3- hexaamines

At pH 7, [13]aneN3 or [12]-[15]aneN4 accommodate only two nitrogen-bound protons and these dipositive ammonium cations are apparently unable to provide sufficient electrostatic attraction to polycarboxylate anions for ion-pair formation. In contrast, the macrocyclic spermines, pentaamines and hexaamines accommodate more than three nitrogen-bound protons at pH 7 and for these ligands 1 1 associations... 

The new macrocyclic hexaamine ligand X has the mixed protonation constants, log K of 10.10, 10.01, 8.96 and 8.02 at 25 °C and 1=0.2 M for the four most basic amines. The values for other weaker bases, including the six carboxylates, are all less than 5. From a comparison with logA values of the parent macrocycle [18]aneN6, it was deduced that the initial four protonations occur to the macrocyclic amine bases. Thus, the most abundant species of X at neutral pH is depicted as XI. 

Poly(dG-dC) poly(dG-dC) and its methylated analogue structures assume left-handed conformation (Z-DNA) in high molar sodium salt (Na", K" ), in low molar divalent cations (Ca", Mg", Ni ), micromolar concentrations of hexaamine cobalt chloride (Co(NH3)6)Cl3 and in millimolar concentrations of polyamines. In order to analyse the binding of berberine to Z-form DNA, Kumar et al. [186] reported that the Z-DNA structure of poly(dG-dC) poly(dG-dC) prepared in either a high salt concentration (4.0 M) or in 40 mM (Co(NH3)6)Cl3 remained invariant in the presence of berberine up to a nucleotide phosphate/alkaloid molar ratio of 0.8 and suggested that berberine neither bormd to Z-form DNA nor converted the Z-DNA to the... 

The [Co(phen)3]3+ complex is photoactive and a powerful oxidant in its excited state. The ion has no H-bonding groups and hence is considerably more hydrophobic1279 than hexaamine relatives. These properties have proven particularly useful. Aryl and alkyl substituted [Co(phen)3]3+ complexes have received a great deal of attention due to their ability to intercalate within the helical structure of DNA through a combination of electrostatic and hydrophobic forces. The chirality of the tris-chelate complex is crucial in determining the degree of association between the complex and... 

The S-oxygenation of the hexaamine-dithiophenolate macrocycles should provide a potential entry into the novel class of binucleating polyamine-disulfonate and -disulfinate macrocycles. Indeed, such ligands can be prepared by the oxidation of dinuclear nickel complexes of the parent hexaaza-dithiopheno-late macrocycles followed by the decomposition of the oxidation products in acidic solution. The dinuclear nickel complexes [Nin2(L36)(L )]+ (L = Cr (70) and OAc (71)) of the hexaaza-diphenylsulfonate ligand (L36)2- (Fig. 38) are obtained by... 

Forms a number of coordination compounds (ammonia complex) with several metals adds to AgCl forming soluble complex [Ag(NH3)2]Cl forms tetraamine complex [Cu(NH3)4]S04 with CUSO4 and forms many hexaamine complexes with cobalt, chromium, palladium, platinum and other metals. 

Diamino-3,6,9,12-tetiaazatetradecane, co-balt(III) hexaamines, 35 145-147 Diaminotetracarboxylatocobaltates, circular di-chrosims, 9 205... 

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