Cu[Al(OR^F)₄] Starting Materials and their Application in the Preparation of [Cu(S_<i>n</i>)]⁺ (<i>n</i>=12, 8) Complexes

Abstract

Abstract Naked copper…︁? A newly developed simple two‐step route to weakly coordinated Cu I starting materials that were used to prepare novel copper–cyclosulfur adducts, including the first M + –S 12 complex (see figure, R F = C(CF 3 ) 3 , C(CH 3 )(CF 3 ) 2 , or CH(CF 3 ) 2 ). Reactions with the [Al{OC(CF 3 ) 3 } 4 ] − counterion mimic gas‐phase chemistry inside a mass spectrometer (to form [Cu(S 12 )] + ). magnified image An effective route to stable, almost‐“naked” Cu I salts of weakly coordinating anions (WCAs) of the type [Al(OR F ) 4 ] − has been developed. Born–Fajans–Haber cycles and theoretical calculations suggest that this methodology is useful for the generation of Cu I salts regardless of the larger WCA used. The first homoleptic Cu I –arene complex [Cu(1,2‐F 2 C 6 H 4 ) 2 ] + [Al{OC(CF 3 ) 3 } 4 ] − ( 1 ), the first Cu I –methylenechloride complex [Cu(CH 2 Cl 2 )Al{OC(CH 3 )(CF 3 ) 2 } 4 ] ( 2 ), and the donor‐free dimer [CuAl{OCH(CF 3 ) 2 } 4 ] 2 ( 3 ) were synthesized in quantitative yields by sonicating Li[Al(OR F ) 4 ] (R F =C(CF 3 ) 3 , C(CH 3 )(CF 3 ) 2 , or CH(CF 3 ) 2 ), AgF, and a three‐fold excess of CuI in 1,2‐F 2 C 6 H 4 ( 1 ) or CH 2 Cl 2 ( 2 , 3 ). Substances 1 – 3 are good starting materials for further Cu I chemistry, and the reaction of 1 – 3 with the weak Lewis base cyclooctasulfur gave the first Cu I –sulfur complexes of type [Cu(S 12 )(S 8 )] + [Al{OC(CF 3 ) 3 } 4 ] − ( 4 ), [Cu(CH 2 Cl 2 )(S 12 )] + [Al{OC(CF 3 ) 3 } 4 ] − ( 5 ), [A 1 Cu(1,5‐η 1 ,η 1 ‐S 8 )CuA 1 ] ( 6 ; A 1 =[Al{OC(CH 3 )(CF 3 ) 2 } 4 ] − ), and a Cu I –S 8 1D coordination polymer with [Cu 2 (S 8 ) 2 A 2 2 ] ( 7 ; A 2 =[Al{OCH(CF 3 ) 2 } 4 ] − ), as a monomeric repeat unit. Complexes 4 and 5 are the first example of any metal coordinated to cyclo‐S 12 and 4 is the first example of a complex having an element in two allotropic modifications as a ligand.