Circular dichroism of a second geometrical isomer of ethylenediamine-N,N'diacetato-N,N'-di-3-propionatocobaltate(III) ion

Synthetic, Crystallographic, and Computational Study of Copper(II) Complexes of Ethylenediaminetetracarboxylate Ligands

“…With respect to the carboxylate donors, the three possible isomers are shown in Figure 1, where the nomenclature trans(O 5 ) and trans(O 6 ) refers to axial acetato and propionate groups, respectively. 9,10 The sixmembered carboxylate rings of ethylenediamine-N,N′-diacetato-N,N′-dipropionato ion ([eddadp] 4− ) serve better for the formation of less-strained G rings favoring the trans(O 5 ) isomer of [M(eddadp)] n− complexes when M = Co III , 23,24 Cr III , 25,26 and Rh III or Ni II . 11,27,28 It is worth noting that, for Co III and Rh III , the less stable trans(O 5 O 6 ) isomer is also found and characterized.…”

“…22 For the edta-type ligands having mixed (five-and six-membered) carboxylate arms, geometrical isomers are possible that differ in the number (0, 1, 2, or 3) of six-membered rings lying in the G plane. Such 23,24 Cr III , 25,26 and Rh III or Ni II . 11,27,28 It is worth noting that, for Co III and Rh III , the less stable trans(O 5 O 6 ) isomer is also found and characterized.…”

“…Such ligands (ethane or 1,3-propanediamine- N , N ′-diacetate- N , N ′-di-3-propionate ions ({[eddadp] 4– or [pddadp] 4– , respectively}) relieve in-plane strain, thus allowing the complexes to attain bite angles closer to the octahedral ideal with apparently less strain in the M–L bonds. With respect to the carboxylate donors, the three possible isomers are shown in Figure , where the nomenclature trans(O 5 ) and trans(O 6 ) refers to axial acetato and propionate groups, respectively. , The six-membered carboxylate rings of ethylenediamine- N , N ′-diacetato- N , N ′-dipropionato ion ([eddadp] 4– ) serve better for the formation of less-strained G rings favoring the trans(O 5 ) isomer of [M(eddadp)] n − complexes when M = Co III , , Cr III , , and Rh III or Ni II . ,, …”

Cobalt(II) complexes with aminopolycarboxylate 1,3-pdta-type ligands: synthesis and characterization of trans(O6)-[Mg(H2O)6][CoII(1,3-pddadp)]·H2O

“…In relation to edta these structurally related ligands have changes in the diamine chain (1,3-propanediminetetraacetate ion, 1,3-pdta [3][4][5][6][7][8][9][10][11]) or in the carboxylate arms (ethylenediamine-N,N¢-diacetate-N,N¢-di-3-propionate ion, eddadp [2,[12][13][14][15][16][17][18][19][20][21][22]), but most of them have longer diamine chains as well as longer single or more carboxylate arms (1,3propane-diamine-N,N¢-diacetate-N,N¢-di-3-propionate ion, 1,3-pddadp [23][24][25][26][27][28]). The coordination chemistry of these edta-type ligands is very interesting because they can form hexadentate complexes with rather large metal ions and under their hexadentate coordination more geometrical isomers can be obtained.…”