Monomeric and polymeric copper and zinc tripyrrins

Neutral transition metal complexes of different alpha,omega-dimethyltripyrrins TrpyMX with M = Cu(II) and Zn(II) have been prepared with a variety of anionic halogeno and pseudohalogeno ligands X, and have been studied with respect to coordination modes and structural distortion. Only four- and five-coordinate species have been observed throughout the series. All four-coordinate species display unstrained, but distorted tetrahedral or strained and distorted square-planar coordination environments for zinc(II) and copper(II) species, respectively, thus following the expectations from simple ligand field arguments. Five-coordinate species do not form easily and were observed either in donor solvents or in the solid as 1D coordination polymers with distorted trigonal-bipyramidal coordination and different topologies.     

Free-base porphyrin polymer for bifunctional electrochemical water splitting

Water splitting is considered a promising approach for renewable and sustainable energy conversion. The development of water splitting electrocatalysts that have low-cost, long-lifetime, and high-performance is an important area of research for the sustainable generation of hydrogen and oxygen gas. Here, we report a metal-free porphyrin-based two-dimensional crystalline covalent organic polymer obtained from the condensation of terephthaloyl chloride and 5,10,15,20-tetrakis(4-aminophenyl) porphyrin which is stabilized by an extensive hydrogen bonding network. This material exhibits bifunctional electrocatalytic performance towards water splitting with onset overpotentials, η, of 36 mV and 110 mV for HER (in 0.5 M H₂SO₄) and OER (in 1.0 M KOH), respectively. The as-synthesized material is also able to perform water splitting in neutral phosphate buffer saline solution, with 294 mV for HER and 520 mV for OER, respectively. Characterized by electrochemical impedance spectroscopy (EIS) and chronoamperometry, the as-synthesized material also shows enhanced conductivity and stability compared to its molecular counterpart. Inserting a non-redox active zinc metal center in the porphyrin unit leads to a decrease in electrochemical activity towards both HER and OER, suggesting the four-nitrogen porphyrin core is the active site. The high performance of this metal-free material towards water splitting provides a sustainable alternative to the use of scarce and expensive metal electrocatalysts in energy conversion for industrial applications.

Water splitting is considered a promising approach for renewable and sustainable energy conversion.     

空心酞菁光物理性质的取代基效应

合成了一系列可溶性的2，9，16，23-四取代的空心酞菁，并研究了其光物理性质，实验表明，烷基、烷氧基、芳氧基取代空心酞菁的最低电子跃迁能和最低激发单重态能量与Hammett间位取代基常数线性相关．而强吸电子基如硝基和强给电子基如氨基取代则会诱导分子内电荷转移和使酞菁聚集，导致吸收光谱畸变和激发态量子产率下降．但取代基对酞菁的振动能级没有影响．     

新型氯代苯基咔咯的合成及电化学和光谱性质

通过吡咯和具有相应取代基的苯甲醛在甲醇和水的混合溶剂中生成胆色烷, 然后用四氯苯醌氧化胆色烷, 合成了2种新型的咔咯化合物: 三(4-氯苯基)咔咯[(ClPh)₃CorH₃]和三(2,4-二氯苯基)咔咯[(Cl₂Ph)₃CorH₃]. 采用紫外-可见、荧光、¹H NMR、MS和IR等光谱技术对化合物进行了表征. 研究了化合物在二氯甲烷和二甲基甲酰胺中的电化学及光谱电化学性质. 讨论了溶剂和取代基对紫外-可见光谱以及氧化还原电位和电子转移过程的影响. 提出了化合物在2种不同溶剂中的氧化还原反应机理.     

Selective and sensitive "turn-on" fluorescent Zn2+ sensors based on di- and tripyrrins with readily modulated emission wavelengths

Di- and tripyrrin sensors D1-D4 exhibit CHEF-type fluorescence enhancement by factors up to 72 upon addition of 1 equiv. Zn(2+), with tunable emission colours between green (D1) and red (D4).