Crystal structure of (4α,4aα,8aα)-(±)-octahydro-2-(phenylmethyl)-2H-1,2-benzoxazin-4-ol, 4-methylbenzenesulfonate(ester)

The title compound, a bicyclic tetrahydro-1,2-oxazine, crystallizes in a monoclinic lattice, space group P2₁/c, with a = 12.9809(18)Å, b = 12.920(2)Å, c = 13.631(2)Å, = 110.713(12)°, and Z = 4. The structure found in the solid state for this conformationally mobile molecule shows the tosyl group in an axial position and a benzyl group in an equatorial position of the bicyclic system.     

The syntheses and crystal structures of two chromium(III) and molybdenum(III) coordination compounds with 4-ethylpyridine

The structures of trichlorotris(4-ethylpyridine)chromium(III), [CrCl₃(C₇H₉N)₃] (I), and trichlorotris(4-ethylpyridine)molybdenum(III), [MoCl₃(C₇H₉N)₃] (II), consist of neutral molecules where three 4-ethylpyridine and three chloro ligands coordinate to the metal with a meridional configuration. Compound I crystallizes in a trigonal space group P3₁ with a = 11.515(2) Å and c = 15.378(3) Å. Compound II crystallizes in a monoclinic space group C2/c with a = 24.200(3) Å, b = 18.089(3) Å, c = 22.6004(7) Å and = 106.7137(6)°.     

A new class of flexible energetic salts, part 4: The crystal structures of hexaaquomagnesium(II), hexaaquomanganese(II), and hexaaquozinc(II) dihydrate salts of dinitramide

The crystal structures of the hexaaquomagnesium (1), hexaaquomanganese (2), and hexaaquozinc (3) dihydrate salts of dinitramide have been determined. 1 crystallizes in the monoclinic space group P2₁/n with cell dimensions a = 9.589(2), b = 7.420(1), c = 11.116(2) Å, = 108.25(3)°, 2 crystallizes in the monoclinic space group P2₁/n with cell dimensions a = 9.623(4), b = 7.477(2), c = 11.274(3) Å, = 108.38(3)°, and 3 crystallizes in the monoclinic space group P2₁/n with cell dimensions a = 9.513(1), b = 7.4270(8), c = 11.164(1) Å, = 108.806(6)°. The three structures are isostructural, consisting of hexaaquo cations, dinitramide anions and water molecules interlinked by an extensive three dimensional hydrogen bonding interactions. All oxygen atoms as well as the central nitrogen atom of the dinitramide anion are involved in acceptor hydrogen bonds with neighboring water protons. As a consequence of the constraints imposed by these hydrogen bonds the dinitramide ions are almost planar with average deviations of 0.01 Å for 1, 0.03 Å for 2 and 0.03 Å for 3.     

Molecular structures of two conjugated ene-ynes derived from thiophene

The crystal structures of two conjugated ene-yne derivatives of thiophene are described, 2,5-di-(trimethylsilylethynyl)-3,4-dibromothiophene (1), is triclinic P witha=6.3281(4)Å,b=9.7421(6)Å,c=16.3669(9)Å; =80.516(5)°, =84.810(5)°, =74.072(5)°,Z=2,R=0.054; 2,3,4,5-tetra(trimethylsilylethynyl)thiophene (2), is monoclinic, P2₁/c with a=20.928(2)Å b=5.852(1)Å,c=23.907(2)Å; =100.245(6)°,Z=4,R=0.049. The ethynylic C atoms of both compounds lie near the thiophene plane, with deviations in the range 0.010(3)–0.455(4)Å. The phenyl groups of2 form a dihedral angle of 13.0(4)°.     

The crystal structure of a N-(2-thiophenyl)-salicylaldiminopiperidino nickel(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂OSNi, has been determined by direct methods. The compound crystallizes in monoclinic crystal system witha=11.968(1),b=12.182(1),c=12.399(1) Å, =115.23(1)°, space group P2₁/n. Nickel is in a slightly distorted square-planar environment of two nitrogens [1.881(2) and 1.952(2) Å] and one oxygen [1.856(3) Å] and one sulphur [2.138(2) Å] atom. Ni is 0.005 Å out of the plane of its ligands.     

