ABSTRACT
Six novel copper(I) cluster-based coordination polymers (CPs) [Cu9(pzt)7Cl2]n (1), [Cu2(pzt)Cl]n (2), [Cu4(pzt)3Br]n (3), [Cu(pzt)]n (4), [Cu4(pzt)3I]n (5), and [Cu7(pzt)6I]n (6) were solvothermally synthesized using Hpzt (Hpzt = pyrazine-2-thiol) ligand and well-characterized by elemental analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD). Six CPs exhibit either 2D (4 and 6) or 3D (1-3, and 5) network based on diverse multinuclear {CuxSy} clusters. The structural evolutions of 1-6 are greatly influenced by types of metal halides and the ligand-to-metal molar ratio used in the reaction. Among them, compound 1 displays interesting temperature-dependent photoluminescence arising from triplet cluster-centered (3CC) excited state from the cluster metal core. Compounds 1-6 also exhibit photocurrent responses upon visible-light illumination (λ = 420 nm) in the order 6 > 5 > 3 > 1 > 4 > 2. This work not only shows the structural diversity of {CuxSy} clusters-based CPs but also provides an interesting insight into structural modulation using crystal engineering concept.
ABSTRACT
The exquisite combination of hetreometallic [TbIIINiII(COO)3(H2O)] clusters with a designed hexatopic ligand generates one highly robust three-dimensional heterometallic TbIII/NiII-organic framework material {[TbNi(HTDP)(H2O)]·3DMF·2H2O}n (NUC-2; H6TDP = 2,4,6-tri(2,4-dicarboxyphenyl)pyridine). Gas adsorption measurements reveal that the activated NUC-2 exhibits ultrahigh C2H2 adsorption capacity but negligible uptake of C2H4, which is ascribed to its high stability and ultrahigh functional internal surface. Furthermore, dynamic breakthrough experiments confirm that NUC-2 can effectively fulfill the separation of a C2H2/C2H4 (1 : 99) mixture. Such excellent performance makes NUC-2 a promising adsorbent for practical C2H2/C2H4 separation and provides new insights into heterometallic MOFs for gas separation.