Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes

Bonnie E. Klamm; Cory J. Windorff; Cristian Celis-Barros; Maria J. Beltran-Leiva; Joseph M. Sperling; Thomas E. Albrecht-Schönzart

doi:10.1021/acs.inorgchem.0c02455

Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes

Bonnie E. Klamm, Cory J. Windorff, Cristian Celis-Barros, Maria J. Beltran-Leiva, Joseph M. Sperling, Thomas E. Albrecht-Schönzart

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

19 Scopus citations

Abstract

A pair of neptunium Schiff base coordination complexes, NpVIO2L(MeOH) and NpIVL2 {H2L = N,N-bis[(4,4-diethylamino)salicylidene]-1,2-phenylenediamine}, have been synthesized and analyzed by several characterization methods including single-crystal X-ray diffraction, electronic absorption, 1H NMR, cyclic voltammetry, and theoretical interpretation. Structural analysis reveals that NpVIO2L(MeOH) and NpIVL2 are isomorphous with the previously reported UVIO2L(MeOH) and MIVL2 (M = Pu, Ce, U, Th) complexes, respectively, allowing for a direct comparison across the series. The reduction of NpVIO2L(MeOH) in situ or direct synthesis from a (NpVO2)+ source shows evidence of a pentavalent neptunyl (NpVO2L)xn- species as determined by UV/vis/NIR and 1H NMR spectroscopy. The synthesis of (NpVO2L)xn- directly from a (NpVO2)+ starting material gives a similar spectrum. Theoretical analysis offers insight into the electronic structure for a better understanding of the bonding patterns and relative stability of the different oxidation states. Computational results show that the Np-L covalent interactions in NpIVL2 are similar to those in the NpVIO2L(MeOH) complex, indicating that neither the presence of the axial oxo ligands nor the oxidation state significantly modify the nature of the Np-L bonds.

Original language	English
Pages (from-to)	18035-18047
Number of pages	13
Journal	Inorganic Chemistry
Volume	59
Issue number	24
DOIs	https://doi.org/10.1021/acs.inorgchem.0c02455
State	Published - Dec 21 2020
Externally published	Yes

Funding

We thank Dr. Benjamin Stein, Samuel Greer, and Maksim Livshits (LANL) for synthesis and spectroscopic support. The Np used in this research was supplied by the U.S. Department of Energy Isotope Program, managed by the Office of Science for Nuclear Physics. We thank the Department of Energy (DOE) Chemical Sciences, Geosciences, and Biosciences Division of the Office of Basic Energy Sciences (BES) for supporting the research as part of the Center for Actinide Science and Technology (CAST) funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (award no. DE-SC0016568, TEAS). Finally, we thank Mr. Jason Johnson and Ms. Ashley Gray of Florida State University for radiological assistance. 237

Access to Document

10.1021/acs.inorgchem.0c02455

Cite this

@article{334d204ee6d5434eba2a79f103109624,

title = "Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes",

abstract = "A pair of neptunium Schiff base coordination complexes, NpVIO2L(MeOH) and NpIVL2 {H2L = N,N-bis[(4,4-diethylamino)salicylidene]-1,2-phenylenediamine}, have been synthesized and analyzed by several characterization methods including single-crystal X-ray diffraction, electronic absorption, 1H NMR, cyclic voltammetry, and theoretical interpretation. Structural analysis reveals that NpVIO2L(MeOH) and NpIVL2 are isomorphous with the previously reported UVIO2L(MeOH) and MIVL2 (M = Pu, Ce, U, Th) complexes, respectively, allowing for a direct comparison across the series. The reduction of NpVIO2L(MeOH) in situ or direct synthesis from a (NpVO2)+ source shows evidence of a pentavalent neptunyl (NpVO2L)xn- species as determined by UV/vis/NIR and 1H NMR spectroscopy. The synthesis of (NpVO2L)xn- directly from a (NpVO2)+ starting material gives a similar spectrum. Theoretical analysis offers insight into the electronic structure for a better understanding of the bonding patterns and relative stability of the different oxidation states. Computational results show that the Np-L covalent interactions in NpIVL2 are similar to those in the NpVIO2L(MeOH) complex, indicating that neither the presence of the axial oxo ligands nor the oxidation state significantly modify the nature of the Np-L bonds.",

author = "Klamm, {Bonnie E.} and Windorff, {Cory J.} and Cristian Celis-Barros and Beltran-Leiva, {Maria J.} and Sperling, {Joseph M.} and Albrecht-Sch{\"o}nzart, {Thomas E.}",

note = "Publisher Copyright: {\textcopyright} ",

year = "2020",

month = dec,

day = "21",

doi = "10.1021/acs.inorgchem.0c02455",

language = "English",

volume = "59",

pages = "18035--18047",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "24",

