The 2 ′ -deoxyribofuranoside of 3-phenyltetrahydropyrimido[4,5-c]pyridazin-7-one: a bicyclic nucleoside with sugar residues in N and S conformations, and its molecular recognition
The title compound 3-phenyltetrahydropyrimido[4,5-c]pyridazine 2 ′ -deoxyribonucleoside [systematic name: 6-(2-deoxy- β -d-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-3-phenylpyrimido[4,5-c]pyridazin-7-one monohydrate, C17H18N4O4 · H2O, 1] shows two conformations in the crystalline state and the two conformers (1a and 1b) adopt different sugar puckers. The sugar residue of 1a shows a C2 ′ -endo S-type conformation, while 1b displays a C3 ′ -endo N-type sugar pucker. Both conformers adopt similar anti conformations around the N-glycosylic bonds, with χ = − 97.5 (3) ° for conformer 1a and χ = − 103.8 ...
Source: Acta Crystallographica Section C - June 13, 2022 Category: Chemistry Authors: Mei, H. Budow-Busse, S. Kondhare, D. Eickmeier, H. Reuter, H. Seela, F. Tags: 2 ′ -deoxyribonucleoside pyrimido[4,5-c]pyridazine pKa value crystal structure hydrogen bonding base pair research papers Source Type: research
Two-dimensional rare-earth-metal coordination polymers based on biphenyl-3,3 ′ ,5,5 ′ -tetracarboxylic acid displaying luminescence
Two coordination polymers were rationally designed and successfully constructed using the rigid multicarboxylic acid ligand biphenyl-3,3 ′ ,5,5 ′ -tetracarboxylic acid (H4BPTC) and rare earth metal ions (Eu3+ and Ho3+) under solvothermal conditions. The compounds are poly[[tetra- μ 2-acetato-bis( μ 6-biphenyl-3,3 ′ ,5,5 ′ -tetracarboxylato)tetrakis(dimethylacetamide)tetraeuropium(III)] dimethylacetamide disolvate dihydrate], {[Eu4(C16H6O8)2(C2H3O2)4(C4H9NO)4] · 2C4H9NO · 2H2O}n, and poly[[tetra- μ 2-acetato-bis( μ 6-biphenyl-3,3 ′ ,5,5 ′ -tetracarboxylato)tetrakis(dimethylacetamide)tetraholmium(III)] pent...
Source: Acta Crystallographica Section C - June 7, 2022 Category: Chemistry Authors: Zhou, J. Zhang, X. Zi, W. Zhou, L. Tags: two-dimensional coordination polymer luminescence crystal structure rare earth multicarboxylic acid ligands research papers Source Type: research
Synthesis, crystal structure and determination of the pKa value of 2,6-dimethoxycyclohexa-2,5-diene-1,4-dione 1-[2-(quinolin-8-yl)hydrazone]
The azo-coupling reaction between 8-aminoquinoline and 3,5-dimethoxyphenol produces 2,6-dimethoxycyclohexa-2,5-diene-1,4-dione 1-[2-(quinolin-8-yl)hydrazone], C17H15N3O3. Crystallization from methanol and strong alkaline solutions produced nonsolvated and solvated crystals, respectively. The crystal structure analysis and 1H NMR spectroscopy studies revealed that the compound exists only as the hydrazone form. A UV – Vis spectroscopic titration study revealed that the hydrazone compound has a relatively high pKa value of 10.0. (Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - June 7, 2022 Category: Chemistry Authors: Kachi-Terajima, C. Inaba, Y. Tsuruga, K. Tags: quinoline hydrazone compound crystal structure tautomerism acidity study research papers Source Type: research
Structural phase transition in a charge-transfer compound: tropylium hexafluoridoantimonate(V) – 1,4-dimethylnaphthalene (1/1)
Molecular motion in crystals has attracted much attention for the development of stimuli-responsive materials. The most studied are molecules with few atoms or highly symmetrical molecules. To develop molecules with new motion characteristics, we synthesized a charge-transfer compound, namely, tropylium hexafluoridoantimonate(V) – 1,4-dimethylnaphthalene (1/1), (C7H7)[SbF6] · C12H12, and studied its structural phase transition. In this compound, the tropylium cation and the 1,4-dimethylnaphthalene molecule have planar geometry, but the latter has low symmetry. They are stacked as a one-dimensional chain structure throug...
