Novel organocycloborates via Grignard reagentsElectronic supplementary information (ESI) available: experimental details and 1H, 13C and 11B NMR data for 1, 2, 3and 4, single crystal X-ray data and additional figures for 3and 4. See http://www.rsc.org/suppdata/cc/b4/b404864d/

2004 ◽  
pp. 1738 ◽  
Author(s):  
Holger Braunschweig ◽  
Giovanni D'Andola ◽  
Tom Welton ◽  
Andrew J. P. White
1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.


2008 ◽  
Vol 63 (11) ◽  
pp. 1267-1275 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Wolfgang Milius

Abstract Triethylborane, BEt3, can act as a 1,2-hydroborating reagent towards alkyn-1-ylsilanes, depending on the nature of the silane. A mechanism is proposed invoking hydrogen transfer from the β -carbon of one ethyl group, quite different from the 1,2-hydroboration mechanism using tri-n-propylborane, BnPr3. The structure of the products has been confirmed by comparison with that obtained using 9-borabicyclo[3.3.1]nonane, 9-BBN, as a well established 1,2-hydroborating reagent. All products have been characterized by a consistent set of NMR data (1H, 11B, 13C and 29Si NMR). The molecular structure of (Z)-1-dichlorosilyl-1-[9-(9-borabicyclo[3.3.1]nonyl)]-2-phenylethene has been determined by single crystal X-ray diffraction.


1988 ◽  
Vol 43 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Jan Ebenhöch

Abstract Trimethylsilylethine (1) has been prepared from C2H2, sodium and Me3SiCl in anisole. The product can be converted into a Grignard reagent Me3SiC≡CMgCl using iPrMgCl. This reagent yields the compounds Me3SiC≡CSiH3, (Me3SiC≡C)2SiH2, (Me3SiC≡C)3SiH, and (Me3SiC≡C)4Si (2-5) when treated with equivalent amounts of H3SiBr, H2SiBr2, HSiCl3, or SiCl4. respectively. The new silanes have been characterized by NMR data. The crystal structure of (Me3SiC≡C)4Si has been determined by single crystal X-ray diffraction. It shows the expected tetrahedral geometry at he central silicon atom with four linear SiC≡CSi linkages.


2006 ◽  
Vol 61 (8) ◽  
pp. 975-978 ◽  
Author(s):  
Jörg Wagler ◽  
Nadia E. A. El-Gamel ◽  
Edwin Kroke

The single crystal X-ray structure of the DMSO solvate of cyameluric acid C6N7O3H3 ·3DMSO, 2b’ has been determined. The results show that the most stable tautomer of solid cyameluric acid is the tri-keto form 2b with C3h symmetry. 1H and 13C NMR data indicate that this isomer is also present in solution, with slow interchange of the N-H protons. This confirms previous theoretical results although almost all derivatives reported in the literature are derivatives of the tri-hydroxy tautomer 2a


1996 ◽  
Vol 51 (5) ◽  
pp. 744-746 ◽  
Author(s):  
A. Franken ◽  
H. Thomsen ◽  
W. P reetz

By reaction of conjuncto-[B6H6-B6H6]2- in alkaline solution with excess bromine the heptabromo-closo-heptaborate, [B7Br7]2 is formed. The crystal structure of [(CsH3N)2CH2][B7Br7] has been determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/a with a = 15.0843(14), b = 9.8882(14), c = 17.057(2) Å, β = 114.039°(7)). In accordance with the D5h point symmetry, the anion shows two singlets at -23.3 and -0.1 ppm with the intensity ratio 2:5 in its 11B NMR spectrum.


2002 ◽  
Vol 67 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Axel Fischer ◽  
Frank T. Edelmann ◽  
Klaus Jacob ◽  
Ivan Pavlík ◽  
Martin Pavlišta

The heterodinuclear complex [W(CO)5(Me2NCH2Fc)] (Fc = ferrocenyl) (1) resulting from the reaction of [(dimethylamino)methyl]ferrocene (2) and [W(CO)6] was studied by single-crystal X-ray diffraction. Its molecular structure confirms the coordination of the amine nitrogen in 2 to tungsten (d(W-N) = 2.359(5) Å) and reveals its trans-influence in the W(CO)5 moiety. The structure is discussed in relation to several previously referred spectroscopic (IR, UV-VIS, 13C NMR) data.


2008 ◽  
Vol 73 (8-9) ◽  
pp. 1161-1176 ◽  
Author(s):  
Vojtech Varga ◽  
Jiří Pinkas ◽  
Ivana Císařová ◽  
Róbert Gyepes ◽  
Karel Mach ◽  
...  

Half-sandwich pentamethylcyclopentadienyltitanium chloroisopropoxides [Ti(η5-C5Me5)-Ti(Oi-Pr)nCl3-n] (n = 1 (1) or 2 (2)) and methylisopropoxides [Ti(η5-C5Me5)Ti(Oi-Pr)nMe3-n] (n = 1 (3) or 2 (4)) were prepared and characterized by spectroscopic methods, and compound 1 by single crystal X-ray diffraction analysis. Compounds 3 and 4 were reacted with an equimolar quantity of B(C6F5)3, however, only compound 4 afforded a crystalline product of limited stability at ambient temperature. Its single crystal X-ray diffraction analysis revealed that it is the zwitterionic complex [(η5-C5Me5)Ti(Oi-Pr)2]+[(μ-Me)B(C6F5)3]- (5) and its crystal structure is very similar to the recently reported tert-butoxy complex [(η5-C5Me5)-Ti(Ot-Bu)2]+[(μ-Me)B(C6F5)3]- (6). The 1H, 13C, and 19F NMR spectra in C6D6 solution also showed the features analogous to those of 6. 1D NOESY experiments proved a close through space interaction of irradiated C5Me5 or OCHMe2 protons with the bridging Ti···Me-B group. The NMR data indicate the inner sphere ion pair structure of 5 in C6D6, like for 6. The crystal structure geometry of the C-H bonds of the Ti···Me-B group fulfils conditions for their agostic interaction with the titanium centre. Although structurally similar to 6, compound 5 is less thermally stable apparently due to a lower bulkiness of Oi-Pr group compared to that of Ot-Bu group.


1984 ◽  
Vol 39 (4) ◽  
pp. 424-430 ◽  
Author(s):  
Elisabeth Hanecker ◽  
Josef Moll ◽  
Heinrich Nöth

Ca(BH4)2·2(CH3OCH2CH2OCH3)2, (1) has been prepared from Ca(BH4)2·2 THF by ligand displacement. IR and NMR data are in agreement with the presence of a nonionic BH4 group, but a specific binding to calcium could not be deduced unambiguously. However, the X-ray structure analysis of a single crystal of 1 reveals that the lattice is built up from molecules of 1 in which each BH4 group binds to Ca via three hydrogen atoms, and the ether forms a chelate. Therefore, calcium in 1 is decacoordinated. Taking the boron atoms as the center of gravity for the BH4 groups one can best describe the coordination as being derived from a strongly distorted octahedron due to repulsive interactions of the BH4 groups as well as of the "bite” of the chelating diether which im poses a O-Ca-O bond angle of ~ 67°.


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