Scorpionate complexes of the middle to late 3d transition metals [(L) M (NCMe) 3](BF4) n (M= Mn, Fe, Co, Ni: 1 M, L= tris (3, 5-dimethylpyrazol-1-yl) methane, TpmMe, Me, n= 2; 2 M, L= tris (3-phenylpyrazol-1-yl) methane, TpmPh, n= 2; 3 M except 3 Mn, L= hydrotris (3, 5-