Synthesis and Crystal Structure of Bis (<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylethylendiammonium) Octaiodo Pentachloroantimonate (III)

Abstract  

The synthesis and Crystal structure are given for the bis (N,N,N′,N′-tetramethylethylendiammonium) octaiodo pentachloroantimonate (III) salt. An X-ray investigation has shown that the title compound crystallizes in a monoclinic system, space group P2₁/m with the following lattice parameters a = 9.786(2) Ǻ, b = 14.024(5) Ǻ, c = 14.336(3) Ǻ, β = 91.35(2)° and Z = 2. The structure was solved from 3085 independent reflections with R ₁ = 0.0402 and wR ₂ = 0.0952 and refined with 152 parameters. The structure shows a layer arrangement perpendicular to the [(b)\vec] \vec{b} -axis: planes of [SbCl₅]²⁻, I₃ ⁻ and I₅ ⁻ anions alternate with planes of [(CH₂)₂(NH(CH₃)₂)₂]²⁺ cations. The [SbCl₅]²⁻ square pyramids present an active lone electron pair (LEP) on the Sb atoms and they are interconnected by means of N–H···Cl hydrogen bond originating from [(CH₂)₂(NH(CH₃)₂)₂]²⁺ entities. The polyiodides (I₃ ⁻ and I₅ ⁻) anions form a planer zigzag polymeric chains via I···I linking interactions. These chains are linked to the [SbCl₅]²⁻ anions by a long range contact.     

Synthesis and crystal structure of <Emphasis Type="Italic">N</Emphasis>-(6methoxylbenzothiazol-2-yl)-1-(4-fluorophenyl)<Emphasis Type="Italic">O</Emphasis>,<Emphasis Type="Italic">O</Emphasis>-dipropyl-<Emphasis Type="Italic">α</Emphasis>-aminophosphonate

Molecular and crystal structure of N-(6-methoxybenzothiazol-2-yl)-1-(4-fluorophenyl)-O,O-dipropyl-α-aminophosphonate, C₂₁H₂₆FN₂O₄PS, have been determined by single-crystal X-ray diffraction study. The title compound is tetragonal, with a = 21.35(3) Å, c = 20.16(5) Å, Z = 16, D _x = 1.308 Mg/m³, μ(MoKα) = 0.247 mm^?1, and space group is I4₁/a. The structure was solved by direct method and refined to a final R = 0.0687 for 2370 reflections with I > 2σ(I). The compound shows a fully delocalized benzothiazole system with a sp² hybridization of the N(2). There is a strong intermolecular hydrogen bond between P=O and NH. The crystal structure is stabilized by a strong intermolecular N–H?sO hydrogen bond.     

Preparation,characterisation, and crystal structure analysis of (2<Emphasis Type="Italic">E</Emphasis>,2′<Emphasis Type="Italic">E</Emphasis>)-3,3′-(1,4-phenylene)bis(1-(2-aminophenyl)prop-2-en-1-one

A novel bis-chalcone, (2E,2′E)-3,3′-(1,4-phenylene)bis(1-(2-aminophenyl)prop-2-en-1-one) is synthesized through a base catalyzed Claisen-Schmidt condensation reaction of terephthalaldehyde with 2-aminoacetophenone. Its structure (sp. gr. P\(\bar 1\), Z = 2) is determined from single crystal X-ray diffraction data. There are two independent centrosymmetric molecules with no significant differences in bond lengths and angles between them. The NMR, IR, HRMS, and UV spectral data of the prepared bis-chalcone are presented.     

