“…The resulting five-coordinate intermediate exchange of H(12 a ) and H(12 b ) may now occur via Berry-type pseudorotational processes. In this respect, it is interesting that slight amounts of Cl - or acetone may also enhance the alkene site-exchange rates of complex 2 , probably via five-coordinate intermediates. − However, intermediates with monodentate ligands are also possible in the light of mounting evidence for N−N ligands. ,, 8 Mechanism for Exchange of the Four N-Atoms in 10 …”
Section: Discussionmentioning
confidence: 99%
“…In this respect, it is interesting that slight amounts of Cl -or acetone may also enhance the alkene site-exchange rates of complex 2, probably via five-coordinate intermediates. [26][27][28][29][30] However, intermediates with monodentate ligands are also possible in the light of mounting evidence for N-N ligands. 24,25,31 When we increase the temperature, intermolecular ligand exchange becomes feasible, but at lower rates than the previous process.…”
Section: Synthesis and Characterization Of [Rhcl(26-(c(h)dn-rmentioning
Reactions of [RhCl(diene)]2 (diene=NBD,COD) with bi-and terdentate nitrogen ligands. X-ray structures of five-coordinate complexes Haarman, H.F.; Bregman, F.R.; Ernsting, J.M.; Veldman, N.; Spek, A.L.; Vrieze, K.
Published in: Organometallics
DOI:10.1021/om960760bLink to publication
Citation for published version (APA):Haarman, H. F., Bregman, F. R., Ernsting, J. M., Veldman, N., Spek, A. L., & Vrieze, K. (1997). Reactions of [RhCl(diene)]2 (diene=NBD,COD) with bi-and terdentate nitrogen ligands. X-ray structures of five-coordinate complexes. Organometallics, 16, 54-67. DOI: 10.1021/om960760b General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons).
Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Reaction of [RhCl(diene)] 2 (diene ) 1,5-cyclooctadiene (COD) or bicyclo[2.2.1] hepta-2,5-diene (NBD)) with the N-N-N nitrogen ligands 2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N in CD 2 Cl 2 or CH 2 Cl 2 yielded the five-coordinate complexes [RhCl(2,6-(C(H)dN-R 2 ) 2 C 5 H 3 N)(diene)] (diene ) NBD; R 2 ) i- Pr, t-Bu, and p-anisyl), which has been isolated for NBD but not for COD. A single-crystal X-ray determination showed that [RhCl(2,6-(C(H)dN-p-anisyl) 2 C 5 H 3 N)(NBD)] has a distorted trigonal bipyramidal configuration with the pyridyl N-atom, one imine N-atom, and one alkene double bond in the equatorial plane, while the second alkene bond and the chloride atom occupy the axial positions. This conformation containing one noncoordinated imine moiety is clearly retained at 183 K in CD 2 Cl 2 , as is also the case for the other complexes. For the COD complexes, the reaction is more complicated, as the intermediates that are observed depend on the substituents R 1 and R 2 of the N-N-N nitrogen ligand. The five-coordinate complexes [RhCl(2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N)(COD)] could be observed at low temperatures for R
IntroductionRecently we reported novel Rh(I) complexes which were able to cleave C-Cl bonds of reagents such as dichloromethane, chloroform, benzyl chloride, and R,Rdichlorotoluene by oxidative addition. 1 By employment of N-N-N nitrogen ligands of the type 2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N (R 1 ) H, R 2 ) i-Pr, t-Bu, cyclohexyl, and p-anisyl; R 1 ) Me, R 2 ) p-anisyl and i-Pr), we succeeded in preparing very nucleophilic and very reactive Rh(I) complexes via reaction of [RhCl(alkene) 2 ] 2 (alkene ) cyclooctene or...
“…The resulting five-coordinate intermediate exchange of H(12 a ) and H(12 b ) may now occur via Berry-type pseudorotational processes. In this respect, it is interesting that slight amounts of Cl - or acetone may also enhance the alkene site-exchange rates of complex 2 , probably via five-coordinate intermediates. − However, intermediates with monodentate ligands are also possible in the light of mounting evidence for N−N ligands. ,, 8 Mechanism for Exchange of the Four N-Atoms in 10 …”
Section: Discussionmentioning
confidence: 99%
“…In this respect, it is interesting that slight amounts of Cl -or acetone may also enhance the alkene site-exchange rates of complex 2, probably via five-coordinate intermediates. [26][27][28][29][30] However, intermediates with monodentate ligands are also possible in the light of mounting evidence for N-N ligands. 24,25,31 When we increase the temperature, intermolecular ligand exchange becomes feasible, but at lower rates than the previous process.…”
Section: Synthesis and Characterization Of [Rhcl(26-(c(h)dn-rmentioning
Reactions of [RhCl(diene)]2 (diene=NBD,COD) with bi-and terdentate nitrogen ligands. X-ray structures of five-coordinate complexes Haarman, H.F.; Bregman, F.R.; Ernsting, J.M.; Veldman, N.; Spek, A.L.; Vrieze, K.
Published in: Organometallics
DOI:10.1021/om960760bLink to publication
Citation for published version (APA):Haarman, H. F., Bregman, F. R., Ernsting, J. M., Veldman, N., Spek, A. L., & Vrieze, K. (1997). Reactions of [RhCl(diene)]2 (diene=NBD,COD) with bi-and terdentate nitrogen ligands. X-ray structures of five-coordinate complexes. Organometallics, 16, 54-67. DOI: 10.1021/om960760b General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons).
Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Reaction of [RhCl(diene)] 2 (diene ) 1,5-cyclooctadiene (COD) or bicyclo[2.2.1] hepta-2,5-diene (NBD)) with the N-N-N nitrogen ligands 2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N in CD 2 Cl 2 or CH 2 Cl 2 yielded the five-coordinate complexes [RhCl(2,6-(C(H)dN-R 2 ) 2 C 5 H 3 N)(diene)] (diene ) NBD; R 2 ) i- Pr, t-Bu, and p-anisyl), which has been isolated for NBD but not for COD. A single-crystal X-ray determination showed that [RhCl(2,6-(C(H)dN-p-anisyl) 2 C 5 H 3 N)(NBD)] has a distorted trigonal bipyramidal configuration with the pyridyl N-atom, one imine N-atom, and one alkene double bond in the equatorial plane, while the second alkene bond and the chloride atom occupy the axial positions. This conformation containing one noncoordinated imine moiety is clearly retained at 183 K in CD 2 Cl 2 , as is also the case for the other complexes. For the COD complexes, the reaction is more complicated, as the intermediates that are observed depend on the substituents R 1 and R 2 of the N-N-N nitrogen ligand. The five-coordinate complexes [RhCl(2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N)(COD)] could be observed at low temperatures for R
IntroductionRecently we reported novel Rh(I) complexes which were able to cleave C-Cl bonds of reagents such as dichloromethane, chloroform, benzyl chloride, and R,Rdichlorotoluene by oxidative addition. 1 By employment of N-N-N nitrogen ligands of the type 2,6-(C(R 1 )dN-R 2 ) 2 C 5 H 3 N (R 1 ) H, R 2 ) i-Pr, t-Bu, cyclohexyl, and p-anisyl; R 1 ) Me, R 2 ) p-anisyl and i-Pr), we succeeded in preparing very nucleophilic and very reactive Rh(I) complexes via reaction of [RhCl(alkene) 2 ] 2 (alkene ) cyclooctene or...
“…This process is often observed in Rh(I)−diolefin complexes. It has been proposed to occur by a Berry mechanism in pentacoordinated intermediates formed by coordination of coordinating solvents or anions such as BF 4 - . Other authors propose a different mechanism involving intermediates with a monodentate P,N-ligand .…”
The stereochemistry of the chelate rings of a number of rhodium aminophosphine complexes is studied by NMR spectroscopy. The similarity in the variable-temperature behavior for the different compounds is consistent with them having in common highly preferred chelate ring conformations. The six-membered metallacycle of coordinated (R)-PN (PN = o-diphenylphosphino-alpha-methyl-N,N-dimethylbenzylamine) adopts a delta conformation in the solid state. NMR experiments indicate that this conformation is strongly favored in solution as well. The preferred sense of helicity is imposed by the absolute configuration of the stereogenic carbon atom on the ligand, which exerts an important steric control. The complex [Rh(TFB)((C(6)H(4)CHMeNMe(2))(2)P(C(6)H(4)CHMeNHMe(2)))](BF(4))(2).H(2)O.Me(2)CO crystallizes in the monoclinic space group P2(1) with a = 12.0548(11) A, b = 16.139(2) A, c = 12.1804(10) A, beta = 100.742(9) degrees, Z = 4.
Keywords: Alkenes / Hydrogenations / N ligands / Phosphanes / RhodiumThe reaction of [Rh 2 (µ-Cl) 2 (COD) 2 ] (COD = 1,5-cyclooctadiene) or [Rh 2 (µ-Cl) 2 (TFB) 2 ] (TFB = tetrafluorobenzobicyclo[2.2.2]octatriene) with the N-donor chelating ligand OP-Py 2 Ph (Py = 2-pyridyl) in the presence of TlBF 4 affords cationic complexes [Rh(diene)(OPPy 2 Ph)](BF 4 ) (1, diene: COD; 2, diene: TFB). Compounds 1 or 2 react with CO to give [Rh(CO) 2 (OPPy 2 Ph)](BF 4 ) (4), which is also obtained by treatment of [Rh 2 (µ-Cl) 2 (CO) 4 ] with OPPy 2 Ph and TlBF 4 . In a similar way, the complexes [Rh(diene)(OPPy 3 )](BF 4 ) (5, diene: COD; 6, diene: TFB) are obtained when using OPPy 3 ; they react with CO to give [Rh 2 (µ-CO) 3 (OPPy 3 ) 2 ](BF 4 ) 2 (9). The [a] 289 behavior of the complexes in solution is reported. The complexes with OPPy 3 , 5 and 6, show equivalence of the three Py groups in their NMR spectra. Complex 5 is square-planar in the solid state, and in solution, and the uncoordinated and coordinated Py groups undergo fast exchange in solution. Complex 6 is pentacoordinated in the solid state and in solution, and its Py groups exchange their coordination sites in a fast topomerization process. The single-crystal X-ray structures of 5 and 6 have been solved. The behavior of 1 and 5 as catalysts in hydrogenation reactions of cyclohexene, acetone, and cyclohexanone is also reported.
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