by fullmatrix least squares toR+0.071 andR _w+0.083 forI, andR+0.047 andR _w+0.061 forII.     

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.     

Structures of 355-1355-1355-1tricarbonyl: structural evidence for the near-electroneutrality of the dialkylacetal substituent

The structures of the (benzene dialkylacetal)tricarbonyl chromium complexes [⁶-C₆H₅-CH(OR)₂]Cr(CO)₆ (R=Me,1; Et,2), are reported. The compounds were examined as part of a study of the conformations of the tripodal tricarbonylchromium group. For [⁶-C₆H₅-CH(OMe)₂]Cr(CO)₃,1, monoclinic,P2₁/c (# 14),a=15.235(1) Å,b=6.5304(5) Å,c=12.702 Å, =103.197(1)^o,Z=4. For [⁶-C₆H₅-CH(OEt)₂]Cr(CO)₃,2, monoclinic,P2₁/c (# 14),a=9.859(3) Å,b=10.547(3) Å,c=15.138(3) Å, =108.42(2)^o,Z=4. The data show that the molecules adopt the expected three-legged piano stool structure. The carbonyl ligands in1 adopt an eclipsed arrangement with respect to the arene ring and its substituent, while those in2 are staggered. These conformations are consistent with the notion that the acetal substituent behaves largely as an electroneutral group, or at most as a weak electronic acceptor.     

Crystal structures and energy refinement of some 2,2′-disubstituted biphenyl compounds

Synthesis and structural determination by X-ray crystallography of three substituted biphenyl structures are reported: (2) is monoclinic P2₁/n witha=10.805(4),b=8.079(3),c=16.232(6)Å, =100.96(5)°: (4) is monoclinic P2₁/n witha=9.966(3),b=10.007(3),c=13.053(4) Å, =96.74(5)°; (5) is triclinic witha=12.033(5),b=16.903(8),c=9.752(4)Å, =94.70(3)°, =112.56(3)° =76.12(3)°. In all compounds the biphenyl has two identical substituents in an ortho position to the center inter-ring bond and present variable inter-ring twist angles. In the process of investigating molecular geometry, we are interested in studying whether the calculated conformations of our molecules can fit the crystallographic structures.     

Crystal structures of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes

The crystal and molecular structure of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1–5) have been determined by single crystal X-ray diffraction analysis. In all five compounds, the tetraazabicycloundecane portion of the molecule assumes a cage-like, folded structure with the aryltriazene moieties aligned approximately parallel; the structure is held in the folded configuration by either intramolecular or intermolecular – stacking forces. Crystal data: 1 C₁₉H₂₂N₁₀O₄, monoclinic space group P2₁/c, a = 10.1846(7), b = 9.9556(7), c = 20.819(2) Å, = 98.725(1)°, V = 2086.5 (3) ų, Z = 4; 2 C₂₃H₂₈N₈O₄, triclinic, space group P, a = 6.7064(7), b = 12.9662(14), c = 14.054(2) Å, = 94.796(2), = 91.621(2), = 104.836(2)°, V = 1175.7(2) ų, Z = 2; 3 C₁₉H₂₂N₁₀O₄, monoclinic, space group P2₁/c, a = 14.237(2), b = 13.520(2), c = 11.5805(12) Å, = 113.514(2)°, V = 2044.0(4) ų, Z = 4; 4 C₂₁H₂₂N₁₀, monoclinic, space group C2/c, a = 54.247(3), b = 11.5531(7), c = 12.9670(7) Å, = 95.710(1)°, V = 8086.4(8) ų, Z = 16; 5 C₂₅H₃₂N₈ 0₄, monoclinic, space group P2₁/c, a = 10.2908(7), b = 16.5687(12), c = 15.1662(10) Å, = 94,188(1)°, V = 2579.0(3) ų, Z = 4.     

Resolution of optical isomers of 4-amino-p-chlorobutyric acid lactam by co-crystallization

4-Amino-p-chlorobutyric acid lactam crystallizes as racemic crystals in the monoclinic space groupP2₁/n, witha=5.006(2),b=6.783(2),c=27.652(2) Å, =92.25(1)°,Z=4,R=0.035 for 1618 unique reflections. As both enantiomers are present in a single crystal it is not possible to effect enantiomeric separation by crystal growth inhibition. This lactam may, however, be co-crystallized with (2R,3R)-(+)-tartaric acid forming a 2:1 complex in which only the (R) enantiomer is present. The complex crystallizes in the monoclinic space groupP2₁ witha=10.074(2),b=10.132(6),c=12.238(6) Å, =99.13(2)°,Z=2,R=0.036 for 2291 unique reflections. Complex formation is effected by hydrogen bonding but enantioselectivity does not involve the chiral center of the title compound directly.     

