A linker conformation induced metal-organic framework with high stability and efficient upgrading of natural gas.

Natural gas plays an important role in daily life and the petrochemical industry, but there are often large amounts of impurities which prevent the full use of methane in natural gas. Developing excellent adsorbents to purify CH4 from multi-component mixtures is crucial, but also faces great challenges. Here, by utilizing a ligand conformation preorganization strategy, we employ a flexible nonplanar hexacarboxylate ligand with C2 symmetry to successfully construct a robust microporous metal-organic framework {[Cu3(bmipia)(H2O)3]·(DMF)(CH3CN)2}n (GNU-1, bmipia = 5-[N,N-bis(5-methylisophthalic acid)amion] isophthalate) with an unprecedented topology. More importantly, the obtained GNU-1 not only exhibits good stability in acid-base and water environments, but also shows potential utility as an adsorbent for efficient separation and purification of natural gas under ambient conditions. The adsorption isotherms of GNU-1a (activated GNU-1) exhibit strong binding affinities for C2H6 and C3H8, a remarkable uptakes of C3H8 (6.64 mmol g-1) and C2H6 (4.6 mmol g-1) and an excellent selectivity of 330.1 and 17.5 for C3H8/CH4 and C2H6/CH4 mixtures, respectively, at 298 K and 1 bar. The breakthrough experiments demonstrate that the ternary CH4/C2H6/C3H8 mixtures are completely separated using a fixed-bed separator packed with GNU-1a at ambient temperature and also show great potential for recovering the C2H6 and C3H8 contents from natural gas. Finally, Grand Canonical Monte Carlo simulations are adopted to ascertain potential gas adsorption mechanisms. This work proves the feasibility of optimizing the structure and pore size of MOF materials by regulating the conformation of ligands for application in the field of light hydrocarbon adsorption/separation.

Synthesis, structural characterization and antitumor activity of six rare earth metal complexes with 8-hydroxyquinoline derivatives.

The rare earth metal Gd(III), Yb(III), Lu(III), Eu(III), Tb(III) and Ho(III) complexes 1-6 with 2-((2-(pyridin-2-yl)hydrazono)methyl)quinolin-8-ol (H-L) as ligands were synthesized. The in vitro cytotoxicity assay indicated that the cytotoxicity of 1 was equivalent to cisplatin and higher than that of H-L and other complexes towards T24 tumor cells. The mechanism study indicated that 1 caused significant up-regulation of the proteins p27, p21 and p53 in T24 cells and cell cycle arrest in G2 phase. In addition, 1 induced effective T24 cells apoptosis via mitochondrial dysfunction pathway, which was indicated by changes in mitochondrial membrane potential (Δψ), reactive oxygen species (ROS), intracellular Ca2+ and the mitochondria-related proteins (including cytochrome C (Cyt C), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated x (Bax) and apoptotic protease activating factor-1 (Apaf-1)). Moreover, 1 could activate caspase-3/8/9 in T24 cells. Therefore, complex 1 is a promising and potent anticancer drug candidate.

Synthesis, structural characterization and luminescent properties of a series of Cu(I) complexes based on polyphosphine ligands.

