Syntheses, Structures, and Spectroscopic Properties of Alkoxide, Hydroxide, and Siloxide Complexes with (η3-Allyl)Mo Moieties

1999 ◽  
Vol 54 (4) ◽  
pp. 473-481 ◽  
Author(s):  
Cornelia Borgmann ◽  
Christian Limberg ◽  
László Zsolnai ◽  
Katja Heinze

Salts with binuclear anions of the general formula [(η3-C3H4R)(CO)2Mo(μ-OR′)2(μ-OR″)-Mo(CO)2(η3-C3H4R)]- (R = h , R′, R″ = Me, 2 ; R = CH3, R′ = CH(CH3)2, R″ = OH, 3; R = CH3, R′ = OH, R″ = OSiMe3, 4) have been synthesised via reaction of [(η3-C3H4R)- Mo(CO)2(CH3CN)2(thf)]+BF4- , 1, with NaOMe, NaOiPr, and KOSiMe3. All products were characterised spectroscopically and investigated by single crystal X-ray analysis. In the case of 3 low temperature 2D-NMR spectra revealed that the solid state structure is maintained in solution and that the compound shows a trigonal twist-rearrangement at room temperature.

1996 ◽  
Vol 49 (6) ◽  
pp. 701 ◽  
Author(s):  
YM Syah ◽  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White

The solid-state structure of the semicarbazone derivative (3) of the aldehyde diacid (1), an acyclic diterpene isolated from Eremophila species, has been determined by a single-crystal room-temperature X-ray study. Crystals of (3) are triclinic, Pī , a 14.642(7), b 14.371(6), c 12.823(6) Ǻ, α 76.59(4), β 66.09(4), γ 72.97(4)°, Z = 4; R was 0.052 for 2265 independent 'observed' (I > 3σ(I)) diffractometer reflections.


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.


1994 ◽  
Vol 47 (6) ◽  
pp. 1193 ◽  
Author(s):  
F Almassi ◽  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White

The solid-state structure of the fungal metabolite E-dehydrocurvularin (2), an inhibitor of microtubule assembly, has been determined by a single-crystal room-temperature X-ray study for comparison with curvularin (1). Crystals of (2) are orthorhombic, P212121, a 17.757(9), b 10.031(6), c 8.069(4) Ǻ, Z = 4; R was 0.060 for 988 independent 'observed' [I > 3σ(I)] diffractometer reflections. The results of this study show that (1) and (2) adopt opposite helicity in the solid state.


1995 ◽  
Vol 48 (10) ◽  
pp. 1771 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White

The solid-state structure of torquatone (1), an acylphloroglucinol derivative from the essential oils of a number of Eucalyptus species, has been determined by a single-crystal room-temperature X-ray study. Crystals of (1) are monoclinic, P21/c, a 10.470(8), b 20.53(1), c 7.696(6) Ǻ, β 95.91(7)۰, Z = 4; R was 0.054 for 1877 independent 'observed' [I > 3σ(I)] diffractometer reflections.


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.


2010 ◽  
Vol 75 (9) ◽  
pp. 971-980 ◽  
Author(s):  
Michael A. Beckett ◽  
Peter N. Horton ◽  
Michael B. Hursthouse ◽  
James L. Timmis ◽  
K. Sukumar Varma

[C6H5CH2NH3][B5O6(OH)4] was obtained as colourless crystals in high yield from a MeOH/ H2O (1:1) solution of benzylamine and boric acid (1:5). A single-crystal X-ray study confirmed that the solid-state structure was comprised of a supramolecular H-bonded pentaborate anion lattice, templated by the benzylammonium cations which occupy positions within the lattice cavities. Each pentaborate anion formed 4 H-bonds to 4 neighbouring pentaborate anions at α,α,α,β acceptor sites. Additionally, each cation H-bonds to 3 pentaborate anions. Crystals were monoclinic, P21/c, with a = 9.3511(2) Å, b = 14.5157(4) Å, c = 10.4670(2) Å, β = 90.778(2)°, T = 120 K, V = 1420.64(6) Å3, and Z = 4. TGA/DSC analysis showed that [C6H5CH2NH3][B5O6(OH)4] thermally decomposed in air at 800 °C to 2.5B2O3, via a low-temperature (200–250 °C) dehydration step to a condensed pentaborate.


2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.


2018 ◽  
Vol 14 ◽  
pp. 3011-3017
Author(s):  
Akın Sağırlı ◽  
Yaşar Dürüst
Keyword(s):  
2D Nmr ◽  
X Ray ◽  
H Nmr ◽  
Tof Ms ◽  

The present work describes an unfamiliar reaction of 5-(chloromethyl)-3-substituted-phenyl-1,2,4-oxadiazoles with KCN affording trisubstituted 1,2,4-oxadiazol-5-ylacetonitriles and their parent alkanes, namely, 1,2,3-trisubstituted-1,2,4-oxadiazol-5-ylpropanes. To the best of our knowledge, the current synthetic route leading to decyanated products will be the first in terms of a decyanation process which allows the transformation of trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title compounds were identified by means of IR, 1H NMR, 13C NMR, 2D NMR spectra, TOF–MS and X-ray measurements.


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.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 983
Author(s):  
Hang Ren ◽  
Haoyun An ◽  
Jingchao Tao

Glycosylation of 6-amino-4-methoxy-1H-pyrazolo[3,4-d]pyrimidine and its iodo- and bromo- analogues with the protected ribofuranose and 2′-deoxyribofuranose under different conditions resulted in the synthesis of N9- and N8-glycosylated purine nucleosides. Five key intermediate nucleosides, having 6-methoxy, 7-iodo, and 2-bromo groups, were further derivatized to 23 final 8-aza-7-deazapurine nucleoside derivatives. The structures of N9- and N8-glycosylated products were assigned based on UV and NMR spectra. HMBC analysis of 2D NMR spectra and X-ray crystallographic studies of the representative compounds unambiguously verified the connection of ribose ring to N9- or N8-position of the purine ring. The anticancer activity of these new compounds was evaluated.


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