Main-Chain Oligomers from NiII- and CuII-Centered Unsymmetrical N2O2 Schiff-Base Complexes: Synthesis and Spectral, Structural, and Second-Order Nonlinear Optical Properties. - Celedón, Salvador; Dorcet, Vincent; Roisnel, Thierry; Singh, Anu; Ledoux‐Rak, Isabelle; Hamon, Jean‐René; Carrillo, David; Manzur, Carolina (European Journal of Inorganic Chemistry, 2014)