Infrared studies of cis- and trans-bis(halogenoacetato)bis(ethylenediamine)-cobalt(III) complexes

Abstract

The infrared spectra have been studied for cis-and trans-isomers of complexes of the type [Co(en),-(halac),]C104, where en = ethylenediamine and halac = CH3CO2-, CH2ClC0,-, CHCIZCO,-, CCl,CO,-, CHBr,C02-, and CF3C0,-. Characteristic differences between the spectra of cis-and :mlrs-isomers have been examined and correlated mith data for similar complexes. The most consistent variations are in the 500-610 cm-I region where Co-N stretching modes occur.

Thermodynamics and kinetic investigation of electron transfer reactions of surfactant cobalt(iii) complexes containing diimine ligands with iron(ii) in the presence of liposome vesicles and amphiphilic salt media

“…For our studies, only unilamellar vesicles (ULV) were used and these were prepared by ethanol injection. 38 A solution of the lipid in ethanol was injected rapidly into the buffer with the help of a ne needle and maintained at 50 C under optimized conditions. The volume of ethanol injected was always <1% v/v in order to avoid any damage to the liposome.…”

First X-ray structure of a cis-isomer of cobalt(III) aromatic carboxylate: Synthesis, and characterization of [cis-Co(en)2(C8H7O2)2](C8H7O2)·2H2O, where C8H7O2=p-methylbenzoate

“…Although cis-and trans-isomers of Co(III) complexes, e.g., [Co(en) 2 (H 2 O)Cl] 2+ [1], [Co(en) 2 (halogenoacetato) 2 ] + [2], [Co(en) 2 (N 3 )(C 2 O 4 )] [3] are known in the literature but in the case of [Co(pn) 2 (p-chlorobenzoato) 2 ] + [4] as well as [Co(en) 2 (benzoate) 2 ] namely, [Co(en) 2 (p-fluorobenzoato) 2 ] [5], [Co(en) 2 )(p-aminobenzoato) 2 ] + [6], all the complexes known have trans-configuration where pn = propylenediamine and en = ethylenediamine. During investigation of the reactions of [trans-Co(en) 2 )Cl 2 ]Cl with various sodium benzoate salts, we have isolated and characterized for the first time a cis-compound, [Co(en) 2 [7] in continuation of our interest in cobalt(III) salts [8][9][10].…”

“…During investigation of the reactions of [trans-Co(en) 2 )Cl 2 ]Cl with various sodium benzoate salts, we have isolated and characterized for the first time a cis-compound, [Co(en) 2 [7] in continuation of our interest in cobalt(III) salts [8][9][10]. X-ray structure determination of this compound [11] is described here.…”

“…[trans-Co(en) 2 In the complex cation [cis-Co(en) 2 (C 8 H 7 O 2 ) 2 ] + , the cobalt(III) is bonded to four nitrogen atoms, originating from two ethylenediamine molecules, and two oxygen atoms of two carboxylate groups showing an octahedral geometry around cobalt.…”

“…The complex cation and the non-coordinated anion are associated in ionic pairs through two H-bonds, from each en molecule towards each oxygen atom of the carboxylate (see Fig. 3 2 ] structure which means this is first structure of its type.…”