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1.
Ambarish Mondal Rajat K. Tripathy Parul Dutta Manas Kumar Santra Anvarhusein A. Isab Christopher W. Bielawski Hemanta K. Kisan Swapan K. Chandra Joydev Dinda 《应用有机金属化学》2019,33(1)
The syntheses, structures, and chemotherapeutic activities of Ag(I)‐, Au(I)‐, and Ru(II)‐complexes ligated to a novel N‐heterocyclic carbene ligand, 2‐(4‐nitrophenyl)imidazo[1,5‐a]pyridin‐2‐ylidene ( 1 ), are described. The corresponding complexes, [Ag( 1 )2][PF6], [Au( 1 )2][PF6] ( 3 ), and [Ru( 1 )(p‐cymene)Cl][PF6] ( 4 ), were prepared using convenient transmetallation chemistry and characterized using a range of spectroscopic and analytical techniques. X‐ray crystallography revealed that complexes 2 and 3 adopted linear structures whereas 4 exhibited a prototypical “piano‐stool”‐like geometry; the structural assignments were further supported by DFT calculations. A series of in vitro studies revealed that while the aforementioned Ag(I), Au(I) and Ru(II) complexes exhibited significant cytotoxicities against the human colon adenocarcinoma (HCT 116), lung cancer (A549), and breast cancer (MCF7) cell lines, the Ru derivative was most prominent. 相似文献
2.
Sirsendu Das Adhikary Ambarish Mondal Hemanta K. Kisan Christopher W. Bielawski Joydev Dinda 《应用有机金属化学》2020,34(2):e5335
A series of silver(I) and gold(I) carbene complexes of the type [M(L)(2,2′-bipyridine)][PF6] (L = 1-benzyl-3-(2-pyridylmethyl)benzimidazolylidene; M = Ag ( 1 ); M = Au ( 3 )) and [M(L)(carbazole)] (M = Ag ( 2 ); M = Au ( 4 )) were synthesized and analyzed using a range of spectroscopic and crystallographic techniques. Inspection of the solid-state structures of 1 , 2 and 4 revealed a number of intermolecular noncovalent interactions. In the solid-state structure adopted by 1 , π–π and Ag–Ag interactions directed the complexes to orient in a head-to-tail fashion. The photophysical properties were found to be influenced by the ancillary ligands in solution as well as in the solid-state. Calculations were performed to support the aforementioned structural and optoelectronic assignments. 相似文献
3.
Alexander Bechtoldt Hans‐Wolfram Lerner Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(6):448-451
The aurophilicity exhibited by AuI complexes depends strongly on the nature of the supporting ligands present and the length of the Au–element (Au—E) bond may be used as a measure of the donor–acceptor properties of the coordinated ligands. A binuclear iron–gold complex, [1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene‐2κC2]dicarbonyl‐1κ2C‐(1η5‐cyclopentadienyl)gold(I)iron(II)(Au—Fe) benzene trisolvate, [AuFe(C5H5)(C27H36N2)(CO)2]·3C6H6, was prepared by reaction of K[CpFe(CO)2] (Cp is cyclopentadienyl) with (NHC)AuCl [NHC = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]. In addition to the binuclear complex, the asymmetric unit contains three benzene solvent molecules. This is the first example of a two‐coordinated Au atom bonded to an Fe and a C atom of an N‐heterocyclic carbene. 相似文献
4.
Rosenani A. Haque Muhammad Adnan Iqbal Srinivasa Budagumpi Mohamed B. Khadeer Ahamed Amin M. S. Abdul Majid Noorhafizah Hasanudin 《应用有机金属化学》2013,27(4):214-223
Salts of meta‐xylyl‐linked N‐ethyl/n‐butyl/benzyl‐substituted bis‐benzimidazolium having hexafluorophosphate counterions have been synthesized. The corresponding binuclear Ag(I)‐N‐heterocyclic carbene complexes were prepared by the reaction of Ag2O. The N‐heterocyclic carbene (NHC) ligand precursor 7 and Ag(I)–NHC complexes 10 and 11 have been structurally characterized by single‐crystal X‐ray diffraction technique. All of the reported compounds have been tested for their anticancer activity using human colorectal (HCT 116) cancer cell lines. Sterically varied benzimidazolium salts displayed significant activity against HCT 116 cell line, yielding IC50 values in the range 0.1–19.4 µ m , while Ag(I)–carbene complexes showed exceptionally good activity (0.2–1.3 µ m ) against tested cancer cell lines. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
5.
