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Kaushik K, Sarkar A, Kamilya S, Li Y, Dechambenoit P, Rouzières M, Mehta S, Mondal A. Light-Induced, Structural Matrix Guided Stepwise Spin-State Switching in 3d-5d Molecular Assembly. Inorg Chem 2024; 63:7604-7612. [PMID: 38556753 DOI: 10.1021/acs.inorgchem.3c03970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
A new iron(II) molecular complex {[W(CN)8][Fe(bik*)3]2}BF4·7H2O·1.5CH3OH (1.7H2O·1.5CH3OH) was synthesized using a versatile octacyanotungstate(V) building block and N-donor bidentate ligand (bik* = bis(1-ethyl-1H-imidazol-2-yl)ketone) and detailed characterizations were carried out. The crystal structure of 1.7H2O·1.5CH3OH is composed of an ionic salt from one anionic [W(CN)8]3- unit, two isolated cationic [Fe(bik*)3]2+ units, and one BF4- counteranion in the asymmetric unit. Magnetic studies of 1.7H2O·1.5CH3OH display interesting two-step reversible thermo-induced spin-state switching and the partially desolvated form 1.7H2O shows a photomagnetic effect at low temperatures. Additionally, the physical properties of 1.7H2O·1.5CH3OH were compared with the monomeric unit of {[Fe(bik*)3]2}·4ReO4·H2O (2.H2O) and detailed photophysical investigations were also performed to study the effect of a structural matrix {[W(CN)8]3- and ReO4- unit} on the spin-state switching properties of the [Fe(bik*)3]2+ unit in both systems (1.7H2O·1.5CH3OH and 2.H2O).
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Affiliation(s)
- Krishna Kaushik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, 560012 Bangalore, India
| | - Archita Sarkar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, 560012 Bangalore, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, 560012 Bangalore, India
| | - Yanling Li
- Institut Parisien de Chimie Moléculaire, CNRS UMR 8232, Sorbonne Université, 4 place Jussieu, F-75252 Paris, cedex 5, France
| | - Pierre Dechambenoit
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, 560012 Bangalore, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, 560012 Bangalore, India
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Guha S, Dalui A, Sarkar PK, Roy S, Paul A, Kamilya S, Mondal A, Dasgupta I, Sarma DD, Acharya S. Stereochemically Active Lone Pair Leads to Birefringence in the Vacancy Ordered Cs 3Sb 2Cl 9 Perovskite Single Crystals. J Phys Chem Lett 2024; 15:3061-3070. [PMID: 38466659 DOI: 10.1021/acs.jpclett.3c03419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Stereochemically active lone pair (SCALP) cations are attractive units for realizing optical anisotropy. Antimony(III) chloride perovskites with the SCALP have remained largely unknown to date. We synthesized a new vacancy ordered Cs3Sb2Cl9 perovskite single crystals with SbCl6 octahedral linkage containing the SCALP. Remarkably, all-inorganic halide perovskite Cs3Sb2Cl9 single crystals exhibit an exceptional birefringence of 0.12 ± 0.01 at 550 nm. The SCALP brings a large local structural distortion of the SbCl6 octahedra promoting birefringence optical responses in Cs3Sb2Cl9 single crystals. Theoretical calculations reveal that the considerable hybridization of Sb 5s and 5p with Cl 3p states largely contribute to the SCALP. Furthermore, the change in the Sb-Cl-Sb bond angle creates distortion in the SbCl6 octahedral arrangement in the apical and equatorial directions within the crystal structure incorporating the required anisotropy for the birefringence. This work explores pristine inorganic halide perovskite single crystals as a potential birefringent material with prospects in integrated optical devices.
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Affiliation(s)
- Shramana Guha
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Amit Dalui
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Piyush Kanti Sarkar
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Sima Roy
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Atanu Paul
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Indra Dasgupta
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
- Technical Research Center, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - D D Sarma
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Somobrata Acharya
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
- Technical Research Center, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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Kaushik K, Mehta S, Das M, Ghosh S, Kamilya S, Mondal A. Stimuli-responsive magnetic materials: impact of spin and electronic modulation. Chem Commun (Camb) 2023; 59:13107-13124. [PMID: 37846652 DOI: 10.1039/d3cc04268e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Addressing molecular bistability as a function of external stimuli, especially in spin-crossover (SCO) and metal-to-metal electron transfer (MMET) systems, has seen a surge of interest in the field of molecule-based magnetic materials due to their enormous potential in various technological applications such as molecular spintronics, memory and electronic devices, switches, sensors, and many more. The fine-tuning of molecular components allow the design and synthesis of materials with tailored properties for these vast applications. In this Feature Article, we discuss a part of our research work into this broad topic, pertaining to the recent discoveries in the field of switchable molecular magnetic materials based on SCO and MMET systems, along with some historical background of the area and related accomplishments made in recent years.