Source: Acta Crystallographica Section C - May 25, 2022 Category: Chemistry Authors: Liao, R.-M. An, Z. Ye, H.-Y. Tags: molecular motion plane rotation phase transition crystal structure naphthalene hexafluoridoantimonate(V) tropylium research papers Source Type: research
Solvent media as the driving force in the formation of one-dimensional silver(I) coordination polymers with 2-methylidene-1,3-bis(nicotinoyloxy)propane
Two kinds of silver(I) coordination polymers consisting of the same chemical composition, [Ag(CF3SO3)(L)] [L is 2-methylidene-1,3-bis(nicotinoyloxy)propane], were synthesized and characterized by infrared (IR) and photoluminescence (PL) spectroscopy, elemental and thermal analyses, and single-crystal X-ray diffractometry; these are catena-poly[[(trifluoromethanesulfonato- κ O)silver(I)]- μ -2-methylenepropane-1,3-diyl dinicotinate- κ 2N:N ′ ], [Ag(CF3SO3)(C16H14N2O4)]n, and its chloroform monosolvate, {[Ag(CF3SO3)(C16H14N2O4)] · CHCl3}n. The X-ray crystallographic measurements revealed that the silver(I) compounds ex...
Source: Acta Crystallographica Section C - May 19, 2022 Category: Chemistry Authors: Jo, S.M. Noh, T.H. Tags: silver(I) crystal structure nicotinoyloxy one-dimensional coordination polymer intermolecular interactions photoluminescence research papers Source Type: research
Crystal and molecular structures of fac-[Re(Bid)(PPh3)(CO)3] [Bid is tropolone (TropH) and tribromotropolone (TropBr3H)]
Two rhenium complexes, namely, fac-tricarbonyl(triphenylphosphane- κ P)(tropolonato- κ 2O,O ′ )rhenium(I), [Re(C7H5O2)(C18H15P)(CO)3] or fac-[Re(Trop)(PPh3)(CO)3] (1), and fac-tricarbonyl(3,5,7-tribromotropolonato- κ 2O,O ′ )(triphenylphosphane- κ P)rhenium(I), [Re(C7H2Br3O2)(C18H15P)(CO)3] or fac-[Re(TropBr3)(PPh3)(CO)3] (2) (TropH is tropolone and and TropBr3H is tribromotropolone), were synthesized and their crystal and molecular structures confirmed by single-crystal X-ray diffraction. Both crystallized in the space group P\overline{1} and display an array of inter- and intramolecular interactions which were co...
Source: Acta Crystallographica Section C - May 17, 2022 Category: Chemistry Authors: Schutte-Smith, M. Visser, H.G. Tags: tropolone triphenylphosphane crystal structure solid-state NMR spectroscopy Hirshfeld analysis research papers Source Type: research
A comparison of three crystalline forms of miconazole: solvent-free, ethanol monosolvate and hemihydrate
The crystal structures of miconazole {MIC, C18H14Cl4N2O, systematic name (RS)-1-[2-(2,4-dichlorobenzyloxy)-2-(2,4-dichlorophenyl)ethyl]-1H-imidazole}, its ethanol monosolvate (C18H14Cl4N2O · C2H5OH) and its hemihydrate (C18H14Cl4N2O · 0.5H2O) were compared. A detailed comparison of the molecular conformation of the miconazole molecules showed a structural similarity of the solvate forms, whereas the unsolvated form is related to the gas-phase structure. This suggests that the molecular conformation of miconazole is influenced by solvent molecules. The crystal architectures of the considered solvatomorphs are differentiat...