Benzimidazole‐based silver(I)–N‐heterocyclic carbene complexes as anti‐bacterials: synthesis,crystal structures and nucleic acids interaction studies
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Patrick O. Asekunowo Rosenani A. Haque Mohd. R. Razali Srinivasa Budagumpi 《应用有机金属化学》2015,29(3):126-137
A series of new benzimidazolium salts as N‐heterocyclic carbene (NHC) precursors has been synthesized. Reactions of these salts with Ag2O with varying metal‐to‐salt ratio facilitate the formation of a series of new binuclear and mononuclear Ag(I)–NHC complexes. All compounds were characterized using physicochemical and spectroscopic techniques. Single‐crystal X‐ray diffraction study reveals a binuclear structure for one of the complexes and a mononuclear one for two others. These complexes exist as cationic Ag(I)–NHC complexes with the chelation of carbene carbons to the silver centre in an almost linear manner. The compounds were screened for their anti‐bacterial activities against Staphylococcus aureus (ATCC 12600) as a Gram‐positive bacterium and Escherichia coli (ATCC 25922) as a Gram‐negative bacterium. The results show that both bacteria appear markedly inhibited. Furthermore, the results suggest the possibility of steric variation as a modulation of the anti‐bacterial activities. The nuclease activities of the compounds were assessed using gel electrophoresis and the results indicate that these complexes can cleave or degrade DNA and RNA via a non‐oxidative mechanism. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
《应用有机金属化学》2017,31(10)
A series of symmetrically n ‐alkyl‐substituted mono benzimidazolium salts with steady increase in n ‐alkyl chain length have been prepared by stepwise N ‐alkylation resulting in salts ( 1 – 8 ). The mono N‐heterocyclic carbene (NHC)–Ag(I) complexes ( 9 – 16 ) derived from the respective salts were readily accessible by in situ deprotonation using Ag2O. All the salts and the complexes were characterized using Fourier transform infrared, 1H NMR, 13C NMR and elemental analyses. Furthermore, the structures of salts 3 and 7 and complex 16 were elucidated using X‐ray crystallography, which established that this mono NHC–Ag(I) complex has a linear bis‐carbene arrangement (C2–Ag). The proligands and the respective Ag(I) complexes were studied for their in vitro anticancer potential against human colon cancer cell line (HCT‐116) using 5‐fluorouracil as a standard. From the IC50 values of all the tested compounds, it can be postulated that there is an influential relationship between the increase in chain length of the wingtip n ‐alkyl groups and the anticancer potential. The proligands 4 – 8 and their respective complexes 12 – 16 with long n ‐alkyl chain lengths (n = 6–10) showed better IC50 values (0.3–3.9 μM) than the standard drug with the complexes displaying markedly better antiproliferation activity against HCT‐116 cell line than the respective proligands and the standard drug (IC50 = 10.2 μM). 相似文献
7.
Rosenani A. Haque Srinivasa Budagumpi Sze Yii Choo Mei Kee Choong Bhadravathi Eswara Lokesh Kumar Sudesh 《应用有机金属化学》2012,26(12):689-700
Various nitrile‐functionalized benzimidazol‐2‐ylidene carbene complexes of Hg(II) and Ag(I) were synthesized by the interaction of 1‐benzyl/1‐butyl‐3‐(cyano‐benzyl)‐3 H‐benzimidazol‐1‐ium mono/dihexafluorophosphate with Hg(OAc)2/Ag2O in acetonitrile. Two of the benzimidazolium salts were structurally characterized by single crystal X‐ray diffraction technique. Structures of reported compounds were characterized by 1 H, 13C NMR, FT‐IR, UV–visible spectroscopic techniques, and molar conductivity and elemental analyses. For bis‐benzimidazolium salt, dinuclear Hg(II)– and Ag(I)–carbene complexes were obtained. Nuclease activity and binding interactions of the synthesized benzimidazolium salts and their Ag(I)–carbene complexes with DNA were studied using agarose gel electrophoresis and, absorption spectroscopy and viscosity measurements, respectively. Ag(I)–carbene complexes showed higher DNA binding activity compared to their respective benzimidazolium salts. However, a benzimidazolium salt and two of the Ag(I) complexes showed remarkably higher nuclease activity both, in the presence and absence of an oxidizing agent. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
8.
