Stereochemistry of Ethylenediaminetetraacetato Complexes. II. The Structure of Crystalline Rb[Fe(OH2)Y].H2O. III. The Structure of Crystalline Li[Fe(OH2)Y.2H2O

Lind, Mats; Hamor, M. J.; Hamor, T. A.; Hoard, J. L.

doi:10.1021/ic50011a007

Cited by 197 publications

(44 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These coordinating atoms lie at the vertices of a pentagonal bipyramid. This coordination is similar to those obtained in other heptacoordinated EDTA complexes (Richards, Pedersen, Silverton & Hoard, 1964;Lind, Hamor, Hamor & Hoard, 1964;Stezowski, Countryman & Hoard, 1973;Passer et al, 1977;Solans et al, 1983b) which changes from the monocapped trigonal prism to the pentagonal bipyramid.…”

supporting

confidence: 66%

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

1983

View full text Add to dashboard Cite

supporting

confidence: 66%

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

1983

View full text Add to dashboard Cite

“…Can In view of the conclusions of Hoard and coworkers (22-30) the assumption of six-coordination is doubtful. They found the coordination numbers in aminopolycarboxylate complexes of the following ions were: Mn(II), seven (25); Fe(III), seven (26,30); Zr(IV), eight (27); Ln(III), eight to ten (28,29). Coordination numbers of seven and eight for Fe(II1) in aminopolycarboxylate complexes have also been proposed on the basis of Mossbauer studies (39,40).…”

Section: Cadmium (11)-dtpa Solutionsmentioning

confidence: 99%

“…A survey of the coordination chemistry of divalent metal -aminopolycarboxylate complexes revealed evidence for preferred octahedral coordination (17)(18)(19)(20)(21) but the X-ray crystallographic studies of Hoard and co-workers (22)(23)(24)(25)(26)(27)(28)(29)(30) indicate that this is a simplification and some principles for prediction of coordination number were proposed. DTPA is a potentially octadentate ligand.…”

Section: Figmentioning

confidence: 99%

Metal – Aminopolycarboxylic Acid Complexes. I. Studies of Lead(II) and Cadmium(II) Complexes with Diethylenetriaminepentaacetic Acid in Aqueous Solution by Proton Magnetic Resonance Spectroscopy

Letkeman¹,

Westmore²

1971

Can. J. Chem.

View full text Add to dashboard Cite

Lead(I1) and cadmium(I1) each form a 1 :1 complex with DTPA. Nuclear magnetic resonance (n.m.r.) spectroscopy was used to show that each complex has three metal-nitrogen bonds and labile metal-oxygen bonds to terminal acetate groups. The latter lead to proton equivalence for the methylene protons of the terminal acetate groups of the lead complex, and near equivalence for those of the cadmium complex. The central carboxylate group is coordinated to the lead but not to the cadmium. Protonation occurs below pH 5.5 for the lead complex and occurs predominantly at a terminal nitrogen atom with consequent breaking of the metal-nitrogen bond. In the cadmium complex protonation occurs below p H 5 at the terminal nitrogen, breaking the metal-nitrogen bond, and also to almost the same extent at the central, uncoordinated carboxylate group. These differences in behavior of the lead and cadmium complexes are attributed to differences in ionic size. Possible structures are proposed and allowances are made for the possibility of coordination number greater than six. In the protonated complexes, structures and interconversion of protonated forms are discussed in the light of the observed simplification of the n.m.r. spectra.Le plomb(I1) et le cadmium(I1) forment chacun un complexe 1 :I avec le DTPA. La spectroscopie r.m.n. a ktk utiliske pour montrer que chaque complexe possede trois liaisons mktal-azote et des liaisons labiles mktal-oxygene aux groupes acktates terminaux. Ces dernikre rendent kquivalent les protons du groupe mkthylene situks sur les groupes acktates terminaux dans le complexe avec le plomb. Une quasikquivalence est obtenue pour le complexe avec le cadmium. Le groupe carboxylate central est coordonnk au plomb mais pas au cadmium. Dans le cas d'un complexe avec le plomb, la protonation se fait pour un p H infkrieur a 5.5 et de prkfkrence sur un atome d'azote terminalavec pour conskquence la rupture de la liaison m6tal-azote. Avec le complexe du cadmium, la protonation se situe en dessous de p H 5 sur l'atome d'azote terminal, provoquant la rupture de la liaison mktal-azote, et avec la m&me importance sur le groupe carboxylate central non coordonnk. Ces diffkrences de comportement entre le complexe du plomb et celui du cadmium sont attribuables a des diffkrences de grosseurs ioniques. Des structures possibles sont proposkes et il est tenu compte de la possibilitk de nombres de coordination supkrieurs a six. Dans les complexes protonks, les structures et I'interconversion des formes protonkes sont discutkes a la lumiere de la simplification observke dans les spectres r.m.n.Canadian Journal of Chemistry, 49, 2073Chemistry, 49, (1971 IntroductionThe use of proton magnetic resonance (p.m.r.) spectroscopy for the study of aqueous solutions of aminopolycarboxylic acids (1-5) and their diamagnetic complexes with metal ions (5-16) is wellestablished. In this paper we describe a systematic study of the behavior of the aqueous systems: lead(I1)-DTPA and cadmium(I1)-DTPA, where DTPA represents diethylenetriaminepentaac...