A series of Cu(I) complexes with a [Cu(NN)(PP)](+) moiety, [Cu(phen)(pba)](BF(4)) (1a), [Cu(2)(phen)(2)(pbaa)](BF(4))(2) (2a), [Cu(2)(phen)(2)(pnaa)](BF(4))(2) (3a), [Cu(2)(phen)(2)(pbbaa)](BF(4))(2) (4a), [Cu(dmp)(pba)](BF(4)) (1b), [Cu(2)(dmp)(2)(pbaa)](BF(4))(2) (2b), [Cu(2)(dmp)(2)(pnaa)](BF(4))(2) (3b) and [Cu(2)(dmp)(2)(pbbaa)](BF(4))(2) (4b) (phen = 1,10-phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline, pba = N,N-bis((diphenylphosphino)methyl)benzenamine, pbaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)benzene-1,4-diamine, pnaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)naphthalene-1,5-diamine and pbbaa = N,N,N',N'-tetrakis((diphenylphosphino)methyl)biphenyl-4,4'-diamine), were rationally designed and synthesized. These complexes were characterized by (1)H and (31)P NMR, electrospray mass spectrometry, elemental analysis and X-ray crystal structure analysis. Introduction of different central arene spacers (phenyl, naphthyl, biphenyl) into ligands, resulting in the size variation of these complexes, aims to tune the photophysical properties of the complexes. Each Cu(I) ion in these complexes adopts a distorted tetrahedral geometry constructed by the chelating diimine and phosphine groups. Intermolecular C-H···π and/or π···π interactions are involved in the solid states. The dmp-containing complex exhibits better emission relative to the corresponding phen complex due to the steric encumbrance of bulky alkyl groups. Furthermore, for complexes with identical diimine but different phosphine ligands, the tendency of increased emission lifetime as well as blue-shifted emission in the solid state follows with the decrease in size of complexes. Intermolecular C-H···π interactions have an influence on the final solid state photophysical properties through vibrationally relaxed non-radiative energy transfer in the excited state. Smaller-sized complexes show better photophysical properties due to less vibrationally relaxed behavior related to flexible C-H···π bonds. Nevertheless, the tendency for increased quantum yield and emission lifetime, as well as blue-shifted emission in dilute solution goes with the increase in size of complexes. The central arene ring (phenyl, naphthyl or biphenyl) has an influence on the final photophysical properties. The larger the π-conjugated extension of central arene ring is, the better the photophysical properties of complex are. The rigid and large-sized complex 3b, with a high quantum yield and long lifetime, is the best luminophore among these complexes.

{µ-trans-N,N'-Bis[(diphenyl-phosphan-yl)meth-yl]benzene-1,4-diamine-κP:P'}bis-{(acetonitrile-κN)[dipyrido[3,2-a:2',3'-c]phenazine-κN,N]copper(I)} bis-(tetra-fluoridoborate).

In the centrosymmetric dinuclear title compound, [Cu(2)(C(2)H(3)N)(2)(C(18)H(10)N(4))(2)(C(32)H(30)N(2)P(2))](BF(4))(2), the Cu(I) centre is coordinated by two N atoms from a dipyridophenazine ligand, one P atom from an N,N'-bis-[(diphenyl-phosphan-yl)meth-yl]benzene-1,4-diamine (bpbda) ligand, and one N atom from an acetonitrile mol-ecule in a distorted tetra-hedral geometry. The bpbda ligand, lying on an inversion center, bridges two Cu(I) centres into a Z-shaped complex. Intra-molecular π-π inter-actions between the dipyridophenazine ligand and the benzene ring of the bpbda ligand are observed [centroid-centroid distance = 3.459 (3) Å]. The crystal structure also involves inter-molecular π-π inter-actions between the dipyridophenazine ligands [centroid-centroid distance = 3.506 (3) Å], which lead to a one-dimensional supra-molecular structure.

[µ-N,N'-Bis(diphenyl-phosphinometh-yl)benzene-1,4-diamine-κP:P']bis-[(2,2'-bipyridine-κN,N')silver(I)] bis-(per-chlorate) acetone disolvate.

The title complex, [Ag(2)(C(10)H(8)N(2))(2)(C(32)H(30)N(2)P(2))](ClO(4))(2)·2CH(3)COCH(3), is a centrosymmetric dimer with pairs of Ag(I) atoms bridged by N,N'-bis-(diphenyl-phosphinometh-yl)ben-zene-1,4-diamine ligands. In addition, each Ag(I) atom is coordin-ated by one chelating 2,2'-bipyridine ligand, giving a distorted trigonal coordination environment.

[µ-N,N,N',N'-Tetra-kis(diphenyl-phosphino-meth-yl)benzene-1,4-diamine-κP,P':P'',P''']bis-[bis-(nitrato-κO)palladium(II)].

The asymmetric unit of the title complex, [Pd(2)(NO(3))(4)(C(58)H(52)N(2)P(4))], contains one half-mol-ecule, in which the central benzene ring is located on a crystallographic centre of inversion. The Pd atom has a distorted square-planar coordination consisting of two P and two O atoms. In the crystal structure, inter-molecular C-H⋯O inter-actions link the mol-ecules into chains, and π-π contacts between the phenyl rings [centroid-centroid distance = 3.928 (3) Å] may further stabilize the structure.