Polyamine complexes

Thermochemistry of metal-polyamine complexes. P. Paoletti, L. Fabrizzi and R. Barbucci, Inorg. Chim. Acta, Rev., 1973,7, 43-68 (100). 

Kimura, E., Kurogi, Y. and Takahashi, T. (1991) The first gold(III) macrocydic polyamine complexes and application to selective gold(III) uptake. Inorganic Chemistry, 30, 4117. 

It was proposed that mono-protonation of [CuL]2+ to yield [Cu(HL)]2+ occurs initially at the axial nitrogen atom since this Cu-N bond is expected to be weaker as a result of Jahn-Teller distortion. With respect to this, it should be noted that species such as [Cu(HL)]3+ are commonly observed during potentiometric studies of the formation of Cu(n) polyamine complexes. From the proposed mechanism, the following rate law can be deduced ... 

The dissociation rate constant measures directly the value of k 2 in (4.52). The strain resident in multi-ring complexes is clearly demonstrated by some hydrolysis rate studies of nickel(II) complexes. The AFT values for the first bond rupture for Ni(II)-polyamine complexes fall neatly into groups. They are highest for en, containing the most strain-free ring (84 kJ mol ), about 75 kJ mol for complexes with terdentate ligands and only —63 kJ mol for complexes of quadridentate and quinquedentate amines and with NH3 itself. See also Ref. 109. 

Of course, when highly dentated ligands have to be replaced, more complicated behavior is observed. In this category, are the well-studied ligand exchange reactions of edta and polyamine complexes, a typical one of which (charges omitted) is... 

Modem work on these and related bare post-transition element clusters began in the 1960s after Corbett and coworkers found ways to obtain crystalline derivatives of these post-transition element clusters by the use of suitable counterions. Thus, crystalline derivatives of the cluster anions had cryptate or polyamine complexed alkali metals as countercations [8]. Similarly, crystalline derivatives of the cluster cations had counteractions, such as AlCLj, derived from metal halide strong Lewis acids [9]. With crystalhne derivatives of these clusters available, their structures could be determined definitively using X-ray diffraction methods. 

Polyamine complexes of organolithlum compounds have been extensively studied (8). Recent work by Fontanllle et al (24) has shown that also in these systems two isomeric ion pair complexes can be formed. The spectrophotometrlc "ion pair probe" used was 9-propylfluorenylllthlum (PFl ,Li+), which was complexed with tetramethyl ethylene diamine (TMEDA), hexamethyl triethylene tetramlne (HMTT) and tetramethyl tetraaza cydotet-radecane... 

The subject matter of this chapter will be subdivided into sections concerning template synthesis of the complexes structural and thermodynamic properties of the complexes with synthetic cyclic polyamines complexes with mixed-donor macrocycles reactivity of the complexes cryptates and complexes with phthalocyanines and porphyrins. 

Kimura, E., Shionoya, M., Hoshino, A., Ikeda, T., Yamada, Y., A model for catalytically active zinc(II) ion in liver alcohol-dehydrogenase - a novel hydride transfer-reaction catalyzed by zinc (II) -macrocyclic polyamine complexes. J. Am. Chem. Soc. 1992,114, 10134-10137. 

Copper(II) polyamine complexes are substitutionally labile, in a manner similar to the corresponding nickel(II) complexes. This means that individual donor atoms may at times decoordinate and thus be available for derivatization reactions, e.g., with suitable carbonyl compounds. More complex ligands may thus be constructed, including macrocycles (35), polymacrocycles (36 38), and concave chelators (35). The copper(II) complex of 1 was synthesized as a starting material for reactions aiming at the derivatization of the pentaamine ligand (24-28). 

Koike T, Kimura E (1991) Roles of zinc(II) ion in phosphatases - a model study with zinc(II) macrocyclic polyamine complexes. J Am Chem Soc 113 8935-8941... 

Table 51 Electronic Spectra of some Polyamine Complexes of Rhm...

The kinetics of the thermal decomposition of Cupy4(NCS)2 have been studied (425), as have the thermodynamics of the reaction of NCS with various polyamine complexes of copper(III) leading to the formation of bonds (70). 

Since coordinatively unsaturated Zn polyamine complexes display a good affinity towards the COO group, the [Zn (42)] + platform was first tested for fluorescent sensing of carboxylate anions. For instance, there is evidence from spec-trophotometric titration experiments that [Zn (42)] + forms a stable adduct with benzoate, in ethanolic solution at 25 °C. However, even after the addition of a large excess of benzoate to an ethanolic solution of [Zn (42)] +, the typical fluorescent emission of the anthracene fragment is not altered at all. Quite interestingly, when a solution of [Zn (42)] " is titrated with the 4-A,JV-dimethylamine-benzoate anion, the anthracene emission is progressively quenched the fluorescence intensity, Ip, versus anion equivalents profile corresponds to the formation of a T. 1 adduct, and... 

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