Synthesis of Triferrocenylbenzenes by Tantalum(V)-Catalyzed Cyclotrimerization of Ethynylferrocene. The Crystal Structure of 1,3,5-Triferrocenylbenzene

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.

1988 ◽  
Vol 43 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Theo F. Berlitz ◽  
Heike Sinning ◽  
Jörg Lorberth ◽  
Ulrich Müller

AbstractReaction of SbCl3 with KPcp (Pep = pentamethylcyclopentadienyl) in etheral solution at -78 °C affords dimeric pentamethylcyclopentadiene and orange-red (PcpSb)4 in high yield. 1H, 13 C NMR, IR, UV and mass spectra are reported. The tetrameric structure was found by a crystal structure determination carried out with X-ray diffraction data collected at -50 °C (928 independent observed reflexions. R = 0.055). Crystal data: tetragonal, space group I41/amd, a = 2400.0(5), c = 781.7(5) pm, Z = 4. The (PcpSb)4 molecules have a non-planar Sb4 ring with Sb -Sb bond lengths of 285.6(1) pm, one η1-Pcp ring is attached to each Sb atom. Contrary to the solid state structure, monomeric molecules are found in benzene and hexane solutions.


2008 ◽  
Vol 63 (3) ◽  
pp. 339-341 ◽  
Author(s):  
Ajay Venugopal ◽  
Alexander Willner ◽  
Norbert W. Mitzel

The reaction of N,O-bis(trimethylsilyl)hydroxylamine with potassium hydride in pentane affords a product of the formula {K6[OSiMe3]4[ON(SiMe3)2]2}, resulting from deprotonation followed by N-O bond cleavage and 1,2-silylshift. The compound was characterised by elemental analysis and by single crystal X-ray diffraction. The aggregate consists of a K3O3 bis-cubane core, with N(SiMe3)2 groups at the oxygen atoms shared by the two cubes, andMe3Si groups attached to the four O vertices. Two weak K···N interactions are also detected in the solid state structure.


1995 ◽  
Vol 50 (4) ◽  
pp. 699-701 ◽  
Author(s):  
Norbert W. Mitzel ◽  
Jürgen Riede ◽  
Klaus Angermaier ◽  
Hubert Schmidbaur

The solid-state structure of N,N-dibenzylhydroxylamine (1) has been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 21/n with four formula units in the unit cell. N,N-dibenzylhydroxylamine dimerizes to give N2O2H2 sixmembered rings as a result of the formation of two hydrogen bonds O - H ··· N in the solid state.


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.


2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.


2015 ◽  
Vol 70 (4) ◽  
pp. 279-282 ◽  
Author(s):  
Raphael J.F. Berger ◽  
Surajit Jana ◽  
Roland Fröhlich ◽  
Norbert W. Mitzel

AbstractA mixed lithium/beryllium diethylhydroxylaminate compound containing nbutyl beryllium units of total molecular composition nBe(ONEt2)2 [(LiONEt2)2nBuBeONEt2]2 (1) was isolated from a reaction mixture of nbutyl lithium, N,N-diethylhydroxylamine and BeCl2 in diethylether/thf. The crystal structure of 1 has been determined by X-ray diffraction. The aggregate is composed of two ladder-type subunits connected in a beryllium-centered distorted tetrahedron of four oxygen atoms. Only the lithium atoms are engaged in coordination with the nitrogen donor atoms. The DFT calculations support the positional occupation determined for Li and Be in the crystal structure. The DFT and the solid-state structure are in excellent agreement, indicating only weak intermolecular interactions in the solid state. Structural details of metal atom coordination are discussed.


2013 ◽  
Vol 69 (12) ◽  
pp. i84-i84 ◽  
Author(s):  
Aicha Mbarek ◽  
Fadhila Edhokkar

The crystal structure of strontium diarsenate has been reinvestigated from single-crystal X-ray diffraction data. In contrast to the previous determinations of this structure [Weilet al.(2009).Solid State Sci.11, 2111–2117; Edhokkaret al.(2012).Mater. Sci. Eng.,28, 012017] and to all isotypicA2B2O7compounds that crystallize in the space groupP41, the current redetermination revealed theP43enantiomorph of Sr2As2O7with a purity of 96.3 (8)%. The crystal structure is made up from two eclipsed As2O7diarsenate groups (symmetry 1) with characteristically longer As—O bridging bonds [1.756 (4)–1.781 (4) Å] than the terminal As—O bonds [1.636 (4)–1.679 (4) Å] and four Sr2+sites with coordination numbers ranging from seven to nine. The building units are arranged in sheets parallel to (001).


Author(s):  
LYDIE MICHAUDET ◽  
DOMINIQUE FASSEUR ◽  
ROGER GUILARD ◽  
ZHONGPING OU ◽  
KARL M. KADISH ◽  
...  

The metalation of several free base porphyrins by the bismuth salts Bi(NO3)3 and Bi(SO3CF3)3 in DMF or pyridine is described. The resulting stable Bi(III) porphyrin complexes are characterized by electrochemistry, 1H NMR and UV-vis spectroscopy. The structure of ( OEP ) Bi ( SO 3 CF 3) was also determined by single-crystal X-ray diffraction and shows that ( OEP ) Bi ( SO 3 CF 3) exists as a dimer which is stabilized by electrostatic interactions in which the two [(OEP)Bi]+ cations are linked via oxygen atoms of two symmetrically related [Formula: see text] anions, leading to a heptacoordinated bismuth center. Electrochemical oxidation of ( OEP ) Bi ( SO 3 CF 3) and ( T p TP ) Bi ( SO3CF3 ) shows that only the porphyrin macrocycles are oxidized.


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