《应用有机金属化学》2017,31(7)
Four new Ag(I)–N‐heterocyclic carbene (NHC) complexes ( 5 – 8 ) bearing symmetrically substituted NHC ligands have been synthesized starting from the corresponding benzimidazolium bromide salts which are accessible in a single step from N ‐substituted benzimidazoles (N ‐alkyl and N ‐aryl) and subsequently reacted with the basic metal source Ag2O in acetonitrile–methanol. These compounds were characterized using elemental analyses, 1H NMR, 13C NMR, Fourier transform infrared and UV–visible spectroscopic techniques, and molar conductivity. Single‐crystal structural studies for complex 5 show that the Ag(I) centre has a perfectly linear C–Ag–C coordination, with quasi‐parallel pairs of aromatic benzimidazole planes. All the complexes interact with Aedes albopictus DNA via intercalation mode by a large hypochromicity of 22 and 27% and smaller hypochromicity of 16 and 19%. Furthermore, all complexes exhibit efficient DNA cleavage activity via a non‐oxidative mechanistic pathway. The DNase activities of the test compounds revealed a time‐ and concentration‐dependent activity pattern. The Ag(I)–NHC complexes showed considerably higher DNA cleavage activity compared to their respective benzimidazolium salts at a lower concentration. The DNA cleavage of these complexes changed from a moderate effect to a good one, corresponding to the increasing lipophilicity order of the complexes as 5 < 6 < 7 < 8 (1.02, 1.05, 1.78 and 2.06 for 5 – 8 , respectively). This order is further corroborated with the DNA binding study, but with the exception of complex 5 , which shows a better binding ability for DNA (K b = 3.367 × 106) than complexes 6 – 8 (6.982 × 105, 8.376 × 105 and 1.223 × 106, respectively). 相似文献
9.
New Cu(I) Coordination Complexes Based on Tetrathiafulvalene Substituted Triazol‐pyridine Ligand: Synthesis,Properties and Theoretical Studies
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Two Cu(I) complexes based on the thioethyl‐bridged triazol‐pyridine ligand with tetrathiafulvalene unit (TTF‐TzPy, L ), [Cu(I)(Binap)(L)]BF4 ( 5 , Binap=2,2’‐bis(diphenylphosphino)‐1,1’‐binaphthyl) and [Cu(I)(Xantphos)(L)]BF4 ( 6 , Xantphos=9,9‐dimethyl‐4,5‐bis(diphenylphosphino)‐xanthene), have been synthesized. All new compounds are characterized by elemental analyses, 1H NMR and mass spectroscopies. The complex 5 has been determined by X‐ray structure analyses which shows that the central copper (I) ion assumes distorted tetrahedral geometry. The photophysical, computational and electrochemical properties of L and 5 ‐ 6 have been investigated. The most representative molecular orbital energy‐level diagrams and the spin‐allowed singlet? singlet electronic transitions of the three compounds have been calculated with density functional theory (DFT) and time‐dependent DFT (TD‐DFT). The luminescence bands of Cu(I) complexes 5 ‐ 6 have been assigned as mixed intraligand and metal‐to‐ligand charge transfer 3(MLCT+π→π*) transitions through analysis of the photophysical properties and DFT calculations. The electrochemical studies reveal that 5 ‐ 6 undergo reversible TTF/TTF+?/TTF2+ redox processes and one irreversible Cu+→Cu2+ oxidation process. 相似文献
10.
Daniel T. Marake Penny P. Mokolokolo Hendrik G. Visser Alice Brink 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(6):423-429
Two tricarbonyl complexes of rhenium(I) and manganese(I) coordinated by the ligand 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate are reported, viz. fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN3)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)rhenium(I) methanol monosolvate, [Re(C16H14N3O4)(CO)3]·CH3OH, (I), and fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN3)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)manganese(I), fac‐[Mn(C16H14N3O4)(CO)3], (II), display facial coordination in a distorted octahedral environment. The crystal structure of (I) is stabilized by O—H...O, N—H...O and C—H...O hydrogen‐bond interactions, while that of (II) is stabilized by N—H...O hydrogen‐bond interactions only. These interactions result in two‐dimensional networks and π–π stacking for both structures. 相似文献
11.
