60350-13-2Relevant academic research and scientific papers
Macrocyclic Ligands with Pendant Phosphonic Acid Groups
Clegg, William,Iveson, Peter B.,Lockhart, Joyce C.
, p. 3291 - 3298 (1992)
Small aza- and oxaaza-macrocycles bearing two aliphatic nitrogens have been derivatised with pendant methylenephosphonates.Multinuclear NMR studies (31P and 1H) have elicited the protonation behaviour of one of these macrocycles.Improved methods of separation and purification of the ligands are discussed.The crystal structure of the parent 1,4,7-triazacyclononane-1,4,7-triyltris(methylenephosphonic acid) has been determined, indicating that two of the nitrogens are protonated under the conditions of crystallisation.Extensive hydrogen-bonding networks are evident in the structure.The Cambridge Structural Database has been used to survey structures based on 1,4,7-triazacyclononane and other amino(alkylphosphonates), amino(alkylphosphinates), and amino(alkanecarboxylates) and their metal complexes, for comparison.
From Cyclen to 12-Crown-4 Copper(II) Complexes: Exchange of Donor Atoms Improves DNA Cleavage Activity
Hormann, Jan,Van Der Meer, Margarethe,Sarkar, Biprajit,Kulak, Nora
, p. 4722 - 4730 (2015/10/19)
Macrocyclic CuII complexes with [NXOY] donor sets of different N/O ratios were synthesised resulting in a series ranging from cyclen (X = 4, Y = 0: 1) to 12-crown-4 (X = 0, Y = 4: 6) complexes. In order to elucidate the structure of the complexes UV/Vis spectroscopy and X-ray crystallography were applied, focusing especially on the literature-unknown compounds with regioisomeric [N2O2] and [NONO] donor sets (3, 4). The complexes were subjected to DNA cleavage experiments under reducing conditions and were also tested in the absence of a reducing agent. Although 3 and 6 were the most active DNA cleavers in the presence of reducing ascorbate, both of them and 4 also cleaved DNA (not hydrolytically) in its absence. This brings up questions regarding the cleavage mechanism. The present study is an expansion of our previously reported finding that heterosubstitution in macrocyclic ligands leads to changes in oxidative DNA cleavage activity of CuII complexes.
MACROHETEROCYCES. XXXVI. A CONVENIENT METHOD FOR SYNTHESIS OF DI- AND POLYAZACROWN ETHERS
Luk'yanenko, N.G.,Basok, S.S.,Filonova, L.K.
, p. 1562 - 1571 (2007/10/02)
A method is proposed for the production of di- and polyazacrown ethers by the condensation of bissulfonamides with dibromides or ditosyloxy derivatives in a two-phase aqueous alkali-toluene (benzene) system.The optimum concentration range for the substrate and the alkylating agent is 0.017-0.1 M.The catalytic activity of the quaternary ammonium salts decreases in the order (Bu)4NI > (Bu4)NBr > (Bu4)NCl > (Bu4)NHSO4 > (C2H5)3C6H5CH2NCl >> (Et)4NI > (Et)4NBr.The highest yields of te 12-membered azacrown ethers are obtained in the presence of lithium hyroxide, and the largest yields of the crown ethers with larger ring sizes are obtained in the presence of sodium or potassium hydroxide, and this is probably due to the matrix effects of the cation.
Macrobicyclic Amonoethers with Twelve-membered Rings
Alfheim, Tore,Buoeen, Solfrid,Dale, Johannes,Krautwurst, Klaus D.
, p. 40 - 49 (2007/10/02)
A one-pot reaction between alkane-1,2-diamines and triethyleneglycol ditosylate, or similar compounds having tosylamine functions instead of ether functions, gives without high dilution good yields of bicyclic compounds consisting of two twelve-membered rings with the alkane-diamine unit in common.The simplest representatives, 4,7,13,16-tetraoxa-1,10-diaza-bicycloeicosane and its 19-substituted derivatives, show strong cation complexation with a high selectivity for Na+ over Li+ and K+.Dynamic NMR spectroscopy shows that confomational processes, including amine inversion, are fast when the ethylene bridge is unsubstituted but become hindered when a methyl substituent is present.