Synthesis,spectroscopic and structural studies of <Emphasis Type="Italic">N</Emphasis>-(1<Emphasis Type="Italic">H</Emphasis>-benzimidazol-2-yl)-<Emphasis Type="Italic">N</Emphasis>′-benzyl propionamidine

N-(1H-Benzimidazol-2-yl) propionimidic acid ethyl ester (1) reacts with benzylamine to yield the corresponding N-(1H-Benzimidazol-2-yl)-N′-benzyl proponamidine (2). The structure and conformation of the amidine 2 were determined by ¹H and ¹³C NMR and X-ray diffraction. The product crystallizes in monoclinic system with space group P2₁/c, a = 10.7913 ?, b = 15.5164 ?, c = 9.1130 ?, β = 108.378° and Z = 4. In the crystal there are two N–HN hydrogen bonds, the first is intramolecular H-Bond links H4 to N1; the second one is intermolecular and it links H2 to N3 of a second molecule leading to inversion-related dimers. The X-ray results were compared with those obtained by semi-empirical and ab-initio calculations.     

Synthesis,Characterization, and Crystal Structure of <Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">p</Emphasis>-Bromophenyl-<Emphasis Type="Italic">N</Emphasis>′-Phenylacetylthiourea

Abstract   N-p-bromophenyl-N′-phenylacetylthiourea was characterized by elemental analysis, IR and ¹H NMR etc. Single crystal structure of the title compound was determined on X-ray diffraction instrument. The title compound crystallizes in monoclinic space group c2/c, with a = 21.442(5) ?, b = 12.208(2) ?, c = 11.955(2) ?, β = 109.375(4)°, and D _calc = 1.571 g/cm³ for Z = 8. An intermolecular hydrogen bond N–H···S which links two thiourea molecules as a dimer and an offset face-to-face π–π stacking interaction were observed in the title compound. The strong non-covalent interaction influences the conformation and property of thiourea derivatives. Index Abstract  The title compound, N-p-bromophenyl-N′-phenylacetylthiourea, was synthesized by the treatment of phenylacetyl chloride with 4-bromoaniline and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that hydrogen bonds and face-to-face π–π stacking interactions have strong influence on the conformation and molecular stacking of the title compound.      

Solid-state Spectroscopic and Structural Investigation of <Emphasis Type="Italic">cis</Emphasis>-(CH<Subscript>3</Subscript>)<Subscript>2</Subscript>Au(<Emphasis Type="Italic">O</Emphasis>,<Emphasis Type="Italic">O</Emphasis>′-acac)

Abstract  The structure of cis-(CH₃)₂Au(O,O′-acac) was investigated by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Cmca with unit cell dimensions a = 6.7831(13) ?, b = 15.080(3) ?, c = 18.073(3) ? and α = β = γ = 90°. The molecule is planar but lacks a C₂ axis in the solid-state, with two Au–C bond lengths that differ by 0.078(21) ? due to crystal packing effects. The inequivalence of the crystallographic carbon positions is evident in the solid-state ¹³C CP-MAS NMR spectrum, which was recorded at low temperature due to the thermal sensitivity of the compound during magic-angle spinning. Head-to-tail stacking, which creates short intermolecular paths, was reproduced computationally in a dimer model. Graphical Abstract   Solid-state Spectroscopic and Structural Investigation of cis -(CH ₃ ) _Au 2 ( O , O ′-acac) Miyako Hisamoto • Swarup Chattopadhyay • Juergen Eckert • Guang Wu • Susannah L. Scott In the solid state, cis-(CH₃)₂Au(O,O′-acac) has no C₂ axis, two different Au–C bond lengths (1.960, 2.038 ?; Δd = 0.078(21) ?) and a close Au–C…C–Au contact; these features give rise to additional features in the ¹³C CP-MAS NMR spectrum.     

Crystal and molecular structure of bis-(1-<Emphasis Type="Italic">tert-</Emphasis>butyl-1,2-dibenzoylhydrazine)-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-sulfide

The structure of the title compound bis-(1-tert-butyl-1,2-dibenzoylhydrazine)-N,N- sulfide was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2(1)/c with the following crystallographic parameters: a = 14.681(7) Å, b = 14.501(7) Å, c = 16.535(8) Å, = 90°, = 109.173(9)°, = 90°, V = 3325(3) Å ³, z = 4, Dx = 1.244 mg/m³, F(000) = 1320, T = 293(2) K, 1.47° 25.00°, the final R factor: R₁ = 0.0584, wR₂ = 0.1111. The bond distances and angles in the tert-butyl groups are different, that can interpret its ¹H NMR spectra, which are very unusual for the absorption of –CMe₃ being multiple.     