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Affiliation(s)
- Krishna Kaushik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Mayurika Das
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sounak Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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Bagchi S, Kamilya S, Mehta S, Mandal S, Bandyopadhyay A, Narayan A, Ghosh S, Mondal A. Spin-state switching: chemical modulation and the impact of intermolecular interactions in manganese(III) complexes. Dalton Trans 2023; 52:11335-11348. [PMID: 37530419 DOI: 10.1039/d3dt01707a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
A series of mononuclear manganese(III) complexes [Mn(X-sal2-323)](ReO4) (X = 5 Cl, 1; X = 5 Br, 2; X = 3,5 Cl, 3; X = 3,5 Br, 4; and X = 5 NO2, 5), containing hexadentate ligands prepared using the condensation of N,N'-bis(3-aminopropyl)ethylenediamine and 5- or 3,5-substituted salicylaldehyde, has been synthesized. Variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, electrochemical, and spectroelectrochemical analyses, and theoretical calculations have been used to explore the role of various ligand substituents in the spin-state switching behavior of the prepared manganese(III) complexes. All five complexes consist of an analogous distorted octahedral monocationic MnN4O2 surrounding offered by the flexible hexadentate ligand and ReO4- as the counter anion. However, a disordered water molecule was detected in complex 4. Complexes 1 (X = 5 Cl) and 5 (X = 5 NO2) show gradual and complete spin-state switching between the high-spin (HS) (S = 2) and the low-spin (LS) (S = 1) state with T1/2 values of 146 and 115 K respectively, while an abrupt and complete transition at 95 K was observed for complex 2 (X = 5 Br). Alternatively, complex 3 (X = 3, 5 Cl) exhibits an incomplete and sharp transition between the HS and LS states at 104 K, while complex 4 (X = 3, 5 Br) (desolvated) remains almost LS up to 300 K and then displays gradual and incomplete SCO at a higher temperature. The nature of the spin-state switch and transition temperature suggest that the structural effect (cooperativity) plays a more significant role in comparison with the electronic effect coming from various substituents (Cl, Br, and NO2), which is further supported by the detailed structural, electrochemical, and theoretical studies.
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Affiliation(s)
- Sukanya Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Subhankar Mandal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Arka Bandyopadhyay
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Awadhesh Narayan
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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Kamilya S, Mehta S, Lescouëzec R, Li Y, Pechousek J, Semwal M, Mondal A. Near room temperature stepwise spin state switching and photomagnetic effect in a mixed-valence molecular square. Dalton Trans 2023. [PMID: 37489028 DOI: 10.1039/d3dt01615c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
A two-step thermo-induced spin-state switching was observed in a cyanide-bridged [Fe2Fe2] molecular square complex, {[Fe(pzTp)(CN)3]2[Fe(L)2]2}[Fe(pzTp)(CN)3]2·4CH3OH·2H2O [1·4MeOH·2H2O; pzTp = tetrakis(pyrazol-1-yl)borate and L = bis(1-ethylimidazol-2-yl)ketone (bik*)], which was characterized fully by single-crystal X-ray diffraction, (photo)magnetic measurements, and spectroscopic techniques. 1·4MeOH·2H2O exhibited a two-step thermo-induced spin transition with T1/2 (1) ↑ = 306 K and T1/2 (2) ↑ = 370 K converting the low-temperature ground state, {[(FeIIILS)2(FeIILS)2](FeIIILS)2} into the high-temperature state, {[(FeIIILS)2(FeIIHS)2](FeIIILS)2} via a stable intermediate phase. The desolvated phase, 1 also exhibited a gradual but reversible thermo-induced spin state change with a T1/2 value of 190 K, significantly shifted to a lower temperature. It also exhibited photo-induced spin-state switching at 20 K with the TLIESST value of 60 K.
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Affiliation(s)
- Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore-560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore-560012, India.
| | - Rodrigue Lescouëzec
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, Paris 750005, France
| | - Yanling Li
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, Paris 750005, France
| | - Jiri Pechousek
- Department of Experimental Physics, Palacký University Olomouc, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Mohini Semwal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore-560012, India.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore-560012, India.
