Bo Tao

Supramolecular architectures based on various macrocyclic metallic tectons with 1,3,5-triazine-2,4,6-triamine hexaacetic acid ligand

Reactions of series of macrocycle derivatives [Ni(hto)]Cl2·2H2O (1) (hto = 1,3,6,9,11,14-hexaazatri-cyclo[12.2.1.16,9]octadecane), [Ni(CHA)](ClO4)2 (2) (CHA = 1,3,6,8,11,14-hexaazatri-cyclo[12.2.1.18,11]octadecane), [Ni(PCHA)](ClO4)2 (3) and [Cu(PCHA)](ClO4)2 (4) (PCHA = 4-methyl-1,3,6,8,11,14-hexaazatri-cyclo[12.2.1.18,11]octadecane), with a flexible hexapodal ligand H6TTHA (H6TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid) resulted in eight supramolecular coordination polymers (SCPs), formulated as α-[Ni(hto)][H4TTHA]·5H2O (5), β-[Ni(hto)][H4TTHA]·4H2O (6), [Ni(CHA)][H4TTHA]·2H2O (7), [Ni(PCHA)][H4TTHA]·3H2O (8), [Cu(PCHA)][H4TTHA]·1.5H2O (9), [Ni(PCHA)][H5TTHA](ClO4)·4H2O (10), [Ni(PCHA)][H4TTHA]·DMSO·H2O (11) and [Ni(PCHA)][H4TTHA]·DMF (12). These compounds are structurally characterized by X-ray diffraction analyses. The predominant driving forces that connect macrocyclic metallic tectons with hexaacetic acid ligand in compounds 5–12 are hydrogen bonds, by which the compounds assemble into SCPs with versatile structures. The single-crystal X-ray diffraction analysis reveals that compounds 5 and 6 contain a rhombic 2-D layer network structure constructed of hydrogen bonds. Compound 7 exhibits a 3-D supramolecular network with 12 × 10.4 A2 1-D brick wall net structure along the c-axis, and all the water molecular guests adorned the brick wall net. Compounds 8 and 9 show a nonporous 3-D framework also stabilized by the hydrogen bonds. Tuning by solvents, in compound 10, an elliptical 2-D network was found to accommodate water molecules and perchlorate in the channels, with grid dimensions of 11 × 10 A2; compounds 11 and 12 show 2-D honeycomb-like networks with diameter 12 A. In conclusion, the crystal structures and regulatory effect of thev N-donor on the macrocyclic ligands in these compounds are discussed.

Synthesis, crystal structures and luminescent properties of nickel (II) and copper (II) hexaazamacrocyclic compounds with 1,3,5-benzenetricarboxylate ligands

In this paper the focus is set on a modified Chua’s circuit model equation with saw-tooth function in place of piece-wise linear function of Chua’s circuit displaying multi-scroll chaotic attractors. We study the characteristic properties of first passage times (tFPTs) to nth scroll chaotic attractor, residence times (tRTs) on a scroll attractor and returned times (tRETs) to the middle-scroll attractor. tFPTs exhibit a series of Gaussian-like distribution followed by a long tail continuous distribution. tRTs and tRETs show completely discrete distribution. Power-law variation of mean values of tFPTs, tRTs and tRETs with a control parameter is found. On the other hand, mean values of tFPTs and tRETs have linear dependence with the number of the scroll attractors for fixed values of the control parameter. For the system with infinite scroll chaotic attractors normal diffusive motion occurs. In the normal diffusion process the mean square displacement grows linearly with time. PACS numbers: 02.50.-r, 05.45.-a, 05.60.cd

Syntheses, crystal structures and properties of three cyano-bridged one-dimensional coordination polymers based on macrocyclic metallic tectons

