Synthesis and photophysical properties of naphthyl-, phenanthryl-, and pyrenyl-appended bis(pyridyl)triazine ligands and their Zn(II) and Ru(II) complexes1

A family made of four bis(pyridyl)triazine ligands with appended aryl rings, including three fused aromatic rings, have been synthesized, and their corresponding homoleptic Ru(II) and Zn(II) complexes have been prepared and characterized by several means. The free ligands 2,4-di(2-pyridyl)-6-phenyl-1,3,5-triazine (L1); 2,4-di(2-pyridyl)-6-(1-naphthyl)-1,3,5-triazine (L2); 2,4-di(2-pyridyl)-6-(9-phenanthryl)-1,3,5-triazine (L3); and 2,4-di(2-pyridyl)-6-(1-pyrenyl)-1,3,5-triazine (L4) were formed in triazine ring-forming reactions from the reactions of the cyano-functionalized aromatic rings with LiNMe2 followed by the addition of 2 equiv. of 2-cyanopyridine. The metal complexes examined in this study are the homoleptic Ru(II) complexes Ru(L1)22+ (2a), Ru(L2)22+ (2b), Ru(L3)22+ (2c), and Ru(L4)22+ (2d) and Zn(II) complexes Zn(L1)22+ (3a), Zn(L2)22+ (3b), Zn(L3)22+ (3c), and Zn(L4)22+ (3d). Also, crystallographic data for the free ligands and Zn(II) and Ru(II) complexes have been obtained in some cases. The redox behaviour and absorption spectra of all the species have been investigated, together with the luminescence properties of the free ligands at room temperature in fluid solution and of the Ru(II) complexes both at room temperature in fluid solution and at 77 K in rigid matrix. The redox data indicate that the free ligands are reduced twice at relatively mild potentials (< –2.30 V vs. SCE), with the first reduction almost independent of the nature of the substituted aryl group. The UV absorption spectra of all the compounds are dominated by intense spin-allowed π–π* transitions mainly centered on the bis(pyridyl)triazine moiety; however, in L2–L4, moderately intense intraligand charge-transfer (ILCT) bands are also present. Such bands are red-shifted in the Zn(II) compounds, while they are obscured in the Ru(II) species by the more intense spin-allowed metal-to-ligand charge-transfer (MLCT) bands. The free ligands exhibit interesting emission properties, ranging from fluorescence from π–π* states to excimeric (in L4) and ILCT (in L2 and L3) emission. In the Ru(II) complexes, strong emission is found at 77 K from triplet MLCT states. For 2c and 2d, the emissive MLCT states are mixed with low-lying triplet ligand-centered states.Key words: triazine ligands, ruthenium complexes, zinc complexes, ILCT emission.

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Synthesis and Photophysical Properties of New Three-Coordinate N-Heterocyclic Carbene Copper Complex

Materials Science Forum ◽

10.4028/www.scientific.net/msf.878.18 ◽

2016 ◽

Vol 878 ◽

pp. 18-21

Author(s):

Shao Bo Liu ◽

Cheng Yi ◽

Hong Ying Xia ◽

Feng Zhao

Keyword(s):

Excited State ◽

Charge Transfer ◽

Absorption Band ◽

Energy Absorption ◽

Copper Complex ◽

Room Temperature ◽

Photophysical Properties ◽

Emission Spectrometry ◽

Emission Maximum ◽

Ligand Charge Transfer

A three-coordinateopper (I) complex supported by N-heterocyclic carbene (NHC) ligand and bis [2-(diphenylphosphino) phenyl] ether (POP) ligand were successfully reported and characterized. The corresponding photophysical properties were investigated using UV-vis and emission spectrometry. The lowest-energy absorption band at 343 nm was assigned to metal-to-ligand charge transfer (MLCT) transtion. The emission maximum located at 470 nm upon excitation at 290 nm in PMMA films at room temperature originates from the typical 3MLCT excited state.

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Synthesis, Characterization and Photophysical Properties of Rhenium(I) Complexes Containing 4,5-Diazafluorene Ligan

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2612 ◽

2011 ◽

Vol 239-242 ◽

pp. 2612-2615

Author(s):

Jie Xiu Wang ◽

Feng Zhao

Keyword(s):

Charge Transfer ◽

Fluorescence Spectra ◽

Photophysical Properties ◽

Absorption And Fluorescence Spectra ◽

Rhenium Complexes ◽

H Nmr ◽

Ligand Charge Transfer

Two related tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=4,5-diazafluoren-9-one (Dafo-Re) and 9-(phenylamino)-4,5-diazafluoren (PADF-Re) were successfully synthesized with the aim to explore the effect of the geometry of Dafo on Rhenium(I) coordination, and characterized by1H NMR. Photophysical behaviors are investigated by UV–vis absorption and Fluorescence spectra. The two complexes Dafo-Re and PADF-Re show metal-to-ligand charge transfer absorptions at ca.391nm, ca.394 nm and emissions at ca.492nm, ca.470nm, respectively.