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Pariari D, Mehta S, Mandal S, Mahata A, Pramanik T, Kamilya S, Vidhan A, Guru Row TN, Santra PK, Sarkar SK, De Angelis F, Mondal A, Sarma DD. Realizing the Lowest Bandgap and Exciton Binding Energy in a Two-Dimensional Lead Halide System. J Am Chem Soc 2023. [PMID: 37440690 DOI: 10.1021/jacs.3c03300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
Finding stable analogues of three-dimensional (3D) lead halide perovskites has motivated the exploration of an ever-expanding repertoire of two-dimensional (2D) counterparts. However, the bandgap and exciton binding energy in these 2D systems are generally considerably higher than those in 3D analogues due to size and dielectric confinement. Such quantum confinements are most prominently manifested in the extreme 2D realization in (A)mPbI4 (m = 1 or 2) series of compounds with a single inorganic layer repeat unit. Here, we explore a new A-site cation, 4,4'-azopyridine (APD), whose size and hydrogen bonding properties endow the corresponding (APD)PbI4 2D compound with the lowest bandgap and exciton binding energy of all such compounds, 2.19 eV and 48 meV, respectively. (APD)PbI4 presents the first example of the ideal Pb-I-Pb bond angle of 180°, maximizing the valence and conduction bandwidths and minimizing the electron and hole effective masses. These effects coupled with a significant increase in the dielectric constant provide an explanation for the unique bandgap and exciton binding energies in this system. Our theoretical results further reveal that the requirement of optimizing the hydrogen bonding interactions between the organic and the inorganic units provides the driving force for achieving the structural uniqueness and the associated optoelectronic properties in this system. Our preliminary investigations in characterizing photovoltaic solar cells in the presence of APD show encouraging improvements in performances and stability.
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Affiliation(s)
- Debasmita Pariari
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Sayak Mandal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Arup Mahata
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO) Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta" (CNR-SCITEC), Via Elce di Sotto 8, 06123 Perugia, Italy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana 502285, India
| | - Titas Pramanik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Arya Vidhan
- Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Tayur N Guru Row
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - Pralay K Santra
- Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru 562162, India
| | - Shaibal K Sarkar
- Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Filippo De Angelis
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO) Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta" (CNR-SCITEC), Via Elce di Sotto 8, 06123 Perugia, Italy
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
- Department of Natural Sciences & Mathematics, College of Sciences & Human Studies, Prince Mohammad Bin Fahd University, P.O. Box 1664, Al Khobar 31952 Kingdom of Saudi Arabia
- SKKU Institute of Energy Science and Technology (SIEST) Sungkyunkwan University, Suwon 440-746, Korea
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
| | - D D Sarma
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bengaluru 560012, India
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Kamilya S, Mehta S, Semwal M, Lescouëzec R, Li Y, Pechousek J, Reddy VR, Rivière E, Rouzières M, Mondal A. ON/OFF Photo(switching) along with Reversible Spin-State Change and Single-Crystal-to-Single-Crystal Transformation in a Mixed-Valence Fe(II)Fe(III) Molecular System. Inorg Chem 2023. [PMID: 36867089 DOI: 10.1021/acs.inorgchem.2c03972] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
A mixed-valence Fe(II)Fe(III) molecular system, {[Fe(pzTp)(CN)3]2[Fe(bik)2]2}·[Fe(pzTp)(CN)3]2·4MeOH (1·4MeOH) (bik = bis-(1-methylimidazolyl)-2-methanone, pzTp = tetrakis(pyrazolyl)borate), exhibits single-crystal-to-single-crystal (SC-SC) transformation while increasing the temperature and is converted into {[Fe(pzTp)(CN)3]2[Fe(bik)2]2}·[Fe(pzTp)(CN)3]2 (1). Both complexes exhibit thermo-induced spin-state switching behavior along with reversible SC-SC transformation, where the low-temperature [FeIIILSFeIILS]2 phase transforms into a high-temperature [FeIIILSFeIIHS]2 phase. 1·4MeOH exhibits an abrupt spin-state switching with T1/2 at 355 K, whereas 1 undergoes a gradual and reversible spin-state switching with a lower T1/2 at 338 K. Astonishingly, 1 exhibits ON/OFF photo-induced spin-state switching with TLIESST = 67 K, whereas 1·4MeOH does not show such an effect.
