| 1 | Author
| Bernd Wrackmeyer, Udo Dörfler, Wolfgang Milius, Max Herberhold | Requires cookie* | | Title
| Triferrocenylborane -Molecular Structure in Solution and in the Solid State  | | | Abstract
| 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 [P 2 Jc\ monoclinic; Z = 4; a = 1353.5(3), b = 1695.6(3), c = 1056.4(2) pm, ß = 109.27(3)°]. The simu lated X-ray powder pattern of the single crystal is identical with the powder diagram o f a macroscopic sample, indicating the presence of a single diastereomer (l a) in the solid state. How ever, at low temperature (< -9 5 °C) in solution, the 13C NM R spectra suggest the pres ence of the second diastereomer (lb) in which one ferrocenyl group is oriented opposite to the other two with respect to the central BC3-plane. | | |
Reference
| Z. Naturforsch. 50b, 201—2 (1995); received July 25 1994 | | |
Published
| 1995 | | |
Keywords
| Triferrocenylborane, 13C NMR Spectra, Dynamic Processes, X-Ray | | |
Similar Items
| Find | | DEBUG INFO
| | | | TEI-XML for
| default:Reihe_B/50/ZNB-1995-50b-0201.pdf | | | Identifier
| ZNB-1995-50b-0201 | | | Volume
| 50 | |
2 | Author
| C. P., R. S. Tu D, Wolfgang Baumann, Yuri Oprunenko, Harald Günther | Requires cookie* | | Title
| D  | | | Abstract
| y n a m ic B e h a v io u r o f T e tra m e th y le th y le n e D ia m in e (T M E D A) L ig a n d s in S o lid O r g a n o lith iu m C o m p o u n d s : A V a r ia b le T e m p e r a tu r e 13C a n d 15N Dedicated to Professor Dr. W . Müller-Warmuth on the occasion of his 65th birthday The dynamic behaviour of tetramethylethylene diamine (TMEDA) ligands in three organometallic complexes, dimeric phenyllithium, [Li(tmeda)/*-Ph]2 (1), lithium cyclopentadienide, [Li(tmeda)]C5H5 (2), and dilithium naphthalendiide, trans-[Li(tmeda)]2C10H8 (3), has been studied by CP/MAS 13C and 15N as well as 7Li MAS NMR spectroscopy of powdered samples. Two dynamic processes with free activation enthalpies of 40 and 68 kJ mol-1, respectively, were detected for 1. The first one can be assigned to ring inversion of the five-membered Li-TMEDA rings, while the second is caused by a complete rotation of the TMEDA ligands or a ring inversion of the central four-membered C-Li-C-Li metallacycle. Fast rotation of the ligands on the NMR time scale was found for 2, while 3 shows 180° ring flips of the Li-TMEDA groups, which are characterized by an energy barrier AG" (317) of 64 kJ mol-1. | | |
Reference
| Z. Naturforsch. 50a, 429—438 (1995); received November 8 1994 | | |
Published
| 1995 | | |
Keywords
| CP/MAS NMR, 13C-NMR, 15N-NMR, 7Li NMR, dynamic processes, organometallics | | |
Similar Items
| Find | | DEBUG INFO
| | | | TEI-XML for
| default:Reihe_A/50/ZNA-1995-50a-0429.pdf | | | Identifier
| ZNA-1995-50a-0429 | | | Volume
| 50 | |
|