High Thermodynamic Stability and Extraordinary Kinetic
Inertness of Cu(II) Complexes with
1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic
acid): Example of a Rare Isomerism between Kinetically Inert
Penta- and Hexacoordinated Cu(II) Complexes

J 2003

High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes

KOTEK, Jan, Přemysl LUBAL, Petr HERMANN, Ivana CÍSAŘOVÁ, Ivan LUKEŠ et. al.

Basic information

Original name

High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes

Authors

KOTEK, Jan (203 Czech Republic), Přemysl LUBAL (203 Czech Republic), Petr HERMANN (203 Czech Republic, guarantor), Ivana CÍSAŘOVÁ (203 Czech Republic), Ivan LUKEŠ (203 Czech Republic), Tomáš GODULA (203 Czech Republic), Ivona SVOBODOVÁ (203 Czech Republic), Petr TÁBORSKÝ (203 Czech Republic) and Josef HAVEL (203 Czech Republic)

Edition

Chemistry - A European Journal, Weinheim, WILEY-VCH Verlag, 2003, 0947-6539

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10406 Analytical chemistry

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 4.353

RIV identification code

RIV/00216224:14310/03:00007933

Organization unit

Faculty of Science

UT WoS

000180368600020

Keywords in English

cyclam derivatives; kinetics ; macrocyclic ligands ; phosphonate ligands ; stability constants

Abstract

V originále

In an aqueous solution at room temperature, 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L1) and CuII form a pentacoordinated (pc) complex, pc-[Cu(L1)]2-, exhibiting conformation I of the cyclam ring. At high temperature, the complex isomerises to a hexacoordinated isomer, trans-O,O-[Cu(L1)]2-, with a trans-III[Note ] conformation of the cyclam ring. In pc-[Cu(L1)]2-, four ring nitrogen atoms and one phosphonate oxygen atom are arranged around CuII in a structure that is half-way between a trigonal bipyramid and a tetragonal pyramid, with one phosphonic acid group uncoordinated. In the trans-O,O-[Cu(L1)]2- isomer, the nitrogen atoms form a plane and the phosphonic acid groups are in a mutually trans configuration. A structurally very similar ligand, 4-methyl-1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L2), forms an analogous pentacoordinated complex, pc-[Cu(L2)]2-, at room temperature. However, the complex does not isomerise to the octahedral complex analogous to trans-O,O-[Cu(L1)]2-. Because of the high thermodynamic stability of pc-[Cu(L1)]2-, (log =25.40(4), 25 degrees of Celsius, I=0.1 mol dm-3 KNO3) and the formation of protonated species, CuII is fully complexed in acidic solution (-log [H+] ~ 3). Acid-assisted decomplexation of both of the isomers of [Cu(H2L1)] takes place only after protonation of both uncoordinated oxygen atoms of each phosphonate moiety and at least one nitrogen atom of the cycle. The exceptional kinetic inertness of both isomers is illustrated by their half-lives 1/2=19.7 min for pc-[Cu(H2L1)] and about seven months for trans-O,O-[Cu(H2L1)] for decomplexation in 5 M HClO4 at 25 degrees of Celsius. The mechanism of formation of pc-[Cu(L1)]2- is similar to those observed for other macrocyclic complexes.

Links

GA203/02/0493, research and development project

Name: Bifunkční cheláty. Syntéza a komplexotvorné vlastnosti

Investor: Czech Science Foundation, Bifunctional chelates. Synthesis and complexing properties

GA203/03/0168, research and development project

Name: Kineticky inertní komplexy iontů přechodných kovů a lanthanoidů. Design, syntéza a kinetická studia

MSM 143100011, plan (intention)

Name: Struktura a vazebné poměry, vlastnosti a analýza syntetických a přírodních molekulových ansamblů

Investor: Ministry of Education, Youth and Sports of the CR, Structure and character of bonding, properties and analysis of synthetic and natural molecular ensembles

Citovat

KOTEK, Jan, Přemysl LUBAL, Petr HERMANN, Ivana CÍSAŘOVÁ, Ivan LUKEŠ, Tomáš GODULA, Ivona SVOBODOVÁ, Petr TÁBORSKÝ and Josef HAVEL. High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes. Chemistry - A European Journal. Weinheim: WILEY-VCH Verlag, 2003, vol. 9, No 1, p. 233-248. ISSN 0947-6539.