Domain structure and properties of triglycine sulfate crystals with profile <Emphasis Type="Italic">D</Emphasis>,<Emphasis Type="Italic">L</Emphasis>-α- and <Emphasis Type="Italic">L</Emphasis>-α-alanine-doped layers

A complex investigation of the domain structure and dielectric properties of triglycine sulfate (TGS) crystals containing profile layers doped with D,L-α-alanine (DLATGS) and L-α-alanine (LATGS) impurities is carried out. The images of the DLATGS and LATGS layers and ferroelectric domains are obtained by piezoelectric force microscopy; the parameters of the domain structure and the degree of unipolarity are determined. It is established that DLATGS layers are multidomain and LATGS stripes are mainly single-domain. The experimental data on the macroscopic dielectric properties of the crystals are compared with the results of a microscopic analysis of the domain structure.     

Synthesis and Crystal Structure of New <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis[1-(4-methoxyphenyl)-5-methyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazole-4-carbonyl]hydrazide

Abstract  The N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide 6 was synthesized from aryl triazole acids and its structure is established by MS, IR, and ¹H NMR spectral data. Compound 6, C₂₂H₂₂N₈O₄, Mr = 462.48, crystallizes in the monoclinic space group P2(1)/c with unit cell parameters a = 15.3451(8), b = 8.6486(4), c = 16.8502(9) ?, α = 90.00, β = 95.731(2), γ = 90.00o, V = 2225.1(2) ?³, Z = 4, and Dx = 1.381 mg m⁻³. The final R was 0.0450. The four aromatic rings are close to linear because of N···H–N hydrogen bonds. Index Abstract  Synthesis and crystal structures of N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide Heng-Shan Dong, Yan-Fei, Wang, Hong-Ru Dong, Bin, Wang, Bin Quan N,N′-Bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide was synthesized.      

Intermolecular Hydrogen Bonds and the Supramolecular Structure of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis(<Emphasis Type="Italic">p</Emphasis>-tolylsulfonyl)diethylenetriamine

Abstract  The title compound N,N′-bis(p-tolylsulfonyl)diethylenetriamine (1) was synthesized and its crystal structure determined by X-ray diffraction. Adjacent molecules of 1, symmetrically related through a c-glide, are linked by alternating hydrogen bonds that form molecular chains along [0 0 1]. Two molecular chains occur in each unit cell and pack to form alternating layers in a three-dimensional supramolecular structure. The compound crystallizes in the Pca2₁ space group stabilized by the inclusion of solvent dichloromethane molecules in structural voids between molecules of 1. The dichloromethane molecules are related through a twofold screw rotation axis and are not disordered. Index Abstract  Intermolecular hydrogen bonds involving sulfonamide moieties of title compound afford a supramoleular structure that accommodates the inclusion of dichloromethane in alternating layers.      

Synthesis and Structure Determination of <Emphasis Type="Italic">S</Emphasis>,<Emphasis Type="Italic">S</Emphasis>′-(Naphthalen-2-ylmethyl sulfanyl (1-<Emphasis Type="Italic">p</Emphasis>-tolyl-ethylidene) Hydrazine

Abstract  

S,S′-(Naphthalen-2-ylmethyl sulfanyl (1-p-tolyl-ethylidene) hydrazine (SNM4MA) was prepared by the condensation of S-napthalen-2-ylmethyldithiocarbazate (SNMDTC) and 4-methylacetophenone. Yellow needles of SNM4MA were obtained upon slow evaporation of a 50:50 mixture of acetonitrile and DMSO over a period of weeks. The compound crystallizes in the monoclinic system with the space group C 2/c and Z = 4. The unit cell parameters are a = 7.0221(2) ?, b = 22.8428(6) ?, c = 23.5127(6) ? with β = 94.0222(13)°. Single crystal X-ray analysis shows that the molecule has crystallographic two-fold rotational symmetry coincident with the S–S bond. The title compound exists as a trans–cis conformer in which the naphthalene group is trans with respect to the thione sulfur while the benzyl group adopts a cis geometry. ¹³C and ¹H spectra confirm that the dimeric nature is retained in DMSO solution.     