Source: Acta Crystallographica Section C - May 16, 2022 Category: Chemistry Authors: Kaspiaruk, H. Ch ę ci ń ska, L. Tags: miconazole antifungal agent ethanol solvate crystal structure hydrate Hirshfeld surface energy frameworks research papers Source Type: research
Step-stool conformation of a cyclic Schiff base derived from ethylenediamine and heptane-2,4,6-trione: evidence for partial hydrolysis in metal coordination
A Schiff base derived from ethylenediamine and heptane-2,4,6-trione, namely, 5,9,14,18-tetramethyl-1,4,10,13-tetraazacyclooctadeca-5,8,14,17-tetraene-7,16-dione (C18H28N4O2), abbreviated H4daaden, was prepared and characterized for the first time by single-crystal X-ray diffraction. The atoms of the Schiff base occupy two different planes and thus the molecule is essentially nonplanar. An axis running through the C — C atoms of the ethylenediamine groups separate the two planes and these two planes are connected by bridging ethylene groups showing an angle of 117.34 (8) ° . As a result, the side view of the molecule...
Source: Acta Crystallographica Section C - May 16, 2022 Category: Chemistry Authors: Ranaweera, S.A. Bruno, D. Henry, W.P. White, M.G. Tags: heptane-2,4,6-trione ethylenediamine cyclic Schiff base crystal structure step-stool conformation research papers Source Type: research
Hexamethylenetetramine – tridecanedioic acid (1/1): temperature-induced order – disorder structural phase transitions with phase co-existence
The cocrystal hexamethylenetetramine – tridecanedioic acid (1/1) (HMT – C13), C6H12N4 · C13H24O4, was investigated by single-crystal X-ray diffraction techniques at several temperatures during cooling and heating processes. Our results show the formation of two crystalline phases, separated by a large temperature phase co-existence between 290 and 340 K. Phase I, stable above 341 K, presents an orthorhombic structure described in the space group Bmmb, with one N4(CH2)6 · C13H22O4 adduct in its asymmetric unit. Phase II, stable below 290 K, presents a monoclinic symmetry described by the space group P21/c,...
Source: Acta Crystallographica Section C - May 9, 2022 Category: Chemistry Authors: Zapata, M.J.M. Oliveira, W.X.C. Pinheiro, C.B. Tags: cocrystal order – disorder phase transition crystal structure phase co-existence hexamethylenetetramine tridecanedioic acid research papers Source Type: research
Weaving a 2D net of hydrogen and halogen bonds: cocrystal of a pyrazolium bromide with tetrafluorodiiodobenzene
Hydrohalides of Lewis bases may act as halogen bond (XB) acceptors and combine two directional interactions, namely, hydrogen bonds (HB) and XBs in the same solid. 3-(1,3,5-Trimethyl-1H-pyrazol-4-yl)acetylacetone (C11H16N2O2, HacacMePz) was protonated with HX (X = Cl or Br) to afford the hydrohalides, C11H17N2O2+ · X − or H2acacMePz+ · X − (1, X = Cl; 2, X = Br). Hydrohalides 1 and 2 are isomorphous and adopt a classical dipole packing. Consistent with the observation for most β -diketones, the enol form with an intramolecular HB is observed. Additional noteworthy interactions are HBs of the protonated pyra...
Source: Acta Crystallographica Section C - May 9, 2022 Category: Chemistry Authors: van Terwingen, S. Ebel, B. Wang, R. Englert, U. Tags: crystal engineering halogen bonds hydrogen bonds QTAIM electron density research papers Source Type: research
Comment on molybdenum polyoxo clusters: from the `Blues' to the `Reds'
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - May 9, 2022 Category: Chemistry Authors: Krebs, B. Tags: giant assemblies building blocks lanthanides molecular wheels molecular cages molecular hybrids polyoxomolybdate scientific commentaries Source Type: research
A new chiral rare-earth organic framework constructed by tartaric acid: synthesis, structural, thermal investigations and optical properties
Hydrothermal reactions of rare-earth cerium with l-tartaric acid afford a new coordination polymer, namely, poly[[triaqua( μ 4-l-tartrato)cerium(III)] chloride], {[Ce(C4H4O6)(H2O)3]Cl}n, (1). The structure was determined by single-crystal X-ray diffraction analysis and further characterized by IR and UV – Vis spectroscopy, powder X-ray diffraction and thermogravimetric analysis. Single-crystal X-ray diffraction analysis revealed that the compound is a new two-dimensional (2D) double-layered structure with one-dimensional left-handed helical chains. The different intermolecular interactions were confirmed using Hirshfeld...
