70067-45-7Relevant articles and documents
Coordination polymers derived from a flexible bis(pyridylurea) ligand: Conformational change of the ligand and structural diversity of the complexes
Hao, Yongjing,Wu, Biao,Li, Shaoguang,Jia, Chuandong,Huang, Xiaojuan,Yang, Xiao-Juan
, p. 215 - 222 (2011)
The assembly of a bis(pyridylurea) ligand, N,N′-ethane-1,2-diylbis(3- pyridin-4-ylurea) (L), with Zn(AcO)2, CdCl2, CdSO 4 or CuSO4 led to four coordination polymers, {[Zn(AcO)2L]·H2O·CH3OH} n (1), {[CdCl2L2]·2DMF}n (2), {[CdSO4L(H2O)3]·3H2O} n (3), and {[CuSO4L(H2O)2] ·2H2O}n (4). Compound 1 is an infinite 1D zigzag chain with alternate Zn(AcO)2 units and L molecules. The cadmium(ii) dichloro complex 2 features a corrugated sheet structure with a (4,4) net topology, while the sulfato complex 3 shows a unique 1O/2U interwoven 3D structure assembled from zigzag chains. The copper(ii) complex 4 is an exceptional diamondoid network with an unusual 12-fold [6 + 6] interpenetration mode. Interestingly, the ligand shows the expected flexibility in the formation of the coordination polymers. In 1, 3 and 4, the central ethylene spacer adopts the anti conformations and is roughly linear, whereas in 2 it assumes a gauche form and exists as a V-shaped linker. The structural variation of these coordination polymers as well as the conformational change of the ligand in the presence of different counter anions and metal ions is discussed.
Making and breaking of gels: Stimuli-responsive properties of bis(pyridyl-n-oxide urea) gelators
Damodaran, Krishna K.,Ghosh, Dipankar,Jayabhavan, Sreejith Sudhakaran
, (2021/11/01)
The structural modification of existing supramolecular architecture is an efficient strategy to design and synthesize supramolecular gels with tunable and predictable properties. In this work, we have modified bis(pyridyl urea) compounds with different linkers, namely hexylene and butylene, to their corresponding bis(pyridyl-N-oxide urea). The gelation properties of both the parent and the modified compounds were studied, and the results indicated that modification of the 3-pyridyl moieties to the corresponding 3-pyridyl-N-oxides induced hydrogelation. The stability of the parent and modified compounds were evaluated by sol-gel transition temperature (Tgel ) and rheological measurements, and single-crystal X-ray diffraction was used to analyze the solid-state interactions of the gelators. The morphologies of the dried gels were analyzed by scanning electron microscopy (SEM), which revealed that the structural modification did not induce any prominent effect on the gel morphology. The stimuli-responsive behavior of these gels in the presence of salts in DMSO/water was evaluated by rheological experiments, which indicated that the modified compounds displayed enhanced gel strength in most cases. However, the gel network collapsed in the presence of the chloride salts of aluminum(III), zinc(II), copper(II), and cadmium(II). The mechanical strength of the parent gels decreased in the presence of salts, indicating that the structural modification resulted in robust gels in most cases. The modified compounds formed gels below minimum gel concentration in the presence of various salts, indicating salt-induced gelation. These results show the making and breaking ability of the gel network in the presence of external stimuli (salts), which explains the potential of using LMWGs based on N-oxide moieties as stimuli-responsive materials.
Synthesis and structure-activity relationship study of pyrrolidine-oxadiazoles as anthelmintics against Haemonchus contortus
Ruan, Banfeng,Zhang, Yuezhou,Tadesse, Solomon,Preston, Sarah,Taki, Aya C.,Jabbar, Abdul,Hofmann, Andreas,Jiao, Yaqing,Garcia-Bustos, Jose,Harjani, Jitendra,Le, Thuy Giang,Varghese, Swapna,Teguh, Silvia,Xie, Yiyue,Odiba, Jephthah,Hu, Min,Gasser, Robin B.,Baell, Jonathan
supporting information, (2020/02/04)
Parasitic roundworms (nematodes) are significant pathogens of humans and animals and cause substantive socioeconomic losses due to the diseases that they cause. The control of nematodes in livestock animals relies heavily on the use of anthelmintic drugs. However, their extensive use has led to a widespread problem of drug resistance in these worms. Thus, the discovery and development of novel chemical entities for the treatment of parasitic worms of humans and animals is needed. Herein, we describe our medicinal chemistry optimization efforts of a phenotypic hit against Haemonchus contortus based on a pyrrolidine-oxadiazole scaffold. This led to the identification of compounds with potent inhibitory activities (IC50 = 0.78–22.4 μM) on the motility and development of parasitic stages of H. contortus, and which were found to be highly selective in a mammalian cell counter-screen. These compounds could be used as suitable chemical tools for drug target identification or as lead compounds for further optimization.
