1
|
Serrano-Guarinos J, Jiménez-García A, Bautista D, González-Herrero P, Vivancos Á. Synthesis, Luminescence, and Electrochemistry of Tris-Chelate Platinum(IV) Complexes with Cyclometalated N-Heterocyclic Carbene Ligands and Aromatic Diimines. Inorg Chem 2024. [PMID: 39698802 DOI: 10.1021/acs.inorgchem.4c04446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2024]
Abstract
Dicationic, C2-symmetrical, tris-chelate Pt(IV) complexes of general formula [Pt(trz)2(N∧N)](OTf)2, bearing two cyclometalated 4-butyl-3-methyl-1-phenyl-1H-1,2,3-triazol-5-ylidene (trz) ligands and one aromatic diimine [N∧N = 2,2'-bipyridine (bpy, 2), 4,4'-di-tert-butyl-2,2'-bipyridine (dbbpy, 3), 4,4'-dimethoxi-2,2'-bipyridine (dMeO-bpy, 4), 1,10-phenanthroline (phen, 5), 4,7-diphenyl-1,10-phenanthroline (bphen, 6), dipyrido[3,2-a:2',3'-c]phenazine (dppz, 7), or 2,3-diphenylpyrazino[2,3-f][1,10]phenanthroline (dpprzphen, 8)] are obtained through chloride abstraction from [PtCl2(trz)2] (1) using AgOTf in the presence of the corresponding diimine. Complexes 2-4 show long-lived phosphorescence from 3LC excited states involving the diimine ligand, with quantum yields that reach 0.18 in solution and 0.58 in the solid matrix at room temperature for 3. Derivatives with more extended aromatic systems show dual phosphorescent/fluorescent emissions (5, 6) or mainly fluorescence (7, 8) in solution. Comparisons with similar complexes bearing cyclometalated 2-arylpyridines instead of aryl-N-heterocyclic carbenes indicate that the {Pt(trz)2} subunit is crucial to enable efficient emissions from diimine-centered excited states. It is also shown that the introduction of protective bulky substituents on the diimine, such as the tert-butyl groups in 3, is a key strategy to reach higher emission efficiencies. The new compounds represent rare examples of luminescent Pt(IV) complexes that show quasi-reversible one-electron reductions, indicating an unusually high redox stability.
Collapse
Affiliation(s)
- José Serrano-Guarinos
- Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| | - Adrián Jiménez-García
- Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| | - Delia Bautista
- Área Científica y Técnica de Investigación, Universidad de Murcia, Campus de Espinardo, 21, 30100 Murcia, Spain
| | - Pablo González-Herrero
- Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| | - Ángela Vivancos
- Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| |
Collapse
|
2
|
Rueda-Espinosa J, Zhou W, Love JA, Pal S. Intramolecular Csp 3-H Activation at a Platinum(IV) Center Resulting from O 2 Activation: The Role of a Proton-Responsive Ligand and Trans Influence. J Am Chem Soc 2024; 146:34442-34451. [PMID: 39630995 DOI: 10.1021/jacs.4c11054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2024]
Abstract
Aerobic oxidation of a dimethylplatinum(II) complex featuring 1,1-di(2-pyridyl)ethanol as a supporting ligand leads to the formation of two unexpected PtIV complexes (in ∼1:1 ratio), neither of which results from direct oxidation typical for PtII centers supported by popular κ2-(N,N) ligands. While one product features an isomerized PtIV center stabilized by the κ3-(N,N,O) ligand coordination mode, surprisingly, the other product results from intramolecular activation of the ligand methyl fragment. Mechanistic studies, reactivity of model complexes, and DFT calculations reveal that the critical proton-responsive nature of the ligand allows formation of intermediates that result in a concerted metalation deprotonation (CMD)-like C-H activation at PtIV. To the best of our knowledge, this is the first mechanistic delineation of Csp3-H activation at PtIV, despite being known for other high-valent platinum group metal centers.