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Affiliation(s)
- Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Mohini Semwal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Rodrigue Lescouëzec
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, Paris 750005, France
| | - Yanling Li
- Sorbonne Université, Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, 4 place Jussieu, Paris 750005, France
| | - Jiri Pechousek
- Department of Experimental Physics, Palacký University Olomouc, 17, listopadu 1192/12, 771 46 Olomouc, Czech Republic
| | - Varimalla R Reddy
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, India
| | - Eric Rivière
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, UMR 8182, bât. 420, Université Paris-Sud, 11 rue George Clémenceau, 91405 Orsay Cedex, France
| | - Mathieu Rouzières
- Centre de Recherche Paul Pascal, UMR 5031, Université de Bordeaux, CNRS, 33600 Pessac, France
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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Ghosh S, Ghosh S, Kamilya S, Mandal S, Mehta S, Mondal A. Impact of Counteranion on Reversible Spin-State Switching in a Series of Cobalt(II) Complexes Containing a Redox-Active Ethylenedioxythiophene-Based Terpyridine Ligand. Inorg Chem 2022; 61:17080-17088. [PMID: 36264687 DOI: 10.1021/acs.inorgchem.2c02313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The self-assembly of a redox-active ethylenedioxythiophene (EDOT)-terpyridine-based tridentate ligand and cobalt(II) unit with different counteranions has led to a series of new cobalt(II) complexes [Co(L)2](X)2 (X = BF4 (1), ClO4 (2), and BPh4 (3)) (L = 4'-(3,4-ethylenedioxythiophene)-2,2':6',2″-terpyridine). The impact of various counteranions on stabilization and spin-state switching of the cobalt(II) center was explored through detailed magneto-structural investigation using variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, electrochemical, and spectroelectrochemical studies. All three complexes 1-3 consisted of an isostructural dicationic distorted octahedral CoN6 coordination environment offered by the two L ligands in a bis-meridional fashion and BF4-, ClO4-, and BPh4- as a counteranion, respectively. Complex 2 with ClO4- counteranion showed a reversible, gradual, and nearly complete spin-state switching between low-spin (LS) (S = 1/2) and high-spin (HS) (S = 3/2) states, while an incomplete spin-state switching behavior was observed for complexes 1 (BF4-) and 3 (BPh4-) in the measured temperature range of 350-2 K. The non-covalent cation-anion interactions played a significant role in stabilizing the spin-state in 1-3. Additionally, complexes 1-3 also exhibited interesting redox-stimuli-based reversible paramagnetic HS cobalt(II) (S = 3/2) to diamagnetic LS cobalt(III) (S = 0) conversion, offering an alternate way to switch the magnetic properties.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Sounak Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Subhankar Mandal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
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Ghosh S, Kamilya S, Mehta S, Herchel R, Kiskin M, Veber S, Fedin M, Mondal A. Effect of Ligand Chain Length for Tuning of Molecular Dimensionality and Magnetic Relaxation in Redox Active Cobalt(II) EDOT Complexes (EDOT = 3,4-Ethylenedioxythiophene). Chem Asian J 2022; 17:e202200404. [PMID: 35617522 DOI: 10.1002/asia.202200404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/17/2022] [Indexed: 11/07/2022]
Abstract
Four cobalt(II) complexes, [Co(L1)2(NCX)2(MeOH)2] (X = S (1), Se (2)) and {[Co(L2)2(NCX)2]}n (X = S (3), Se (4)) (L1 = 2,5dipyridyl-3,4,-ethylenedioxylthiophene and L2 = 2,5diethynylpyridinyl-3,4-ethylenedioxythiophene), were synthesized by incorporating ethylenedioxythiophene based redox-active luminescence ligands. All these complexes have been well characterized using single-crystal X-ray diffraction analyses, spectroscopic and magnetic investigations. Magneto-structural studies showed that 1 and 2 adopt a mononuclear structure with CoN4O2 octahedral coordination geometry while 3 and 4 have a 2D [4 x 4] rhombic grid coordination networks (CNs) where each cobalt(II) center is in a CoN6 octahedral coordination environment. Static magnetic measurements reveal that all four complexes displayed a high spin (HS) (S = 3/2) state between 2 and 280 K which was further confirmed by X-band and Q-band EPR studies. Remarkably, along with the molecular dimensionality (0D and 2D) the modification in the axial coligands lead to a significant difference in the dynamic magnetic properties of the monomers and CNs at low temperatures. All complexes display slow magnetic relaxation behavior under an external dc magnetic field. For the complexes with NCS- as coligand observed higher energy barrier for spin reversal in comparison to the complexes with NCSe- as coligand, while mononuclear complex 1 exhibited a higher energy barrier than that of CN 3. Theoretical calculations at the DFT and CASSCF level of theory have been performed to get more insight into the electronic structure and magnetic properties of all four complexes.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, 560012, Bangalore, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, 560012, Bangalore, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, 560012, Bangalore, India
