RT info:eu-repo/semantics/article
T1 Group 4 Half-Sandwich Tris(trimethylsilylmethyl) Complexes: Thermal Decomposition and Reactivity with N,N¿Dimethylamine-Borane.
A1 Greño Ocariz, Maider
A1 Horno Martín, Estefanía del
A1 Mena Montoro, Miguel
A1 Pérez Redondo, Adrián
A1 Varela Izquierdo, Víctor
A1 Yélamos Sánchez, Carlos
K1 Química
K1 Chemistry
AB The thermal decomposition of group 4 trimethylsilylmethyl derivatives [M(eta5-C5Me5)(CH2SiMe3)3] (M = Ti (1), Zr (2), Hf (3)) in solution and their reactivity with N,N-dimethylamine-borane were investigated. Heating of hydrocarbon solutions of compounds 2 and 3 at 130?200 °C results in the elimination of SiMe4 and the clean formation of the singular alkylidene-alkylidyne zirconium and hafnium compounds [{M(eta5-C5Me5)}3{(mu-CH)3SiMe}(mu3-CSiMe3)] (M = Zr (4), Hf (5)). The reaction of 2 and 3 with NHMe2BH3 (?1 equiv) at room temperature affords the dialkyl(dimethylamidoborane) complexes [M(eta5-C5Me5)(CH2SiMe3)2(NMe2BH3)] (M = Zr (6), Hf (7)). Compounds 6 and 7 are unstable in solution and decompose with formation of the alkyl(dimethylamino)borane [B(CH2SiMe3)H(NMe2)] (8), SiMe4, and other minor byproducts, including the tetranuclear zirconium(III) octahydride complex [{Zr(eta5-C5Me5)}4(mu-H)8] (9) in the decomposition of 6. Addition of NHMe2BH3 to the titanium tris(trimethylsilylmethyl) derivative 1 gives the trinuclear mixed valence Ti(II)/Ti(III) tetrahydride complex [{Ti(eta5-C5Me5)(mu-H)}3(mu3-H)(mu3-NMe2BH2)] (10) at 45?65 °C. While the complete conversion of 1 under argon atmosphere requires excess NHMe2BH3 (up to 15 equiv), complex 10 is readily prepared with 3 equiv of NHMe2BH3 under a hydrogen atmosphere indicating that the formation of 10 involves hydrogenolysis of 1 in the presence of (NMe2BH2)2. In absence of amine?borane, the reaction of 1 with H2 leads to the tetranuclear titanium(III) octahydride [{Ti(eta5-C5Me5)}4(mu-H)8] (11), which upon addition of NHMe2BH3 and subsequent heating at 65 °C affords complex 10. The X-ray crystal structures of 2, 4, 5, 10, and 11 were determined.
SN 0020-1669
YR 2017
FD 2017-09-18
LK http://hdl.handle.net/10017/50004
UL http://hdl.handle.net/10017/50004
LA eng
NO Este artículo se publicó como open access article dentro de la revista, tras el pago que exigía la editorial.
NO Ministerio de Economía y Competitividad de España, Universidad de Alcalá
DS MINDS@UW
RD 25-abr-2024