Collapse
Affiliation(s)
- Juan Rueda-Espinosa
- Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Wen Zhou
- Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada
| | - Jennifer A Love
- Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Shrinwantu Pal
- Department of Chemistry, Brandon University, 270 18th Street, Brandon, Manitoba R7A 6A9, Canada
| |
Collapse
|
3
|
Yoshimura A, Zhdankin VV. Recent Progress in Synthetic Applications of Hypervalent Iodine(III) Reagents. Chem Rev 2024; 124:11108-11186. [PMID: 39269928 PMCID: PMC11468727 DOI: 10.1021/acs.chemrev.4c00303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 08/18/2024] [Accepted: 08/29/2024] [Indexed: 09/15/2024]
Abstract
Hypervalent iodine(III) compounds have found wide application in modern organic chemistry as environmentally friendly reagents and catalysts. Hypervalent iodine reagents are commonly used in synthetically important halogenations, oxidations, aminations, heterocyclizations, and various oxidative functionalizations of organic substrates. Iodonium salts are important arylating reagents, while iodonium ylides and imides are excellent carbene and nitrene precursors. Various derivatives of benziodoxoles, such as azidobenziodoxoles, trifluoromethylbenziodoxoles, alkynylbenziodoxoles, and alkenylbenziodoxoles have found wide application as group transfer reagents in the presence of transition metal catalysts, under metal-free conditions, or using photocatalysts under photoirradiation conditions. Development of hypervalent iodine catalytic systems and discovery of highly enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important recent achievement in the field of hypervalent iodine chemistry. Chemical transformations promoted by hypervalent iodine in many cases are unique and cannot be performed by using any other common, non-iodine-based reagent. This review covers literature published mainly in the last 7-8 years, between 2016 and 2024.
Collapse
Affiliation(s)
- Akira Yoshimura
- Faculty
of Pharmaceutical Sciences, Aomori University, 2-3-1 Kobata, Aomori 030-0943, Japan
| | - Viktor V. Zhdankin
- Department
of Chemistry and Biochemistry, University
of Minnesota Duluth, Duluth, Minnesota 55812, United States
| |
Collapse
|
4
|
Yin Y, Luo R, Wang W, Wang R, Jiang N, Chen P, Yu HJ, Bi SY, Shao F. A dysprosium(III)-based triple helical-like complex as a turn-on/off fluorescence sensor for Al(III) and 4,5-dimethyl-2-nitroaniline. Dalton Trans 2024; 53:5544-5552. [PMID: 38426260 DOI: 10.1039/d3dt03546h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
A novel triple helical-like complex [Dy2K2L3(NO3)2]·3DMF (1) based on a designed Schiff base N'1,N'3-bis((E)-3-ethoxy-2-hydroxybenzylidene)-malonohydrazide (H4L) was synthesized with good chemical and thermal stabilities. Single-crystal X-ray structural analysis showed that 1 presents a tetranuclear triple helical-like structure via the coordination mode of Dy : K : L with 2 : 2 : 3 stoichiometry. Fluorescence measurements showed that 1@EtOH has excellent fluorescence turn-on/off response ability for aluminium ions and 4,5-dimethyl-2-nitroaniline (DMNA) with outstanding selectivity, sensitivity, and anti-interference ability. The calculated limit of detection (LOD) values for 1@EtOH to Al3+ and DMNA were found to be 0.53 and 3.33 μM, respectively. Density functional theory (DFT) calculation showed that the fluorescence response mechanism can be explained by the photoinduced electron transfer (PET) mechanism; meanwhile, the inner filter effect (IFE) of DMNA can also affect the emission of 1@EtOH.