[CaSb2(EDTA)2(H2O)8]n: synthesis, crystal structure, and thermal behavior

The synthesis and crystal structure of a new EDTA complex, [CaSb₂(EDTA)₂(H₂O)₈]_n, are reported. This compound crystallizes in the monoclinic space group P2₁/n, with a = 7.132(1) Å, b = 21.893(3) Å, c = 10.891(2) Å, = 91.15(2)°. Sb(EDTA) entities are connected through carboxylate bridges to the calcium atoms resulting in layers parallel to the (101) plane. These layers are linked through a weak Sb···O bond (3.171 Å). Pyrolysis of this complex under sulfur vapor, between 400 and 800°C, leads to a mixture of the monometallic sulfides. Pyrolysis in air above 700°C allows the easy preparation of the mixed oxide CaSb₂O₆.     

Crystal structures of [WI2(CO)3{Ph2P(CH2) n PPh2}] (n = 2 or 3)

[WI₂(CO)₃{Ph₂P(CH₂)₂PPh₂}] (1) crystallizes out in the monoclinic space group P2₁/n, with a = 13.852(7) Å, b = 14.789(19) Å, c = 14.915(19) Å, = 102.86(1)°, Z = 4. [WI₂(CO)₃{Ph₂P(CH₂)₃PPh₂}] (2) crystallizes out in the monoclinic space group P2₁/n, with a = 10.499(15) Å, b = 14.58(2) Å, c = 20.75(3) Å, = 103.59(1)°, Z = 4. Both structures show the metal in a seven-coordinate environment with a carbonyl in the unique capping position, two further carbonyls and a phosphorus in the capped face, and two iodides and the second phosphorus in the uncapped face.     

Cage-annulated thiacrown ethers and thiacryptands

A series of cage-annulated sulfur-containing crown ethers and cryptands have been synthesized as possible specific metal host systems. The synthesis and structures of seven compounds are described, including a thiacryptand complex with Hg(II). The trishomocubane cage is essentially spherical except for a methylene group, which imparts no steric restrictions, and two disordered superimposed orientations occur in most structures. This superposition of four- and five-membered rings usually cannot be resolved into separate entities, resulting in distorted distances, angles, and thermal parameters for the cage. (3) I4₁ cd, a = 13.207(3) Å, b = 13.207(3) Å, c = 35.876(12) Å; (10) C2, a = 14.551(2) Å, b = 10.028(1) Å, c = 10.491(1) Å, = 107.108(2)°; (14) P2₁/n, a = 10.6277(8) Å, b = 9.8488(7) Å, c = 21.822(2) Å, = 97.945(2)°; (19) P2₁/c, a = 15.381(3) Å, b = 6.667(1) Å, c = 18.158(3) Å, = 94.838(4)°; (25) C2/c, a = 34.386(4) Å, b = 11.318(1) Å, c = 13.409(2) Å, = 110.044(2)°; (28) , a = 10.4487(8) Å, b = 11.5677(9) Å, c = 13.354(1) Å, = 71.042(1)°, = 87.344(1)°, = 65.839(1)°; (29) P2₁/c, a = 10.8138(5) Å, b = 16.4949(8) Å, c = 22.054(1) Å, = 96.087(1)°.     

Synthesis, crystal structure of a one-dimensional cobalt—azide complex through hydrogen bond

A one-dimensional chain complex, {[Co(bpm)₂(N₃)₂][Co(bpm)₂(H₂O)₂]} (ClO₄)₂, (bpm being bis(pyrazol-l-yl)methane), has been synthesized and characterized by X-ray diffraction: triclinic, space group P - 1 with a = 8.805(2) Å, b = 8.902(2) Å, c = 13.621(3) Å, = 84.27(3)°, = 84.63(3)°, = 80.05(3)°, V = 1043.2(4) ų, Z = 1. Two cobalt atoms have ideal octahedral environments with different coordination atoms. One cobalt atom is six-coordinated with nitrogen atoms from two bpm ligands and two azide ligands, while the other cobalt atom is coordinated by four nitrogen atoms from bpm and two oxygen atoms from water molecules. The complex forms one-dimensional chain through hydrogen bonds.     

