Stereochemistry Determination by Powder X-Ray Diffraction Analysis and NMR Spectroscopy Residual Dipolar Couplings

2009 ◽  
Vol 48 (31) ◽  
pp. 5670-5674 ◽  
Author(s):  
Manuela E. García ◽  
Silvina Pagola ◽  
Armando Navarro-Vázquez ◽  
Damilola D. Phillips ◽  
Chakicherla Gayathri ◽  
...  
2009 ◽  
Vol 121 (31) ◽  
pp. 5780-5784 ◽  
Author(s):  
Manuela E. García ◽  
Silvina Pagola ◽  
Armando Navarro-Vázquez ◽  
Damilola D. Phillips ◽  
Chakicherla Gayathri ◽  
...  

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 ◽  
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.


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.


Synthesis ◽  
2017 ◽  
Vol 49 (11) ◽  
pp. 2389-2393 ◽  
Author(s):  
Stefanie Pelzer ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Nikolai Ignat’ev ◽  
Reint Eujen ◽  
...  

This paper describes the synthesis and comprehensive characterization of tetrakis(pentafluoroethyl)germane. In addition to a complete NMR spectroscopic characterization, including the rarely used 73Ge NMR spectroscopy, Ge(C2F5)4 was studied by IR spectroscopy, mass spectrometry as well as X-ray diffraction analysis. A 73Ge NMR investigation as well as an X-ray diffraction study of the related germane Ge(CF3)4 are also included.


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.


IUCrData ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Rui Li ◽  
Xin-E Duan ◽  
Wei Cao ◽  
Xue-Hong Wei

The title compound, C14H20N4Si2 or [(Apy)2(μ-SiMe)2], systematic name 2-[2,2,4,4-tetramethyl-3-(pyridin-2-yl)-1,3,2,4-diazadisiletidin-1-yl]pyridine, was obtained as a side product from the reaction of 2-amino-pyridine with LiBu n followed by the addition of Me2NMe2SiCl in hexane. The compound was characterized by single-crystal X-ray diffraction analysis and NMR spectroscopy. The title compound lies about an inversion center at the centroid of the cyclodisilazane ring. The four-membered Si2N2 core is strictly planar with the two pyridyl rings placed centrosymmetrically on either side of the Si2N2 plane and are almost coplanar with the central four-membered ring.


1997 ◽  
Vol 62 (8) ◽  
pp. 1239-1253 ◽  
Author(s):  
Jonathan Bould ◽  
Paul Brint ◽  
John D. Kennedy ◽  
Mark Thornton-Pett ◽  
Lawrence Barton ◽  
...  

[6-(CO)-6-H-6,9-(PPh3)2-6P,5C-μ-(2-Ph2PC6H4)-arachno-6-IrB9H11] (1) results from the reaction of [6-H-6-(PPh3)-6P,5C-μ-(2-Ph2PC6H4)-nido-6-IrB9H12] (2) with carbon monoxide in refluxing benzene. It is characterised by NMR spectroscopy and by single-crystal X-ray diffraction analysis. Crystals were triclinic, space group P1, with a = 10.688(2), b = 13.114(3), c = 22.356(5) Å, α = 78.33(2), β = 89.482(10), γ = 70.884(12)°, and Z = 2. The compound is of the little-examined arachno ten-vertex metallaborane structural type. A second compound of this type, [6-(CO)-6-H-6,6-(PMe2Ph)2-9-(PPh3)-arachno-6-IrB9H11] (3), isolated from a reaction system involving [Ir(CO)Cl(PPh3)2], PMe2Ph and the [nido-B9H12]- anion, has also been characterised crystallographically. Crystals were triclinic, space group P1, with a = 10.389(1), b = 10.511(1), c = 19.699(3) Å, α = 75.03(1), β = 85.53(1), γ = 74.88(1)°, and Z = 2.


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