Collapse
Affiliation(s)
- Yi Yin
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Rong Luo
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Wen Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Rui Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Nan Jiang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Peng Chen
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Hai-Jun Yu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| | - Shuang-Yu Bi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Feng Shao
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
| |
Collapse
|
5
|
Manca L, Senzacqua G, Stoccoro S, Zucca A. Regioselective C(sp 2)-C(sp 3) Coupling Mediated by Classical and Rollover Cyclometalation. Molecules 2024; 29:707. [PMID: 38338451 PMCID: PMC10856536 DOI: 10.3390/molecules29030707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
By taking advantage of a sequence of oxidative addition/reductive elimination reactions, Pt(II) cyclometalated derivatives are able to promote a rare C(sp2)-C(sp3) bond coupling, resulting in the production of novel methyl-substituted pyridines and bipyridines. Starting from 6-phenyl-2,2'-bipyridine, the step-by-step full sequence of reactions has been followed, leading to the unprecedented 3-methyl-6-phenyl-2,2'-bipyridine, which was isolated and fully characterized. The synthesis involves the following steps: (1) rollover cyclometalation to give the starting complex [Pt(N^C)(DMSO)Me]; (2) the synthesis of a more electron-rich complex [Pt(N^C)(PPh3)Me] by the substitution of DMSO with triphenylphosphine; (3) oxidative addition with methyl iodide to give the Pt(IV) complex [Pt(N^C)(PPh3)(Me)2(I)]; (4) iodide abstraction with silver tetrafluoborate to give an unstable pentacoordinate intermediate, which rapidly evolves through a carbon-carbon reductive coupling, forming a new C(sp3)-C(sp2) bond; (5) finally, the extrusion and characterization of the newly formed 3-methyl-6-phenyl-2,2'-bipyridine. The reaction has been therefore extended to a well-known classical cyclometalating ligand, 2-phenylpyridine, demonstrating that the method is not restricted to rollover derivatives. Following the same step-by-step procedure, 2-phenylpyridine was converted to 2-o-tolyl-pyridine, displaying the potential application of the method to the larger family of classical cyclometalated complexes. The application of this protocol may be useful to convert an array of heterocyclic compounds to their methyl- or alkyl-substituted analogs.
Collapse
Affiliation(s)
- Lorenzo Manca
- Dipartimento di Scienze Chimiche, Fisiche, Matematiche e Naturali, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari, Italy; (L.M.); (G.S.); (S.S.)
| | - Giacomo Senzacqua
- Dipartimento di Scienze Chimiche, Fisiche, Matematiche e Naturali, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari, Italy; (L.M.); (G.S.); (S.S.)
- Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), Villa La Rocca, Via Celso Ulpiani, 27, 70126 Bari, Italy
| | - Sergio Stoccoro
- Dipartimento di Scienze Chimiche, Fisiche, Matematiche e Naturali, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari, Italy; (L.M.); (G.S.); (S.S.)
- Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), Villa La Rocca, Via Celso Ulpiani, 27, 70126 Bari, Italy
| | - Antonio Zucca
- Dipartimento di Scienze Chimiche, Fisiche, Matematiche e Naturali, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari, Italy; (L.M.); (G.S.); (S.S.)
- Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), Villa La Rocca, Via Celso Ulpiani, 27, 70126 Bari, Italy
| |
Collapse
|
6
|
Greenberg M, Tulloch KM, Reynoso ME, Knapp JL, Sayem FH, Bartkus DD, Lum RH, LaFratta CN, Tanski JM, Anderson CM. Synthesis, Structure, and Photophysical Properties of Platinum Compounds with Thiophene-Derived Cyclohexyl Diimine Ligands. ACS OMEGA 2023; 8:38587-38596. [PMID: 37867690 PMCID: PMC10586441 DOI: 10.1021/acsomega.3c05567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023]
Abstract
Platinum(II) and platinum(IV) compounds were prepared by the stereoselective and regioselective reactions of thiophene-derived cyclohexyl diimine C^N^N-ligands with [Pt2Me4(μ-SMe2)2]. Newly synthesized ligands were characterized by NMR spectroscopy and elemental analysis, and Pt(II)/Pt(IV) compounds were characterized by NMR spectroscopy, elemental analysis, high-resolution mass spectrometry, and single-crystal X-ray diffraction. UV-vis absorbance and photoluminescence measurements were performed on newly synthesized complexes, as well as structurally related Pt(II)/Pt(IV) compounds with benzene-derived cyclohexyl diimine ligands, in dichloromethane solution, as solids, and as 5% by weight PMMA-doped films. DFT and TD-DFT calculations were performed, and the results were compared with the observed spectroscopic properties of the newly synthesized complexes. X-ray total scattering measurements and real space pair distribution function analysis were performed on the synthesized complexes to examine the local- and intermediate-range atomic structures of the emissive solid states.
