2018, Dong, Kaiwu, Sang, Rui, Wei, Zhihong, Liu, Jie, Dühren, Ricarda, Spannenberg, Anke, Jiao, Haijun, Neumann, Helfried, Jackstell, Ralf, Franke, Robert, Beller, Matthias

Mechanistic studies of the catalyst [Pd2(dba)3/1,1′-bis(tert-butyl(pyridin-2-yl)phosphanyl)ferrocene, L2] for olefin alkoxycarbonylation reactions are described. X-ray crystallography reveals the coordination of the pyridyl nitrogen atom in L2 to the palladium center of the catalytic intermediates. DFT calculations on the elementary steps of the industrially relevant carbonylation of ethylene (the Lucite α-process) indicate that the protonated pyridyl moiety is formed immediately, which facilitates the formation of the active palladium hydride complex. The insertion of ethylene and CO into this intermediate leads to the corresponding palladium acyl species, which is kinetically reversible. Notably, this key species is stabilized by the hemilabile coordination of the pyridyl nitrogen atom in L2. The rate-determining alcoholysis of the acyl palladium complex is substantially facilitated by metal-ligand cooperation. Specifically, the deprotonation of the alcohol by the built-in base of the ligand allows a facile intramolecular nucleophilic attack on the acyl palladium species concertedly. Kinetic measurements support this mechanistic proposal and show that the rate of the carbonylation step is zero-order dependent on ethylene and CO. Comparing CH3OD and CH3OH as nucleophiles suggests the involvement of (de)protonation in the rate-determining step.

2010, Beweries, T., Spannenberg, A., Rosenthal, U.

C41H61HfN2, monoclinic, P21/n (no. 14), a = 13.4410(4) Å, b = 13.9983(6) Å, c = 21.1996(8) Å, β = 98.144(3)°, V = 3948.5 Å3, Z = 4, Rgt(F) = 0.051, wRref(F2) = 0.121,T = 200 K. © 2014 Oldenbourg Wissenschaftsverlag, München.

2008, Spannenberg, A., Burlakov, V.V., Rosenthal, U.

C54.50H51BF15O2Ti, triclinic, P1̄ (no. 2), a = 11.603(2) Å, b = 12.872(3) Å, c = 18.142(4) Å, α = 76.47(3)°, β = 77.99(3)°, γ = 69.13(3)°, V = 2438.2 Å5, Z = 2, Rgt(F) = 0.048, wRobs(F2) = 0.114, T = 200 K. © by Oldenbourg Wissenchaftsverlag.

2009, Boualy, B., el Firdoussi, L., Ali, M.A., Karim, A., Spannenberg, A.

C12H16Cl6, orthorhombic, P2 12121 (no. 19), a = 6.0742(3) Å, b = 9.7189(6) Å, c = 26.700(1) Å, V = 1576.2 Å3, Z = 4, Rgt(F) = 0.019, wRref(F2) = 0.045, T= 200 K. © by Oldenbourg Wissenschaftsverlag.

2010, Klahn, M., Spannenberg, A., Rosenthal, U.

C44H78HfPSi2, tetragonal, P4 1212 (no. 92), a = 14.9634(2) Å, c = 44.9270(8) Å, V = 10059.3 Å3, Z = 8, Rgt(F) = 0.026, wRref(F2) = 0.073, T = 200 K. © by Oldenbourg Wissenschaftsverlag, München.

2009, Lamač, M., Spannenberg, A., Arndt, P., Rosenthal, U.

The title compound, [Ti(C10H15)(C20H 26Si)], was obtained from the reaction of [Ti{5: 1-C5Me4(CH2)}(5-C 5Me5)] with the alkynylsilane PhC2SiMe 2H. The complex crystallizes with two independent mol-ecules in the asymmetric unit, which differ in the conformation of the propenyl unit, resulting in their having opposite helicity. No inter-molecular inter-actions or inter-actions involving the Si- H bond are present. The observed geometrical parameters are unexceptional compared to known structures of the same type.

2009, Peitz, S., Peulecke, N., Müller, B.H., Spannenberg, A., Rosenthal, U.

The title compound, [CrCl2(CH3CN)2(C 26H36N2)]·CH3CN, was synthesized by the reaction of CrCl2(THF)2 with N,N′-bis-(2,6- diisopropyl-phen-yl)ethane-1,2-diimine in dichloro-methane/acetonitrile. The chromium center is coordinated by two N atoms of the chelating diimine ligand, two chloride ions in a trans configuration with respect to each other, and by two N atoms of two acetonitrile mol-ecules in a distorted octa-hedral geometry.

2007, Holz, J., Börner, A., Heller, D., Drexler, H.-J.

C23H32BF4O3P2Rh, orthorhombic, P212121 (no. 19), a = 10.147(2) Å, b = 13.246(3) Å, c = 18.827(4) Å, V = 2530.5 Å3, Z = 4, Rgt(F) = 0.025, wRref(F 2) = 0.067, T = 200 K. © by Oldenbourg Wissenschaftsverlag,.

2010, Kessler, M., Spannenberg, A., Rosenthal, U.

In the title complex mol-ecule, [Ti(C10H15) 2I], the paramagnetic Ti(III) atom is coordinated by two penta-methyl-cyclo-penta-dienyl (Cp*) ligands and one iodide ligand. The two Cp*ligands are in a staggered orientation. The coordination geometry at the titanium atom can be described as distorted trigonal-planar.

2009, El Farrouji, A., el Firdoussi, L., Ali, M.A., Karim, A., Spannenberg, A.

C30H46Cl2Pd2, monoclinic, Cl 21 (no. 5), a = 22.0083(6) Å, b = 6.1827(2) Å, c = 21.5654(7) Å, ß = 91.252(2)°, V = 2933.7 Å3, Z = 4, Rgt(F) = 0.019, wRref(F2) = 0.039, T =200K. © 2014 Oldenbourg Wissenschaftsverlag GmbH, Rosenheimer Str. 145, 81671 München. All rights reserved.