Highly fluorinated tris(indazolyl)borate hydrocarbyl complexes of calcium and magnesium: Synthesis and structural studies

Nuria Romero (1, 2) , Quentin Dufrois (1, 2) , Laure Vendier (1) , Chiara Dinoi (1, 2) , Michel Etienne (1, 2)

1 LCC - Laboratoire de chimie de coordination
2 UT3 - Université Toulouse III - Paul Sabatier

Heteroleptic phenylacetylide complexes [F12-Tp4Bo,3PhAe(C≡CPh)]x of calcium (Ae = Ca, x = 2; 2) and magnesium (Ae = Mg, x = 1; 4) containing the highly fluorinated 3-phenyl hydrotris(indazolyl)borate F12-Tp4Bo,3Ph− ligand have been synthesized by acid–base reactions between the corresponding silylamido derivatives [F12-Tp4Bo,3PhAeN(SiRMe2)2] (R = Me, Ae = Ca (1); R = H, Ae = Mg (3)) and PhC≡CH. Compounds 2 and 4 have been characterized by NMR spectroscopy and X-ray diffraction analysis. 2 crystallizes as a dinuclear complex, showing two nonsymmetrical “side-on” (π-type) interactions between the acetylide units and the Ca centers, whereas 4 crystallizes as a mononuclear complex, displaying a four-coordinate magnesium. The molecular structure of the complex [F12-Tp4Bo,3PhMgN(SiMe2H)2] (3), obtained by the salt metathesis reaction between [MgN(SiMe2H)22] and [TlF12-Tp4Bo,3Ph], is also reported. 3 is also four-coordinate and exhibits a Mg···β-Si–H agostic distortion. The synthesis and in situ characterization of the heteroleptic alkyl complex [F12-Tp4Bo,3PhCaCH(SiMe3)2(THF)] (5) is also reported, although attempts to isolate this compound failed due to its extreme sensitivity to temperature.

Domaines: Chimie de coordination

Nuria Romero, Quentin Dufrois, Laure Vendier, Chiara Dinoi, Michel Etienne. Highly fluorinated tris(indazolyl)borate hydrocarbyl complexes of calcium and magnesium: Synthesis and structural studies. Organometallics, 2017, 36 (3), pp.564-571. ⟨10.1021/acs.organomet.6b00783⟩. ⟨hal-01939581⟩