Investigation of longitudinal 31P relaxation in metal selenophosphate compounds

Christian G. Canlas; Rajendra B. Muthukumaran; Mercouri G. Kanatzidis; David P. Weliky

doi:10.1016/S0926-2040(03)00047-X

Investigation of longitudinal ³¹P relaxation in metal selenophosphate compounds

Christian G. Canlas, Rajendra B. Muthukumaran, Mercouri G. Kanatzidis, David P. Weliky^*

^*Corresponding author for this work

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

8 Scopus citations

Abstract

Molten salt syntheses yield a rich variety of metal selenophosphate compounds which have a wide range of ³¹P T₁ longitudinal relaxation times (20-3000 s). There is a qualitative positive correlation between squared dipolar couplings and 1/T₁, suggesting that these interactions contribute to relaxation. However, two of the compounds, K ₂CdP₂Se₆ and Rb₂CdP ₂Se₆, have T₁ which are significantly shorter than what is expected from dipolar couplings. The ESR spectra of these compounds show the presence of unpaired electrons which may accelerate the rate of ³¹P relaxation. The importance of relaxation in application of ³¹P NMR to these systems is demonstrated in analysis of the mixture of crystalline products formed in a Ag₄P₂Se₆ synthesis. At short relaxation delays, the NMR intensities are non-quantitative and overestimate the concentration of an Ag₇PSe₆ impurity.

Original language	English (US)
Pages (from-to)	110-122
Number of pages	13
Journal	Solid State Nuclear Magnetic Resonance
Volume	24
Issue number	2-3 SPEC.
DOIs	https://doi.org/10.1016/S0926-2040(03)00047-X
State	Published - Sep 2003
Externally published	Yes

Bibliographical note

Funding Information:
We acknowledge support from NSF DMR-9977650 and DMR-0127644. David P. Weliky acknowledges support from a Camille and Henry Dreyfus Foundation New Faculty Award. We thank Bryan Schmidt for assistance with the ESR spectroscopy.

Keywords

31P
Couplings
Dipolar
ESR
Longitudinal
NMR
Paramagnetic
Relaxation
Selenophosphates
T1

ASJC Scopus subject areas

Radiation
General Chemistry
Nuclear and High Energy Physics
Instrumentation

Access to Document

10.1016/S0926-2040(03)00047-X

Cite this

@article{b5047112fe7347e9b49253abaab321b2,

title = "Investigation of longitudinal 31P relaxation in metal selenophosphate compounds",

abstract = "Molten salt syntheses yield a rich variety of metal selenophosphate compounds which have a wide range of 31P T1 longitudinal relaxation times (20-3000 s). There is a qualitative positive correlation between squared dipolar couplings and 1/T1, suggesting that these interactions contribute to relaxation. However, two of the compounds, K 2CdP2Se6 and Rb2CdP 2Se6, have T1 which are significantly shorter than what is expected from dipolar couplings. The ESR spectra of these compounds show the presence of unpaired electrons which may accelerate the rate of 31P relaxation. The importance of relaxation in application of 31P NMR to these systems is demonstrated in analysis of the mixture of crystalline products formed in a Ag4P2Se6 synthesis. At short relaxation delays, the NMR intensities are non-quantitative and overestimate the concentration of an Ag7PSe6 impurity.",

keywords = "31P, Couplings, Dipolar, ESR, Longitudinal, NMR, Paramagnetic, Relaxation, Selenophosphates, T1",

author = "Canlas, {Christian G.} and Muthukumaran, {Rajendra B.} and Kanatzidis, {Mercouri G.} and Weliky, {David P.}",

note = "Funding Information: We acknowledge support from NSF DMR-9977650 and DMR-0127644. David P. Weliky acknowledges support from a Camille and Henry Dreyfus Foundation New Faculty Award. We thank Bryan Schmidt for assistance with the ESR spectroscopy.",

year = "2003",

month = sep,

doi = "10.1016/S0926-2040(03)00047-X",

language = "English (US)",

volume = "24",

pages = "110--122",

journal = "Solid State Nuclear Magnetic Resonance",

issn = "0926-2040",

publisher = "Elsevier B.V.",

number = "2-3 SPEC.",

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T1 - Investigation of longitudinal 31P relaxation in metal selenophosphate compounds

AU - Canlas, Christian G.

AU - Muthukumaran, Rajendra B.

AU - Kanatzidis, Mercouri G.

AU - Weliky, David P.

N1 - Funding Information: We acknowledge support from NSF DMR-9977650 and DMR-0127644. David P. Weliky acknowledges support from a Camille and Henry Dreyfus Foundation New Faculty Award. We thank Bryan Schmidt for assistance with the ESR spectroscopy.

PY - 2003/9

Y1 - 2003/9

N2 - Molten salt syntheses yield a rich variety of metal selenophosphate compounds which have a wide range of 31P T1 longitudinal relaxation times (20-3000 s). There is a qualitative positive correlation between squared dipolar couplings and 1/T1, suggesting that these interactions contribute to relaxation. However, two of the compounds, K 2CdP2Se6 and Rb2CdP 2Se6, have T1 which are significantly shorter than what is expected from dipolar couplings. The ESR spectra of these compounds show the presence of unpaired electrons which may accelerate the rate of 31P relaxation. The importance of relaxation in application of 31P NMR to these systems is demonstrated in analysis of the mixture of crystalline products formed in a Ag4P2Se6 synthesis. At short relaxation delays, the NMR intensities are non-quantitative and overestimate the concentration of an Ag7PSe6 impurity.

AB - Molten salt syntheses yield a rich variety of metal selenophosphate compounds which have a wide range of 31P T1 longitudinal relaxation times (20-3000 s). There is a qualitative positive correlation between squared dipolar couplings and 1/T1, suggesting that these interactions contribute to relaxation. However, two of the compounds, K 2CdP2Se6 and Rb2CdP 2Se6, have T1 which are significantly shorter than what is expected from dipolar couplings. The ESR spectra of these compounds show the presence of unpaired electrons which may accelerate the rate of 31P relaxation. The importance of relaxation in application of 31P NMR to these systems is demonstrated in analysis of the mixture of crystalline products formed in a Ag4P2Se6 synthesis. At short relaxation delays, the NMR intensities are non-quantitative and overestimate the concentration of an Ag7PSe6 impurity.

KW - 31P

KW - Couplings

KW - Dipolar

KW - ESR

KW - Longitudinal

KW - NMR

KW - Paramagnetic

KW - Relaxation

KW - Selenophosphates

KW - T1

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U2 - 10.1016/S0926-2040(03)00047-X

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M3 - Article

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