Source: Acta Crystallographica Section C - April 26, 2022 Category: Chemistry Authors: Belhouas, R. Trifa, C. Bouacida, S. Benmerad, B. Souici, A.H. Boudaren, C. Merazig, H. Tags: coordination polymer tartaric acid crystal structure topology TG/DTA luminescence property research papers Source Type: research
Solid forms and β -cyclodextrin complexation of turinabol
4-Chloro-17 β -hydroxy-17 α -methylandrosta-1,4-dien-3-one (C20H27ClO2), known as turinabol, is a synthetic anabolic – androgenic agent which belongs to the steroid class. Recrystallization from various solvents was performed and the following new solid forms of turinabol were obtained: the hemihydrate (C20H27ClO2 · 0.5H2O), the anhydrous form (C20H27ClO2), the multicomponent acetic acid hydrate (2C20H27ClO2 · C2H4O2 · H2O) and the 2,2,2-trifluoroethanol hemisolvate (C20H27ClO2 · 0.5C2H3F3O). The absolute structures were determined by single-crystal X-ray diffraction. The starting hemihydrate form contains one turi...
Source: Acta Crystallographica Section C - April 24, 2022 Category: Chemistry Authors: Turza, A. Ulici, A. Muresan-Pop, M. Borodi, G. Tags: turinabol 4-chloro-17 β -hydroxy-17 α -methylandrosta-1,4-dien-3-one steroid crystal structure cyclodextrin complex research papers Source Type: research
Synthesis and characterization of the `Japanese rice-ball'-shaped Molybdenum Blue Na4[Mo2O2(OH)4(C6H4NO2)2]2[Mo120Ce6O366H12(OH)2(H2O)76] ∼ 200H2O
The hybridized lanthanide-containing molybdenum blue (Ln-MB) wheel Na4[Mo2O2(OH)4(C6H4NO2)2]2[Mo120Ce6O366H12(OH)2(H2O)76] ∼ 200H2O ({Mo2(C6H4NO2)2}2{Mo120Ce6}) was assembled in an aqueous one-pot synthesis. The Ln-MB was hybridized with 2-picolinic acid through the generation of the organometallic counter-ion [Mo2O2(OH)4(C6H4NO2)2]2+. Control experiments demonstrated that the position of the carboxylic acid group (2-position to the N atom) in the hybridization component is critical in yielding single crystals of Ln-MB. In addition to single-crystal X-ray diffraction (XRD) analysis, which revealed a `Japanese rice-ball'-...
Source: Acta Crystallographica Section C - April 20, 2022 Category: Chemistry Authors: Al-Sayed, E. Tanuhadi, E. Giester, G. Rompel, A. Tags: polyoxomolybdate cerium hybrid organic – inorganic nanocluster crystal structure Molybdenum Blue research papers Source Type: research
A molecular substitutional disorder case study suitable for instruction: L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L is 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide)
A solution of CrII and CrIII complexes, bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)(tetrahydrofuran)chromium(II) – bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)[(trimethylsilyl)methyl]chromium(III) (0.88/0.12), [Cr(C30H38N3)2(C4H8O)]0.88[Cr(C30H38N3)2(C4H11Si)]0.12 or L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L = 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide and THF is tetrahydrofuran), in pentane crystallizes in the monoclinic space group P21/c. The structure obtained shows most of the atoms coincident but with THF disordered with the (trimethylsilyl)methyl ligand. Stru...
Source: Acta Crystallographica Section C - April 12, 2022 Category: Chemistry Authors: Salisbury, B.A. Young, J.F. Theopold, K.H. Yap, G.P.A. Tags: chromium complex crystal structure crystallographic case study substitutional disorder research papers Source Type: research
