Nitrate-selective electrode based on a cyclic bis-thiourea ionophore

Amanda S. Watts; Vasilis G. Gavalas; Arthur Cammers; Pilar Sánchez Andrada; Mateo Alajarín; Leonidas G. Bachas

doi:10.1016/j.snb.2006.09.048

Nitrate-selective electrode based on a cyclic bis-thiourea ionophore

Amanda S. Watts, Vasilis G. Gavalas, Arthur Cammers, Pilar Sánchez Andrada, Mateo Alajarín, Leonidas G. Bachas

Chemistry

Research output: Contribution to journal › Article › peer-review

33 Citations (SciVal)

Abstract

Compounds containing urea and thiourea groups can hydrogen bond oxoanions and, as such, represent a class of potential ionophores for anion-selective electrodes. We have evaluated cyclic and linear bis-thiourea compounds as ionophores in polymer membrane ion-selective electrodes. An improvement in the selectivity coefficient of nitrate against chloride of greater than one order of magnitude was observed with the cyclic ionophore in comparison to the Hofmeister lipophilicity series (log K_{N O3-, C l-}^pot of -3.50 with ionophore versus -2.40 with no bis-thiourea ionophore), indicating the preference of the cyclic ionophore for nitrate. This preference for nitrate over chloride may be attributed to the spatial arrangement of the thiourea hydrogen atoms, which are capable of forming hydrogen bonds with nitrate, as well as the size of the ionophore binding cavity. In the lowest-energy conformation, all thiourea hydrogen atoms point toward a putative nitrate binding site, likely contributing to enhanced coordination.

Original language	English
Pages (from-to)	200-207
Number of pages	8
Journal	Sensors and Actuators, B: Chemical
Volume	121
Issue number	1
DOIs	https://doi.org/10.1016/j.snb.2006.09.048
State	Published - Jan 30 2007

Bibliographical note

Funding Information:
Arthur Cammers is an Associate Professor of organic chemistry at the University of Kentucky. He earned a Bachelor of Science degree from the University of Wisconsin-Eau Claire and a doctorate in synthetic organic chemistry with Edwin Vedejs from the University of Wisconsin-MADISON. Arthur Cammers joined the faculty at the University of Kentucky after an NIH postdoctoral fellowship with Daniel Kemp at the Massachusetts Institute of Technology. Cammers is a NSF career awardee. His work focuses on solution and solid state hydrogen bonding, designing molecular recognition between molecules and at the nanometer scale. He has also investigated ring current anisotropy as a probe for molecular conformation.

Funding Information:
This work was supported by the National Aeronautics and Space Administration. ASW thank the National Science Foundation (IGERT) and the Research Challenge Trust Fund for fellowship support. PSA and MA thank the MEC-FEDER (Project CTQ2005-02323/BQU) and the Fundación Séneca-CARM (Project PI-1/00749/FS/01) for funding.

Keywords

Bis-thiourea
Ion-selective electrode
Ionophore
Nitrate

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Instrumentation
Condensed Matter Physics
Surfaces, Coatings and Films
Metals and Alloys
Electrical and Electronic Engineering
Materials Chemistry

Access to Document

10.1016/j.snb.2006.09.048

Cite this

@article{ac079b0e018741d5bf21f23d0a0d8ab6,

title = "Nitrate-selective electrode based on a cyclic bis-thiourea ionophore",

abstract = "Compounds containing urea and thiourea groups can hydrogen bond oxoanions and, as such, represent a class of potential ionophores for anion-selective electrodes. We have evaluated cyclic and linear bis-thiourea compounds as ionophores in polymer membrane ion-selective electrodes. An improvement in the selectivity coefficient of nitrate against chloride of greater than one order of magnitude was observed with the cyclic ionophore in comparison to the Hofmeister lipophilicity series (log KN O3-, C l-pot of -3.50 with ionophore versus -2.40 with no bis-thiourea ionophore), indicating the preference of the cyclic ionophore for nitrate. This preference for nitrate over chloride may be attributed to the spatial arrangement of the thiourea hydrogen atoms, which are capable of forming hydrogen bonds with nitrate, as well as the size of the ionophore binding cavity. In the lowest-energy conformation, all thiourea hydrogen atoms point toward a putative nitrate binding site, likely contributing to enhanced coordination.",

keywords = "Bis-thiourea, Ion-selective electrode, Ionophore, Nitrate",

author = "Watts, {Amanda S.} and Gavalas, {Vasilis G.} and Arthur Cammers and Andrada, {Pilar S{\'a}nchez} and Mateo Alajar{\'i}n and Bachas, {Leonidas G.}",

