Facile Entrapment of a Hydride inside the Tetracapped Tetrahedral CuI8 Cage Inscribed in a S12 Icosahedral Framework

Reaction of [Cu(CH3CN)4](PF6) and NH4[S2P(OR)2] in a 4:3 ratio in acetone at room temperature produces octanuclear dicationic copper complexes [Cu8{S2P(OR)2}6](PF6)2 (R = iPr, 1; Et, 3) in 81 and 83% yields, respectively. On the other hand, reaction of [Cu(CH3CN)4](PF6), NH4[S2P(OR)2], and NaBH4 in an 8:6:1 molar ratio in THF for 1 h yields [Cu4(H)(μ3-Cu)4{S2P(OR)2}6](PF6) (R = iPr, 2a; Et, 4a) in 87 and 82% yields, respectively. In a similar reaction when NaBD4 is used instead of NaBH4, [Cu4(D)(μ3-Cu)4{S2P(OR)2}6](PF6) (R = iPr, 2b; Et, 4b) are obtained in 83 and 78% yields, respectively. Structural elucidations of 2a and 4a reveal the tetracapped tetrahedral Cu8 cage with an interstitial hydride. Each of the Cu(I) centers is trigonally coordinated by three S atoms, and each of the six dithiophosphate ligands is connected to a Cu4 butterfly, where the hinge positions are occupied by two copper atoms situated at the vertex of the central tetrahedron and the wingtips are two capping Cu atoms. The 12 S atom...