Synthesis of μ-diborolyl triple-decker complexes [CpCo(1,3-C3B2Me5)Ru(arene)]+

Abstract

Cationic triple decker complexes [CpCo(1,3 C 3 B 2 Me 5 )Ru(arene)]PF 6 (arene is benzene (2a), p cymene (2b)) with a bridging diborolyl ligand were synthesized by the reaction of the sand wich anion [CpCo(1,3 C 3 B 2 Me 5 )] -(1) with [(arene)RuCl 2 ] 2 . The structure of [2b]PF 6 was confirmed by X ray diffraction analysis.The main method for the preparation of cationic triple decker complexes is the electrophilic stacking of sand wich compounds with the cationic fragments [(ring)M] n+ (n = 1, 2). 1-5 We have previously studied the reaction of the sandwich anion [CpCo(1,3 C 3 B 2 Me 5 )] -(1) with the monocationic half sandwich fragments [(C 5 R 5 )Ru] + (R = H, Me), resulting in the formation of the neutral triple decker complexes CpCo(1,3 C 3 B 2 Me 5 )Ru(C 5 R 5 ). 6 We have recently shown 7 that the similar reaction of an ion 1 with the dicationic fragments [(C 5 R 5 )M] 2+ (R = H, Me; M = Rh, Ir) affords the cationic triple decker complexes [CpCo(1,3 C 3 B 2 Me 5 )M(C 5 R 5 )] + . In the present work, we describe the reactions of sandwich anion 1 with the species [(arene)Ru] 2+ . Results and DiscussionThe reaction of the thallium derivative of anion 1 with the chloride complexes [(arene)RuCl 2 ] 2 (acting as equiva lents of the species [(arene)Ru] 2+ ) in acetonitrile afforded cationic triple decker complexes 2a,b in 60-75% yields (Scheme 1).* The behavior of anion 1 in this reaction resembles that of the cyclopentadienide anion reacting with [(C 6 H 6 )RuCl 2 ] 2 with the formation of [CpRu(C 6 H 6 )] + . 8 Hexafluorophosphates and tetraphenylborates of cat ions 2a,b are brightly colored solid substances stable in air. These salts are well soluble in polar organic solvents, such as CH 2 Cl 2 and acetone. Their structures were con Scheme 1 R 1 = R 2 = H (2a); R 1 = Me, R 2 = Pr i (2b).

Monocationic μ-Diborolyl Triple-Decker Complexes [CpCo(μ-1,3-C3B2Me5)M(ring)]+: Synthesis, Structures, and Electrochemistry

“…Structures of the triple-decker complexes 2a BPh 4 , 2b PF 6 , 4a PF 6 , 5a OTf, and 5c PF 6 were determined by X-ray diffraction (Figures –, respectively). Selected parameters for these structures and for the previously described 3b PF 6 , 4b PF 6 , and 5b PF 6 are given in Table (see also Table S1 in the Supporting Information for selected bond lengths and angles). All of the cations 2a , b , 3b , 4a , b , and 5a – c are formed by three cyclic ligands, between which two metal atoms are located.…”

“…Herein we describe a straightforward approach to the 30-VE cationic complexes [CpCo(μ-1,3-C 3 B 2 Me 5 )M(ring)] + , on the basis of the reactions of anion 1 (as a thallium derivative) with [M(ring)X 2 ] 2 . The electrochemical behavior and structural features of the complexes synthesized are also described.…”

Synthesis of dicationic μ-diborolyl triple-decker complexes [CpCo(μ-1,3-C3B2Me5)M(C6H6)]2+ (M = Rh, Ir)

“…We found that the reactions of compounds 1 and 2 with AgBF 4 in nitromethane followed by the addition of benzene yields the 30 electron triple decker complexes [CpCo(1,3 C 3 B 2 Me 5 )M(C 6 H 6 )] 2+ (3,4) in 80-85% yields (Scheme 1). * It is assumed that the reaction pro ceeds through the intermediate formation of labile solvate complexes [CpCo(μ 1,3 C 3 B 2 Me 5 )M(MeNO 2 ) 3 ] 2+ .…”