1
|
Kapurwan S, Sahu PK, Konar S. Single-Molecule Magnet Behavior of Confined Dy(III) in a Mixed Heteroatom-Substituted Polyoxotungstate. Inorg Chem 2024; 63:4492-4501. [PMID: 38416533 DOI: 10.1021/acs.inorgchem.3c03095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Two heteroatom-templated Dy(III)-confined polyoxotungstates [H2N(CH3)2]7Na7[Dy2(H2O)7(W4O9)(HPSeW15O54)(α-SeW9O33)2]·31H2O (1) and [H2N(CH3)2]14K2Na18{[Dy2(H2O)13W14O40]2[α-SeW9O33]4[HPSeW15O54]2}·44H2O (2) were synthesized by a one-pot aqueous reaction and structurally characterized. The most distinctive structural feature of complexes 1 & 2 is the simultaneous presence of both trivacant Keggin [α-SeW9O33]8- and Dawson [HPSeW15O54]10- building blocks containing P(III)-Se(IV) heteroatoms. The trimeric polyanion of 1 can be represented as a fusion of two trivacant Keggin [α-SeW9O33]8- and Dawson [HPSeW15O54]10- building units encapsulating the [Dy2(H2O)7(W4O9)]12+ cluster. On the other hand, hexameric polyoxoanions of 2 are described as four trivacant Keggin [α-SeW9O33]8- and two Dawson [HPSeW15O54]10-, building units anchoring a [Dy4(H2O)26W28O80]20+ cluster. The magnetic investigation revealed the presence of significant magnetic anisotropy and slow relaxation of magnetization behavior for complex 1 with a phenomenological energy barrier, Ueff = 13.58 K in the absence of an external magnetic field, and Ueff = 24.57 K in the presence of a 500 Oe external dc magnetic field. On the other hand, complex 2 favors the QTM relaxation process in the absence of an external magnetic field and shows field-induced slow relaxation of magnetization with Ueff = 11.11 K at 1500 Oe applied dc field. The in-depth analysis of magnetic relaxation dynamics shows that the relaxation process follows the Orbach as well as Raman relaxation pathways. Further, the ab initio calculation of the studied complexes confirms that the highly axial ground and first excited energy states (containing pure highest mJ states) are responsible for the observed single-molecule magnet (SMM) behavior. Remarkably, this is the first example of a mixed heteroatom-based Dy(III)-substituted polyoxotungstate with both trimeric Keggin [α-SeW9O33]8- and Dawson [HPSeW15O54]10- building units showing SMM behavior.
Collapse
Affiliation(s)
- Sandhya Kapurwan
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Pradip Kumar Sahu
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| | - Sanjit Konar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462066, India
| |
Collapse
|
2
|
Iftikhar T, Izarova NV, Kögerler P. Organoarsonates Enable Single-Site Condensation of Hexalacunary {P 2W 12} Polyoxotungstates. Inorg Chem 2024; 63:99-107. [PMID: 38111082 DOI: 10.1021/acs.inorgchem.3c01051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
A systematic study of the condensation reactions of arylarsonic-functionalized [α-P2W12O48]14- units in acidic aqueous media identified that the specific presence of an amino group in the ortho position of the phenyl rings induces a dimerization process that allowed isolation of discrete dimeric polyanions [(o-H2N-C6H4-AsO3)4P4W24O85]14- (1) with an unprecedented polyoxometalate skeleton characterized by two seminal {P2W12} groups joined via a single W-O-W bridge. At the same time, addition of divalent transition metal ions (MnII, CoII, and NiII) in the reaction mixture directed a condensation process on a completely different pathway resulting in one-dimensional (1D) coordination polymers based on V-shaped [{M(H2O)4}P4W24O92(C6H6AsNO)2]14- polyanions (M = MnII (2), CoII (3), and NiII (4)). All polyanions were isolated as hydrated mixed potassium/dimethylammonium salts and thoroughly characterized in the solid state. 31P NMR studies showed that the discrete cluster 1 is comparatively stable in 1 M LiCl aqueous solution and thus represents a potential precursor for subsequent reactions.
