The Chelating AgentN,N,N',N'',N''',N'''-Triethylenetetraminehexacetic Acid (TTHA)

N,N-Bis(2-oxopyrrolidin-1-ylmethyl)glycine

“…The planar carboxylmethyl group is approximately parallel to the plane defined by N2, 03, C3, C4--C7 with a dihedral angle of 10.7 (1) °, while it is slanted to the plane defined by N3, 04, C8, C9-C12 with a dihedral angle of 57.61 (8) °. The bond lengths and angles in the molecule are in good agreement with corresponding values previously reported (2-oxo-l-pyrrolidinyl)acetamide (Admiraal et al, 1982;LouSr et al, 1995), PMRCT (Bandoli et al, 1987), N, N,N',N",N'",N"'-triethylenetetraminehexacetic acid (TTHA) (Finnen & Pinkerton, 1997) and N-(hydroxyethyl)ethylenediaminetriacetic acid (H3heedta) (Kettmann et al, 1993). In the molecule, the nine C--N bonds can be divided into two groups, of which seven C--N bonds lengths, falling in the range 1.440 (2)-1.459 (2)A, characterize C--N single bonds showing that the central N1 atom is a neutral one (Billing et al, 1991;Finnen & Pinkerton, 1997).…”

“…The bond lengths and angles in the molecule are in good agreement with corresponding values previously reported (2-oxo-l-pyrrolidinyl)acetamide (Admiraal et al, 1982;LouSr et al, 1995), PMRCT (Bandoli et al, 1987), N, N,N',N",N'",N"'-triethylenetetraminehexacetic acid (TTHA) (Finnen & Pinkerton, 1997) and N-(hydroxyethyl)ethylenediaminetriacetic acid (H3heedta) (Kettmann et al, 1993). In the molecule, the nine C--N bonds can be divided into two groups, of which seven C--N bonds lengths, falling in the range 1.440 (2)-1.459 (2)A, characterize C--N single bonds showing that the central N1 atom is a neutral one (Billing et al, 1991;Finnen & Pinkerton, 1997). The two shorter C--N bonds, C4--N2 [1.353 (2)A] and C9--N3 [1.339 (2),~], together with the coplanarity of the non-H atoms around N2 or N3 atoms, indicate the conjugation of the lone pair of electrons of N with the adjacent C==O group (Admiraal et al, 1982;Billing et al, 1991).…”

“…The two shorter C--N bonds, C4--N2 [1.353 (2)A] and C9--N3 [1.339 (2),~], together with the coplanarity of the non-H atoms around N2 or N3 atoms, indicate the conjugation of the lone pair of electrons of N with the adjacent C==O group (Admiraal et al, 1982;Billing et al, 1991). The seven C---C single bond distances from 1.494 (3) to 1.519 (3)A,, and the two C==O distances of the 2-pyrrolidone group, 1.220 (2) and 1.235 (2),~, are CI2HI9N304 all comparable with those bond distances found in the literature (Admiraal et al, 1982;Bandoli et al, 1987;Billing et al, 1991;Finnen & Pinkerton, 1997;LouEr et al, 1995;Mtiller et al, 1996). The two dissymmetric CmO bonds [1.201 (2) and 1.319 (2)A,] of the carboxyl group agree with those found in TTHA (Finnen & Pinkerton, 1997), H3heedta (Kettmann et al, 1993), and some derivatives or complexes of betaine (Ilczyszyn, Barnes et al, 1995;Ilczyszyn, Lis & Ratajczak, 1995;Ratajczak et al, 1994), and show that the carboxyl group is in an acid form.…”

“…Derivatives of 2-pyrrolidone and polyaminocarboxylates have been used widely to form transition metal or lanthanide complexes (Doyle et al, 1993(Doyle et al, , 1995Finnen & Pinkerton, 1997;Goodgame et al, 1996) with interesting structures and properties. Recently we have synthesized the title compound, (I), which contains 2pyrrolidone as well as aminocarboxylate groups, and found that some lanthanide complexes with this ligand exhibited interesting properties such as photochromicity (Jin et al, unpublished work).…”