1.3- Propanediamine metal complexes

Propanediamine, V-[2-(2-aminoethyl)amino]ethyi-metal complexes, 2, 51... 

Siddiqi et al. (109) prepared a number of tetrakis(dithiocarbamate) complexes, [M(S2CNHR)4] (M = Ti, Zr), derived from primary amines. These can be accessed from the reaction of the pre-formed dithiocarbamate salt, as is the case for propanediamine dithiocarbamate complexes (R = CH2CH2CH2NH2), or from their in situ generation in the presence of the metal tetrachloride (R = A -phenyl-a-naphthylamines, 2-amino-benzothiazole, benzidine, 2,4-tolylene-diamine) (616). 

Absorption and c.d. spectra of the complex formed between oxovanadium-(iv) and the Schiff base derived from (J )-l,2-propanediamine and two moles of acac indicate that the co-ordinated Schiff base moiety is close to planarity. The lack of spin-spin coupling between metal centres in iViV -propy-lenebis(salicyliminato)oxovanadium(iv) molecules (// = 1.78BM) has been discussed. Some seven new oxovanadium(iv) complexes with iV-(2-hydroxy-... 

Kx for copper (II)-diamine complex is 10.36 and 9.45 for 1,2-ethanediamine and 1,3-propanediamine, respectively (-2)]. The large difference in the stabilities of the two copper (II)-diamine complexes is attributed to an unfavorable entropy effect associated with an increase in the size of the metal-chelate ring (2). Extrapolating to the / -ketoimine derivatives, it seems reasonable to expect that the stability of bisacetylacetonetrimethylenediiminocopper(II) would be less than that of the ethylenediamine analog and to suspect that the former compound is less stable than bis-(4-iminopentane-2-ono) copper (II). That this is reasonable is... 

Trace levels of soluble metal compounds, particularly copper, catalyze the oxidative degradation of gasoline by promoting the formation of gums and deposits. Metal deactivators overcome this problem by chelating the metal and rendering it inactive. The most widely used metal deactivator is N, N -disalicylidene-l,2-propanediamine, the copper complex of which is shown in Figure 3. 

Figure 3. Structure of the copper complex of the most widely used metal deactivator N, N -disalicylidene-l,2-propanediamine.

It has been found4 that a good yield may be obtained rapidly by allowing the commercially available green chromic chloride, CrCl8-6H20, in methanol to boil under reflux with ethylenedi-amine in the presence of metallic zinc. The product, hydrated tris(ethylenediamine)chromium(III) chloride, is obtained as a solid and is readily purified. An exactly similar procedure may be used for the complex of 1,2-propanediamine. 

The condensation of 2V,A -bis(3-aminopropyl)ethylenediamine (7V,A -ethylene-bis[l,3-propanediamine]) as its acid salt with 2,3-butanedione (biacetyl) in the presence of cobalt(II) or nickel(II) acetate gives complexes of 2,S-Mej [14] - 1,3-diene-l,4,8,11-N4 containing one a-diimine linkage. Experiments have shown that the presence of H ion determines whether or not a macrocyclic complex forms and that, in the presence of H, the time at which the metal acetate is added to the reaction mixture influences the yield of the complex. Unlike the reaction between biacetyl and 1,3-propanediamine to form 2,3,9,10-Me4[14]-1,3,8,10-tetraene-l,4,8,11-N4 (Sec. 4), the condensation of biacetyl withTVA -bis(3-aminopropyl)ethylenediamine is particularly sensitive to excess acetate so that the procedures given use the optimized conditions. 

Carboxamides containing alkylamine arms like (34), synthesized from dialkylmalonate and ethylene-diamine, act as chelating dianionic N4-donors,44,45 whereas the geometric isomer (35) was prepared from 1,3-diaminopropane and chloroacetyl chloride.46 The hexadentate bis(pyrazine)-carboxamides (36) and (37) can be obtained by the addition of 1,3-propanediamine to the appropriate carboxylic acid.47 Compound (36), in the dianionic form, can be used to obtain homo- and hetero-metal bridged complexes, whereas (37) has been shown to yield tetranuclear copper(II) complexes involving opened-up dianionic ligand molecules.47... 

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