%0 Journal Article %1 Baumann.1999 %A Baumann, F. %A Dormann, E. %A Ehleiter, Y. %A Kaim, W. %A Karcher, J. %A Kelemen, M. %A Krammer, R. %A Saurenz, D. %A Stalke, D. %A Wachter, C. %A Wolmershauser, G. %A Sitzmann, H. %D 1999 %J Journal of Organometallic Chemistry %K bulky carbonyl cobalt complex complex;mol complex;nitrosyl cyclopentadienyl prepn reaction;crystal structure structure;cobalt %N 2 %P 267--283 %R 10.1016/S0022-328X(99)00332-0 %T Structure and reactivity of paramagnetic cyclopentadienyl cobalt complexes with bulky alkyl substituents %V 587 %X Na tetraisopropylcyclopentadienide or Li 1,2,4-tri(tert-butyl)cyclopentadienide reacts with Co(II) chloride in THF to give the corresponding dimers (C5HR4)Co(m-Cl)2 (1a, R = CHMe2) or (C5H2R3-1,2,4)Co(m-Cl)2 (1b, R = CMe3) in good yield. The nitrosyl complexes (C5HR4)Co(m-NO)2 (2a), (C5HR4)Co(m-Cl)(m-NO)Co(C5HR4) (3a), and (C5HR4)Co(NO)Cl (4a) (R = CHMe2) or the tri(tert-butyl)cyclopentadienyl derivs. 2b, 3b, and 4b were obtained from CoCl2, the resp. cyclopentadienide, and nitric oxide. From the disproportionation of 1a or 1b with CO, (C5HR4)Co(m-Cl)3Co(C5HR4)+2Cl2Co(m-Cl)-2 (5a, R = CHMe2) and the dicarbonyl complex (C5HR4)Co(CO)2 (6a, R = CHMe2) or the tri(tert-butyl)cyclopentadienyl derivs. 5b and 6b were isolated. Compds. 6a and 6b were converted to the carbonyl-bridged dimers (C5HR4)Co(m-CO)2 (7a, R = CHMe2) or (C5H2R3-1,2,4)Co(m-CO)2 (7b, R = CMe3) by UV irradn. Compd. 1a was cleaved with MeCN to yield the novel 17 valence electron cation (C5HR4)Co(MeCN)2+ (8, R = CHMe2), which in MeCN soln. could be further oxidized to (C5HR4)Co(MeCN)32+ (9, R = CHMe2) by electrochem. means or chem. with ferrocenium hexafluorophosphate. Compd. 1a gave the neutral 17 VE complex (C5HR4)Co(PMe3)Cl (10, R = CHMe2) with trimethylphosphine, which could be converted to the Me-substituted odd-electron compd. (C5HR4)Co(PMe3)CH3 (11, R = CHMe2) by treatment with MeLi. Hydrolysis of complex 11 proceeded with phosphine loss and gave the hydroxo-bridged dimer (C5HR4)Co(m-OH)2 (12, R = CHMe2). Crystal structure analyses were carried out for 1a, 3b, 5a, 7a, 7b, 8, 10, and 12. For growth of single crystals tetraisopropylcyclopentadiene turned out to be a well-suited solvent. on SciFinder(R)

@article{Baumann.1999, abstract = {Na tetraisopropylcyclopentadienide or Li 1,2,4-tri(tert-butyl)cyclopentadienide reacts with Co(II) chloride in THF to give the corresponding dimers [(C5HR4)Co(\textgreek{m}-Cl)]2 (1a, R = CHMe2) or [(C5H2R3-1,2,4)Co(\textgreek{m}-Cl)]2 (1b, R = CMe3) in good yield. The nitrosyl complexes [(C5HR4)Co(\textgreek{m}-NO)]2 (2a), [(C5HR4)Co(\textgreek{m}-Cl)(\textgreek{m}-NO)Co(C5HR4)] (3a), and [(C5HR4)Co(NO)Cl] (4a) (R = CHMe2) or the tri(tert-butyl)cyclopentadienyl derivs. 2b, 3b, and 4b were obtained from CoCl2, the resp. cyclopentadienide, and nitric oxide. From the disproportionation of 1a or 1b with CO, [(C5HR4)Co(\textgreek{m}-Cl)3Co(C5HR4)]+2[Cl2Co(\textgreek{m}-Cl)]-2 (5a, R = CHMe2) and the dicarbonyl complex [(C5HR4)Co(CO)2] (6a, R = CHMe2) or the tri(tert-butyl)cyclopentadienyl derivs. 5b and 6b were isolated. Compds. 6a and 6b were converted to the carbonyl-bridged dimers [(C5HR4)Co(\textgreek{m}-CO)]2 (7a, R = CHMe2) or [(C5H2R3-1,2,4)Co(\textgreek{m}-CO)]2 (7b, R = CMe3) by UV irradn. Compd. 1a was cleaved with MeCN to yield the novel 17 valence electron cation [(C5HR4)Co(MeCN)2]+ (8, R = CHMe2), which in MeCN soln. could be further oxidized to [(C5HR4)Co(MeCN)3]2+ (9, R = CHMe2) by electrochem. means or chem. with ferrocenium hexafluorophosphate. Compd. 1a gave the neutral 17 VE complex [(C5HR4)Co(PMe3)Cl] (10, R = CHMe2) with trimethylphosphine, which could be converted to the Me-substituted odd-electron compd. [(C5HR4)Co(PMe3)CH3] (11, R = CHMe2) by treatment with MeLi. Hydrolysis of complex 11 proceeded with phosphine loss and gave the hydroxo-bridged dimer [(C5HR4)Co(\textgreek{m}-OH)]2 (12, R = CHMe2). Crystal structure analyses were carried out for 1a, 3b, 5a, 7a, 7b, 8, 10, and 12. For growth of single crystals tetraisopropylcyclopentadiene turned out to be a well-suited solvent. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Baumann, F. and Dormann, E. and Ehleiter, Y. and Kaim, W. and Karcher, J. and Kelemen, M. and Krammer, R. and Saurenz, D. and Stalke, D. and Wachter, C. and Wolmershauser, G. and Sitzmann, H.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2d4bdbecf008b9138ce67042ed232b7dd/huebleriac}, doi = {10.1016/S0022-328X(99)00332-0}, interhash = {8f33229f00072d1fc2ec608824c63019}, intrahash = {d4bdbecf008b9138ce67042ed232b7dd}, journal = {Journal of Organometallic Chemistry}, keywords = {bulky carbonyl cobalt complex complex;mol complex;nitrosyl cyclopentadienyl prepn reaction;crystal structure structure;cobalt}, number = 2, pages = {267--283}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Structure and reactivity of paramagnetic cyclopentadienyl cobalt complexes with bulky alkyl substituents}, volume = 587, year = 1999 }