Co-ordination of alkali metals to sulfur-based organometallic ligands: 133Cs and 19F nuclear magnetic resonance studies of Cs[Mo(SC6F5)4(η5-C5H5)], the first example of caesium–fluorine spin–spin coupling

Abstract

Reactions of the complexes [Mol₃(CO)₂(η⁵-C₅H₅)] and [W(SC₆F₅)₃(CO)(η⁵-C₅H₅)] with M′(SC₆F₅) give Cs[Mo(SC₆F₅)₄(η⁵-C₅H₅)], M′[W(SC₆F₅)₄(η⁵-C₅H₅)](M′= Cs, Rb or K) and solvated derivatives (M = Mo or W) M′[W(SC₆F₅)₄(η⁵-C₅H₅)]·nthf (M′= Li, n= 4; or Na, n= 1); ¹³³Cs and ¹⁹F NMR studies of Cs[M(SC₆F₅)₄(η⁵-C₅H₅)] reveal co-ordination between the Cs⁺ and the organometallic anion and Cs–F coupling involving four o-fluorines of the SC₆F₅ groups, J(Cs–F)≈ 58 Hz.