TY - JOUR
T1 - Synthesis and Characterization of Chelating Alkyl-borohydride Complexes of Thorium and Uranium
T2 - Th(CH2NMe2BH3)4 and U(CH2NMe2BH3)4
AU - Lastowski, R. Joseph
AU - Caroff, Christopher M.
AU - Vogiatzis, Konstantinos D.
AU - Girolami, Gregory S.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/10/9
Y1 - 2023/10/9
N2 - This paper describes the synthesis and characterization of two actinide alkyls: thorium and uranium compounds of stoichiometry M(CH2NMe2BH3)4 (M = Th, U) where CH2NMe2BH3- is the boronatodimethylaminomethyl group (abbreviated BDAM). The crystal structures of these compounds show that the coordination geometry of the metal center can be described in terms of a D2d dodecahedron, whose eight vertices are defined by the four metal-bound carbon atoms and the four boron atoms of the BH3 groups. Two of the BH3 groups in each compound bind to the metal centers in a κ2 fashion (i.e., by means of two B-H-M bridges) and two in a κ1 fashion. Thus, both compounds can also be described as ten-coordinate in which four carbon atoms and six hydrogen atoms form the inner coordination sphere. The structures of both complexes and the nature of the BH3-M interactions were investigated computationally. The NMR spectra of the diamagnetic thorium(IV) compound and paramagnetic uranium(IV) compound are discussed; both compounds are fluxional in solution even at −124 °C. Variable temperature magnetization studies of the paramagnetic uranium(IV) compound in the solid state are consistent with its tetravalent oxidation state.
AB - This paper describes the synthesis and characterization of two actinide alkyls: thorium and uranium compounds of stoichiometry M(CH2NMe2BH3)4 (M = Th, U) where CH2NMe2BH3- is the boronatodimethylaminomethyl group (abbreviated BDAM). The crystal structures of these compounds show that the coordination geometry of the metal center can be described in terms of a D2d dodecahedron, whose eight vertices are defined by the four metal-bound carbon atoms and the four boron atoms of the BH3 groups. Two of the BH3 groups in each compound bind to the metal centers in a κ2 fashion (i.e., by means of two B-H-M bridges) and two in a κ1 fashion. Thus, both compounds can also be described as ten-coordinate in which four carbon atoms and six hydrogen atoms form the inner coordination sphere. The structures of both complexes and the nature of the BH3-M interactions were investigated computationally. The NMR spectra of the diamagnetic thorium(IV) compound and paramagnetic uranium(IV) compound are discussed; both compounds are fluxional in solution even at −124 °C. Variable temperature magnetization studies of the paramagnetic uranium(IV) compound in the solid state are consistent with its tetravalent oxidation state.
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U2 - 10.1021/acs.organomet.3c00306
DO - 10.1021/acs.organomet.3c00306
M3 - Article
AN - SCOPUS:85172875977
SN - 0276-7333
VL - 42
SP - 2839
EP - 2848
JO - Organometallics
JF - Organometallics
IS - 19
ER -