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Lippi M, Wadepohl H, Comba P, Cametti M. A Bispidine based CuII/ZnII Heterobimetallic Coordination Polymer. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Martina Lippi
- Politecnico di Milano Department of Chemistry, Materials and Chemical Engineering ITALY
| | - Hubert Wadepohl
- Heidelberg University Interdisciplinary Center of Scientific Computing GERMANY
| | - Peter Comba
- Heidelberg University Anorganisch-Chemisches Institut GERMANY
| | - Massimo Cametti
- Politecnico di Milano Dipartimento di Chimica, Materiali ed Ingegneria Chimica Via Luigi Mancinelli 7 20131 Milano ITALY
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2
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Spillecke L, Tripathi S, Koo C, Bahr A, Swain A, Haldar R, Ansari M, Jasinski J, Rajaraman G, Shanmugam M, Klingeler R. Role of Coordination Geometry on the Magnetic Relaxation Dynamics of Isomeric Five-Coordinate Low-Spin Co(II) Complexes. Inorg Chem 2021; 61:317-327. [PMID: 34918918 DOI: 10.1021/acs.inorgchem.1c02881] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To investigate the influence of the coordination geometry on the magnetization relaxation dynamics, two geometric isomers of a five-coordinate low-spin Co(II) complex with the general molecular formula [Co(DPPE)2Cl]SnCl3 (DPPE = diphenylphosphinoethane) were synthesized and structurally characterized. While one isomer has a square pyramidal geometry (Co-SP (1)), the other isomer figures a trigonal bipyramidal geometry (Co-TBP (2)). Both complexes were already reported elsewhere. The spin state of these complexes is unambiguously determined by detailed direct current (dc) magnetic data, X-band, and high-frequency EPR measurements. Slow relaxation of magnetization is commonly observed for systems with S > 1/2. However, both 1 and 2 show field-induced slow relaxation of magnetization. Especially 1 shows relaxation times up to τ = 35 ms at T = 1.8 K, which is much longer than the reported values for undiluted Co(II) low-spin monomers. In 2, the maximal field-induced relaxation time is suppressed to τ = 5 ms. We attribute this to the change in g-anisotropy, which is, in turn, correlated to the spatial arrangement of ligands (i.e., coordination geometry) around the Co(II) ions. Besides the detailed electronic structure of these complexes, the experimental observations are further corroborated by theoretical calculations.
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Affiliation(s)
- Lena Spillecke
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany
| | - Shalini Tripathi
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Changhyun Koo
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany
| | - Arne Bahr
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany
| | - Abinash Swain
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Rajashi Haldar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mursaleem Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Jerry Jasinski
- Department of Chemistry, Keene State College, 229 Main Street, Keene, New Hampshire 03435-2001, United States
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Maheswaran Shanmugam
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Rüdiger Klingeler
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany.,Center for Advanced Materials, Heidelberg University, 69120 Heidelberg, Germany
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3
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Spillecke L, Koo C, Maximova O, Mironov VS, Kopotkov VA, Korchagin DV, Vasiliev AN, Yagubskii EB, Klingeler R. Magnetic behavior of the novel pentagonal-bipyramidal erbium(III) complex (Et 3NH)[Er(H 2DAPS)Cl 2]: high-frequency EPR study and crystal-field analysis. Dalton Trans 2021; 50:18143-18154. [PMID: 34854436 DOI: 10.1039/d1dt03228c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the synthesis, crystal structure and magnetic properties of the new heptacoordinated mononuclear erbium(III) complex (Et3NH)[Er(H2DAPS)Cl2] (H4DAPS = 2,6-diacetylpyridine bis-(salicylhydrazone)) (1). The coordination polyhedron around the Er(III) ion features a slightly distorted pentagonal bipyramid formed by the pentagonal N3O2 chelate ring of the H2DAPS ligand in the equatorial plane and two apical chloride ligands. Detailed high-frequency/high-field electron paramagnetic resonance (HF-EPR) studies of 1 result in the precise determination of the crystal field (CF) splitting energies (0, 290 and 460 GHz) and effective g-values of the three lowest Kramers doublets (KDs) of the Er(III) ion. The obtained HF-EPR data are in good agreement with the results from CF analysis for the Er(III) ion based on the simulation of the dc magnetic data of 1. The results from dynamic susceptibility measurements indicate that there is no slow relaxation of magnetisation behaviour. This observation is discussed in terms of the electronic structure of 1 obtained from experimental and theoretical results.
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Affiliation(s)
- Lena Spillecke
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany.
| | - Changhyun Koo
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany.
| | - Olga Maximova
- Lomonosov Moscow State University, Moscow 119991, Russia
| | - Vladimir S Mironov
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia. .,Shubnikov Institute of Crystallography of Federal Scientific Research Centre 'Crystallography and Photonics', RAS, Moscow 119333, Russia.
| | | | - Denis V Korchagin
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia.
| | - Alexander N Vasiliev
- Lomonosov Moscow State University, Moscow 119991, Russia.,National University of Science and Technology "MISiS", Moscow 119049, Russia
| | - Eduard B Yagubskii
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia.
| | - Rüdiger Klingeler
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany. .,Centre for Advanced Materials (CAM), Heidelberg University, Germany
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A high-frequency EPR study of magnetic anisotropy and intermolecular interactions of Co(II) ions. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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