Near-infrared luminescence and RNA cleavage ability of lanthanide Schiff base complexes derived from N,N'-bis(3-methoxysalicylidene)ethylene-1,2-diamine ligands.
J Inorg Biochem 2016;
163:194-205. [PMID:
27554192 DOI:
10.1016/j.jinorgbio.2016.07.017]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 07/14/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
Abstract
A complete series of lanthanide Schiff base salen-type complexes were prepared with trivalent lanthanide ions (Ln3+) and the N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine ligand (Ln3+=La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+). Three unique crystal structures of La3+ and Pr3+N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine complexes, with the La3+ complex prepared in two different synthetic approaches, are reported, namely a dimeric [La(H2L)(NO3)3]2 (H2L=N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine) complex, an asymmetric two-centered [La2(H2L)2(NO3)6] complex and a discrete mononuclear [Pr(H2L)(NO3)2(H2O)2] complex. For Nd3+ and Sm3+, an isotypic mononuclear [Nd(H2L)(NO3)3] and 1D polymeric [Sm(H2L)(NO3)3(MeOH)]n structure was obtained, respectively. The whole series of complexes was tested for their ability to cleave the 20-mer RNA oligonucleotide 5'-AGC-GAU-AAG-AUU-CAU-AUA-UC-3'. Additionally three complexes (Ln3+=Nd3+, Sm3+, Ho3+) were tested for the cleavage of the 12-mer RNA oligonucleotide 5'-GCA-CCC-UGU-CAG-3'. A detailed luminescence study was additionally carried out and revealed that the Eu3+ complex emitted bright red light upon excitation at both 285.8nm and 394.4nm. The Nd3+, Er3+, and Yb3+ complexes showed strong emission in the near-infrared region after excitation at 380nm.
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