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, CZ-771 46, Olomouc, Czech Republic
| | - Mikhail Kiskin
- N. S. Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 31, 119991, Moscow, Russia
| | - Sergey Veber
- International Tomography Center of the Siberian Branch of the Russian Academy of Sciences, Institutskaya Str. 3a, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova Str. 1, 630090, Novosibirsk, Russia
| | - Matvey Fedin
- International Tomography Center of the Siberian Branch of the Russian Academy of Sciences, Institutskaya Str. 3a, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova Str. 1, 630090, Novosibirsk, Russia
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, 560012, Bangalore, India
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10
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Ghosh S, Bagchi S, Kamilya S, Mehta S, Sarkar D, Herchel R, Mondal A. Impact of counter anions on spin-state switching of manganese(III) complexes containing an azobenzene ligand. Dalton Trans 2022; 51:7681-7694. [PMID: 35521740 DOI: 10.1039/d2dt00660j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four mononuclear manganese(III) complexes coordinated with photo-active hexadentate azobenzene ligands, [Mn(5azo-sal2-323)](X) (X = Cl, 1; X = BF4, 2; X = ClO4, 3; X = PF6, 4), were prepared. The impact of various counter anions on the stabilization and switching of the spin state of the manganese(III) center was explored through detailed magneto-structural investigation using variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, and spectroelectrochemical studies, along with theoretical calculations. All four complexes consisted of an isostructural monocationic distorted octahedral MnN4O2 coordination environment offered by the hexadentate ligand and Cl-, BF4-, ClO4-, and PF6- as counter anions respectively. Complex 1 with a spherical Cl- counter anion showed a reversible and gradual spin-state switching between low-spin (LS) (S = 1) and high-spin (HS) (S = 2) states above 400 K, where non-covalent cation-anion interactions played a significant role in stabilizing the LS state. While, irrespective of the shape of the counter anion, complexes 2-4 remained in the HS state throughout the measured temperature range of 300-2 K, where strong π-π interaction between the azobenzene motifs among cationic units played a substantial role in stabilizing the HS state. Furthermore, magnetic data analyses revealed significantly large zero-field splitting in the S = 1 state for 1 (D = 19.4 cm-1, E/D = 0.008) in comparison with that in the S = 2 state for 2-4 (D = 3.99-4.97 cm-1, E/D = 0.002-0.195). Spectroelectrochemical investigations revealed the quasi-reversible reduction and oxidation of the manganese(III) center to manganese(II) and manganese(IV), respectively. A detailed theoretical calculation at the DFT and CASSCF level of theory was carried out to better understand the magneto-structural correlation.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sukanya Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Debopam Sarkar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, CZ-771 46 Olomouc, Czech Republic
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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11
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Shyam M, Verma H, Bhattacharje G, Mukherjee P, Singh S, Kamilya S, Jalani P, Das S, Dasgupta A, Mondal A, Das AK, Singh A, Brucoli F, Bagnéris C, Dickman R, Basavanakatti VN, Naresh Babu P, Sankaran V, Dev A, Sinha BN, Bhakta S, Jayaprakash V. Mycobactin Analogues with Excellent Pharmacokinetic Profile Demonstrate Potent Antitubercular Specific Activity and Exceptional Efflux Pump Inhibition. J Med Chem 2022; 65:234-256. [PMID: 34981940 DOI: 10.1021/acs.jmedchem.1c01349] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we have designed and synthesized pyrazoline analogues that partially mimic the structure of mycobactin, to address the requirement of novel therapeutics to tackle the emerging global challenge of antimicrobial resistance (AMR). Our investigation resulted in the identification of novel lead compounds 44 and 49 as potential mycobactin biosynthesis inhibitors against mycobacteria. Moreover, candidates efficiently eradicated intracellularly surviving mycobacteria. Thermofluorimetric analysis and molecular dynamics simulations suggested that compounds 44 and 49 bind to salicyl-AMP ligase (MbtA), a key enzyme in the mycobactin biosynthetic pathway. To the best of our knowledge, these are the first rationally designed mycobactin inhibitors to demonstrate an excellent in vivo pharmacokinetic profile. In addition, these compounds also exhibited more potent whole-cell efflux pump inhibition than known efflux pump inhibitors verapamil and chlorpromazine. Results from this study pave the way for the development of 3-(2-hydroxyphenyl)-5-(aryl)-pyrazolines as a new weapon against superbug-associated AMR challenges.