Synthesis and crystal structure of 1-vinyl-cis-2,3-diphenylaziridine

1-Vinyl-cis-2,3-diphenylaziridine, C₁₆H₁₅N, has been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. The structure was studied at room temperature (2a) (18°C) and at low temperature (2b) (–70°C). The title compound crystallizes in the space group Cm with Z=2 showing no phase transformation between the two temperatures. The cell parameters area=8.258(3),b=15.880(3),c=5.827(2)Å, =122.32(2)° for (2a) anda=8.188(2),b=15.762(3),c=5.724(1)Å, =121.57(2)° for (2b). Both the studies show nearly the same conformation. With the exception of the vinyl group, the molecule hasm symmetry, so, the asymmetric unit is half a molecule. The mirror plane of the space group cuts the aziridine ring through the N atom. The vinyl group is distributed on two symmetrical positions by means of the same mirror plane. In this way, the crystal is built with the two diastereoisomers of the title compound.     

Crystal structures of the cis and trans isomers of a tetrathia[3.3.3.3]cyclophane

Both the cis and trans isomers of 3,11,18,26-tetrathiatricyclo[26.2.2.1^5,9.2^13,16.1^20,24] hexatriaconta-5,7,9,20,22,24-hexene have been prepared and structurally characterized. Each of these centrosymmetric tetrathia dimers includes two cyclohexane rings in chair conformations with either 1,4-cis or 1,4-trans bonding and two meta-substituted benzene rings. The cis isomer packs into the monoclinic space group P2₁/a with a = 10.485(3)Å, b = 10.3956(18)Å, c = 14.1343(10)Å, = 105.200(13)°, Z = 2 and refined to an R factor of 0.046. The trans isomer crystallizes in the monoclinic space group P2₁/c with a = 10.7217(12)Å, b = 5.6797(7)Å, c = 25.415(5)Å, = 96.001(12)°, Z = 2 and refined to an R factor of 0.043. In the cis structure each benzene ring faces a cyclohexane ring while in the trans structure the cyclohexane rings face one another.     

Study of the sulfur atom as hydrogen bond acceptor in N(2)-pyridylmethyl-N′-arylthioureas

The hydrogen acceptor capability of the sulfur atom in the biologically relevant N-2-pyridylmethyl-N-arilthioureas was explored. N-2-Pyridylmethyl thioreas were selected to avoid the formation of intramolecular six-membered hydrogen-bonded ring. The compounds studied were N-2-pyridylmethyl-N-phenylthiourea (1), N-2-pyridylmethyl-N-2-methoxythiourea (2), N-2-pyridylmethyl-N-4-methoxyphenylthiourea (3), and N-2-pyridylmethyl-N-4-bromophenylthiourea (4). 1 crystallizes in the monoclinic space group P2₁/c, with a = 7.419(1) Å, b = 18.437(2) Å, c = 9.656(1) Å, = 106.277(6)°, V = 1267.8(3) ų, Z = 4. 2 crystallizes in the monoclinic space group P2₁/c, with a = 8.064(2) Å, b = 18.382(7) Å, c = 9.865(5) Å, = 97.81(3)°, V = 1448.8(11) ų, Z = 4. 3 crystallizes in the monoclinic space group P2₁/c, with a = 11.472(1) Å, b = 13.520(1) Å, c = 10.088(1) Å, = 112.60(1)°, V = 1444.5(2) ų, Z = 4. 4 crystallizes in the triclinic space group P-1, with a = 4.583(3) Å, b = 10.263(3) Å, c = 14.396(3) Å, = 77.92(2)°, = 88.55(4)°, = 80.02(4)°, V = 652.1(5) ų, Z = 2. Both thiourea N–H groups form intermolecular hydrogen bonds, one with the thione sulfur atom and the other with the pyridine nitrogen atom but the H-bonding schemes are not the same maybe due to the flexibility of the molecules.     