Yang Guo Yue Ma Na Zhou Zhan‐Quan Liu Qing‐Lun Wang Shi‐Ping Yan Dai‐Zheng Liao Prof. Dr. 《无机化学与普通化学杂志》2010,636(5):865-871
To investigate the influence of the non‐covalent interactions, such as hydrogen‐bonding, π–π packing and d10–d10 interactions in the supramolecular motifs, three cyanido‐bridged heterobimetallic discrete complexes {Mn(bipy)2(H2O)[Ag(CN)2]}[Ag(CN)2] ( 1 ), {Mn(phen)2(H2O)[Au(CN)2]}2[Au(CN)2]2 · 4H2O ( 2 ), and {Cd(bipy)2(H2O)[Au(CN)2]}[Au(CN)2] ( 3 ) (bipy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline), which are based on dicyanidometallate(I) groups with 1:2 stoichiometry of metal ions and 2,2′‐bipyridyl‐like co‐ligands were synthesized and structurally characterized. In compound 1 , hydrogen bonding and π–π interactions governed the supramolecular contacts. In compound 2 , the incorporation of aurophilic, hydrogen bonding and π–π interactions result in a 3D supramolecular network. In compound 3 , hydrogen bonding and π–π stacking interactions result in a 2D supramolecular layer. In the three complexes, hydrogen‐bonding, π–π packing and/or d10–d10 interactions can play important roles in increasing the dimensionality of supramolecular assemblies. 相似文献
12.
Miguel A. Rosero-Mafla Jhon Zapata-Rivera M. Concepcin Gimeno Renso Visbal 《Molecules (Basel, Switzerland)》2022,27(23)
A series of neutral acridine-based gold(III)-NHC complexes containing the pentafluorophenyl (–C6F5) group were synthesized. All of the complexes were fully characterized by analytical techniques. The square planar geometry around the gold center was confirmed by X-ray diffraction analysis for complexes 1 (Trichloro [1-methyl-3-(9-acridine)imidazol-2-ylidene]gold(III)) and 2 (Chloro-bis(pentafluorophenyl)[1-methyl-3-(9-acridine)imidazol-2-ylidene]gold(III)). In both cases, the acridine rings play a key role in the crystal packing of the solid structures by mean of π–π stacking interactions, with centroid–centroid and interplanar distances being similar to those found in other previously reported acridine-based Au(I)-NHC complexes. A different reactivity when using a bulkier N-heterocyclic carbene ligand such as 1,3-bis-(2,6-diisopropylphenyl)-2-imidazolidinylidene (SIPr) was observed. While the use of the acridine-based NHC ligand led to the expected organometallic gold(III) species, the steric hindrance of the bulky SIPr ligand led to the formation of the corresponding imidazolinium cation stabilized by the tetrakis(pentafluorophenyl)aurate(III) [Au(C6F5)4]− anion. Computational experiments were carried out in order to figure out the ground state electronic structure and the binding formation energy of the complexes and, therefore, to explain the observed reactivity. 相似文献
13.
Jayaraman Selvakumar Meredith H. Miles David A. Grossie Kuppuswamy Arumugam 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(4):462-468
Diffraction‐quality single crystals of two gold(I) complexes, namely bis(1,3‐dimesityl‐4,5‐naphthoquinoimidazol‐2‐ylidene)gold(I) chloride benzene monosolvate, [Au(C29H26N2O2)2]Cl·C6H6 or [(NQMes)2Au]Cl·C6H6, 2 , and bis(1,3‐dimesityl‐4,5‐naphthoquinoimidazol‐2‐ylidene)gold(I) dichloridoaurate(I) dichloromethane disolvate, [Au(C29H26N2O2)2][AuCl2]·2CH2Cl2 or [(NQMes)2Au][AuCl2]·2CH2Cl2, 4 , were isolated and studied with the aid of single‐crystal X‐ray diffraction analysis. Compound 2 crystallizes in a monoclinic space group C2/c with eight molecules in the unit cell, while compound 4 crystallizes in the triclinic space group P with two molecules in the unit cell. The crystal lattice of compound 2 reveals C—H…Cl? interactions that are present throughout the entire structure representing head‐to‐tail contacts between the aromatic (C—H) hydrogens of naphthoquinone and Cl? counter‐ions. Compound 4 stacks with the aid of short interactions between a naphthoquinone O atom of one molecule and the mesityl methyl group of another molecule along the a axis, leading to a one‐dimensional strand that is held together by strong π–η2 interactions between the imidazolium backbone and the [AuCl2]? counter‐ion. The bond angles defined by the AuI atom and two carbene C atoms [C(carbene)—Au—C(carbene)] in compounds 2 and 4 are nearly rectilinear, with an average value of ~174.1 [2]°. Though 2 and 4 share the same cation, they differ in their counter‐anion, which alters the crystal lattice of the two compounds. The knowledge gleaned from these studies is expected to be useful in understanding the molecular interactions of 2 and 4 under physiological conditions. 相似文献
14.
