Tetraazacyclotetradecane derivative

Figure 4 Bicyclam derivatives (A) JM2763 and (B) JM3100, each consisting of two cyclam (1,4,8,11-tetraazacyclotetradecane) moieties tethered via a propylene (JM2763) or phenylenebis(methylene) bridge (JM3100).

The first structurally characterized example of a platinum(II) derivative containing a saturated tetraamine macrocycle, 6,13-dimethyl-l,4,8,ll-tetraazacyclotetradecane-6,13-diamine has been reported (80).251 The species crystallizes as the colorless tetra-cationic complex from dilute HC104 solution by slow evaporation, where the two pendant primary amines are protonated. Other macrocyclic tetraamine complexes including [Pt([14]aneN4)]Cl2 have also been described.252... 

Complexation and determination of formation constants has been studied with the tetramethyl-cyclam (l,4,8,ll-tetramethyl-l,4,8,ll-tetraazacyclotetradecane) ligand.686 A series of zinc N4 donor macrocyclic complexes with different ring sizes were synthesized and characterized for comparison with cadmium derivatives.687... 

Spin crossover in iron(III) has been generated using the N4-donating macro-cyclic ligands 1,4,8,11-tetraazacyclotetradecane (cyclam) and its tetramethy-lated derivative (tmcyclam), as well as with the Schiff base system H2amben (Fig. 13). 

Dong, Y., Lawrance, G. A., Lindoy, L. F., and Turner, P. (2003) Macrocyclic ligand design. Interaction of a series of successively N-benzylated derivatives of 1,4,8,11-tetraazacyclotetradecane (cyclam) with copper(II) and nickel(II), Dalton Trans. (8), 1567-1576. 

Since publication of CHEC-II(1996), the field covered by this chapter has expanded enormously. The development is driven mainly by an extensive use of the cycles in metal and/or anion complexation, in modeling of enzyme reactions, in catalysis, and, mostly, in medicine as contrast agents (CAs) for magnetic resonance imaging (MRI), radiopharmaceuticals, or drugs. The chemistry is mainly focused on derivatives of two of the most important macrorings 1,4,7,10-tetraazacyclododecane (cyclen) 1 and 1,4,8,11-tetraazacyclotetradecane (cyclam) 2. From related compounds, tetrakis(acetic acid) derivatives DOTA 3 (DOTA= 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and TETA 4 (TETA = 1,4,8,1 l-tetraazacyclotetradecane-l,4,8,ll-tetraacetic acid) and their analogs/derivatives are of the main interest. 

Tritopic cyclen- and isocyclam- (isocyclam = 1,4,7,11-tetraazacyclotetradecane) based ligands 121 and 122 were prepared according to Scheme 17. Tosylated tren derivative (tren = tris(2-aminoethyl)amine) was cyclized under Richman-Atkins conditions to give the fully tosylated amines in relatively high yield considering the [1+3] reaction <2002JOC9107>. 

The tetradentate ligand, 1,4,8,11-tetraazacyclotetradecane (cyclam), forms solid diamagnetic orange to brown Ni(II) complexes with iodide and perchlorate anions (9). When the anions are changed to chloride and bromide, the solid complexes are paramagnetic (9). However, all the complexes are soluble in water, methanol, and benzene, giving yellow solutions. The yellow color remains on treatment with 12N HCl and excess chloride ion (9). It is interesting to note that this amine is a derivative of a reduction product of the template syntheses between bis(ethylenediamine)-nickel(II) and acetone reported earlier. 

A normal coordinate analysis (NCA) for hexazacyclophane Cu(II) complex was performed by using the Wilson s force field geometrical matrix (FG) method . An INDO/1 optimized molecular geometry was used to build the G matrix . The CuN distance is 1.84 A for the copper atom in the macrocycle plane this bond length is relatively short in comparison to that reported for the non-macrocycle tris-(l,10-phenantroline)Cu(II) (2.1 A) the planar macrocycles copper porphin (2.031 and tetraazacyclotetradecane Cu(II) derivatives (2.08... 

The first example shows the synthesis of a C-C-bridged bis-macrocycle (Figure 2) [7]. The preparation of 1 is a condensation of a polyamine with a malonic ester derivative, in analogy to the procedure developed by Tabushi et al [8]. The tetraamide 1 is so insoluble that it precipitates and can be obtained practically pure from the reaction mixture. Its reduction to the octaamine takes place if the reaction with is done in diglyme (bis-(2-methoxyethyl)ether), in which 1 is partially soluble. The product 2 is an ideal ditopic ligand,since it has all the typical properties of 1,4,8,11-tetraazacyclotetradecane (cyclam), i. e. the thermodynamic and kinetical stability of its complexes and the C-C linkage between the two macrocyclic subunits does not reduce the coordination tendency of the amine nitrogens. 

Tetraheterodecalin podands, their linkers, and resulting macrocycles A hoard of constitutionally and stereochemically dynamic systems 13IJC45. Thermodynamics and kinetics of CO2, CO, and H binding to the metal centre of CO2 reduction catalysts, in particular, cobalt and nickel complexes of 1,4,8,11-tetraazacyclotetradecane (cyclam) and its derivatives 12CSR2036. 

With tetraazacyclotetradecane and derivatives [Ni l,4,8,ll-(CH3)4CioH2oN4 Cl]C104 room 3.3 five-coordination suggested 73B11... 

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