Electrophilic Ln(III) Cations Protected by C–F → Ln Interactions and Their Coordination Chemistry with Weak σ- and π-Donors

Abstract

A homoleptic cerium(III) amide complex, Ce(NPh(F)2)3 (1-Ce) (Ph(F) = pentafluorophenyl), in an unusual pseudo-trigonal planar geometry featuring six C-F → Ce interactions was prepared. The C-F → Ln interactions in solution were evident by comparison of the (19)F NMR shifts for the paramagnetic 1-Ce with those of the 4f(0) lanthanum(III) analogue. Coordination of weak σ- and π-donors, including ethers and neutral arene molecules, was achieved by the reversible displacement of the weak C-F → Ce interactions. Computational studies on Ce(NPh(F)2)3 and Ce(NPh(F)2)3(η(6)-C6H3Me3) provide information on the F → Ce interactions and Ce-η(6)-arene bonding.

Cerium(III/IV) Formamidinate Chemistry, and a Stable Cerium(IV) Diolate

“…Thus, cerium has a formal coordination number of ten. The CeF distances in complex 3 are longer than those reported for other ligand systems which also show o ‐FCe coordination,16a,b such as the eight‐coordinate cerium diaminate complex tris( N,N′ ‐diethyl‐ N′ ‐2,3,5,6‐tetrafluorophenylethane‐1,2‐diaminato)cerium(III), which displays three shorter CeF interactions at 2.686, 2.764, and 2.779 Å and has good thermal stability 16a. Investigations into a potential CF bond activation of the coordinating fluorine atoms in complex 3 has not yet been undertaken.…”

Modulation der Koordinationssphäre von f‐Element‐Komplexen durch Fluorkohlenwasserstoffe

“…Der von der gleichen Arbeitsgruppe8b hergestellte Komplex [La{N(C 6 F 5 ) 2 } 3 ] ist ein interessantes Beispiel für die Vielseitigkeit der R‐F→M‐Wechselwirkung. In dieser Struktur stellt jedes perfluorierte Amid zwei intramolekulare F→La‐Kontakte zur Verfügung.…”

Lanthanides and actinides: Annual survey of their organometallic chemistry covering the year 2013

“…Computational studies on Ce[N(C 6 F 5 ) 2 ] 3 and Ce[N(C 6 F 5 ) 2 ] 3 ( 6 -C 6 H 3 Me 3 ) (Fig. 3) provided information on the F → Ce interactions and Ce-6 -arene bonding [82].…”