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Affiliation(s)
- Mousumi Shyam
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India.,Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Harshita Verma
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Gourab Bhattacharje
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | | | | | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, CV Raman Avenue, Bangalore 560012, India
| | - Pushpendu Jalani
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Swetarka Das
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Arunava Dasgupta
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, CV Raman Avenue, Bangalore 560012, India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | | | - Federico Brucoli
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, U.K
| | - Claire Bagnéris
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Rachael Dickman
- Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, University of London, London WC1N 1AX, U.K
| | | | | | - Vadivelan Sankaran
- Eurofins Advinus Limited, 21 & 22, Peenya Industrial area, Bengaluru 560058, India
| | - Abhimanyu Dev
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
| | - Barij Nayan Sinha
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Venkatesan Jayaprakash
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
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12
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Kamilya S, Ghosh S, Mehta S, Mondal A. Effect of Ligand Modulation on Metal-to-Metal Electron Transfer in a Series of [Fe 2Co 2] Molecular Square Complexes. J Phys Chem A 2021; 125:4775-4783. [PMID: 33890768 DOI: 10.1021/acs.jpca.1c02032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of three new cyanide-bridged [FeCo] molecular square complexes, namely, {[Fe(Tp*)(CN)3]2[Co(L)2]2}(BF4)2·2DMF (L = bik (1), bik* (2), and vbik (3); Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate, bik = bis(1-methyl-1H-imidazol-2-yl)ketone, bik* = bis(1-ethyl-1H-imidazol-2-yl)ketone, and vbik = bis(1-vinyl-1H-imidazol-2-yl)ketone; DMF = dimethylformamide) were synthesized and characterized by single-crystal X-ray diffraction analyses and by magnetic, electrochemical, and spectroscopic measurements. Magnetic studies reveal that all three complexes exhibit temperature-induced metal-to-metal electron transfer (MMET) from a high-spin Co(II) center to a low-spin Fe(III) center, transforming a high-temperature paramagnetic {FeIIILS-CN-CoIIHS} ground state into a low-temperature diamagnetic {FeIILS-CN-CoIIILS} state with a decrease in the temperature from 300 to 100 K. Complexes 1 and 3 show the interconversion of the paramagnetic {FeIIILS-CN-CoIIHS} ground state into a diamagnetic {FeIILS-CN-CoIIILS} state in a single-step transition with T1/2 values of 180 and 186 K, respectively, while a two-step MMET with T1/2 value of 214 and 178 K was observed for complex 2.
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Affiliation(s)
- Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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13
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Ghosh S, Kamilya S, Pramanik T, Mohanty A, Rouzières M, Herchel R, Mehta S, Mondal A. Thermo- and photoinduced spin state switching in an iron(II) 2D coordination network associated with large light-induced thermal hysteresis and tuning of dimensionality via ligand modulation. Dalton Trans 2021; 50:7725-7735. [PMID: 33988205 DOI: 10.1039/d1dt00212k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three iron(ii) complexes, [Fe(L1)2(NCS)2(MeOH)2] (1), [Fe(L1)2(NCSe)2(MeOH)2] (2), and [Fe(L2)2(NCS)2]n (3) (L1 = 2,5-dipyridyl-3,4-ethylenedioxythiophene and L2 = 2,5-diethynylpyridinyl-3,4-ethylenedioxythiophene), have been synthesized using redox-active luminescent ethylenedioxythiophene (EDOT)-based ligands, and characterized by variable temperature single-crystal X-ray diffraction, (photo)magnetic, optical reflectivity, and spectroscopy studies. Magneto-structural investigations revealed that 1 and 2 are mononuclear with a FeN4O2 octahedral coordination geometry and remain in a high-spin (HS) (S = 2) state in a temperature range of 2-280 K. Interestingly, a 2D coordination network structure with FeN6 surrounding each iron center was observed for 3, which exhibits reversible thermo-induced spin-state switching between the paramagnetic high-spin (HS) (S = 2) and diamagnetic low-spin (LS) (S = 0) states at around 105 K (T1/2). Furthermore, optical reflectivity and photomagnetic measurements at low temperature confirmed that 3 shows reversible ON/OFF switching between the photoinduced excited paramagnetic HS metastable state and diamagnetic LS state under light irradiation (ON mode using red light and OFF mode using green light). Finally, the photoinduced excited HS state can be reversibly relaxed back to the diamagnetic ground LS state by heating the system at ca. 88 K (TLIESST = 88 K) (light-induced excited spin state trapping (LIESST) effect). Furthermore, 3 also showed an exciting and unique 18 K wide light-induced thermal hysteresis (LITH) effect above liquid nitrogen temperature (100 K). DFT and CASSCF level theoretical calculations were utilized to better understand the magneto-structural correlations of these complexes.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Titas Pramanik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Ashutosh Mohanty
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR 5031, 33600 Pessac, France
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, CZ-771 46 Olomouc, Czech Republic
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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14
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Kaushik K, Ghosh S, Kamilya S, Rouzières M, Mehta S, Mondal A. Reversible Photo- and Thermo-Induced Spin-State Switching in a Heterometallic { 5d-3d} W 2Fe 2 Molecular Square Complex. Inorg Chem 2021; 60:7545-7552. [PMID: 33929177 DOI: 10.1021/acs.inorgchem.1c01014] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Following the complex-as-a-ligand strategy, self-assembly of [W(CN)8]3- and iron(II) with bidentate nitrogen donor ligand bik (bik = bis(1-methyl-1H-imidazol-2-yl)ketone) ligand affords a cyanide-bridged [W2Fe2] molecular square complex [HNBu3]2{[W(CN)8]2[Fe(bik)2]2}·6H2O·CH3OH (1). The complex was characterized by single-crystal X-ray diffraction analyses, (photo)magnetic studies, optical reflectivity, electrochemical studies, and spectroscopic studies. Structural analyses revealed that in the [W2Fe2] square motif tungsten(V) and iron(II) centers reside in an alternate corner of the square and are bridged by the cyanide ligands. Complex 1 exhibits thermo-induced spin crossover (SCO) between {WV (S = 1/2) - FeIILS (S = 0)} and {WV (S = 1/2) - FeIIHS (S = 2)} pairs near room temperature and photoinduced spin-state switching with TLIESST = 70 K under light irradiation at low temperature. To the best of our knowledge, 1 represents the first complex containing iron(II) and [WV(CN)8]3- units exhibiting both SCO and photomagnetic effect.