Collapse
Affiliation(s)
- Matthew
W. Greenberg
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Kris M. Tulloch
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Michelle E. Reynoso
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Juliette L. Knapp
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Farman H. Sayem
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Daphne D. Bartkus
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Ryan H. Lum
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Christopher N. LaFratta
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| | - Joseph M. Tanski
- Department
of Chemistry, Vassar College, Poughkeepsie, New York 12604, United States
| | - Craig M. Anderson
- Department
of Chemistry & Biochemistry, Bard College, 30 Campus Road,Annandale-on-Hudson, New York 12504, United States
| |
Collapse
|
7
|
Gómez de Segura D, Giménez N, Rincón-Montón D, Moreno MT, Pichel JG, López IP, Lalinde E. A new family of luminescent [Pt(pbt) 2(C 6F 5)L] n+ ( n = 1, 0) complexes: synthesis, optical and cytotoxic studies. Dalton Trans 2023; 52:12390-12403. [PMID: 37594064 DOI: 10.1039/d3dt01759a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Given the widely recognized bioactivity of 2-arylbenzothiazoles against tumor cells, we have designed a new family of luminescent heteroleptic pentafluorophenyl-bis(2-phenylbenzothiazolyl) PtIV derivatives, fac-[Pt(pbt)2(C6F5)L]n+ (n = 1, 0) [L = 4-Mepy 1, 4-pyridylbenzothiazole (pybt) 2, 4,4'-bipyridine (4,4'-bpy) 3, 1,2-bis-(4-pyridyl)ethylene (bpe) 4 (E/Z ratio: 90/10), 1,4-bis-(pyridyl)butadiyne (bpyb) 5, trifluoroacetate (-OCOCF3) 6] and a dinuclear complex [{Pt(pbt)2(C6F5)}2(μ-bpyb)](PF6)27, in which the trans ligand to the metalated C-(pbt) was varied to modify the optical properties and lipophilicity. Their photophysical properties were systematically studied through experimental and theoretical investigations, which were strongly dependent on the identity of the N-bonded ligand. Thus, complexes 1, 3 and 6 display, in different media, emission from the triplet excited states of primarily intraligand 3ILCT nature localized on the pbt ligand, while the emissions of 2, 5 and 7 were ascribed to a mixture of close 3IL'(N donor)/3ILCT(pbt) excited states, as supported by lifetime measurements and theoretical calculations. Irradiation of the initial E/Z mixture of 4 (15 min) led to a steady state composed of roughly 1 : 1.15 (E : Z) and this complex was not emissive at room temperature due to an enhanced intramolecular E to Z isomerization process of the 1,2-bis-(4-pyridyl)ethylene ligand. Complexes 1-3 and 6 showed excellent quantum yields for the generation of singlet oxygen in aerated MeCN solution with the values of ϕ(1O2) ranging from 0.66 to 0.86 using phenalenone as a reference. Cationic complexes 1-3 exhibited remarkable efficacy in the nanomolar range against A549 (lung carcinoma) and HeLa (cervix carcinoma) cell lines with notable selectivity relative to the non-tumorigenic BEAS-2B (bronchial epithelium) cells. In the A549 cell line, the neutral complex 6 showed low cytotoxicity (IC50: 29.40 μM) and high photocytotoxicity (IC50: 5.75) when cells were irradiated with blue light for 15 min. These complexes do not show evidence of DNA interaction.
Collapse
Affiliation(s)
- David Gómez de Segura
- Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
| | - Nora Giménez
- Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
| | - David Rincón-Montón
- Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
| | - M Teresa Moreno
- Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
| | - José G Pichel
- Lung Cancer and Respiratory Diseases Unit (CIBIR), Fundación Rioja Salud, 26006, Logroño, Spain.
