Synthesis and complexation properties of a new macrocyclic polyaza polyphosphinate ligand, DOTEP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate))

Istvan Lazar, A. Dean Sherry, Ravichandran Ramasamy, E. Brücher, R. Király

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

A new macrocycle, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate) (DOTEP), has been synthesized, and its protonation constants and metal ion binding properties have been examined. The first two chelate protonations occur at nitrogens (log K1 and log K2: 10.94 and 8.24, respectively) while the pendant phosphinate groups are protonated only below pH 4. DOTEP forms less stable complexes with the alkaline-earth-metal cations, Cu2+, Zn2+, and Cd2+, and the trivalent lanthanides (Ln3+) than does the tetraacetate analogue, DOTA, largely due to the lower basicity of the nitrogen and oxygen donor atoms of DOTEP. Like DOTA, DOTEP forms complexes with the trivalent lanthanide ions rather slowly in the pH range 6-7 but, once formed, the Ln(DOTEP)- complexes release free Ln3+ slowly in strong acid.

Original languageEnglish
Pages (from-to)5016-5019
Number of pages4
JournalInorganic Chemistry
Volume30
Issue number26
Publication statusPublished - 1991

Fingerprint

Lanthanoid Series Elements
Protonation
Complexation
Nitrogen
Alkaline Earth Metals
Ligands
nitrogen
ligands
alkaline earth metals
synthesis
Alkalinity
chelates
Metal ions
Cations
metal ions
ions
Ions
analogs
Oxygen
cations

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Synthesis and complexation properties of a new macrocyclic polyaza polyphosphinate ligand, DOTEP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate)). / Lazar, Istvan; Sherry, A. Dean; Ramasamy, Ravichandran; Brücher, E.; Király, R.

In: Inorganic Chemistry, Vol. 30, No. 26, 1991, p. 5016-5019.

Research output: Contribution to journalArticle

@article{64aebf7fbb5546af9084cab14755ca87,
title = "Synthesis and complexation properties of a new macrocyclic polyaza polyphosphinate ligand, DOTEP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate))",
abstract = "A new macrocycle, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate) (DOTEP), has been synthesized, and its protonation constants and metal ion binding properties have been examined. The first two chelate protonations occur at nitrogens (log K1 and log K2: 10.94 and 8.24, respectively) while the pendant phosphinate groups are protonated only below pH 4. DOTEP forms less stable complexes with the alkaline-earth-metal cations, Cu2+, Zn2+, and Cd2+, and the trivalent lanthanides (Ln3+) than does the tetraacetate analogue, DOTA, largely due to the lower basicity of the nitrogen and oxygen donor atoms of DOTEP. Like DOTA, DOTEP forms complexes with the trivalent lanthanide ions rather slowly in the pH range 6-7 but, once formed, the Ln(DOTEP)- complexes release free Ln3+ slowly in strong acid.",
author = "Istvan Lazar and Sherry, {A. Dean} and Ravichandran Ramasamy and E. Br{\"u}cher and R. Kir{\'a}ly",
year = "1991",
language = "English",
volume = "30",
pages = "5016--5019",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "26",

}

TY - JOUR

T1 - Synthesis and complexation properties of a new macrocyclic polyaza polyphosphinate ligand, DOTEP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate))

AU - Lazar, Istvan

AU - Sherry, A. Dean

AU - Ramasamy, Ravichandran

AU - Brücher, E.

AU - Király, R.

PY - 1991

Y1 - 1991

N2 - A new macrocycle, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate) (DOTEP), has been synthesized, and its protonation constants and metal ion binding properties have been examined. The first two chelate protonations occur at nitrogens (log K1 and log K2: 10.94 and 8.24, respectively) while the pendant phosphinate groups are protonated only below pH 4. DOTEP forms less stable complexes with the alkaline-earth-metal cations, Cu2+, Zn2+, and Cd2+, and the trivalent lanthanides (Ln3+) than does the tetraacetate analogue, DOTA, largely due to the lower basicity of the nitrogen and oxygen donor atoms of DOTEP. Like DOTA, DOTEP forms complexes with the trivalent lanthanide ions rather slowly in the pH range 6-7 but, once formed, the Ln(DOTEP)- complexes release free Ln3+ slowly in strong acid.

AB - A new macrocycle, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methyleneethylphosphinate) (DOTEP), has been synthesized, and its protonation constants and metal ion binding properties have been examined. The first two chelate protonations occur at nitrogens (log K1 and log K2: 10.94 and 8.24, respectively) while the pendant phosphinate groups are protonated only below pH 4. DOTEP forms less stable complexes with the alkaline-earth-metal cations, Cu2+, Zn2+, and Cd2+, and the trivalent lanthanides (Ln3+) than does the tetraacetate analogue, DOTA, largely due to the lower basicity of the nitrogen and oxygen donor atoms of DOTEP. Like DOTA, DOTEP forms complexes with the trivalent lanthanide ions rather slowly in the pH range 6-7 but, once formed, the Ln(DOTEP)- complexes release free Ln3+ slowly in strong acid.

UR - http://www.scopus.com/inward/record.url?scp=0000477881&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000477881&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0000477881

VL - 30

SP - 5016

EP - 5019

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 26

ER -