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Affiliation(s)
- Krishna Kaushik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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15
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Ghosh S, Bagchi S, Kamilya S, Mondal A. Effect of ligand substituents and tuning the spin-state switching in manganese(iii) complexes. Dalton Trans 2021; 50:4634-4642. [PMID: 33720257 DOI: 10.1039/d1dt00284h] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Three mononuclear manganese(iii) complexes based on flexible hexadentate ligands obtained from the condensation of N,N'-bis(3-aminopropyl)ethylenediamine and salicylaldehyde or salicylaldehyde with substitutions at the 5 or 3,5 positions, namely [Mn(X-sal2-323)](BPh4) (X = 5 H, 1; X = 5 Br, 2, and X = 3,5 Br, 3) have been synthesized. The impact of ligand substituents has been studied by variable temperature single-crystal X-ray diffraction analyses, and magnetic, spectroscopic and electrochemical investigations. The complexes have an analogous monocationic MnN4O2 surrounding offered by the flexible hexadentate ligand in a distorted octahedral geometry. Complex 1 remains in the high spin state over the entire temperature range, while complex 2 shows a reversible and complete two-step thermo-induced spin-state switching. An incomplete spin-state switching from a high spin to an intermediate high-spin low-spin (1 : 1) state was observed for complex 3. Single-crystal X-ray structural studies show the presence of three different spin states in 2 during the occurrence of the spin-state switching process. Electrochemical investigations showed that the reduced state of manganese(iii) centers in 3 is easily accessible in comparison to complexes 1 and 2.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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16
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Ghosh S, Kamilya S, Rouzières M, Herchel R, Mehta S, Mondal A. Reversible Spin-State Switching and Tuning of Nuclearity and Dimensionality via Nonlinear Pseudohalides in Cobalt(II) Complexes. Inorg Chem 2020; 59:17638-17649. [PMID: 33174721 DOI: 10.1021/acs.inorgchem.0c02887] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The self-assembly of a macrocyclic tetradentate ligand, cobalt(II) tetrafluoroborate, and nonlinear pseudohalides (dicyanamide and tricyanomethanide) has led to two cobalt(II) complexes, {[Co(L)(μ1,5-dca)](BF4)·MeOH}n (1) and [Co2(L)2(μ1,5-tcm)2](BF4)2 (2) (L = N,N'-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane; dca- = dicyanamido; tcm- = tricyanomethanido). Both complexes were characterized by single-crystal X-ray diffraction, spectroscopic, magnetic, and electrochemical studies. Structural analyses revealed that 1 displays a one-dimensional (1D) coordination polymer containing [Co(L)]2+ repeating units bridged by μ1,5-dicyanamido groups in cis positions, while 2 represents a discreate dinuclear cobalt(II) molecule bridged by two μ1,5-tricyanomethanido groups in a cis conformation. Both complexes have a CoN6 coordination environment around each cobalt center offered by the tetradentate ligand and cis coordinating bridging ligands. Complex 1 exhibits a high-spin (S = 3/2) state of cobalt(II) in the temperature range of 2-300 K with a weak ferromagnetic coupling between two dicyanamido-bridged cobalt(II) centers. Interestingly, complex 2 exhibits reversible spin-state switching associated with spin-spin coupling. Complexes 1 and 2 also exhibit interesting redox-stimuli-based reversible paramagnetic high-spin cobalt(II) to diamagnetic low-spin cobalt(III) conversion, offering an additional way to switch magnetic properties. A detailed theoretical calculation was consistent with the stated results.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
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17
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Abstract
A mononuclear manganese(iii) complex containing a flexible hexadentate chelating ligand has been prepared and characterized by performing, at various temperatures, single-crystal X-ray diffraction analyses and magnetic, spectroscopic, and electrochemical studies. The complex was shown to consist of an MnN4O2 octahedral coordination environment, and to exhibit reversible two-step thermally induced spin-state switching, a gradual one at 168 K and an abrupt one at 103 K. Structural analyses revealed the existence of three spin-states, namely high-spin, low-spin, and intermediate states, during the spin-state switching process. Electrochemistry studies showed the quasi-reversible reduction and oxidation of the manganese(iii) center with a comparatively easily accessible reduced state.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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18
