Absorption ethylenediamine complexes

Absorption Bands for Ethylenediamine and Ethylenediamine Complex of Platinnm(II)... 

Analysis of Corexit 9527. Corexit 9527 in natural waters can be analyzed. The method is based on the formation of a Z>w(ethylenediamine) copper(II) complex, extraction of the complex into methylisobutylketone, and atomic absorption spectroscopy [1564]. The method is suitable for a concentration range of 2 to 100 mg/liter, with a precision as low as 5% relative to standard deviation for samples in the middle- to high range. Only a small sample volume (10 ml) is required. The sensitivity may be substantially increased for trace analysis by increasing the sample volume. 

Another attempted synthesis of Tc(III)-EDTA and Tc(III)-HEDTA complexes (EDTA ethylenediaminetetraacetic acid HEDTA A -(2-hydroxy-methyl)ethylenediamine-N,AT, iV -triacetic acid) was carried out using [Tc(tu)6]3+ as the starting complex [40]. Technetium-EDTA complexes have been synthesized by the direct reduction of pertechnetate with a suitable reduc-tant in the presence of excess EDTA [41-43]. On addition of EDTA to the Tc(tu) + solution, the intensity of the absorption spectrum decreased with time and the solution color changed from reddish orange to light brown. An electrophoretic analysis for the Tc(III)-EDTA complex showed that more than 70%... 

The preparations proved to be 98 to 99% chromatographically pure, the contaminant always being the other isomer. The various absorption maxima are reported in Table I. All solutions were 0.01 M in complex. Those designated as HC or HT were measured either in water at pH 5-6, or in O.lM sodium acetate-acetic acid buffer at pH 5.5 (no spectral differences resulted) and those designated C or T were adjusted to pH 10.5 with ethylenediamine. 

Figure 20. The circular dichroism and absorption spectra of cobalt(III) complexes containing (-)-propylenediamine and/or ethylenediamine (in aqueous solution).

To 27.5 g. (0.1 mole) of crude (carbonato)bis(ethylenediamine)-cobalt(III) chloride is added 200 ml. of 1.00 N hydrochloric acid. The carbonato complex is dissolved with evolution of carbon dioxide gas and formation of a red solution consisting primarily of the corresponding cw-diaqua species. The solution is evaporated in the steam bath until an almost dry paste has been formed. The purple residue is filtered and washed with three 20-ml. portions of ice-cold water. Drying in air yields 19.5 g. of purple crystals of cu-dichlorobis(ethylenediamine)cobalt(III) chloride. The mother liquor and the washings are again evaporated almost to dryness to yield a second crop of crystals, 5.9 g. The total yield is 25.4 g. (84% based on (carbonato)bis(ethylenediamine)cobalt(III) chloride). The analysis and the visible absorption spectrum of the two fractions are identical. Anal. Calcd. for [Co(en)2Cl2 ] C1 H20 Co, 19.42 N, 18.46 C, 15.82 Cl, 35.05 H, 5.98. Found Co, 19.50 N, 18.57 C, 15.77 C1, 35.15 H, 6.01. 

The sodium tran.y-bis(ethylenediamine)disulfitocobaltate(III) is identical in all respects with the product prepared by Baldwin s method, although the absorption peak for the product obtained by either method is observed at 439 nm., compared with 431 reported by Baldwin. The complex ion undergoes rapid acid or base hydrolysis to form the aquabis(ethylenediamine)sulfito-... 

The absorption bands can easily be classified as MLCT or LC based on their extinction coefficients and band energies. But assigning them to specific ligands in mixed ligand complexes can be quite difficult or impossible on the basis of solution spectra. Ethylenediamine does not have an extended aromatic system... 

This 1 1 complex, a white crystalline solid of considerable stability, is prepared either by heterogeneous absorption of diborane by ethylenediamine in a high vacuum apparatus or by reaction of ethylenediamine with the tetrahydrofurane-borane complex ... 

The Cu ion reacts with [OH] to form [CuOH] , which exhibits a pH-depen-dent absorption with = 300 nm. CopperdH) complexes with NHj, ethylenediamine and various amino acids are characterized by pulse radiolysis . The [Cu(EDTA)] (EDTA = ethylenediaminetetraacetate) and [Cu(NTA)] (NTA = nitrilotriacetate) ions are oxidized to the corresponding Cu(III) species by [OH] Cu(lII) rearranges and then metal-ligand intramolecular electron transfer yields some Cud) species . 

Figure 8 shows absorption spectra of the bis(acetylacetonato) complexes of ethylenediamine (en, N-C-C-N) (12), N-C-C-P, and P-C-C-P in ethanol. The band around 20,000 cm l of each complex can be assigned to the first d-d absorption band, although the intensities increase remarkably with an increase in the number of the ligating phosphorus atoms. From the shift of the band maxima, it is concluded that phosphorus stands at a higher position than nitrogen in the spectrochemical series. 

Figure 6. Absorption and CD spectra of s-cis-[Co(edda)en]NOs H20 and the corresponding complexes of N,N dimethyl and N,N -diethyl ethylenediamine-H,...

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