Crystal Structure of Unsymmetrically <Emphasis Type="Italic">N</Emphasis>-nor-dehydroabietyl-<Emphasis Type="Italic">N</Emphasis>′-isopropyl Urea

Abstract  

The title compound (C₄₆H₇₂N₄O₂, M _r  = 713.08) [systematic name: 1-isopropyl-3-((1R,4aS,10aR)-7-isopropyl-1, 4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl)urea] is a new derivative of dehydroabietic acid. It crystallized in the orthorhombic system, space group P2₁2₁ 2₁ with cell dimensions of a = 9.5950(19) ?, b = 18.740(4) ?, c = 24.654(5) ?, V = 4,433.0(16) ?³, Z = 4, D _c  = 1.068 g/cm³, λ = 0.71073 ?, μ = 0.07 mm⁻¹, F(000) = 1,568, final R = 0.0777 and wR = 0.1731 for 2,048 observed reflections with I > 2σ(I). Two crystallorgraphically independent molecules with different conformations co-exist in the structure. Each molecule exhibit classic tricyclic hydrophenanthrene structure, the two cyclohexane rings form a trans ring junction with chair and half-chair conformations, respectively. The crystal is stabilized by intermolecule hydrogen bonds and the molecules are in a head–tail zigzag arrangement.     

Molecular and crystal structures of 4′-hydroxy derivative of (3<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">R</Emphasis>)-3-methyl-6-isopropyl-2-(4-phenylbenzylidene)cyclohexanone

The molecular and crystal structures of the 4-hydroxy derivative of (3R,6R)-3-methyl-6-isopropyl-2-(4-phenylbenzylidene)cyclohexanone are determined by X-ray diffraction analysis. Single crystals are orthorhombic, a = 9.147(2) Å, b = 12.959(2) Å, c = 15.695(5) Å, V = 1860.4(7) ų, Z = 4, and space group P2₁2₁2₁. The cyclohexanone ring in the crystal structure has an asymmetric chair conformation. The puckering parameters are as follows: the puckering amplitude S is 0.91, and the puckering angles θ and ψ are equal to 20.2° and 10.4°, respectively. It is established that the enone fragment and the cyclohexanone ring in molecules are flattened considerably. In the crystal structure, the molecules are linked by the

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hydrogen bonds (bond length, 1.85 Å). The structural features and the strength of the hydrogen bonds for the compound under investigation and its analogue with one benzene ring are compared using the X-ray diffraction and IR spectroscopic data.

     

2,4-Pentane <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis(2,6-Diisopropylphenyl) ketiminato cobalt (II) (trimethylsilyl)methylene

Abstract  

The title compound [^MeL^iPrCoCH₂Si(CH₃)₃ ^MeL^iPr = 2,4-pentane-N,N′-bis(2,6-diisopropylphenyl) ketiminato] possesses trigonal planar geometry and crystallizes in monoclinic space group P2₁/n with crystal cell parameters a = 10.6155(14) ?, b = 21.279(3) ?, c = 14.8057(19) ?, β = 97.196(2)°, V = 3,318.1(7) ?³, and Z = 4. The title compound is the second reported three coordinated 13 valence electron Co(II) alkyl complex and the first such complex reported with an asymmetrically bonded alkyl group. The steric effects are discussed in comparison of known similar structures of Fe, Co, and Zn.     