show abstract

“…It has been found that EDTA can act as a pentadentate ligand, one-CHz-COOH arm being free (Stephens, 1969;Smith & Hoard, 1959), as a hexadentate ligand in six- (Weakliem & THE CRYSTAL AND MOLECULAR STRUCTURE OF [CreTTHA.2H20].6H20 Porai-Koshits, Novashilova, Polynova, Filippova & Martynenko, 1973) or seven- (Lind & Hoard, 1964;Hamor, Hamor & Hoard, 1964) coordinate complexes or as a bridging ligand (Fillippova, Polynova, Porai-Koshits, Novoshilova & Martynenko, 1973;Park, Glick & Hoard, 1969). The related ligand triethylenetetraminehexaacetic acid (H6TTHA) (a ligand with ten potential coordinating sites) has been extensively used as a coordinating ligand in e.s.r, studies, from which M-M contact distances are derived and possible structures for the complex proposed (Smith & Martell, 1972).…”

Section: Introductionmentioning

confidence: 99%

The crystal and molecular structure of diaquo-μ-triethylenetetramine-hexaacetatodichromium(III) hexahydrate, (Cr₂TTHA.2H₂O).6H₂O

Fallon¹,

Gatehouse²

1974

Acta Crystallogr Sect B

View full text Add to dashboard Cite

Stereochemistry of Ethylenediaminetetraacetato Complexes. II. The Structure of Crystalline Rb[Fe(OH₂)Y].H₂O. III. The Structure of Crystalline Li[Fe(OH₂)Y.2H₂O

Cited by 197 publications

References 0 publications

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

Metal – Aminopolycarboxylic Acid Complexes. I. Studies of Lead(II) and Cadmium(II) Complexes with Diethylenetriaminepentaacetic Acid in Aqueous Solution by Proton Magnetic Resonance Spectroscopy

The crystal and molecular structure of diaquo-μ-triethylenetetramine-hexaacetatodichromium(III) hexahydrate, (Cr₂TTHA.2H₂O).6H₂O

Contact Info

Product

Resources

About

Stereochemistry of Ethylenediaminetetraacetato Complexes. II. The Structure of Crystalline Rb[Fe(OH2)Y].H2O. III. The Structure of Crystalline Li[Fe(OH2)Y.2H2O

Cited by 197 publications

References 0 publications

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

Monopotassium salt of 3-hydroxy-2-methyl-4-nitro-2H-1,2,6-thiadiazine 1,1-dioxide, C4H4N3O5S−.K+

Metal – Aminopolycarboxylic Acid Complexes. I. Studies of Lead(II) and Cadmium(II) Complexes with Diethylenetriaminepentaacetic Acid in Aqueous Solution by Proton Magnetic Resonance Spectroscopy

The crystal and molecular structure of diaquo-μ-triethylenetetramine-hexaacetatodichromium(III) hexahydrate, (Cr2TTHA.2H2O).6H2O

Contact Info

Product

Resources

About

Stereochemistry of Ethylenediaminetetraacetato Complexes. II. The Structure of Crystalline Rb[Fe(OH₂)Y].H₂O. III. The Structure of Crystalline Li[Fe(OH₂)Y.2H₂O

The crystal and molecular structure of diaquo-μ-triethylenetetramine-hexaacetatodichromium(III) hexahydrate, (Cr₂TTHA.2H₂O).6H₂O