Aromatic propellenes. Part 1. NMR spectroscopy, X-ray crystal and molecular structure of hexa(3,5-dimethylpyrazol-1-yl)benzene

Author(s):  
Concepci�n Foces-Foces ◽  
Antonio L. Llamas-Saiz ◽  
Rosa Ma Claramunt ◽  
Nadine Jagerovic ◽  
Mar�a Luisa Jimeno ◽  
...  
1986 ◽  
Vol 41 (6) ◽  
pp. 722-730 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Eduard Michels ◽  
Jürgen Kaub

11-Isopropylidene-bicyclo[4.4.1]undeca-2,4,8-triene (IBU, 1A) and five alkyl substituted de­rivatives (1B-1F) contain a conjugated diene unit and two isolated CC-double bonds, one exocyclic and one incorporated into the bicvclus, each suited for complexation to transition metals. With [Cr(CO)3(CH3CN)3] (2) 1A-1F form [Cr(CO)3(η6-IBU)] complexes (3A−3F). in which the IBU ligands are coordinated to the chromium via the diene unit and the exocyclic CC-double bond. The corresponding [Mo(CO)3(η6-IBU)] complexes (5A−5F) are obtained from the reactions of [Mo(CO)3(diglyme)] (4) with 1A−1F. In addition, the isomeric [Mo(CO)3(η6-IBU)] complexes (6A−6D) are formed, in which the IBU ligands are bound to molybdenum via the three cyclic CC-double bonds. The complexes 3A−3F, 5A−5F and 6A−6D were studied by IR and NMR spectroscopy (1H. 13C) and characterized by C, H elemental analyses. The crystal and molecular structure of 1A was determined by X-ray structure analysis.


2008 ◽  
Vol 63 (9) ◽  
pp. 1035-1039 ◽  
Author(s):  
Hans-Christian Böttcher ◽  
Peter Mayer

The reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with tBu2PH in different solvents in various molar ratios was investigated. Working with a molar ratio of Rh to P = 1 : 2 in heptane overnight afforded [{Rh(μ-Cl)(tBu2PH)2}2] (1) in nearly quantitative yield. Upon tuning the molar ratio (Rh/P) in the range from 1 : 2 to 1 : 0.5, 31P{1H} NMR spectroscopy indicated the formation of [(tBu2PH)2Rh(μ-Cl)2Rh(coe)2] (3) besides the complexes [{Rh(μ-Cl)(coe)(tBu2PH)}2] (cis, 2a; trans, 2b). The constitution of 3 was established by an independent synthesis mixing 1 with [{Rh(μ- Cl)(coe)2}2] or [{Rh(μ-Cl)(cod)}2] (cod = 1.4-cyclooctadiene), respectively, which also yielded [(tBu2PH)2Rh(μ-Cl)2Rh(cod)] (4). Single crystals of 1 have been analyzed by X-ray crystallography (monoclinic, Cc, Z = 8, a = 32.7375(3), b = 11.1294(1), c = 24.5134(3)Å ; β = 106.7228(4)◦; V = 8553.70(15) Å3; T = 200 (2) K).


1987 ◽  
Vol 52 (3) ◽  
pp. 714-726 ◽  
Author(s):  
Tapani A. Pakkanen ◽  
Vesa Nevalainen ◽  
Vladimír Král ◽  
Reino Laatikainen ◽  
Zdeněk Arnold

Crystal and molecular structure of three substituted methylenemalonaldehydes I-III was studied. The spatial arrangement of the monosubstituted derivative I differs significantly from that of the disubstituted methylenemalonaldehydes II and III, not only in the solid state conformation of the malonaldehyde fragment but also in the length of the ethylenic C=C double bond and in its distorsion. The structures found in crystal are compared with conformations in solutions determined by NMR spectroscopy.


1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4089
Author(s):  
Katarzyna Betlejewska-Kielak ◽  
Elżbieta Bednarek ◽  
Armand Budzianowski ◽  
Katarzyna Michalska ◽  
Jan K. Maurin

Racemic ketoprofen (KP) and β-cyclodextrin (β-CD) powder samples from co-precipitation (1), evaporation (2), and heating-under-reflux (3) were analysed using X-ray techniques and nuclear magnetic resonance (NMR) spectroscopy. On the basis of NMR studies carried out in an aqueous solution, it was found that in the samples obtained by methods 1 and 2, there were large excesses of β-CD in relation to KP, 10 and 75 times, respectively, while the sample obtained by method 3 contained equimolar amounts of β-CD and KP. NMR results indicated that KP/β-CD inclusion complexes were formed and the estimated binding constants were approximately 2400 M−1, showing that KP is quite strongly associated with β-CD. On the other hand, the X-ray single-crystal technique in the solid state revealed that the (S)-KP/β-CD inclusion complex with a stoichiometry of 2:2 was obtained as a result of heating-under-reflux, for which the crystal and molecular structure were examined. Among the methods used for the preparation of the KP/β-CD complex, only method 3 is suitable.


Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.


2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.


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