Amido-tert-butylimido-vanadium(V)-Verbindungen. Darstellung, Reaktionen und 51V-NMR-spektroskopische Untersuchungen / Amido-tert-butylimidovanadium(V) Compounds. Synthesis, Reactions and 51V NMR Spectroscopic Studies

2001 ◽  
Vol 56 (11) ◽  
pp. 1100-1108 ◽  
Author(s):  
Fritz Preuss ◽  
Monika Vogel ◽  
Uwe Fischbeck ◽  
Jens Pemer ◽  
Gerhard Overhoff ◽  
...  

The reactions of tBuN = VCl2 · DME with LiX (X = NHtBu, NR2, OSiPh3, SR, Alkyl, Cp) have been studied. LiNHtBu and LiCH3 furnish the binuclear diamagnetic tert-butylimido-vanadium( IV) compounds [(μ-NtBu)2V2X4]; in all other cases only the vanadium(V) compounds tBuN=VX3 and tBuN=VCpCl2 formed by disproportionation reactions of vanadium(IV) can be isolated. The syntheses of various mononuclear amido tert-butylimido-vanadium(V) complexes as well as of the binuclear complexes [μ-NtBu)2V2(NtBu)2Cl2] and [(μ-0)V2(NtBu)2Cp2Cl2] are also described. All compounds obtained have been characterized by 51V NMR spectroscopy. tBuN=V(OMe)3 was investigated by X-ray diffraction analysis; the molecular structure has been found to be that of a binuclear vanadium(V) complex with two bridging methoxo ligands.

Author(s):  
Inna Nikolaevna Kolesnikova ◽  
Vladimir Vladimirovich Kuznetsov ◽  
Alexander Sergeevich Goloveshkin ◽  
Nikolai Andreevich Chegodaev ◽  
Nina Nikolaevna Makhova ◽  
...  

2001 ◽  
Vol 56 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Fritz Preuss ◽  
Uwe Fischbeck ◽  
Frank Tabellion ◽  
Jens Pemer ◽  
Walter Frank ◽  
...  

Abstract Imidovanadium(V) Trichlorides The reactions of Me3SiN=VCl3 (1) with MeOH, PhOH, HCl, PyH+Cl- or LiOtBu have been studied. The reductive decomposition of 1 by hydrogen chloride in toluene yields HN=VCl3 as a labile intermediate which could be isolated only in a small amount. The syntheses of RN=VCl3 (R = neopent, nPr, cyclohex, CPh3, 1-Ad) and [(tBuN)2V2Cl4(μ-OC13H9)2] (15) are also described. All compounds obtained are characterized by 51V NMR spectroscopy, the fluorenolato complex 15 by X-ray diffraction analysis.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3920
Author(s):  
Martin Weber ◽  
Gábor Balázs ◽  
Alexander V. Virovets ◽  
Eugenia Peresypkina ◽  
Manfred Scheer

By reacting [{Cp‴Fe(CO)2}2(µ,η1:1-P4)] (1) with in situ generated phosphenium ions [Ph2P][A] ([A]− = [OTf]− = [O3SCF3]−, [PF6]−), a mixture of two main products of the composition [{Cp‴Fe(CO)2}2(µ,η1:1-P5(C6H5)2)][PF6] (2a and 3a) could be identified by extensive 31P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η4:1-P5Ph2){Cp‴(CO)2Fe}][PF6] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)2}4(µ4,η1:1:1:1-P8)][OTf]2 (5) containing a tetracyclo[3.3.0.02,7.03,6]octaphosphaoctane ligand.


1983 ◽  
Vol 38 (2) ◽  
pp. 190-193 ◽  
Author(s):  
Reinhold Tacke ◽  
Hartwig Lange ◽  
Anke Bentlage ◽  
William S. Sheldrick ◽  
Ludger Ernst

Abstract The 2,2,5,5-tetraorganyl-1,4-dioxa-2,5-disilacyclohexanes 2a-2c were prepared by condensation of the corresponding (hydroxymethyl)diorganylsilanes 1 a-1 c. The constitution of the heterocycles was confirmed by elemental analyses, cryoscopic measurements, mass spectrometry, and NMR-spectroscopic (1H, 13C) investigations. The molecular structure of 2 b was determined by X-ray diffraction analysis.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2875
Author(s):  
Li Ma ◽  
Xiaolin Zhang ◽  
Wenbo Ming ◽  
Shengxin Su ◽  
Xiaoyong Chang ◽  
...  

The reactions of electron-rich organosilicon compounds 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (1), 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (2), and 1,1′-bis(trimethylsilyl)-1,1′-dihydro-4,4′-bipyridine (12) with B-amino and B-aryl dihaloboranes afforded a series of novel B=N-bond-containing compounds 3–11 and 13. The B=N rotational barriers of 7 (>71.56 kJ/mol), 10 (58.79 kJ/mol), and 13 (58.65 kJ/mol) were determined by variable-temperature 1H-NMR spectroscopy, thus reflecting different degrees of B=N double bond character in the corresponding compounds. In addition, ring external olefin isomers 11 were obtained by a reaction between 2 and DurBBr2. All obtained B=N-containing products were characterized by multinuclear NMR spectroscopy. Compounds 5, 9, 10a, 11, and 13a were also characterized by single-crystal X-ray diffraction analysis.


1985 ◽  
Vol 40 (3) ◽  
pp. 363-367 ◽  
Author(s):  
Fritz Preuss ◽  
Edith Fuchslocher ◽  
William S. Sheldrick

tC4H9N = VCl2(NHtC4H9) and the tert-butylamine complex [tC4H9N=VCl2(NHtC4H9)(NH2tC4H9)] have been prepared by reaction of tC4H9N=VCl3 with NH2tC4H9. 1H and 51V NMR data of these compounds are reported. The complex was investigated by X-ray diffraction analysis; the structure has been found to be a binuclear vanadium complex bridged by two Cl-atoms with a distorted octahedral arrangement of the ligands.


2015 ◽  
Vol 68 (3) ◽  
pp. 357 ◽  
Author(s):  
Kevin P. Yeagle ◽  
Darryl Hester ◽  
Nicholas A. Piro ◽  
William G. Dougherty ◽  
W. Scott Kassel ◽  
...  

The aluminium complexes {[κ2-N,O-(t-BuNCOPh)]AlMe2}2 (2), [κ2-N,O-(t-BuNCOPh)]2AlMe (3), and [κ2-N,O-(t-BuNCOPh)]3Al (4) were prepared through the protonolysis reaction between trimethylaluminium and one, two, or three equivalents, respectively, of N-tert-butylbenzamide. Complex 2 was also prepared via a salt metathesis reaction between K(t-BuNCOPh) and dimethylaluminium chloride. Complexes 2–4 were characterized using 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction analysis of the complexes corroborated ligand : metal stoichiometries and revealed that all the amidate ligands coordinate to the aluminium ion in a κ2 fashion. The Al–amidate complexes 2–4 were viable catalyst precursors for the Meerwein–Ponndorf–Verley–Oppenauer reduction–oxidation manifold, successfully interconverting several classes of carbonyl and alcohol substrates.


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