Gunasekaran Balamurugan Sundarraman Balaji Rengan Ramesh Nattamai S.P. Bhuvanesh 《应用有机金属化学》2019,33(1)
A panel of six new arene Ru (II)‐NHC complexes 2a‐f , (NHC = 1,3‐diethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1a , 1,3‐dicyclohexylmethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1b and 1,3‐dibenzyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1c ) were synthesized from the transmetallation reaction of Ag‐NHC with [(η6‐arene)RuCl2]2 and characterized. The ruthenium (II)‐NHC complexes 2a‐f were developed as effective catalysts for α‐alkylation of ketones and synthesis of bioactive quinoline using primary/amino alcohols as coupling partners respectively. The reactions were performed with 0.5 mol% catalyst load in 8 h under aerobic condition and the maximum yield was up to 96%. Besides, the different alkyl wingtips on NHC and arene moieties were studied to differentiate the catalytic robustness of the complexes in the transformations. 相似文献
15.
Elena Maftei Catalin V. Maftei Peter G. Jones Matthias Freytag M. Heiko Franz Gerhard Kelter Heinz‐Herbert Fiebig Matthias Tamm Ion Neda 《Helvetica chimica acta》2016,99(6):469-481
This work presents the synthesis, characterization, and application of several new metal(I) complexes with trifluoromethylpyridine‐containing N‐heterocyclic carbene (NHC) ligands. The metal of choice was gold(I) for compounds 7 – 10 , rhodium(I) for 11 – 12 , and iridium(I) for 13 – 14 , respectively. The trifluoromethylpyridine moiety was incorporated, along with other biologically active moieties, with the intention of modifying the lipophilicity of the complexes, so that the transport of the active units (M–NHC) through the cell wall barrier is facilitated. The biological activity of the complexes was investigated. In vitro assessment of antitumor activity in a panel of 12 human tumor cell lines by a monolayer assay revealed good potency (mean IC50 12.6 μm ) and tumor selectivity for one compound. The solid‐state structures of two solvates of compound 7 , one with MeOH and one with THF, were determined by X‐ray diffraction analysis. 相似文献
16.
CH–π and CF–π Interactions Lead to Structural Changes of N‐Heterocyclic Carbene Palladium Complexes
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Xiangya Xu Benjamin Pooi Prof. Dr. Hajime Hirao Prof. Dr. Soon Hyeok Hong 《Angewandte Chemie (International ed. in English)》2014,53(5):1283-1287
The role of CH–π and CF–π interactions in determining the structure of N‐heterocyclic carbene (NHC) palladium complexes were studied using 1H NMR spectroscopy, X‐ray crystallography, and DFT calculations. The CH–π interactions led to the formation of the cis‐anti isomers in 1‐aryl‐3‐isopropylimidazol‐2‐ylidene‐based [(NHC)2PdX2] complexes, while CF–π interactions led to the exclusive formation of the cis‐syn isomer of diiodobis(3‐isopropyl‐1‐pentafluorophenylimidazol‐2‐ylidene) palladium(II). 相似文献
17.
《Journal of Coordination Chemistry》2012,65(16-18):2787-2799
AbstractMononuclear trans-Pd(II)–NHC complexes (where NHC?=?N-heterocyclic carbene) bearing asymmetrically substituted NHC-ligand have been synthesized via transmetalation reaction between Ag(I)–NHC complexes and [Pd(NCCH3)2Cl2]. The NHC precursors are accessible in two steps by N-n-alkyl reactions of benzimidazole. The resultant benzimidazolium salts were deprotonated with Ag2O by in situ deprotonation to facilitate the formation of mononuclear Ag(I)–NHC complexes. Single-crystal structural study for Pd(II)–NHC shows that the palladium(II) ion exhibits a square-planar geometry of two NHC ligands and two chloride ions. The cytotoxicity study was investigated against breast cancer cell line (MCF-7). The Ag(I)–NHC complexes exhibit better activities than their corresponding Pd(II)–NHC complexes, whereas all benzimidazolium salts are inactive toward MCF-7 cancer cell line. 相似文献
18.