X-ray study of two 1-substituted 3-acylamino-2-pyrazolines

The previously reported IR study on 21 different 1-substituted 3-acylamino-2-pyrazolines assumed thecis configuration for the amide groups. In order to establish the configuration, X-ray structure determinations of two model compounds (1-phenyl-3-benzoylaminopyrazoline, monoclinic,a = 5.218,b = 8.830,c = 14.372 Å, = 90.7 °,Z = 2, P2 ₁; 1-benzyl-3-acetaminopyrazoline, monoclinic,a = 9.529,b = 13.679,c = 18.112 Å, = 96.7 °,Z = 8,P2₁/n) were performed. Both structures were solved by direct methods, and refined to a finalR = 0.075 for 710 andR = 0.122 for 2140 observed reflections. The configurations of the amide groups were found to betrans.     

Crystal and molecular structure studies of tris(2-hydroxy-3-t-butyl-5-methylbenzene)-methane trihydrate and N-benzyl-N-phenyl benzamide

The structures of the title compounds, tris(2-hydroxy-3-t-butyl-5-methylbenzene)-methane)C₃₄H₄₆O₃.3H₂O, 3) and N-benzyl-N-phenylbenzamide (C₂₀H₁₇NO, 6), have been investigated by X-ray crystallography. Compound 3 crystallizes in the trigonal space group with cell parameters a = 14.090(5) Å, b = 14.090(5)Å, c = 10.485(5)Å, Z = 2. Compound 6 crystallizes in the monoclinic space group C2/c with cell parameters a = 24.533(4)Å, b = 9.176(4)Å, c = 16.711(5)Å, = 125.88(2)°, Z = 8. Compound 3 has both intra-and intermolecular hydrogen bonds. It also exhibits a helical columnar arrangement of the molecules and goes into mesophase before melting into an isotropic liquid.     

Two-dimensional nickel(II) tetraaza macrocyclic complex linked by hydrogen bonds

The complex [Ni(L)](PDC) 2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16,4, 0^1.18,0^7.12]docosane; PDC = 3,5-pyrazoledicarboxylate) has been synthesized and characterized by X-ray crystallography. It crystallizes in the monoclinic system P2₁/c with a = 9.739(4) Å, b = 10.491(3) Å, c = 16.884(3) Å, = 97.17(2)°, V = 1711.5(8) ų, Z = 4. The coordination environment around the nickel(II) ion exhibits a slightly distorted square-plane with four secondary amines of the macrocycle. The title compound is interconnected to give a two-dimensional network through the hydrogen-bonding interactions.     

The importance of inter-molecular forces in crystal structure analysis: Solid state study of the diag-to-lat isomerization of (η5-C5H4Me)Re(CO)2Br2

Single crystal X-ray structures of diag and lat-(⁵-C₅H₄Me)Re(CO)₂Br₂ have been determined. The diag form crystallizes in the triclinic space group , a = 6.751(2), b = 8.537(1), c = 9.758(1) Å = 96.70(1), = 93.15(2), = 104.96(2)°, V = 534.8(2) ų, Z = 2. The lat form is monoclinic, P2₁/c, a = 11.820(1), b = 7.133(1), c = 12.924(1) Å = 98.278(8)°, V = 1078.2(2) ų, Z = 4. The unit cell volumes (per Z) of the two isomers differ by ca 1%. Molecular modelling reveals an energy difference between the two isomers of 1 kJ mol^–1 or less. The XRD powder diffraction patterns for the lat isomer produced by crystallization from solution or prepared by thermal isomerization are identical. The evidence thus suggests that the solid state isomerization reaction is a novel example of a reaction which yields a molecular structure determined by crystal packing forces.     

Crystal structure of p-formylphenyl, di(p-methylphenyl)amine, and p-bromophenyl, di(o-bromo-p-methylphenyl)amine

p-Formylphenyl, di(p-methylphenyl)amine (1), and p-bromophenyl, di(o-bromo-p-methylphenyl)amine (2) were prepared and characterized by X-ray crystallography. Formyl-substituted triphenylamine(1) crystallizes in the monoclinic space group P2₁/c with a = 9.068(1), b = 17.115(2), c = 11.297(2) Å, = 106.73(1)°, V = 1679.0(5) ų and Z = 4. Bromo-substituted compound 2 crystallizes in the monoclinic space group P2₁/n with a = 16.170(4), b = 7.9477(8), c = 16.906(4) Å, = 117.67(2)°, V = 1924.1(7) ų and Z = 4. The N atoms deviate slightly from the plane of the bonded C atoms and the benzene ring planes are rotated by 25–67° to avoid overlap of the ortho-substituted atoms. The major force of crystal formation comes from the multiple phenyl embraces (MPE).     