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Cation Sensing Capabilities of A Nitrophenyl Cinnamaldehyde Derivative

Molekul ◽

10.20884/1.jm.2020.15.3.654 ◽

2020 ◽

Vol 15 (3) ◽

pp. 191

Author(s):

Venty Suryanti ◽

Fajar Rakhman Wibowo ◽

Ahmad Marzuki ◽

Meiyanti Ratna Kumala Sari

Keyword(s):

Charge Transfer ◽

Organic Compound ◽

Charge Density ◽

Absorption Spectra ◽

Color Change ◽

Metal Cations ◽

Colorimetric Sensing ◽

Color Changes ◽

Ligand Charge Transfer ◽

Cation Sensing

The cationic chemosensor based on organic compound bearing an aminophenol moiety as a receptor for metal analyte and a cinnamaldehyde moiety as chromophoric fragment has been developed. In this work, we report the colorimetric sensing of nitrophenyl cinnamaldehyde derivative, namely methyl-3-(2-hidroxy-5-nitrophenyl amino)-3-phenylpropanoate, towards a variety of metal cations, such as Cu2+, Fe3+, Ni2+ and Zn2+. The cation sensing abilities of the sensor were observed for Cu2+and Fe3+ with a color change from colorless to pink and faint yellow, respectively, The characteristic UV-Vis spectra changes were observed upon addition of Cu2+and Fe3+ cations. The hypsochromic absorption spectra shifts were obtained, indicating the cations and sensor complexations had formed. A metal-to-ligand-charge-transfer (MLCT) had occurred and the charge density of the sensor changed resulting in appearance of new absorption peaks in the UV-Vis spectra and color changes of the sensor solution upon addition of the Cu2+and Fe3+.

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Theoretical Insight into the Spectral Characteristics of Fe(II)-Based Complexes for Dye-Sensitized Solar Cells—Part I: Polypyridyl Ancillary Ligands

International Journal of Photoenergy ◽

10.1155/2011/316952 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Xiaoqing Lu ◽

Shuxian Wei ◽

Chi-Man Lawrence Wu ◽

Ning Ding ◽

Shaoren Li ◽

...

Keyword(s):

Solar Cells ◽

Charge Transfer ◽

Optical Absorption ◽

Absorption Spectra ◽

Dye Sensitized Solar Cells ◽

Optical Absorption Spectra ◽

Ancillary Ligands ◽

Dye Sensitized ◽

Ligand Charge Transfer ◽

Sensitized Solar Cells

The design of light-absorbent dyes with cheaper, safer, and more sustainable materials is one of the key issues for the future development of dye-sensitized solar cells (DSSCs). We report herein a theoretical investigation on a series of polypyridyl Fe(II)-based complexes of FeL2(SCN)2, [FeL3]2+, [FeL′(SCN)3]-, [FeL′2]2+, and FeL′′(SCN)2(L = 2,2′-bipyridyl-4,4′-dicarboxylic acid, L′ = 2,2′,2″-terpyridyl-4,4′,4″-tricarboxylic acid, L″= 4,4‴-dimethyl-2,2′ : 6′,2″ :6″,2‴-quaterpyridyl-4′,4″-biscarboxylic acid) by density functional theory (DFT) and time-dependent DFT (TD-DFT). Molecular geometries, electronic structures, and optical absorption spectra are predicted in both the gas phase and methyl cyanide (MeCN) solution. Our results show that polypyridyl Fe(II)-based complexes display multitransition characters of Fe → polypyridine metal-to-ligand charge transfer and ligand-to-ligand charge transfer in the range of 350–800 nm. Structural optimizations by choosing different polypyridyl ancillary ligands lead to alterations of the molecular orbital energies, oscillator strength, and spectral response range. Compared with Ru(II) sensitizers, Fe(II)-based complexes show similar characteristics and improving trend of optical absorption spectra along with the introduction of different polypyridyl ancillary ligands.

