Reactions of the borole complex CpRh(η5-C4H4BPh) with monocationic organometallic fragments

(1,2,3,4,7-Pentamethylindenyl)rhodium complexes with arene ligands

“…Recently, we have shown that the reactions of cationic fragments [(ring)M] n+ (n = 1, 2) with the B-phenylborole complex CpRh(g 5 -C 4 H 4 BPh) give either triple-decker or arene-type complexes [12,13]. The reaction of [(g 5 -C 9 H 2 -Me 5 )Rh(MeNO 2 ) 3 ] 2+ with CpRh(g 5 -C 4 H 4 BPh) results in the arene-type complex [CpRh(l-g 5 :g 6 -C 4 H 4 BPh)Rh-(g 5 -C 9 H 2 Me 5 )] 2+ (4) (Scheme 3), similar to reaction with [Cp * Rh(MeNO 2 ) 3 ] 2+ .…”

“…At the glassy-fluid transition, the anisotropic signal drops out and the solution becomes EPR mute. Accounting for the temperature dependent experimental linewidths, an upper limit for the different magnetic interactions can be proposed as DH i ( 103 Rh, 13 C, 1 H) P a i ( 103 Rh, 13 C, 1 H). It is noted that the related complex [(g 5 -C 9 H 7 )Rh(C 5 Me 5 )] 0 in THF solution gives rise to an EPR spectrum with axial symmetry possessing a substantial metallic character too [23].…”

Triple-decker complexes with a central borole ligand C4H4BR

“…(27), (1,5 C 8 H 12 )Ir (28) A DFT quantum chemical study of the systems in question was also carried out. 50 In particular, the total NBO charges on the Ph, Cp, and C 4 H 4 B rings in the model compound CpCo(η C 4 H 4 BPh) were -0.30, -0.41, and -0.42, respectively; the α C atoms in the borole ring were bearing the highest negative change (-0.59). This is in good agreement with the experimentally observed ini tial electrophilic attack on the borole ring with the forma tion of the triple decker complex.…”

“…Greater sta bility of the µ borole dicationic triple decker complexes compared to the monocationic analogs can be explained by the higher orbital symmetry of the former species. 50 In contrast, among the related complexes with the cyclo pentadienyl and boratabenzene bridging ligands, the most stable are the monocationic compounds, which is also due to the higher orbital symmetry of these species. 11,25, 26 The most characteristic feature of the 1 H NMR spec tra of µ borole cationic triple decker complexes is a large low field shift (∆δ = 0.7-1.3 ppm) of the signals of the borole ring protons compared to the corresponding sig nals of the starting sandwich compounds.…”

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

“…Electrophilic stacking of sandwich compounds with the cationic fragments [M(ring)] + (in the form of their labile derivatives) is widely used for the synthesis of triple-decker complexes with bridging Cp, C 4 BH 5 , C 5 BH 6 , C 4 H 4 P, and cyclo-P 5 ligands. In particular, cationic triple-decker complexes with bridging C 4 BH 5 , and C 5 BH 6 , heterocycles were obtained by electrophilic stacking of various sandwich compounds with the labile solvates [M(ring)(solv) 3 ] 2+ . Using the halides [M(ring)X 2 ] 2 as synthons of [M(ring)] 2+ fragments, Grimes et al have synthesized neutral complexes with bifacially bonded C 2 B 3 H 5 ring derivatives .…”