The synthesis and characterisation of a homologous series of monodentate benzimidazolium salts, 1–4 and their mononuclear silver(I)–NHC (where NHC = N-heterocyclic carbene) complexes, 5–8, are reported. The benzimidazolium salts were prepared from the N-alkylation of 1-methyl-benzimidazole with alkyl halides of varying carbon chain lengths. The mono silver(I)-NHC complexes, 5–8, were prepared by the reaction of the benzimidazolium salts with Ag2O. All the synthesised compounds were fully characterised by 1H-nuclear magnetic resonance (1H-NMR), 13C-NMR and fourier-transform infrared (FTIR) spectroscopy. The molecular structures of compounds 3·PF6, 4·PF6, 7 and 8 were elucidated through single-crystal X-ray diffraction analyses. We postulate that the attachment of long alkyl chains to the heterocyclic core of 1-methyl benzimidazole could induce mesophase formation. The liquid crystalline behaviour of the benzimidazolium salts was investigated by polarised optical microscope and differential scanning calorimetry. Salts 3 and 4 were found to be thermotropic liquid crystals which exhibited a smectic A phase. However, upon complexation with silver(I) ions, all the Ag(I)–NHC complexes are found to be non-mesogenic. 相似文献
19.
Joanna Palion-Gazda Agata Szapa-Kula Mateusz Penkala Karol Erfurt Barbara Machura 《Molecules (Basel, Switzerland)》2022,27(21)
Photophysical properties of two Re(I) complexes [ReCl(CO)3(R-C6H4-terpy-κ2N)] with remote amine groups, N-methyl-piperazinyl (1) and (2-cyanoethyl)methylamine (2), were investigated. The complexes show strong absorption in the visible region corresponding to metal-to-ligand charge transfer (1MLCT) and intraligand-charge-transfer (1ILCT) transitions. The energy levels of 3MLCT and 3ILCT excited-states, and thus photoluminescence properties of 1 and 2, were found to be strongly affected by the solvent polarity. Compared to the parent chromophore [ReCl(CO)3(C6H5-terpy-κ2N)] (3), both designed complexes show significantly prolonged (by 1–2 orders of magnitude) phosphorescence lifetimes in acetonitrile and dimethylformamide, contrary to their lifetimes in less polar chloroform and tetrahydrofuran, which are comparable to those for 3. The femtosecond transient absorption (fsTA) measurements confirmed the interconversion between the 3MLCT and 3ILCT excited-states in polar solvents. In contrast, the emissive state of 1 and 2 in less polar environments is of predominant 3MLCT nature. 相似文献
20.
Larica Pathaw Themmila Khamrang Balasubramaniam Selvakumaran Mariappan Murali Pitchan Arul Prakash Mohamed Sultan Mohamed Jaabir Marappan Velusamy 《应用有机金属化学》2021,35(1)
Copper(I) complexes of the types [Cu(N–N)(PPh3)2]NO3 (LC41–LC44) and [Cu(N–N)(PPh3)(NO3)] (LC45) carrying 3‐substituted 1‐pyridine‐2‐ylimidazo[1,5‐a]pyridine (N–N) derivatives and triphenylphosphine (PPh3) ligands have been prepared. The synthesized copper(I)–phosphine complexes were fully characterized by NMR, IR, ESI‐MS and UV–visible spectroscopy as well as by cyclic voltammetry. Selected structures such as LC42, LC43 and LC45 were additionally analysed by single‐crystal X‐ray method, which show that copper(I) centre adopts a highly distorted tetrahedral geometry. The 1H and 13C NMR spectral data of the complexes throw light on the nature of metal–ligand bonding. They display dπ–π* metal‐to‐ligand charge transfer (MLCT) transition and show quasireversible CuI/CuII metal oxidation. Among the copper(I)–phosphine complexes, LC41–LC44 exhibit moderate cytotoxicity (IC50: 24 h, 67–74 μM; 48 h, 58–70 μM) against human lung epithelial adenocarcinoma A549 cells, whereas LC45 displays the best activity (IC50: 24 h, 42 μM; 48 h, 34 μM) for A549 cancer cell line, which is better than that of the commercial antitumor drug cisplatin. All the complexes also displayed excellent selectivity by being relatively inactive against the human lung epithelial L132 normal cell line with selectivity index (SI) values ranging from 3.4 to 7.4. The complexes block cell cycle progression of A549 cells in G0/G1 phase. FACSVerse analyses are suggestive of reactive oxygen species (ROS) generation and apoptotic cell death induced by the LC41, LC43 and LC45. The induction of apoptosis in A549 cells was shown by Annexin V with propidium iodide (PI) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining methods and established the ability of LC41, LC43 and LC45 to accumulate in the cell nuclei. 相似文献