Crystal structures of four complexes produced by reaction of copper(I) cyanide with imidazoles

Four complexes of CuCN with imidazoles have been prepared by adding the ligand to a solution of CuCN in aqueous sodium thiosulfate. The imidazole ligands used were 2-methylimidazole (mim), 1,2-dimethylimidazole (dmim), 5-chloro-1-methylimidazole (clmim), and 2-phenylimidazole (phim). Complex 1, (CuCN)(mim) is monoclinic, C2/c, a = 9.565(3), b = 7.764(5), c = 8.983(8) Å, = 96.76(3)°, Z, = 4, Complex 2, (CuCN)(dmim) is monoclinic, P2₁/c, a = 8.120(2), b = 11.796(4), c = 16.375(9) Å, , = 100.87(4)°, Z = 8. Complex 3, (CuCN) (clmim) is monoclinic, C2/c, a = 24.907(4), b = 6.894(5), c = 18.259(4) Å, = 102.79(2)°, Z = 16. Complex 4, (CuCN)(phim) is orthorhombic, Pca2₁, a = 9.204(4), b = 8.125(2), c = 26.304(6) Å, Z, = 8. Complexes 1, 2, and 4 have one-dimensional chains –Cu–CN–Cu– with an imidazole bonded to each Cu. Complex 3 has a two-dimensional sheet of CuCN, again with an imidazole bonded to each Cu. In 1 the imidazole group is disordered by a two-fold rotation approximately around the N···N direction in the imidazole group. In 3 one of the imidazole groups has a disorder involving exchange of the Cl and CH₃.     

Chemistry of diaminomaleonitrile: synthesis and structure of two unexpected products from its condensation with 2,5-hexanedione

For the synthesis of precursors to cellulose-based ion exchange materials, the condensation of diaminomaleonitrile with 2,4-pentanedione and 2,5-hexanedione was explored. Whilst the former diketone yielded the expected 1,4-diazepine (2), the latter gave either a pyrrole derivative (3) or an unusual triazabicyclononene (4), depending on the conditions used. Compound 2 crystallizes in the monoclinic space group P2₁/c with a = 8.9313(10) Å, b = 9.0370(7) Å, c = 11.4448(9) Å, = 102.48(8)°, V = 901.89(14) ų, and Z = 4. Compound 3 crystallizes in the orthorhombic space group Pna2₁ with a = 12.0342(8) Å, b = 8.3760(8) Å, c = 10.7026(11) Å, V = 1078.81(17) ų, and Z = 4. Compound 4 crystallizes in the monoclinic space group P2₁/c with a = 9.0157(5) Å, b = 13.5374(9) Å, c = 12.8751(16) Å, = 99.506(5)°, V = 1549.82(15) ų, and Z = 4. In both 3 and 4 the aminovinyl substituent shows evidence for involvement of the lone pair on nitrogen with the carbon -system. Also, 3 and 4 are highly associated in the solid state via hydrogen bonding.     

Structure of methylphenylhydrazone form of 2-(2-methylphenylazo)-1,3-indandione

The molecule crystallizes in a ketohydrazone tautomeric form. The tautomeric form is stabilized by a strong intramolecular hydrogen bond of 2.709(2) Å binding the 3-oxo to the nearest nitrogen atom in the azine chain. The compound crystallizes in the monoclinic space group P2_l/c witha=7.0470(4),b=11.3090(9),c=16.2250(4) Å, =90.310(3)°, V=1293.0(1) ų, Z=4,Dx=1.3576 g cm^–3 and (Cu-K)=7.03 cm^–1. The molecule is nearly planar not regarding the methyl group; the small deviations from planarity are indicative of intramolecular interactions between the phenylazo group and indandione group. Some of the bond lengths and angles found in the molecule are distorted due to resonance, -electron delocalization and strain. The relation between these chemical effects and structural results are discussed.