Inorganic Chemistry, Vol.56, No.22, 13785-13793, 2017
In Situ Ligand Modification Strategy for the Construction of One-, Two-, and Three-Dimensional Heterometallic Iodides
Three heterometallic iodides featuring the novel in situ modified ligands N,N',N"-trimethyl-2,4,6-tris (4-pyridy1)-1,3,5-triazine (Me(3)tpt(3+)), N,NI-dimethy1-2,4,6-tris(4-pyridy1)-1,3,5-triazine (Me(2)tpt(2+)), and N-monomethy1-2,4,6-tris(4-pyridy1)-1,3,5-triazine (Metpt), [Pb3CuI10(Me(3)tpt(+))] (1), [Pb5Cu2I16(Me(2)tpt)(2)] (2), and [Pb3Cu6I14(Metpt)(2)] (3), were synthesized. Compound 1 exhibits a chain structure, in which the Pb(4)H(6)units are connected by the CuI3 units. The negative charge of the resulting chain is balanced by the cationic Me(3)tpt(3+) groups. 2 features a layer structure, in which the Pb-I chains are connected by the dimeric Cu, units. The anionic layer is decorated by the Me(2)tpt(2+) motifs via coordinating to the intralayer Cu(I) ions. 3 displays a 3D framework structure, in which the inorganic layer with an 18 -membered ring is composed of the strictly alternating arrangements of trimeric Pb-3 units and hexameric Cub units. The adjacent inorganic layer is further connected by a Metpt+ linker to form the final 3D hybrid framework. It is notable that the in situ N-methylation reaction for tpt has taken place and the resultant motif (Me(3)tpt(3+) for 1, Me(2)tpt(2+) for 2, and Metpt+ for 3) is captured within the corresponding structure. More importantly, the structural diversities from low -dimensional chain and layer to high -dimensional framework is accomplished via the (partial) N-methylation of tripyridine motifs in the heterometallic iodide systems. Our studies offer a new coordination mode of tripyridine motif (N -coordination together with N-methylation) and provide a general strategy to integrate the polypyridine motifs and heterometallic halide systems to generate intriguing hybrid structure and investigate the potential structure -related properties. The UV-vis spectra show that the band gaps for 1-3 are 1.48, 1.35, and 1.34 eV, respectively. Their thermal stabilities have also been studied.