- Spanish Biomedical Research Networking Centre in Respiratory Diseases (CIBERES), ISCIII, E-28029, Madrid, Spain
| | - Icíar P López
- Lung Cancer and Respiratory Diseases Unit (CIBIR), Fundación Rioja Salud, 26006, Logroño, Spain.
| | - Elena Lalinde
- Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
| |
Collapse
|
8
|
Ebrahim RMA, Abdelbagi A, Sulfab Y, Hamdi OAA, Shokri SA, Ali EA. Synthesis, characterization, molecular docking, and antimicrobial activities of dinuclear nickel(ii), palladium(ii), and platinum(iv) complexes. RSC Adv 2023; 13:27501-27511. [PMID: 37720836 PMCID: PMC10501048 DOI: 10.1039/d3ra04768g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 08/25/2023] [Indexed: 09/19/2023] Open
Abstract
New nickel(ii), palladium(ii), and platinum(iv) complexes were synthesized by reacting the metal ions with benzidinedioxime in a 1 : 1 mole ratio. The CHN elemental analysis, spectroscopic analyses, and powder X-ray diffraction (PXRD) results showed that two Ni(ii) and two Pd(ii) ions coordinated to two benzidinedioxime ligands via the nitrogen atoms of both oxime groups and the two azomethine nitrogen atoms. In the case of the dinuclear platinum(iv) complex, however, each Pt(iv) is coordinated with the two oxygen atoms of the oxime group and the two azomethine nitrogen atoms of the ligand. Both elemental analyses and PXRD indicated that the complex ions of Ni(ii) and Pt(iv) have distorted octahedral geometry, whereas Pd(ii) has a square planar geometry. Molecular docking studies showed that the nickel(ii) complex is the most potent dual DHPS/DHFR bacterial inhibitor. The receptor of the DHPS enzyme (3ZTE) showed the best interaction with the nickel(ii) complex when compared to a receptor of the DHFR enzyme (3FRB). All the synthesized complexes and ligand exhibited significant results against PS. Aeruginous than their corresponding SMX-TMP drug. Among the three synthesized complexes, the nickel(ii) complex possessed the highest antimicrobial activities against tested microorganisms.
Collapse
Affiliation(s)
- Reem M A Ebrahim
- Biotechnology Department, Africa City of Technology Khartoum Sudan
- Chemistry Department, Faculty of Science, Sudan University of Science and Technology Khartoum Sudan
| | - Abubakar Abdelbagi
- Pharmaceutical Microbiology Department, Faculty of Pharmacy, Al-Neelain University Khartoum Sudan
| | - Yousif Sulfab
- Chemistry Department, Faculty of Science and Technology, Al-Neelain University Khartoum Sudan
| | | | - Samah A Shokri
- Pharmaceutical Microbiology Department, Faculty of Pharmacy, Al-Neelain University Khartoum Sudan
| | - Elmugdad A Ali
- Chemistry Department, Faculty of Science, Sudan University of Science and Technology Khartoum Sudan
| |
Collapse
|
9
|
López-López JC, Bautista D, González-Herrero P. Photoinduced Reductive C-C and C-Heteroatom Couplings from Bis-cyclometalated Pt(IV) Alkynyl Complexes. Inorg Chem 2023; 62:14411-14421. [PMID: 37616569 PMCID: PMC10481375 DOI: 10.1021/acs.inorgchem.3c02162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Indexed: 08/26/2023]
Abstract
Unsymmetrical dicarboxylato complexes [Pt(tpy)2(O2CR)2] [tpy = cyclometalated 2-(p-tolyl)pyridine, R = Me, CF3] react with the terminal alkynes 4-methoxyphenylacetylene, phenylacetylene, 4-(trifluoromethyl)phenylacetylene or 3,5-difluorophenylacetylene in the presence of a base to produce complexes mer-[Pt(tpy)2(O2CR)(CCAr)], in which the metalated carbon atoms are in a meridional arrangement. Irradiation of the trifluoroacetato derivatives with a 365 nm LED source leads to isomerization to the facial complexes, which can be converted to chlorido derivatives upon reaction with NH4Cl. In contrast, irradiation of the acetato derivatives leads to four different processes, namely, reduction to cis-[Pt(tpy)2], annulations involving one of the tpy ligands and the Cα and Cβ atoms of the alkynyl to give benzoquinolizinium derivatives, isomerization to the facial geometry, or