Structures of the 2:1 adducts of benzyne with 2-methylanisole and benzene

2007 ◽  
Vol 85 (7-8) ◽  
pp. 461-465
Author(s):  
Christopher O Bender ◽  
René T Boeré ◽  
Peter W Dibble ◽  
Ryan T McKay

The 2:1 adduct of benzyne with 2-methylanisole is shown to have the bisbenzotricyclic structure 6,6a,11,11a-tetrahydro-5-methoxy-6-methyl-5,6,11-metheno-5H-benzo[a]fluorene by a single-crystal X-ray diffraction study (C20H18O: Pca21, a = 15.0497(17), b = 9.87783(11), c = 9.6846(11); Z = 4; 1672 data points, R1 = 0.0325). This structure is compared to an unpublished crystal structure of the parent hydrocarbon 6,6a,11,11a-tetrahydro-5,6,11-metheno-5H-benzo[a]fluorene, C18H14. Both structures have also been computed by DFT methods at the B3LYP/6-311(d,p) level of theory. Bond distances and angles between the solid-state measurements and gas-phase calculations are found to agree well; average deviations are well below 1%. The 1H NMR spectra show surprisingly small 3JHH couplings in the central tricyclic cage, but can be assigned using 2D spectroscopy.Key words: Hydrocarbon cages, strained rings, cyclopropane, X-ray crystallography, NMR.


2008 ◽  
Vol 2008 (10) ◽  
pp. 555-558 ◽  
Author(s):  
You Peng ◽  
Zeyuan Deng ◽  
Shaojie Lang ◽  
Yawei Fan

In order to improve bioavailability and anticancer activity of genistein, a series of novel sulfonic acid ester prodrugs of the isoflavone genistein were synthesised in high yield with excellent regioselectivity. Their structures were characterised by IR, MS, elemental analysis and 1H NMR spectra. The crystal structure was examined by X-ray diffraction. X-ray structure determination revealed that all the aromatic rings in the compound are not coplanar. In the crystal structure, molecules are linked through intermolecular C-H···O hydrogen bonds, forming layers parallel to the ab plane.



1997 ◽  
Vol 62 (10) ◽  
pp. 1577-1584 ◽  
Author(s):  
Petr Štěpnička ◽  
Ivana Císařová ◽  
Jan Sedláček ◽  
Jiří Vohlídal ◽  
Miroslav Polášek

Exclusive, high-yield formation of the cyclotrimers of ethynylferrocene (1) was observed when TaCl5 in benzene was employed as catalyst. Analysis of the resulting isomer mixture by means of HPLC and 1H NMR revealed the presence of 1,3,5-triferrocenylbenzene (sym-2) and 1,2,4-triferrocenylbenzene (asym-2) in the ratio of 4 : 6. A small amount of pure sym-2 isomer was isolated, and its solid-state structure was established by single-crystal X-ray diffraction. The molecules of sym-2 possess a distorted up-up-down arrangement of the ferrocenyl groups attached to the benzene ring.



2012 ◽  
Vol 441 ◽  
pp. 387-391 ◽  
Author(s):  
Yin Zhi Jiang ◽  
Yang Zou ◽  
Lian Qun Zhang

(S,S)-N,N’- bi-(benzal)-1,2-cyclohexanediamine Schiff base (1) was synthesized and characterized by 1 H NMR spectra, MS spectra and IR spectra. And the coordination reaction of 1 with chlorate of Ni(II) was studied. The reaction of 1 with NiII salt [NiCl2] generates a new compound (2). 2 was characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Crystal data for 2: space group Coca, with a = 24.580(4)Å, b = 9.5829(13)Å, c = 7.6836(11)Å, α=90.00º, β=90.00º, γ=90.00º, Z=4, V= 1809.8(5)Å3, Dc=1.446 mg.m-3, µ=1.376 mm-1, F(000)=840. There are 6 coordination sites around Ni2+ of 2, which are respectively occupied by two oxygen atoms (all from two H2O molecules) and four nitrogen atoms [all from two 1,2-cyclohexanediamine molecule]. The Ni atom and four chelating nitrogen atoms are coplanar. There exist intra-molecular H-bond and intermolecular H-bond. The mechanism of metal-assisted decomposition of 1 was also discussed briefly.



1992 ◽  
Vol 57 (6) ◽  
pp. 1299-1313 ◽  
Author(s):  
Juraj Bernát ◽  
Ladislav Kniežo ◽  
Gabriela Birošová ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  

Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III. The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position. The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at 4 position. On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V,VI, and VIII. The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).



