181866-50-2Relevant articles and documents
Cytotoxicity of (2,2':6',2-terpyridine)platinum(II) complexes to Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei
Lowe, Gordon,Droz, Anne Sophie,Vilaivan, Tirayut,Weaver, George W.,Tweedale, Lindsay,Pratt, Jonathan M.,Rock, Peter,Yardley, Vanessa,Croft, Simon L.
, p. 999 - 1006 (1999)
A range of (2,2':6',2''-terpyridine)platinum(II) complexes are shown to possess antiprotozoal activity in vitro against Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei, the causative organisms of tropical diseases leishmaniasis and trypanosomiasis. The best compounds caused 100% and 78% inhibition of growth of the intracellular amastigote forms of L. donovani and T. cruzi, respectively, at a concentration of 1 μM and 100% inhibition of growth of the bloodstream trypomastigote forms of T. brucei at a concentration of 0.03 μM. The results obtained with complexes in which the fourth ligand to platinum(II) is capable of being substituted with a substitution inert hydroxyethanethiolate complex are compared. The amine complexes show high antiprotozoal activity suggesting that the trans influence of the 2,2':6',2''-terpyridine ligand has a profound effect on the ease of displacement of the fourth ligand in (2,2':6',2''- terpyridine)platinum(II) complexes, although nonbonded interaction between the amine ligand and the 6 and 6'' hydrogens probably also weakens the ligation to Pt(II).
The synthesis of 4′-aryl substituted terpyridines by Suzuki cross-coupling reactions: Substituent effects on ligand fluorescence
Goodall, Wendy,Wild, Kerstin,Arm, Kathryn J.,Williams, J.A. Gareth
, p. 1669 - 1681 (2007/10/03)
Several 4′-aryl-substituted 2,2′:6′,2″-terpyridines (tpy-C6H4R) have been prepared by palladium-catalysed cross-coupling of 4′-bromoterpyridine or 4′-triflate-terpyridine (triflate = trifluoromethylsulfonyloxy) with aryl boronic acids or esters, RC6H4B(OR′)2 (R = H, m-NH2, p-CHO, -NO2, -CN, -NMe2, -NPh2). The new ligand 4′-mesityl-terpyridine (mesityl = 2,4,6-trimethylphenyl) was prepared in the same way. Similarly, 4′-bromophenylterpyridine (tpy-φ-Br) has been cross-coupled with aryl halides to generate several new biaryl-substituted terpyridines (tpy-φ-C6H4R where R = H, p-CN, NMe2, NPh2), together with two related compounds with pendent 3- or 4-pyridyl groups (tpy-φ-C6H4-py). For selected compounds, the alternative coupling strategy of reaction of a terpyridine-4-boronate or terpyridine-4-phenylboronate with the appropriate aryl halide has also been investigated (e.g. to prepare tpy-φ-C6H4NO2), but was generally found to be less satisfactory. All of the compounds are fluorescent in the UV region of the spectrum, the biaryl-substituted compounds being only slightly red-shifted compared to the monoaryl systems, but with the further red-shift that accompanies protonation being more significant for the former. Fluorescence lifetimes in solution are in the range 1-5 ns. The emission spectra of the aminobiphenyl-substituted compounds (tpy-φ-C6H4NR″2, where R″ = Me or Ph) display a large red-shift with increasing solvent polarity, suggesting the involvement of an intramolecular charge transfer state, as found previously for the two analogues omitting the phenyl ring (tpy-C6H4NR″2). In contrast to the latter, however, protonation or binding of a Lewis acidic metal ion to the aminobiphenyl compounds serves to quench almost completely their emission.
