Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+

Evidence for a Continuum of Metal Ion Hydration States

Mark Woods, Katherine M. Payne, Edward J. Valente, Benjamin E. Kucera, Victor G. Young

Research output: Contribution to journalArticle

Abstract

The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and the octadentate polyamino carboxylate ligand DOTMA are described. A total of 23 individual chelates structures were obtained; in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle −25.0°–−31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3+ chelates are associated with a single inner sphere water molecule; the Ln-OH2 interaction is remarkable for being very long. After a clear break at gadolinium, the number of chelates in the unit cell that have a water molecule interacting with the Ln3+ decreases linearly until at Tm3+ no water is found to interact with the metal ion. The Ln-OH2 distance observed in the chelates of the later Ln3+ ions are also extremely long and increase as the ions contract (2.550–2.732 Å). No clear break between hydrated and dehydrated chelates is observed; rather this series of chelates appear to represent a continuum of hydration states in which the ligand gradually closes around the metal ion as its ionic radius decreases (with decreased hydration) and the metal drops down into the coordination cage.

Original languageEnglish (US)
Pages (from-to)9997-10005
Number of pages9
JournalChemistry - A European Journal
Volume25
Issue number42
DOIs
StatePublished - Jul 25 2019

Fingerprint

Hydration
Metal ions
Crystal structure
Ligands
Ions
Water
Lanthanoid Series Elements
Molecules
Geometry
Gadolinium
Rare earth elements
Torsional stress
Metals
N-(1-(2,3-dioleyloxy)propyl)-N,N,N-trimethylammonium

Keywords

  • coordination mode
  • fractional coordination number
  • hydration
  • ionic radius
  • lanthanides

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Organic Chemistry

Cite this

Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+ : Evidence for a Continuum of Metal Ion Hydration States. / Woods, Mark; Payne, Katherine M.; Valente, Edward J.; Kucera, Benjamin E.; Young, Victor G.

In: Chemistry - A European Journal, Vol. 25, No. 42, 25.07.2019, p. 9997-10005.

Research output: Contribution to journalArticle

Woods, Mark ; Payne, Katherine M. ; Valente, Edward J. ; Kucera, Benjamin E. ; Young, Victor G. / Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+ : Evidence for a Continuum of Metal Ion Hydration States. In: Chemistry - A European Journal. 2019 ; Vol. 25, No. 42. pp. 9997-10005.
@article{795e96469b8f46abbc0da13d2cb21807,
title = "Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+: Evidence for a Continuum of Metal Ion Hydration States",
abstract = "The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and the octadentate polyamino carboxylate ligand DOTMA are described. A total of 23 individual chelates structures were obtained; in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle −25.0°–−31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3+ chelates are associated with a single inner sphere water molecule; the Ln-OH2 interaction is remarkable for being very long. After a clear break at gadolinium, the number of chelates in the unit cell that have a water molecule interacting with the Ln3+ decreases linearly until at Tm3+ no water is found to interact with the metal ion. The Ln-OH2 distance observed in the chelates of the later Ln3+ ions are also extremely long and increase as the ions contract (2.550–2.732 {\AA}). No clear break between hydrated and dehydrated chelates is observed; rather this series of chelates appear to represent a continuum of hydration states in which the ligand gradually closes around the metal ion as its ionic radius decreases (with decreased hydration) and the metal drops down into the coordination cage.",
keywords = "coordination mode, fractional coordination number, hydration, ionic radius, lanthanides",
author = "Mark Woods and Payne, {Katherine M.} and Valente, {Edward J.} and Kucera, {Benjamin E.} and Young, {Victor G.}",
year = "2019",
month = "7",
day = "25",
doi = "10.1002/chem.201902068",
language = "English (US)",
volume = "25",
pages = "9997--10005",
journal = "Chemistry - A European Journal",
issn = "0947-6539",
publisher = "Wiley-VCH Verlag",
number = "42",

}

TY - JOUR

T1 - Crystal Structures of DOTMA Chelates from Ce3+ to Yb3+

T2 - Evidence for a Continuum of Metal Ion Hydration States

AU - Woods, Mark

AU - Payne, Katherine M.

AU - Valente, Edward J.

AU - Kucera, Benjamin E.

AU - Young, Victor G.

PY - 2019/7/25

Y1 - 2019/7/25

N2 - The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and the octadentate polyamino carboxylate ligand DOTMA are described. A total of 23 individual chelates structures were obtained; in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle −25.0°–−31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3+ chelates are associated with a single inner sphere water molecule; the Ln-OH2 interaction is remarkable for being very long. After a clear break at gadolinium, the number of chelates in the unit cell that have a water molecule interacting with the Ln3+ decreases linearly until at Tm3+ no water is found to interact with the metal ion. The Ln-OH2 distance observed in the chelates of the later Ln3+ ions are also extremely long and increase as the ions contract (2.550–2.732 Å). No clear break between hydrated and dehydrated chelates is observed; rather this series of chelates appear to represent a continuum of hydration states in which the ligand gradually closes around the metal ion as its ionic radius decreases (with decreased hydration) and the metal drops down into the coordination cage.

AB - The crystal structures of chelates formed between each stable paramagnetic lanthanide ion and the octadentate polyamino carboxylate ligand DOTMA are described. A total of 23 individual chelates structures were obtained; in each chelate the coordination geometry around the metal ion is best described as a twisted square antiprism (torsion angle −25.0°–−31.4°). Despite the uniformity of the general coordination geometry provided by the DOTMA ligand, there is a considerable variation in the hydration state of each chelate. The early Ln3+ chelates are associated with a single inner sphere water molecule; the Ln-OH2 interaction is remarkable for being very long. After a clear break at gadolinium, the number of chelates in the unit cell that have a water molecule interacting with the Ln3+ decreases linearly until at Tm3+ no water is found to interact with the metal ion. The Ln-OH2 distance observed in the chelates of the later Ln3+ ions are also extremely long and increase as the ions contract (2.550–2.732 Å). No clear break between hydrated and dehydrated chelates is observed; rather this series of chelates appear to represent a continuum of hydration states in which the ligand gradually closes around the metal ion as its ionic radius decreases (with decreased hydration) and the metal drops down into the coordination cage.

KW - coordination mode

KW - fractional coordination number

KW - hydration

KW - ionic radius

KW - lanthanides

UR - http://www.scopus.com/inward/record.url?scp=85068526999&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85068526999&partnerID=8YFLogxK

U2 - 10.1002/chem.201902068

DO - 10.1002/chem.201902068

M3 - Article

VL - 25

SP - 9997

EP - 10005

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 42

ER -