Prof. Dr. Ulrich Behrens

Organyls of the alkali and alkaline earth metals (electropositive metals of the 1st and 2nd group)

This research area deals with the synthesis and structural elucidation of simple and complex organyls of the above-mentioned electropositive main group metals. The important negatively charged organic carbanions cyclopentadienide, pentamethylcyclopentadienide, indenide and fluorenide are used as organyls (Fig. 1).

Abb. 1

Aza analogues such as pyrrolide, pyrazolid and indolide are also investigated as negatively charged organyls (Fig. 2).

Abb. 2

The structures of the simple, solvate-free alkali metal cyclopentadienides and some - pentamethylcyclopentadienides, -indenides and -fluorenides have already been elucidated by us by means of high-resolution powder diffraction (synchrotron radiation) (see publications 1 - 3, 5, 7 and 9 below). In particular, macrocyclic polyethers such as 18-crown-6, 15-crown-5 and 12-crown-4 are used for the synthesis of complex organyls of the metals mentioned (Fig. 3). More details can be found in publications 6, 8, 10 and 13 to 15.

Abb. 3

Solid State Structures of Binary Copper Organics

This research project will lead to the elucidation of the solid-state structures of base-free copper organyls. The compounds are investigated using the powder diffraction method with high-intensity, high-resolution synchrotron radiation. Currently, work is being done on the structure determination of the following base-free binary copper organyls: Methyl copper (CuMe), cyclopentadienyl copper (CuCp), copper pyrrolide (CuNC₄H₄), phenyl copper (CuPh), copper acetylide (CuC≡CCu), vinyl copper (CuCH=CH₂), copper methoxide (CuOMe) and copper phenoxide (CuOPh).

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1. Ab Initio Structure Determination of Two Polymorphs of Cyclopentadienylrubidium in a Single Powder Pattern
R. E. Dinnebier, F. Olbrich, S. van Smaalen, P. W. Stephens
Acta Crystallogr. B53 (1997) 153 - 158.

2. Cyclopentadienylcaesium by High Resolution X-ray Powder Diffraction
R. E. Dinnebier, F. Olbrich, G. M. Bendele
Acta Crystallogr. C53 (1997) 699 - 701.

3. Solid State Structures of Cyclopentadienyllithium. -sodium, and -potassium. Determination by High-Resolution Powder Diffraction
R. E. Dinnebier, U. Behrens, F. Olbrich
Organometallics 16 (1997) 3855 - 3858.

4. Crystal structure of catena-cyclopentadienyl thallium, [Tl(C₅H₅)]
F. Olbrich, U. Behrens
Z. Kristallogr. 212 (1997) 47.

5. Disorder determined by High Resolution Powder Diffraction: The Structure of Pentamethylcyclopentadienyllithium
R. E. Dinnebier, M. Schneider, S. van Smaalen, F. Olbrich, U. Behrens
Acta Crystallogr. B55 (1999) 35 - 44.

6. Cyclopentadienyl, Indenyl, Fluorenyl, and Pentamethylcyclopentadienyl Complexes of Potassium with 18-Crown-6
S. Neander, F. E. Tio, R. Buschmann, U. Behrens, F. Olbrich
J. Organomet. Chem. 582 (1999) 58 - 65.

7. Solid State Structures of Base-Free Indenyllithium and Fluorenylsodium
R. E. Dinnebier, S. Neander, U. Behrens, F. Olbrich
Organometallics 18 (1999) 2915 - 2918.

8. Novel 18-Crown-6 Organometallic Rubidium and Cesium Complexes Containing Cyclopentadienyl, Indenyl, Pentamethylcyclopentadienyl, and Fluorenyl as Carbanions
S. Neander, U. Behrens, F. Olbrich
J. Organomet. Chem. 604 (2000) 59 - 67.

9. Disordered crystal structure of pentamethylcyclopentadienylsodium as seen by high-resolution X-ray powder diffraction
C. Tedesco, R. E. Dinnebier, F. Olbrich, S. van Smaalen
Acta Crystallogr. B57 (2001) 673 - 679.

10. Cyclopentadienyl, indenyl, and fluorenyl complexes of sodium with 15-crown-5
T. Kähler, U. Behrens, S. Neander, F. Olbrich
J. Organomet. Chem. 649 (2002) 50 -54.

11. Novel fluorenyl alkali metal DIGLYME complexes: synthesis and solid state structures
S. Neander, J. Körnich, F. Olbrich
J. Organomet. Chem. 656 (2002) 89 - 96.

12. Synthesis and Structure of [Mg(dmso)₆](C₅H₅)₂ and [Mg(η¹-C₅H₅)(η⁵-C₅H₅)(thf)₂]
A. Jaenschke, J. Paap, U. Behrens
Organometallics 22 (2003) 1167-1169.

13. Strukturen der Alkalimetallsalze aromatischer, heterocyclischer Amide: Synthese und Struktur von Kronenether-Addukten der Alkalimetall-indolide
I. Heldt, T. Borrmann, U. Behrens
Z. Anorg. Allg. Chem 629 (2003) 1980-1985.

14. Polymeric and Monomeric Barocene: Synthesis and Structure of Ba(C₅H₅)₂ * DMSO and Ba(C₅H₅)₂(18-crown-6) (DMSO=dimethylsulfoxide)
K. Fichtel, K. Hofmann, U. Behrens
Organometallics 23 (2004) 4166-4168.

15. Strukturen der Alkalimetallsalze aromatischer, heterocyclischer Amide: Synthese und Struktur von Kronenether-Addukten der Alkalimetall-pyrrolide
I. Heldt, U. Behrens
Z. Anorg. Allg. Chem 630 (2005) im Druck.