Crystal Structure of Antitubercular Complex: <Emphasis Type="Italic">cis</Emphasis>-(chloro)-[<Emphasis Type="Italic">N,N</Emphasis>′-<Emphasis Type="Italic">bis</Emphasis>-(diethyl-2,2′-bipyridine-3,3′-dicarboxylate)]ruthenium(II) Monohydrate

Abstract  Diethyl-2,2′-bipyridine-3,3′-dicarboxylate (3 or L) reacts with RuCl₃ · 3H₂O to give cis-(Cl)-[Ru(L)₂Cl₂] · H₂O (4) and structure of the complex was determined by spectral (IR, ¹H-NMR), and mass spectroscopic data, elemental analyses and X-ray crystallography. The structure is solved in triclinic, space group p-1 with a = 10.658 (2), b = 12.446 (3), c = 14.186 (5) ?, α = 104.856 (3), β = 108.704 (3), γ = 94.973 (2)°, V = 1693.2 (8) ?³, Z = 2 with final R = 0.012. The geometry of the complex is shown to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes with Ru–N distance as 2.021 (2)−2.071 (3) ?. The cis-position is occupied by two chloride atoms with Ru–Cl distance as 2.4156 (12) and 2.4167 (13) ?. The trans-axial Cl2–Ru1–N and Cl1–Ru1–N4 angles are respectively, 172.42 (7) and 174.12 (7)°. A weak hydrogen bonding is observed between the two chlorides and hydrogens of neighbouring molecule [C–H···Cl distance as 2.72, 2.77 (4) ?]. A second type of weak hydrogen bonding is also observed between the oxygens of carboxylate groups and hydrogens of a neighbouring molecule [C–H···O distance as 2.53, 2.56 and 2.34 (4) ?]. Graphical Abstract  The structure of anti-tubercular precursor complexes, cis-(chloro)-[N,N′-bis-(diethyl-2,2′-bipyridine-3,3′-dicarboxylate)]ruthenium(II) monohydrate is solved by single crystal X-ray diffraction analysis which reveals geometry of the complex to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes. The cis-position is occupied by two chloride atoms.      

Molecular and crystal structures of mesomorphic aromatic esters: II. The structure of <Emphasis Type="Italic">p</Emphasis>-ethoxyphenyl <Emphasis Type="Italic">p</Emphasis>′-pentylbenzoate

p-Ethoxyphenyl p′-pentylbenzoate (I), which exhibits a mesophase (K 62.6 N 63.3 I), was studied by X-ray diffraction analysis at 120.0 and 296.0 K. In the molecule I, one of the benzene rings is almost coplanar with the carboxy group COO, whereas another benzene ring is twisted with respect to the carboxy group by 65.9°. The geometric parameters of the molecule I are indicative of possible conjugation between the carboxy group and the former benzene ring and the absence of conjugation between this group and the second benzene ring. In the crystal packing, extended molecules I are oriented along the bc diagonal. The mutual orientation of the nearest benzene rings of any two adjacent molecules is T-shaped, which corresponds to a weak C-H...π-type interaction.     

Synthesis and Crystal Structure of <Emphasis Type="Italic">Tris</Emphasis>-(<Emphasis Type="Italic">N</Emphasis>–<Emphasis Type="Italic">N</Emphasis> dimethyl benzylammonium)-hexachlorobismuthate(III)

Abstract  The salt tris-(N–N dimethyl benzylammonium)-hexachlorobismuthate(III) crystallizes in the triclinic system P1 with unit cell parameters: a = 9.0300(12), b = 9.9220(3), c = 19.575(2) ?, α = 79.955(5), β = 89.952(2), γ = 88.108(6)°, V = 1726.0(3) ?³, Z = 2. The examination of the structure shows an alternate stacking of inorganic layers of hexachlorobismuthate(III) anions and organic layers of [C₆H₅CH₂NH(CH₃)₂]⁺ cations parallel to the a-axis. The cohesion forces of the packing of N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Index Abstract  The examination of the structure shows a layer arrangement parallel to the a-axis: planes of octahedral anions [BiCl₆]³⁻ alternate with planes of [C₆H₅CH₂NH(CH₃)₂]⁺ cations (Fig. 3). The cohesion forces of the packing of the N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis,Spectroscopic Studies and Crystal Structure of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-bis((thiophene-2-carboxamido)propyl)piperazine