Collapse
Affiliation(s)
- Tuba Iftikhar
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen D-52074 ,Germany
- Jülich-Aachen Research Alliance (JARA-FIT) and Peter-Grünberg-Institute 6, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Natalya V Izarova
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen D-52074 ,Germany
- Jülich-Aachen Research Alliance (JARA-FIT) and Peter-Grünberg-Institute 6, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Paul Kögerler
- Institute of Inorganic Chemistry, RWTH Aachen University, Aachen D-52074 ,Germany
- Jülich-Aachen Research Alliance (JARA-FIT) and Peter-Grünberg-Institute 6, Forschungszentrum Jülich, D-52425 Jülich, Germany
| |
Collapse
|
3
|
Kapurwan S, Mondal A, Sahu PK, Konar S. Windmill-like Ln 4 Clusters [Ln = Tb(III) and Dy(III)] Bridged by [α-AsW 9O 33] 9– Unit Showing Zero-Field SMM Behavior: Experimental and Theoretical Investigation. Inorg Chem 2022; 61:17459-17468. [DOI: 10.1021/acs.inorgchem.2c02298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sandhya Kapurwan
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal462066Madhya Pradesh, India
| | - Arpan Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal462066Madhya Pradesh, India
| | - Pradip Kumar Sahu
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal462066Madhya Pradesh, India
| | - Sanjit Konar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal462066Madhya Pradesh, India
| |
Collapse
|
4
|
Amin SS, Cameron JM, Winslow M, Davies ES, Argent SP, Robinson D, Newton GN. A mixed‐addenda Mo/W organofunctionalized hybrid polyoxometalate. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sharad S. Amin
- University of Nottingham School of Chemistry UNITED KINGDOM
| | - Jamie M. Cameron
- University of Nottingham School of Chemistry University of Nottingham NG7 2TU Nottingham UNITED KINGDOM
| | - Max Winslow
- Nottingham Trent University School of Science and Technology UNITED KINGDOM
| | | | | | - David Robinson
- Nottingham Trent University School of Science and Technology UNITED KINGDOM
| | - Graham N. Newton
- University of Nottingham School of Chemistry GSK Carbon Neutral Laboratories for Sustainable ChemistryJubilee Campus NG7 2TU Nottingham UNITED KINGDOM
| |
Collapse
|
5
|
Venu AC, Nasser Din R, Rudszuck T, Picchetti P, Chakraborty P, Powell AK, Krämer S, Guthausen G, Ibrahim M. NMR Relaxivities of Paramagnetic Lanthanide-Containing Polyoxometalates. Molecules 2021; 26:7481. [PMID: 34946561 PMCID: PMC8703889 DOI: 10.3390/molecules26247481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 11/16/2022] Open
Abstract
The current trend for ultra-high-field magnetic resonance imaging (MRI) technologies opens up new routes in clinical diagnostic imaging as well as in material imaging applications. MRI selectivity is further improved by using contrast agents (CAs), which enhance the image contrast and improve specificity by the paramagnetic relaxation enhancement (PRE) mechanism. Generally, the efficacy of a CA at a given magnetic field is measured by its longitudinal and transverse relaxivities r1 and r2, i.e., the longitudinal and transverse relaxation rates T1-1 and T2-1 normalized to CA concentration. However, even though basic NMR sensitivity and resolution become better in stronger fields, r1 of classic CA generally decreases, which often causes a reduction of the image contrast. In this regard, there is a growing interest in the development of new contrast agents that would be suitable to work at higher magnetic fields. One of the strategies to increase imaging contrast at high magnetic field is to inspect other paramagnetic ions than the commonly used Gd(III)-based CAs. For lanthanides, the magnetic moment can be higher than that of the isotropic Gd(III) ion. In addition, the symmetry of electronic ground state influences the PRE properties of a compound apart from diverse correlation times. In this work, PRE of water 1H has been investigated over a wide range of magnetic fields for aqueous solutions of the lanthanide containing polyoxometalates [DyIII(H2O)4GeW11O39]5- (Dy-W11), [ErIII(H2O)3GeW11O39]5- (Er-W11) and [{ErIII(H2O)(CH3COO)(P2W17O61)}2]16- (Er2-W34) over a wide range of frequencies from 20 MHz to 1.4 GHz. Their relaxivities r1 and r2 increase with increasing applied fields. These results indicate that the three chosen POM systems are potential candidates for contrast agents, especially at high magnetic fields.
Collapse
Affiliation(s)
- Aiswarya Chalikunnath Venu
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Rami Nasser Din
- LNCMI-EMFL, CNRS, INSA-T and UPS, Université Grenoble Alpes, Boîte Postale 166, CEDEX 9, 38042 Grenoble, France;
| | - Thomas Rudszuck
- Karlsruhe Institute of Technology (KIT), MVM-VM, Adenauerring 20b, 76131 Karlsruhe, Germany;
| | - Pierre Picchetti
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Papri Chakraborty
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| | - Annie K. Powell
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Steffen Krämer
- LNCMI-EMFL, CNRS, INSA-T and UPS, Université Grenoble Alpes, Boîte Postale 166, CEDEX 9, 38042 Grenoble, France;
| | - Gisela Guthausen
- Karlsruhe Institute of Technology (KIT), MVM-VM, Adenauerring 20b, 76131 Karlsruhe, Germany;
- Karlsruhe Institute of Technology (KIT), EBI-WCWT, Adenauerring 20b, 76131 Karlsruhe, Germany
| | - Masooma Ibrahim
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; (A.C.V.); (P.P.); (P.C.)
| |
Collapse
|
6
|
Wang W, Izarova NV, van Leusen J, Kögerler P. A phosphonate–lanthanoid polyoxometalate coordination polymer: {Ce 2P 2W 16O 60L 2} n zipper chains. CrystEngComm 2021. [DOI: 10.1039/d1ce00896j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first coordination polymer of a polyoxometalate bi-functionalized by phosphonate and lanthanoid groups forms when {CeIII2(α2,-PV2WVI16O60)L2} units are joined by direct inter-cluster Ce–OW bonds into 1D chains.
Collapse
Affiliation(s)
- Wenyan Wang
- Institute of Inorganic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
| | - Natalya V. Izarova
- Institute of Inorganic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance (JARA-FIT), Peter Grünberg Institute 6, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Jan van Leusen
- Institute of Inorganic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
| | - Paul Kögerler
- Institute of Inorganic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance (JARA-FIT), Peter Grünberg Institute 6, Forschungszentrum Jülich, D-52425 Jülich, Germany
| |
Collapse
|