1.A new family of Ru(II) polypyridyl complexes containing open-chain crown ether for Mg2+ and Ca2+ probing.
Cheng F1, Tang N, Yue X. Spectrochim Acta A Mol Biomol Spectrosc. 2009 Jan;71(5):1944-51. doi: 10.1016/j.saa.2008.07.031. Epub 2008 Jul 31.
Six polypyridyl bridging ligands BL(1-6) containing open-chain crown ether, where BL(1-3) formed by the condensation of 4,5-diazafluoren-9-hydrazine with 1,7-bis-(4-formylphenyl)-1,4,7-trioxaheptane, 1,10-bis-(4-formylphenyl)-1,4,7,10-tetraoxadecane, and 1,13-bis-(4-formylphenyl)-1,4,7,10,13-pentaoxatridecane, respectively, BL(4-6) formed by the reaction of 9-(4-hydroxy)phenylimino-4,5-diazafluorene with diethylene glycol di-p-tosylate, triethylene glycol di-p-tosylate, and tetraethylene glycol di-p-tosylate, respectively, have been synthesized. Reaction of Ru(bpy)(2)Cl(2).2H(2)O with BL(1-6), respectively, afforded six bimetallic complexes [(bpy)(2)RuBL(1-6)Ru(bpy)(2)](4+) as PF(6)(-) salts. Cyclic voltammetry of these complexes is consistent with one Ru(II)-centered oxidation around 1.32V and three ligand-centered reductions. These complexes show metal-to-ligand charge transfer absorption at 413-444 nm and emission at 570 nm. Binding behavior of complexes with alkali and alkaline-earth metal ions are investigated by UV-vis absorption, fluorescence, and cyclic voltammetry.
2.Nickel-catalyzed reductive methylation of alkyl halides and acid chlorides with methyl p-tosylate.
Liang Z1, Xue W, Lin K, Gong H. Org Lett. 2014 Nov 7;16(21):5620-3. doi: 10.1021/ol502682q. Epub 2014 Oct 21.
Methylation of unactivated alkyl halides and acid chlorides under Ni-catalyzed reductive coupling conditions led to efficient formation of methylated alkanes and ketones using methyl p-methyl tosylate as the methylation reagent. Moderate to excellent coupling yields as well as excellent functional group tolerance were observed under the present mild and easy-to-operate reaction conditions.
3.Dendrimer adjusted nanocrystals of DAST: organic crystal with enhanced nonlinear optical properties.
Zheng ML1, Chen WQ, Fujita K, Duan XM, Kawata S. Nanoscale. 2010 Jun;2(6):913-6. doi: 10.1039/b9nr00402e. Epub 2010 May 4.
Organic crystals of trans-4-[4-(dimethylamino)-N-methylstilbazolium] p-tosylate (DAST) with enhanced nonlinear optical properties were successfully prepared at the nanometre scale due to the influence of a carbosiloxane dendrimer (CSiO-D).
4.The effect of a cationic porphyrin on Pseudomonas aeruginosa biofilms.
Collins TL1, Markus EA, Hassett DJ, Robinson JB. Curr Microbiol. 2010 Nov;61(5):411-6. doi: 10.1007/s00284-010-9629-y. Epub 2010 Apr 6.
Current studies have indicated the utility of photodynamic therapy using porphyrins in the treatment of bacterial infections. Photoactivation of porphyrins results in the production of singlet oxygen ((1)O(2)) that damages biomolecules associated with cells and biofilms, e.g., proteins, polysaccharides, and DNA. The effect of a cationic porphryin on P. aeruginosa PAO1 biofilms was assessed by exposing static biofilms to 5,10,15,20-tetrakis(1-methyl-pyridino)-21H,23H-porphine, tetra-p-tosylate salt (TMP) followed by irradiation. Biofilms were visualized using confocal laser scanning microscopy (CLSM) and cell viability determined using the LIVE/DEAD BacLight viability assay and standard plate counts. At a concentration of 100 μM TMP, there was substantial killing of P. aeruginosa PAO1 wild-type and pqsA mutant biofilms with little disruption of the biofilm matrix or structure. Exposure to 225 μM TMP resulted in almost complete killing as well as the detachment of wild-type PAO1 biofilms.
