New complexes of fullerenes C-60 and C-70 with Co-II and Mn-II tetraphenylporphyrinates and their ESR study

Complexes of fullerenes C-60 and C-70 With cobalt(II) and manganese(II) tet raphenylporphyrinates of compositions Mn(TPP).(C-60)(2)(CS2)(1.5) (1), Mn(T PP). C-70(CS2)(x), where x less than or equal to 1.25 (2), Co(TPP). C-60(CS 2)(0.5) (3), and Co(TPP). C-70(CS2)(x), where x less than or equal to 0.25 (4), were synthesized and studied by ESR spectroscopy. At 77 K, complexes 1 and 2 have singlet ESR spectra characteristic of the low-spin (S = 1/2) st ate of Mn-II, with g = 2.002 and linewidths of 250 G and 300 G, respectivel y, and differing significantly from that of the initial Mn-II(TPP) (g(perpe ndicular to) = 5.9 and g(parallel to) = 2.0, S = 5/2). The spectra of compl exes 1 and 2 exposed to oxygen exhibit hyperfine structure due to interacti on with Mn-55 and N-14 nuclei. The ESR spectra of complexes 3 and 4 are asy mmetric (< g > = 2.4, Delta H-pp = (500-600) G), which is due to the overla p of parallel and perpendicular spectral components. The absence of ESR sig nals from C-60(.-) and C-70(.-) radical anions makes it possible to conclud e that the formation of complexes 1-4 is not accompanied by electron transf er from Co(TPP) and Mn(TPP) to fullerenes C-60 and C-70.