Synthesis and Crystal Structures of Dimethylsilylene-Bridged (Amidocyclopentadienyl)dichlorotitanium(IV) Complexes with Various Substituents on the Cyclopentadienyl Ligand

2001 ◽  
Vol 66 (4) ◽  
pp. 605-620 ◽  
Author(s):  
Jaroslav Zemánek ◽  
Petr Štěpnička ◽  
Karla Fejfarová ◽  
Róbert Gyepes ◽  
Ivana Císařová ◽  
...  

(Amidocyclopentadienyl)dichlorotitanium(IV) complexes of the general formula [TiCl2{η5:η1(N)-C5(1-SiMe2Nt-Bu-2,3,4-Me3-5-R)}], where R = H (6b), Ph (6c), 4-fluorophenyl (6d) and 1-methylallyl (6e) were synthesized and characterized by spectral methods. Solid-state structure of [TiCl2{η5:η1(N)-C5Me4(SiMe2Nt-Bu)}] (6a) and 6d determined by single-crystal X-ray diffraction showed that variation of the ring substituent R has only a negligible effect on the molecular structure of the complexes. The NMR spectra indicate that motion of the bulky substituent R in compounds 6c, 6d and 6e is hindered below ca 50 °C.

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.


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.


1995 ◽  
Vol 50 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Udo Dörfler ◽  
Wolfgang Milius ◽  
Max Herberhold

According to a single crystal X-ray structure determination all three ferrocenyl substituents of triferrocenylborane (1) adopt the same orientation with respect to the BC3-plane [P21/c monoclinic; Z = 4; a = 1353.5(3), b = 1695.6(3), c = 1056.4(2) pm, β = 109.27(3)°]. The simulated X-ray powder pattern of the single crystal is identical with the powder diagram of a macroscopic sample, indicating the presence of a single diastereomer (1a) in the solid state. However, at low temperature (< - 95 °C) in solution, the 13C NMR spectra suggest the presence of the second diastereomer (1b) in which one ferrocenyl group is oriented opposite to the other two with respect to the central BC3-plane.


2003 ◽  
Vol 68 (10) ◽  
pp. 1897-1903 ◽  
Author(s):  
Martin Kotora ◽  
David Nečas ◽  
Petr Štěpnička

Diferrocenylethyne (1) was synthesized by metathesis of 1-ferrocenylprop-1-yne using various catalytic systems based on [Mo(CO)6] (5 mole %) and a chlorophenol (30 mole %) in toluene. The yields varied for different chlorophenols; the best conversions were obtained with 2,5-dichlorophenol (66%) and 4-chlorophenol (55%). Alkyne 1 was further reduced to the known (E)-1,2-diferrocenylethene and 1,2-diferrocenylethane, and its solid-state structure determined by single-crystal X-ray diffraction.


1996 ◽  
Vol 51 (3) ◽  
pp. 437-440 ◽  
Author(s):  
Adolphus A . H. van der Zeijden ◽  
J. Sieler ◽  
E. Hovestreydt

Abstract A chiral ferrocene (CpE2Fe) was synthesized by reaction of CpELi with FeCl2(THF)1.5 The cyclopentadienyl ligand CpE contains a dimethylamino group that is separated from the Cp backbone by two stereogenic carbon centres. Reaction of CpE2Fe with excess Mel affords the ammonium salt CpE2Fe.2MeI. Its solid state structure was determined by X-ray diffraction methods.


2000 ◽  
Vol 65 (12) ◽  
pp. 1897-1910 ◽  
Author(s):  
Lenka Lukešová ◽  
Jiří Ludvík ◽  
Ivana Císařová ◽  
Petr Štěpnička

A series of complexes [M(CO)5(Hdpf-κP)], where M = Cr (1), Mo (2) and W (3), and Hdpf is 1'-(diphenylphosphanyl)ferrocenecarboxylic acid, was obtained by thermally-induced (2) or photochemically-assisted (1, 3) displacement of carbon monoxide with Hdpf from the corresponding hexacarbonyl complexes. The complexes were characterized by NMR, UV-VIS and IR spectroscopies and further studied by cyclic voltammetry. The solid-state structure of complex 1 has been determined by single-crystal X-ray diffraction.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Kousik Ghosh ◽  
Antonio Frontera ◽  
Shouvik Chattopadhyay

A heteronuclear cobalt(III)/potassium complex, [(L1)2Co2K(L2)2], {Where, H2L1 = N,N-bis(3-ethoxysalicylidene)2,2-dimethyl-1,3-propanediamine and HL2 = 3-ethoxysalicylaldehyde}, has been synthesized and characterized by several analytical techniques including single crystal X-ray diffraction analysis. The energetic...


Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 509 ◽  
Author(s):  
Patrizia Rossi ◽  
Paola Paoli ◽  
Stella Milazzo ◽  
Laura Chelazzi ◽  
Andrea Ienco ◽  
...  

Betaxolol belongs to the class of β1-adrenergic blocking agent. Several polymorphs of racemic betaxolol have been reported in the literature, but only one of them (BE_I) had the crystal structure determined from single-crystal X-ray diffraction. Here, we present a new crystalline phase of betaxolol (BE_IV). Its solid-state structure has been obtained from single-crystal X-ray diffraction data. The molecular and crystal arrangements of betaxolol in BE_IV have been further investigated by molecular modelling, by Cambridge Structural Database (CSD) surveys and by Hirshfeld surface analysis. A comparison with the solid-state structure of BE_I have been carried out. In the two polymorphs the 2-hydroxy-3-(isopropylamino)-propoxy chain, which is common to other β-blocker drugs, adopts a different conformation. In addition, the rotational isomer found in BE_IV is different with respect to the four already observed in the solid-state structure of analogous compounds. In both the polymorphs, the most significant interaction is due to the H-bonds involving the OH group as donor and the NH as acceptor, while the interaction where OH works as acceptor (NH acts as donor) is definitely less important. The resulting H-bond patterns are however different: Alternate R2,2(10) a > a (OH donors) and R2,2(10) b > b (OH acceptors) in BE_I vs. alternate R4,4 (8) a > b > a > b (OH donors) and R2,2 (10) b > b (OH acceptor) in BE_IV.


Sign in / Sign up

Export Citation Format

Share Document