2006 ◽  
Vol 62 (5) ◽  
pp. o1951-o1953 ◽  
Author(s):  
Hong Yan ◽  
Hui-Qin Wang ◽  
Cheng-Liang Ni ◽  
Xiu-Qing Song

A new cage photodimer, tetraethyl 2,4,8,10-tetramethyl-6,12-diphenyl-3,9-dioxapentacyclo[6.4.0.02,7.04,11.05,10]dodecane-1,5,7,11-tetracarboxylate, C38H44O10, was prepared through [2+2]-photocycloaddition of diethyl 2,6-dimethyl-4-phenyl-4H-pyran-3,5-dicarboxylate in the solid state. The molecular structure was elucidated by X-ray diffraction analysis, 1H NMR, IR and mass spectroscopy, and elemental analysis. The molecule possesses a crystallographically imposed centre of symmetry. The crystal structure is stabilized by weak C—H...O hydrogen-bond interactions.



1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.



2020 ◽  
Vol 75 (4) ◽  
pp. 365-369
Author(s):  
Long Tang ◽  
Yu Pei Fu ◽  
Na Cui ◽  
Ji Jiang Wang ◽  
Xiang Yang Hou ◽  
...  

AbstractA new metal-organic framework, [Pb(hmpcaH)2]n (1), has been hydrothermally synthesized from Pb(OAc)2 · 3H2O and 2-hydroxy-6-methylpyridine-4-carboxylic acid (hmpcaH2; 2), and characterized by IR spectroscopy, elemental and thermogravimetric analysis, and single-crystal X-ray diffraction. In complex 1, each hmpcaH− ligand represents a three-connected node to combine with the hexacoordinated Pb(II) ions, generating a 3D binodal (3,6)-connected ant network. The crystal structure of 2 was determined. The solid-state fluorescence properties of 1 and 2 were investigated.



Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4404
Author(s):  
Shengyang Guan ◽  
David C. Mayer ◽  
Christian Jandl ◽  
Sebastian J. Weishäupl ◽  
Angela Casini ◽  
...  

A new solvatomorph of [Au3(1-Methylimidazolate)3] (Au3(MeIm)3)—the simplest congener of imidazolate-based Au(I) cyclic trinuclear complexes (CTCs)—has been identified and structurally characterized. Single-crystal X-ray diffraction revealed a dichloromethane solvate exhibiting remarkably short intermolecular Au⋯Au distances (3.2190(7) Å). This goes along with a dimer formation in the solid state, which is not observed in a previously reported solvent-free crystal structure. Hirshfeld analysis, in combination with density functional theory (DFT) calculations, indicates that the dimerization is generally driven by attractive aurophilic interactions, which are commonly associated with the luminescence properties of CTCs. Since Au3(MeIm)3 has previously been reported to be emissive in the solid-state, we conducted a thorough photophysical study combined with phase analysis by means of powder X-ray diffraction (PXRD), to correctly attribute the photophysically active phase of the bulk material. Interestingly, all investigated powder samples accessed via different preparation methods can be assigned to the pristine solvent-free crystal structure, showing no aurophilic interactions. Finally, the observed strong thermochromism of the solid-state material was investigated by means of variable-temperature PXRD, ruling out a significant phase transition being responsible for the drastic change of the emission properties (hypsochromic shift from 710 nm to 510 nm) when lowering the temperature down to 77 K.



Molecules ◽  
2017 ◽  
Vol 22 (7) ◽  
pp. 1182 ◽  
Author(s):  
Ji-Hun An ◽  
Alice Kiyonga ◽  
Woojin Yoon ◽  
Hyung Ryu ◽  
Jae-Sun Kim ◽  
...  


2003 ◽  
Vol 81 (7) ◽  
pp. 825-831 ◽  
Author(s):  
Chunlin Ma ◽  
Qin Jiang ◽  
Rufen Zhang

The new organotin compound, Ph2Sn(Cl)[S(C7H3N2O2S)]·[(C7H3N2O2S)OEt], assembled by an intermolecular aromatic benzothiazole–benzothiazole π-π stacking interaction, has been synthesized by the reaction of diphenyltin dichloride with 2-mercapto-6-nitrobenzothiazole. The title compound was characterized by elemental, IR, 1H NMR, and X-ray crystallography analyses. Single-crystal X-ray diffraction data reveals that the title compound has two different molecular components. The component Ph2Sn(Cl)[S(C7H3N2O2S)] has a pentacoordinate tin, which further forms an infinite one-dimensional chain by intermolecular non-bonded Cl···S interactions, resulting in an intercalation lattice that holds (C7H3N2O2S)OEt molecules. The formation of the molecule (C7H3N2O2S)OEt as well as its intercalated mechanism has also been discussed.Key words: organotin, assemble, π-π stacking interaction, 2-mercapto-6-nitrobenzothiazole, non-bonded interaction, crystal structure.



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