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Ghosh S, Kamilya S, Pramanik T, Rouzières M, Herchel R, Mehta S, Mondal A. ON/OFF Photoswitching and Thermoinduced Spin Crossover with Cooperative Luminescence in a 2D Iron(II) Coordination Polymer. Inorg Chem 2020; 59:13009-13013. [PMID: 32875794 DOI: 10.1021/acs.inorgchem.0c02136] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A 2D coordination polymer, {[Fe(L)2(NCSe)2]·6MeOH·14H2O}n (1; L = 2,5-dipyridylethynylene-3,4-ethylenedioxythiophene), has been synthesized based on a redox active luminescence ligand. 1 possesses a 2D [4 × 4] square-grid network where the iron(II) center is in a FeN6 octahedral coordination environment. 1 displays reversible thermoinduced high-spin (HS; S = 2) to diamagnetic low-spin (LS; S = 0) ON/OFF spin-state switching with a T1/2 value of 150 K. Interestingly, optical reflectivity and photomagnetic studies at 10 K under light irradiation revealed an efficient conversion to a photoinduced metastable HS excited state from a LS ground state. Remarkably, the photoexcited HS state can be reversibly switched ON and OFF by using 625 and 850 nm light-emitting-diode lights. Intriguingly, the thermal dependence of the luminescence intensity of the maximum emission at 524 nm for 1 shows a minimum at around the spin-crossover (SCO) temperature, indicating a cooperative nature between the SCO and luminescence properties. Theoretical calculations confirmed the above findings.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science (IISc), Sir C. V. Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science (IISc), Sir C. V. Raman Road, Bangalore 560012, India
| | - Titas Pramanik
- Solid State and Structural Chemistry Unit, Indian Institute of Science (IISc), Sir C. V. Raman Road, Bangalore 560012, India
| | - Mathieu Rouzières
- Centre de Recherche Paul Pascal, University of Bordeaux, UMR 5031, CNRS, Pessac 33600, France
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, Olomouc CZ-771 46, Czech Republic
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science (IISc), Sir C. V. Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science (IISc), Sir C. V. Raman Road, Bangalore 560012, India
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19
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Kamilya S, Ghosh S, Li Y, Dechambenoit P, Rouzières M, Lescouëzec R, Mehta S, Mondal A. Two-Step Thermoinduced Metal-to-Metal Electron Transfer and ON/OFF Photoswitching in a Molecular [Fe2Co2] Square Complex. Inorg Chem 2020; 59:11879-11888. [DOI: 10.1021/acs.inorgchem.0c02053] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Yanling Li
- Institut Parisien de Chimie Moléculaire, Sorbonne Université, CNRS, UMR 8232, 4 place Jussieu, Paris 750005, France
| | - Pierre Dechambenoit
- Centre de Recherche Paul Pascal, Université Bordeaux, CNRS, UMR 5031, Pessac 33600, France
| | - Mathieu Rouzières
- Centre de Recherche Paul Pascal, Université Bordeaux, CNRS, UMR 5031, Pessac 33600, France
| | - Rodrigue Lescouëzec
- Institut Parisien de Chimie Moléculaire, Sorbonne Université, CNRS, UMR 8232, 4 place Jussieu, Paris 750005, France
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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20
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Ghosh S, Kamilya S, Das M, Mehta S, Boulon ME, Nemec I, Rouzières M, Herchel R, Mondal A. Effect of Coordination Geometry on Magnetic Properties in a Series of Cobalt(II) Complexes and Structural Transformation in Mother Liquor. Inorg Chem 2020; 59:7067-7081. [DOI: 10.1021/acs.inorgchem.0c00538] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Mayurika Das
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Marie-Emmanuelle Boulon
- Photon Science Institute, Alan Turing Building, office 3.315, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Ivan Nemec
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
- Central European Institute of Technology, CEITEC BUT, Technická 3058/10, 61600 Brno, Czech Republic
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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Ghosh S, Selvamani S, Kamilya S, Mehta S, Mondal A. Tuning of Spin Crossover Properties in a Series of Mononuclear Cobalt(II) Complexes Based on Macrocyclic Tetradentate Ligand and Pseudohalide Coligands. Dalton Trans 2020; 51:9642-9652. [DOI: 10.1039/d0dt02546a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The three mononuclear cobalt(II) complexes, [Co(L)(NCX)2] (L = N,N'-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane, and X = S (1), Se (2), and [C(CN)2] (3)), have been synthesized and characterized using variable temperature single-crystal X-ray crystallography,...
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