C-O couplings between the acetato ligand and one tpy. The first two processes are favored by the presence of electron-donating groups on the alkynyl, whereas electron-withdrawing groups favor the last two. Irradiation of complexes fac-[Pt(tpy)2(O2CCF3)(CCAr)] with a medium-pressure Hg UV lamp leads to a reductive C-C coupling involving the alkynyl Cα atom and one of the tpy ligands to give pyridoisoindolium derivatives, except for the methoxyphenylacetylide derivative, which is photostable. On the basis of TDDFT calculations, the photoreactivity of the mer complexes is attributed to 3LLCT [π(alkynyl) → π*(tpy)] excited states for annulations or 3LMCT [π(alkynyl) → dσ*] excited states for the rest of the processes, which are accessible through thermal population from 3LC(tpy) states. The C-C couplings from the fac complexes are attributed to photoreactive pentacoordinate intermediates.
Collapse
Affiliation(s)
- Juan Carlos López-López
- Departamento
de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| | - Delia Bautista
- Área
Científica y Técnica de Investigación, Universidad de Murcia, Campus de Espinardo, 21, 30100 Murcia, Spain
| | - Pablo González-Herrero
- Departamento
de Química Inorgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, 19, 30100 Murcia, Spain
| |
Collapse
|
10
|
Das S, Pal P, Ganguly T, Baitalik S. Influences of Both N,N,N- and N,N,C-Coordination Modes of Tolyl-terpyridine on the Photophysical Properties of Cyclometalated Ru(II) Complexes: Combined Experimental and Theoretical Investigations on Acid/Base-Dependent Reversible Cyclometalation. Inorg Chem 2023; 62:12872-12885. [PMID: 37506326 DOI: 10.1021/acs.inorgchem.3c01523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
With the goal of developing a new strategy for the synthesis of luminescent Ru(II) complexes, we have prepared herein a new set of bis-tridentate complexes of the type [(py-bpy-Ph-X)Ru(tpy-PhCH3)]ClO4 (X = -CH3, -CH2Br, and -CHO) incorporating both non-cyclometalated and cyclometalated coordination motifs of two isomeric forms of methylphenyl-terpyridine (tpy-PhCH3). Thorough characterization of the synthesized complexes is carried out using standard analytical tools and single crystal X-ray diffraction. Detailed investigations on their photophysical and electrochemical behaviors are carried out in MeCN. The presence of a carbanionic center in the cyclometalating unit increases the absorption spectral window of the complexes into a longer-wavelength region. The complexes also exhibit room-temperature luminescence in the NIR domain with enhanced excited-state lifetimes (up to 20.1 ns) compared to their non-cyclometalated counterpart, [Ru(tpy-PhCH3)2]2+. In the presence of acid, the non-coordinated nitrogen atom in the secondary coordination sphere of the complexes allows fine-tuning of the absorption and emission spectral properties. Excess acid induces de-coordination of the Ru-C bond, which is signaled by a remarkable alteration of their spectral profiles. Cleavage of the Ru-C bond is also possible upon treating the acidified solution of the complexes with visible light. Restoration of the Ru-C bond is again feasible upon treating the solution with base at an elevated temperature (∼70 °C). In essence, "on-off" and "off-on" switching of emission is facilitated upon alternating treatment of the Ru(II) complexes with acid, base, and temperature. DFT and TD-DFT calculations are also performed for assignments of the spectral bands as well as to understand structural changes associated with the switching behaviors of the complexes.
Collapse
Affiliation(s)
- Soumi Das
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
| | - Poulami Pal
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & B Raja S C Mullick Road, Kolkata 700032, India
| | - Tanusree Ganguly
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
| | - Sujoy Baitalik
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
| |
Collapse
|