Qingrong Cheng

Syntheses, crystal structures, and magnetic properties of 1-D coordination polymers

Three coordination polymers of Robson-type macrocycles, {[Cu4L1(4,4′-bipy)2]·4ClO4·H2O}∞ (1), {[Cu4L2(4,4′-bipy)4]·2CH3CN·4ClO4·2H2O}∞ (2), and {[Zn2L2(4,4′-bipy)2]·(ClO4)2}∞ (3) (where H2L1 and H2L2 are the [2 + 2] condensation products of 1,3-diaminopropane with 2,6-diformyl-4-methylphenol and 2,6-diformyl-4-fluorophenol, respectively), have been synthesized and characterized. Magnetic susceptibility was measured for 1 and 2 from 2 to 300 K. The optimized magnetic data were J = –368.5 cm−1, J′ = 40.5 cm−1 with R = 1.69 × 10−6 for 1 and J = –291.22 cm−1, J′ = 83.74 cm−1, ρ = 0.00168 with R = 1.8 × 10−11 for 2, respectively. The data reveal strong antiferromagnetic interactions between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction between the Cu(II) ions in two adjacent macrocyclic units for 1 and 2. Graphical Abstract Three novel coordination polymers of Robson-type dinuclear macrocyclic complexes, bridged by 4,4′-bipyridine, were synthesized and fully characterized, Magnetic data reveal that there are strong antiferromagnetic between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction between the Cu(II) ions in two adjacent macrocyclic units for complexes 1 and 2.

Syntheses, crystal structures, and properties of Cu(II) and Zn(II) complexes with an asymmetric tripodal ligand

[Cu2L2](ClO4)2 (1) and [Zn2L2](ClO4)2 (2) (HL = 2-[bis(3-aminopropyl)amino]propanol) have been synthesized and characterized. X-ray crystallography analyses show that both are dinuclear with bis-μ-alkoxy-bridged structures. Their molecular structures are centro-symmetric. Each metal adopts a trigonal bipyramidal coordination. Cyclic voltammetry indicates that 1 undergoes two irreversible redox processes with big potential differences (E pa−E pc) and ratio of i pa/i pc, while only one reduction peak is observed in 2. Magnetic susceptibility shows that there is a strong antiferromagnetic interaction (J = −69.4(4) cm−1) between the two copper(II) centers in 1. Hydrolysis activities toward 4-nitrophenyl acetate of the two complexes have been investigated and second-order rate constants of 1 and 2 are (4.3 ± 0.3) × 10−2 and (3.1 ± 0.2) × 10−2 M−1s−1 in 10% (v/v) CH3CN aqueous solution at 25 °C.

Synthesis, characterization, and biological activities of macrocyclic polyamine complexes

Two new dinuclear macrocyclic complexes, [Ni2L1(OAc)]·ClO4 (1) and [Co2L2(OAc)]·1.5(ClO4)·0.5Na·2(CH3OH) (2) (where H2L1 and H2L2 are the condensation products of N,N-bis(3-aminopropyl)-4-methoxybenzylamine with 2,6-diformyl-4-brominephenol and 2,6-diformyl-4-methylphenol in the presence of metal ions, respectively) have been synthesized and characterized by infrared spectra, elemental analysis, electrospray mass spectra, and X-ray single crystal diffraction. The interactions of the complexes with CT-DNA have been measured by UV-absorption titrations and fluorescence quenching experiments. Graphical Abstract Two new dinuclear macrocyclic polyamine complexes have been synthesized and characterized by infrared spectra, elemental analysis, ES-MS spectrum, and X-ray single crystal diffraction. The interactions of the complexes with CT-DNA have been measured by spectroscopy, viscosity, electrochemical measurements, and the agarose gel electrophoresis.

Synthesis, crystal structure, and fluorescence properties of two 1-D chain polymers extended by a semi-rigid bis(triazole) ligand

Abstract Two 1-D luminescent metal-organic frameworks with identical structures, {[Mn(BBPTZ)2(MeCN)2]·(ClO4)2}n (1) and {[Zn(BBPTZ)2(MeCN)2]·(MeCN)2·(ClO4)2}n (2), have been synthesized under solvent diffusion evaporation and characterized by elemental analyses, thermal analyses and single-crystal X-ray diffraction. Both complexes crystallize in the monoclinic system, space group C2/c with six-coordinate M(II). Thermal decompositions of the complexes have been studied using thermogravimetric analyses (TGA). The complexes exhibit a significant fluorescence quenching effect to Fe3+ in acetonitrile solution. The LoDs (Limit of Detection) of the complexes to Fe3+ are 2.59 × 10−8 M and 1.57 × 10−8 M for 1 and 2, respectively. The complexes could be applied to efficient chemosensor for Fe3+ detection.