Three cyano-bridged nickel(II) complexes, namely, [NiL1][Ni(CN)4]·3H2O (1), [NiL2][Ni(CN)4]·H2O·CH3CN (2) and [NiL3][Ni(CN)4]·3H2O (3) (L1 = 1,3,6,8,11,14-hexaazatricyclo[12.2.1.18,11]octadecane, L2 = 1,3,6.8.12,15-hexaazatricyclo[13.3.1.18,12]eicosane and L3 = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.16,9]octadecane), have been synthesized and characterized based on different macrocyclic metallic tectons and diamagnetic [Ni(CN)4]2−. Single crystal X-ray analyses reveal that complexes 1–3 exhibit a similar cyano-bridged one-dimensional chain structure, in which one nickel(II) ion is coordinated by four nitrogen atoms from the macrocyclic ligand and two nitrogen atoms from the bridging cyanide ligands, while the residual nickel(II) ion is coordinated by four cyanide ligands. Interestingly, regulated by the peripheral macrocyclic ligand, complex 1 features an unexpected large porous structure with a pore size of 1 nm, which shows pronounced two-step adsorption of CO2 gas at 195 K. In additional, the magnetic properties of complexes 1–3 show the presence of weak intrachain ferromagnetic interactions between the paramagnetic nickel(II) ions through the diamagnetic [Ni(CN)4]2− anions.

Synthesis and crystal structure of a cyanide-bridged one-dimensional nickel(II) complex with alternating [Ni(En)2]2+ and [Ni(CN)4]2− ions

The complex [Ni(En)2][Ni(CN)4] · 3.5H2O (I) (En = ethylenediamine) was synthesized by the reaction of [Ni(En)2](ClO4)2 and K2[Ni(CN)4] in an H-shaped tube. The crystal structure of I has been determined by single-crystal X-ray analysis. The crystal of complex I is orthorhombic, space group Pnna with a = 28.151(3), b = 8.3946(8), c = 14.5441(13)Å, M =404.76, Z = 8, V = 3437.0(5)Å3. The structure of complex I reveals infinite zigzag chains shaped structure are formed by cis-Ni(En)2-μ-(NC)2, cis-μ-(NC)2Ni(CN)2, and trans-μ-(CN)2Ni(En)2.

Synthesis, crystal structure and electrochemical properties of [Co(phen)3] · (H3btec) · (H2btec)0.5 · DMF · 6H2O

A new complex [Co(phen)3] · (H3btec) · (H2btec)0.5 · DMF · 6H2O (1) (H4btec = 1,2,4,5-Benzenetetracarboxylic acid, phen = 1,10-phenanthroline, DMF = dimethylformamide) was synthesized by the reaction of pyromellitic dianhydride, phen · H2O and CoSO4 · 7H2O. Complex 1 crystallizes in the triclinic system, space group P-1 with a = 11.8123(14) Å, b = 13.0356(16) Å, c = 17.575(2) Å, α = 91.461(2)°, β = 101.347(2)°, γ = 99.830(2)°, FW = 1159.94, Z = 2, V = 2609.5(5) Å3. X-ray crystal structural determination indicates that the Co(II) ion is octahedral coordinated by six nitrogen atoms of three phenanthroline ligands. The [Co(phen)3]2+ cation engages its phen ligands in π-π interactions with H2btec anion. Extensive hydrogen bonding interactions occur between water molecules, DMF, H3btec and H2btec anions. The highly-crystalline compounds 1, which are insoluble in water as well as common organic solvents, have been characterized in the solid-state by elemental analysis, thermogravimetric analysis and IR spectra. Moreover, the study of the electrochemistry of complex 1 was carried out by using cyclic voltammetry. It revealed that the Co(II) complex exhibits a quasi-reversible one-electron redox process.

Crystal structure of a nickel(II) complex with the macrocyclic ligand 4-methyl-1,3,5,8,11,14-hexaazatricyclooctadecane

The crystal structure of the macrocyclic complex [Ni(PCHA)](ClO4)2 (II) (PCHA = 4-methyl-1,3,5,8,11,14-hexaazatricyclooctadecane) is described. In the presence of succinate acid, [Ni(PCHA)](ClO4)2 (II) is obtained by recrystallization of orange crystals of [Ni(PCHA)](ClO4)2 (I), whose structure has previously been identified. The [Ni(PCHA)](ClO4)2 (II)crystal belongs to the monoclinic P2(1)/c space group with a = 15.8561(3) Å, b = 9.4409(2) Å, c = 13.9297(2) Å, α = 90°, β = 94.8840(10)°, γ = 90°, Mr = 526.02, Z = 4, V = 2077.65(7) Å3. The structure is ionic with [Ni(L)]2+ and two perchlorate anions with a supermolecular interaction.