note = "Funding Information: Arthur Cammers is an Associate Professor of organic chemistry at the University of Kentucky. He earned a Bachelor of Science degree from the University of Wisconsin-Eau Claire and a doctorate in synthetic organic chemistry with Edwin Vedejs from the University of Wisconsin-MADISON. Arthur Cammers joined the faculty at the University of Kentucky after an NIH postdoctoral fellowship with Daniel Kemp at the Massachusetts Institute of Technology. Cammers is a NSF career awardee. His work focuses on solution and solid state hydrogen bonding, designing molecular recognition between molecules and at the nanometer scale. He has also investigated ring current anisotropy as a probe for molecular conformation. Funding Information: This work was supported by the National Aeronautics and Space Administration. ASW thank the National Science Foundation (IGERT) and the Research Challenge Trust Fund for fellowship support. PSA and MA thank the MEC-FEDER (Project CTQ2005-02323/BQU) and the Fundaci{\'o}n S{\'e}neca-CARM (Project PI-1/00749/FS/01) for funding. ",

year = "2007",

month = jan,

day = "30",

doi = "10.1016/j.snb.2006.09.048",

language = "English",

volume = "121",

pages = "200--207",

number = "1",

}

TY - JOUR

T1 - Nitrate-selective electrode based on a cyclic bis-thiourea ionophore

AU - Watts, Amanda S.

AU - Gavalas, Vasilis G.

AU - Cammers, Arthur

AU - Andrada, Pilar Sánchez

AU - Alajarín, Mateo

AU - Bachas, Leonidas G.

N1 - Funding Information: Arthur Cammers is an Associate Professor of organic chemistry at the University of Kentucky. He earned a Bachelor of Science degree from the University of Wisconsin-Eau Claire and a doctorate in synthetic organic chemistry with Edwin Vedejs from the University of Wisconsin-MADISON. Arthur Cammers joined the faculty at the University of Kentucky after an NIH postdoctoral fellowship with Daniel Kemp at the Massachusetts Institute of Technology. Cammers is a NSF career awardee. His work focuses on solution and solid state hydrogen bonding, designing molecular recognition between molecules and at the nanometer scale. He has also investigated ring current anisotropy as a probe for molecular conformation. Funding Information: This work was supported by the National Aeronautics and Space Administration. ASW thank the National Science Foundation (IGERT) and the Research Challenge Trust Fund for fellowship support. PSA and MA thank the MEC-FEDER (Project CTQ2005-02323/BQU) and the Fundación Séneca-CARM (Project PI-1/00749/FS/01) for funding.

PY - 2007/1/30

Y1 - 2007/1/30

N2 - Compounds containing urea and thiourea groups can hydrogen bond oxoanions and, as such, represent a class of potential ionophores for anion-selective electrodes. We have evaluated cyclic and linear bis-thiourea compounds as ionophores in polymer membrane ion-selective electrodes. An improvement in the selectivity coefficient of nitrate against chloride of greater than one order of magnitude was observed with the cyclic ionophore in comparison to the Hofmeister lipophilicity series (log KN O3-, C l-pot of -3.50 with ionophore versus -2.40 with no bis-thiourea ionophore), indicating the preference of the cyclic ionophore for nitrate. This preference for nitrate over chloride may be attributed to the spatial arrangement of the thiourea hydrogen atoms, which are capable of forming hydrogen bonds with nitrate, as well as the size of the ionophore binding cavity. In the lowest-energy conformation, all thiourea hydrogen atoms point toward a putative nitrate binding site, likely contributing to enhanced coordination.

AB - Compounds containing urea and thiourea groups can hydrogen bond oxoanions and, as such, represent a class of potential ionophores for anion-selective electrodes. We have evaluated cyclic and linear bis-thiourea compounds as ionophores in polymer membrane ion-selective electrodes. An improvement in the selectivity coefficient of nitrate against chloride of greater than one order of magnitude was observed with the cyclic ionophore in comparison to the Hofmeister lipophilicity series (log KN O3-, C l-pot of -3.50 with ionophore versus -2.40 with no bis-thiourea ionophore), indicating the preference of the cyclic ionophore for nitrate. This preference for nitrate over chloride may be attributed to the spatial arrangement of the thiourea hydrogen atoms, which are capable of forming hydrogen bonds with nitrate, as well as the size of the ionophore binding cavity. In the lowest-energy conformation, all thiourea hydrogen atoms point toward a putative nitrate binding site, likely contributing to enhanced coordination.

KW - Bis-thiourea

KW - Ion-selective electrode

KW - Ionophore

KW - Nitrate

UR - http://www.scopus.com/inward/record.url?scp=33846265849&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846265849&partnerID=8YFLogxK

U2 - 10.1016/j.snb.2006.09.048

DO - 10.1016/j.snb.2006.09.048

M3 - Article

AN - SCOPUS:33846265849

VL - 121

SP - 200

EP - 207

IS - 1

ER -

Nitrate-selective electrode based on a cyclic bis-thiourea ionophore

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this