Formation of a Cationic Calcium Hydride Cluster with
a “Naked” Triphenylsilyl Anion by Hydrogenolysis of
Bis(triphenylsilyl)calcium
- Publication date
- Publisher
Abstract
Protonolysis of bis(triphenylsilyl)calcium
[Ca(SiPh<sub>3</sub>)<sub>2</sub>(THF)<sub>4</sub>] (<b>1</b>; THF = tetrahydrofuran) with the NNNN-type macrocyclic amido triamine
(Me<sub>3</sub>TACD)H (TACD = 1,4,7-triazacyclododecane) gave the
heteroleptic calcium complex [Ca(Me<sub>3</sub>TACD)SiPh<sub>3</sub>] (<b>2</b>) in quantitative yield. Hydrogenolysis of <b>2</b> gave the cationic tricalcium dihydride cluster [Ca<sub>3</sub>H<sub>2</sub>(Me<sub>3</sub>TACD)<sub>3</sub>]<sup>+</sup>(SiPh<sub>3</sub>)<sup>−</sup>·2THF (<b>4a</b>) in high yield
with concomitant formation of HSiPh<sub>3</sub>. In the crystal, <b>4a</b> consists of a cluster cation and a free triphenylsilyl
anion. <sup>1</sup>H NMR spectroscopy and deuterium labeling experiments
confirmed the selective cleavage of dihydrogen by the highly polar
Ca–Si bond in <b>1</b>
