Synthesis and Structures of Selected Triazapentadienate of Li, Mn, Fe, Co, Ni, Cu(I), and Cu(II) using 2,4- N , N′ -Disubstituted 1,3,5-Triazapentadienate Anions as Ancillary Ligands: [N(Ar)C(NMe 2 )NC(NMe 2 )N(R)] − (Ar = Ph, 2,6- i Pr 2 −C 6 H 3 ; R = H, SiMe 3 )