Structural characterization of Elisabatin B and Elisabatin C

X-ray structures of Elisabatin B (1) and Elisabatin C (2) have been determined. Crystal data for 1: Triclinic, P (No. 2), a = 7.528(2) Å, b = 9.404(2) Å, c = 11.414(2) Å, = 75.363(3)°, = 86.668(4)°, = 89.683(4)°, and Z = 2. Crystal data for 2: Monoclinic, P2₁/c (No. 14), a = 8.242(2) Å, b = 14.870(2) Å, c = 13.060(2) Å, = 101.458(3)°, and Z = 4. Both compounds are highly unsaturated leading to extended aromatic conjugation. They show different intermolecular O–HO hydrogen bonds, via which 1 forms dimers, and 2 zig-zag polymeric chains.     

Crystal structures of baclofen analogs: 3-thienyl- and 3-furylaminobutyric acids

X-ray crystal structures of 4-amino-3-(2-thienyl) butyric acid (compound1), 4-amino-3-(4-bromo-2-thienyl) butyric acid (compound2), and 4-amino-3-(5-methyl-2-furyl) butyric acid (compound3) are reported. Space groups and unit/cell parameters are: compound1, monoclinic,P2₁ c,a=13.288(3),b=5.231(1),c=12.388(2)Å,=92.3(1)°; compound2, monoclinic,P2₁/c,a=12.610(7),b=5.156(1),c=15.814(8)Å,=101.8(1)°; compound3, orthorhombic, Pccn,a=11.461(1),b=25.284(2),c=6.977(1)Å. FinalR indices are: compound1, 0.057; compound2, 0.069; compound3, 0.060. Conformations of their -aminobutyric chains are compared with the one of -amino--(p-chlorophenyl)-butyric acid (baclofen, compound4). Two different types of conformations are observed, i.e., conformations (i) with folding (compound3) or (ii) without folding (compounds1,2, and4) of the ammonium group toward the heteroaromatic or aromatic ring. However, distances between ionized groups are constant.     

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.     

A structural study of sodium dithionite and its ephemeral dihydrate: A new conformation for the dithionite ion

Raman spectroscopy on solid anhydrous sodium dithionite reveals that it exists in at least two forms in the solid state. MAS²³Na NMR spectra and X-ray powder diffraction patterns of the solids indicate that sodium ions are in different environments in each form of the material. The results suggest that the dithionite anion is conformationally different in each lattice. A single crystal X-ray diffraction study of the recrystallized form of anhydrous sodium dithionite reveals an anion with C₂ geometry and a 16° O-S-S-O torsional angle; nearly eclipsed. (Crystal Data for recrystallized Na₂S₂O₄ area=6.539(1) Å,b=6.552(1) Å,c=6.578(1) Å,V=240.0(1) ų,=121.61(1)°, space group=P2/c,Z=2). Raman spectra of sodium dithionite dihydrate reveal that the dithionite ion is in a different conformation than in either of the anhydrous materials. A single crystal X-ray diffraction study of Na₂S₂O₄·2H₂O reveals a dithionite anion with a substantially shorter S-S bond length than in the anhydrous structure and an O-S-S-O torsional angle of 56°; approximately gauche. (Crystal Data for Na₂S₂O₄·2H₂O area=8.134(1) Å,b=5.756(2) Å,c=14.528(5) Å,V=653.3(3) ų,=106.20(2)°, space group=P2₁/n,Z=4). The structure of the dithionite anion is found to depend critically upon the nature of its external environment.     

Crystal structures of two azo compounds, 2-methyl-2-(4-bromphenylazo)-1,3-indandione and 2-methyl-2-(4-ethoxyphenylazo)-1,3-indandione

In the two title compounds, the 2-methyl-1,3-dioxoindan-2-yl and 4-(brom; ethoxy) phenyl groups aretrans with respect to one another. The phenyl ring and the azo group are not coplanar in the two molecules. The five-membered rings of the two compounds adopt an envelope conformation. The crystallographic parameters are as follows: 2-Methyl-2-(4-bromphenylazo)-1,3-indandione (I): monoclinic, P2₁/a witha=8.098(2),b=14.442(2),c=12.554(1)Å, =100.55(2)^o, andD _calc=1.58 g cm^–3 forZ=4; 2-methyl-2-(4-ethoxyphenylazo)-1, 3-indandione (II): monoclinic, P2₁/a witha=8.258(2),b=14.449(1),c=13.559(2)Å, =101.19(1)^o, andD _calc=1.29 g cm^–3 forZ=4.     

Synthesis of 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone

The acridinone derivative 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone (4) has been prepared in a two step fashion and the molecular structure confirmed by X-ray diffraction. Compound4 crystallizes in the space group P2_l/n witha=6.022(2),b=21.111(2),c=9.604(2) Å, =99.97(2)°, andZ=4. The single crystal analysis showed the acridinone tricyclic ring is virtually planar except in the gem-dimethyl position of C(3) which presented a half-chair conformation.