title: Highly fluorinated hydrotris(indazolyl)borate calcium complexes: the structure and reactivity heavily depend on the ligand's electronic properties.
abstract: Two series of highly fluorinated 3-substituted hydrotris(indazolyl)borate (Fn-Tp(4Bo,3R); R = Ph, n = 12; R = CF3, n = 21) complexes of calcium were synthesized by salt metathesis reactions. CaI2 reacts with 2 and 1 equiv. of Tl(F12-Tp(4Bo,3Ph)) in THF to form the homo- and heteroleptic complexes [Ca(F12-Tp((4Bo,3Ph)*))2] (1) and [(F12-Tp(4Bo,3Ph))CaI(THF)] (2), respectively. 1 has C2h symmetry due to a 1,2-borotropic shift. The reaction of CaI2 with 2 equiv. of the more electron poor Tl(F21-Tp(4Bo,3CF3)) in THF, on the other hand, leads to the salt [Ca(THF)6][F21-Tp(4Bo,3CF3)]2 (3), with [F21-Tp(4Bo,3CF3)] acting as a counter-ion. This emphasizes the tuning ability of Fn-Tp(4Bo,3R) ligands and the consequences on their ability to bind hard electrophilic Ca(2+) centers.
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination), BP 44099, 205 route de Narbonne, F-31077 Toulouse Cedex 4, France. chiara.dinoi@lcc-toulouse.fr michel.etienne@lcc-toulouse.fr.
authors.forename: Nuria
authors.initials: N
authors.lastname: Romero
authors.forename: Laure
authors.initials: L
authors.lastname: Vendier
authors.forename: Chiara
authors.initials: C
authors.lastname: Dinoi
authors.forename: Michel
authors.initials: M
authors.lastname: Etienne