@article{483378,
   author = {Kotek, Jan and Lubal, Přemysl and Hermann, Petr and Císařová, Ivana and Lukeš, Ivan and Godula, Tomáš and Svobodová, Ivona and Táborský, Petr and Havel, Josef},
   article_location = {Weinheim},
   article_number = {1},
   keywords = {cyclam derivatives; kinetics ; macrocyclic ligands ; phosphonate ligands ; stability constants},
   language = {eng},
   issn = {0947-6539},
   journal = {Chemistry - A European Journal},
   title = {High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes},
   url = {http://www3.interscience.wiley.com/cgi-bin/abstract/102521424/START},
   volume = {9},
   year = {2003}
}

TY  - JOUR
ID  - 483378
AU  - Kotek, Jan - Lubal, Přemysl - Hermann, Petr - Císařová, Ivana - Lukeš, Ivan - Godula, Tomáš - Svobodová, Ivona - Táborský, Petr - Havel, Josef
PY  - 2003
TI  - High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes
JF  - Chemistry - A European Journal
VL  - 9
IS  - 1
SP  - 233
EP  - 233
PB  - WILEY-VCH Verlag
SN  - 09476539
KW  - cyclam derivatives
KW  - kinetics
KW  - macrocyclic ligands
KW  - phosphonate ligands
KW  - stability constants
UR  - http://www3.interscience.wiley.com/cgi-bin/abstract/102521424/START
N2  - In an aqueous solution at room temperature, 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L1) and CuII form a pentacoordinated (pc) complex, pc-[Cu(L1)]2-, exhibiting conformation I of the cyclam ring. At high temperature, the complex isomerises to a hexacoordinated isomer, trans-O,O-[Cu(L1)]2-, with a trans-III[Note ] conformation of the cyclam ring. In pc-[Cu(L1)]2-, four ring nitrogen atoms and one phosphonate oxygen atom are arranged around CuII in a structure that is half-way between a trigonal bipyramid and a tetragonal pyramid, with one phosphonic acid group uncoordinated. In the trans-O,O-[Cu(L1)]2- isomer, the nitrogen atoms form a plane and the phosphonic acid groups are in a mutually trans configuration. A structurally very similar ligand, 4-methyl-1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L2), forms an analogous pentacoordinated complex, pc-[Cu(L2)]2-, at room temperature. However, the complex does not isomerise to the octahedral complex analogous to trans-O,O-[Cu(L1)]2-. Because of the high thermodynamic stability of pc-[Cu(L1)]2-, (log =25.40(4), 25 degrees of Celsius, I=0.1 mol dm-3 KNO3) and the formation of protonated species, CuII is fully complexed in acidic solution (-log [H+] ~ 3). Acid-assisted decomplexation of both of the isomers of [Cu(H2L1)] takes place only after protonation of both uncoordinated oxygen atoms of each phosphonate moiety and at least one nitrogen atom of the cycle. The exceptional kinetic inertness of both isomers is illustrated by their half-lives 1/2=19.7 min for pc-[Cu(H2L1)] and about seven months for trans-O,O-[Cu(H2L1)] for decomplexation in 5 M HClO4 at 25 degrees of Celsius. The mechanism of formation of pc-[Cu(L1)]2- is similar to those observed for other macrocyclic complexes.
ER  -

KOTEK, Jan, Přemysl LUBAL, Petr HERMANN, Ivana CÍSAŘOVÁ, Ivan LUKEŠ, Tomáš GODULA, Ivona SVOBODOVÁ, Petr TÁBORSKÝ and Josef HAVEL. High Thermodynamic Stability and Extraordinary Kinetic Inertness of Cu(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic acid): Example of a Rare Isomerism between Kinetically Inert Penta- and Hexacoordinated Cu(II) Complexes. \textit{Chemistry - A European Journal}. Weinheim: WILEY-VCH Verlag, 2003, vol.~9, No~1, p.~233-248. ISSN~0947-6539.

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