}

TY - JOUR

T1 - Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes

AU - Klamm, Bonnie E.

AU - Windorff, Cory J.

AU - Celis-Barros, Cristian

AU - Beltran-Leiva, Maria J.

AU - Sperling, Joseph M.

AU - Albrecht-Schönzart, Thomas E.

PY - 2020/12/21

Y1 - 2020/12/21

N2 - A pair of neptunium Schiff base coordination complexes, NpVIO2L(MeOH) and NpIVL2 {H2L = N,N-bis[(4,4-diethylamino)salicylidene]-1,2-phenylenediamine}, have been synthesized and analyzed by several characterization methods including single-crystal X-ray diffraction, electronic absorption, 1H NMR, cyclic voltammetry, and theoretical interpretation. Structural analysis reveals that NpVIO2L(MeOH) and NpIVL2 are isomorphous with the previously reported UVIO2L(MeOH) and MIVL2 (M = Pu, Ce, U, Th) complexes, respectively, allowing for a direct comparison across the series. The reduction of NpVIO2L(MeOH) in situ or direct synthesis from a (NpVO2)+ source shows evidence of a pentavalent neptunyl (NpVO2L)xn- species as determined by UV/vis/NIR and 1H NMR spectroscopy. The synthesis of (NpVO2L)xn- directly from a (NpVO2)+ starting material gives a similar spectrum. Theoretical analysis offers insight into the electronic structure for a better understanding of the bonding patterns and relative stability of the different oxidation states. Computational results show that the Np-L covalent interactions in NpIVL2 are similar to those in the NpVIO2L(MeOH) complex, indicating that neither the presence of the axial oxo ligands nor the oxidation state significantly modify the nature of the Np-L bonds.

AB - A pair of neptunium Schiff base coordination complexes, NpVIO2L(MeOH) and NpIVL2 {H2L = N,N-bis[(4,4-diethylamino)salicylidene]-1,2-phenylenediamine}, have been synthesized and analyzed by several characterization methods including single-crystal X-ray diffraction, electronic absorption, 1H NMR, cyclic voltammetry, and theoretical interpretation. Structural analysis reveals that NpVIO2L(MeOH) and NpIVL2 are isomorphous with the previously reported UVIO2L(MeOH) and MIVL2 (M = Pu, Ce, U, Th) complexes, respectively, allowing for a direct comparison across the series. The reduction of NpVIO2L(MeOH) in situ or direct synthesis from a (NpVO2)+ source shows evidence of a pentavalent neptunyl (NpVO2L)xn- species as determined by UV/vis/NIR and 1H NMR spectroscopy. The synthesis of (NpVO2L)xn- directly from a (NpVO2)+ starting material gives a similar spectrum. Theoretical analysis offers insight into the electronic structure for a better understanding of the bonding patterns and relative stability of the different oxidation states. Computational results show that the Np-L covalent interactions in NpIVL2 are similar to those in the NpVIO2L(MeOH) complex, indicating that neither the presence of the axial oxo ligands nor the oxidation state significantly modify the nature of the Np-L bonds.

UR - http://www.scopus.com/inward/record.url?scp=85097977253&partnerID=8YFLogxK

U2 - 10.1021/acs.inorgchem.0c02455

DO - 10.1021/acs.inorgchem.0c02455

M3 - Article

C2 - 33238091

AN - SCOPUS:85097977253

SN - 0020-1669

VL - 59

SP - 18035

EP - 18047

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 24

ER -

Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes

Abstract

Funding

Access to Document

Other files and links

Fingerprint

Cite this