Abstract  A new multidentate ligand N,N′-bis((thiophene-2-carboxamide)propyl)piperazine has been synthesized from the reaction of thiophene-2-carbonylchloride and 1,4-bis(3-aminopropyl)piperazine. The title compound has been characterized by elemental analysis, FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. The crystal structure of the title compound (C₂₀H₃₀N₄O₂S₂Cl₂) has also been determined by X-ray analysis. The title compound crystallize in the monoclinic space group P2₁/c with a = 9.768(1), b = 12.895(1), c = 10.083(1) ?, β = 115.12(1)°, V = 1149.9(2) ?³, D _x = 1.425 g cm⁻³ and Z = 2. The crystal structure was solved by direct methods and refined by full-matrix least squares to a find R = 0.039 [I > 2σ (I)] for 2,786 observed reflections. Graphical Abstract  The (N,N’–bis((thiophene-2- carboxamido)propyl)piperazine) molecule has been synthesized and its molecule structure has been investigated by using , FT-IR, 13C NMR and 1H-NMR spectroscopic and crystallographic techniques.

3-[4-Bromo-α(<Emphasis Type="Italic">R</Emphasis>*)-methoxybenzyl]-6-chloro-3(<Emphasis Type="Italic">S</Emphasis>*),4(<Emphasis Type="Italic">S</Emphasis>*)-dihydroxychroman: X-ray and DFT Studies

Sodium borohydride reduction of E-3-benzylidenechromanone epoxides in dry methanol has afforded 3(S*), 4(S*)-dihydroxy-3-[α(R*)-methoxybenzyl]chromans as an interesting class of products, the structures of which have been assigned mainly from spectral data and consideration of the mechanistic aspects. X-ray diffraction study of one of them, 3-[4-bromo-α(R*)-methoxybenzyl]-6-chloro-3(S*),4(S*)- dihydroxychroman, is performed. The title compound crystallizes in the monoclinic sp. gr. P2₁/n, with a = 13.336(6) Å, b = 10.866(5) Å, c = 27.166(11) Å, β = 95.193(6)°, V = 3920(3) ų, and Z = 8. Supramolecular construction of the compound involves O–H···O intermolecular hydrogen bonds as well as three other types of non-covalent interactions which are responsible for crystal packing. Density functional theory was applied for geometry optimization, molecular orbital calculations, and prediction of UV spectral features. The geometric parameters (bond lengths, bond angles, and dihedral angles) for the representative compound obtained from density functional theory with B3LY6-31G basis set were in good agreement with experimental values.     

Structural Report for 2,5-Bis(trifluoroacetyl)cyclohexane-1,4-dione and <Emphasis Type="Italic">o</Emphasis>,<Emphasis Type="Italic">o</Emphasis>′-bis(trifluoroacetyl)-<Emphasis Type="Italic">p</Emphasis>-cresol

Abstract  

The crystal structures of 2,5-bis(trifluoroacetyl)cyclohexane-1,4-dione (1) and o,o′-bis(trifluoroacetyl)-p-cresol (2) is reported. The first compound crystallizes in monoclinic space group P2₁/n with a = 6.5040(10), b = 10.1610(10), c = 8.2420(10) ?, β = 91.690(10)° and V = 0.54445(12) nm³. Double enolization (U-structure) with a considerable electron density delocalization in the enolone backbone was established in this case. Phenol 2 crystallizes in triclinic space group P-1 with a = 7.0690(10), b = 9.4890(10), c = 9.8190(10) ?, α = 103.720(10), β = 110.760(10), γ = 102.150(10)° and V = 0.56598(12) nm³. In contrast to CDCl₃ solution, a “bifurcate” structure of 2 with jumping OH proton is quenched: only one of both trifluoroacetyl moieties is bonded by intramolecular hydrogen bond.