Crystal structures, EPR spectra, and magnetic properties of a series of ionic multi-component complexes [(TBPDA)₂·(C₆₀ ^.-)·(D⁺)] (D = Cp*₂Cr, Cp*₂Co, TDAE)

New ionic multi-component complexes [(TBPDA)₂·(C ₆₀^.-)· (D⁺)] [TBPDA = N,N,N′,N′-tetrabenzyl-p-phenylenediamine; D = decamethylchromocene (Cp*₂Cr, 1) and decamethylcobaltocene (Cp*₂Co, 2)] were obtained additionally to previously characterized [(TBPDA) ₂·(C₆₀^.-T)·(TDAE^.+)] [TDAE = tetrakis(dimethylamino)ethylene, 3]. The presence of D⁺, C60^.-, and neutral TBPDA in 1-3 was proved by the IR and UV/Visible/NIR spectra. D⁺ and C₆₀^.- form loose layers in 1 and 3 and are spatially separated by bulky TBPDA molecules. The C60^.- radical anions alternate in the layer with the phenylene groups of TBPDA to form π-π stacking, whereas disordered Cp* ₂Cr⁺ cations are isolated in the voids formed by eight benzyl groups of TBPDA. The EPR spectra of the complexes show single Lorentzian lines with g = 2.2526 and ΔH = 215 mT (1), g = 1.9999 and ΔH = 6.7 mT (2), and g = 2.0009 and ΔH = 2.93 mT (3) at room temperature. The EPR signal of 2 was attributed to C₆₀^.- (Cp* ₂Co⁺ is diamagnetic) and those in 1 and 3 to resonating signals between C₆₀^.- (g = 1.9996-2.0000) and Cp*₂Cr⁺ [an asymmetric EPR signal with g _⊥ = 4.02(1) and g_∥ = 2.001(1)] (1) or TDAE ^.+ (g = 2.0035; 3) due to indirect coupling. The EPR signals from 2 and 3 are split into two components below 50 and 60 K, respectively, which shift in the opposite directions (to lower and higher fields) with decreasing temperature. The magnetic moments of 1-3 decrease below 50-100 K. Both effects are associated with the formation of field-induced short-range antiferromagnetically ordered clusters. It is shown that the D⁺ cations do not noticeably affect this interaction. Most probably, it is realized mainly between C60^.- spins within the layer and is mediated by the phenylene groups of TBPDA.