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Syntheses, Structures, Characterisation, and Spectroscopic Properties of CuI and AgI Complexes with Extended C–H···π and π···π Interactions

Australian Journal of Chemistry ◽

10.1071/ch13566 ◽

2014 ◽

Vol 67 (6) ◽

pp. 887 ◽

Cited By ~ 2

Author(s):

Ting-Hong Huang ◽

Min-Hua Zhang

Keyword(s):

Charge Transfer ◽

Room Temperature ◽

Spectroscopic Properties ◽

Acetonitrile Solution ◽

Fluorescent Properties ◽

Π Interactions ◽

Π Stacking ◽

Ligand Charge Transfer ◽

The One ◽

Stacking Patterns

Based on the ligands N,N′-bis(pyridin-2-ylmethylene)benzene-1,4-diamine (pmb) and N,N′-bis(pyridin-2-ylmethylene)biphenyl-4,4′-diamine (pmbb), the three compounds [Cu2(pmb) (PPh3)2(Cl)2] (1), [Cu2(pmbb)(CH3CN)2(PPh3)2](BF4)2·2DMF (2), and [Ag2(pmbb)(PPh3)2] (ClO4)2 (3) have been synthesised and characterised. Structural analysis reveals that all of these complexes contain 1D supramolecular arrays, with different variations in π-stacking patterns and intermolecular C–H···π interactions. Crystal structures of 1 and 2 contain 1D tape-like arrays formed by C–H···π and π···π interactions, and an ordered-layer-lattice of DMF and BF4– in 2 is located between the one-dimensional array. For 3, π-stacking interactions lead to the construction of 1D supramolecular arrays and a 2D network. The results indicate that C–H···π and π···π interactions play an important role in the construction of the supramolecular structure. In addition, the absorption peaks of complexes 1 and 3 in the solid state at room temperature show intraligand charge transfer and metal-to-ligand charge transfer absorptions. The optical and fluorescent properties of 2 were also studied in acetonitrile solution at room temperature.

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ChemInform Abstract: A New Class of Room Temperature Luminescent Organometallic Complexes: Luminescence and Photophysical Properties of Permethylscandocene Chloride in Fluid Solution.

ChemInform ◽

10.1002/chin.199011237 ◽

1990 ◽

Vol 21 (11) ◽

Author(s):

B. W. PFENNIG ◽

M. E. THOMPSON ◽

A. B. BOCARSLY

Keyword(s):

Room Temperature ◽

Photophysical Properties ◽

Organometallic Complexes ◽

Fluid Solution ◽

New Class

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Synthesis, Characterization and Photophysical Properties of Thiophene-Containing Chloro Re(I) Complex

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.869 ◽

2010 ◽

Vol 146-147 ◽

pp. 869-872

Author(s):

Jie Xiu Wang ◽

Feng Zhao

Keyword(s):

Charge Transfer ◽

Electron Density ◽

1H Nmr ◽

Photophysical Properties ◽

Red Shift ◽

Rhenium Complexes ◽

Diimine Ligands ◽

Ligand Charge Transfer

Two tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=1,10-phenanthroline (Phen-Re) and 2-(3-thienyl)-imidazo[4,5-f]-1,10-phenanthroline (TIPh-Re), were successfully synthesized and characterized by 1H NMR and UV–Vis with the aim to analyze the effect of the thiophene(TI) moiety on the photophysical properties of TIPh-Re. It was found that the introduction of an π-electron density moiety into diimine ligands leads to a dramatic red shift of the absorption of the corresponding Re(I) complex. At the same time, the results verify that the triplet metal-to-ligand charge-transfer dπ(Re)→π*(N-N) emission (3MLCT) of Phen-Re and TIPh-Re centered at ca. 566 nm and ca.569 nm, respectively.

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Metal-to-Ligand Charge Transfer Excited States in π-Conjugated Systems

MRS Proceedings ◽

10.1557/proc-665-c3.7 ◽

2001 ◽

Vol 665 ◽

Author(s):

Yiting Li ◽

C. Ed Whittle ◽

Keith A. Walters ◽

Kevin D. Ley ◽

Kirk S. Schanze

Keyword(s):

Optical Properties ◽

Charge Transfer ◽

Excited States ◽

Transition Metal Complexes ◽

Transient Absorption ◽

Photophysical Properties ◽

Transient Absorption Spectroscopy ◽

Conjugated Oligomers ◽

Conjugated Systems ◽

Ligand Charge Transfer

ABSTRACTThis paper overviews recent work that examined the optical properties of mono-disperse, PPE-based π-conjugated oligomers that contain a 2,2-bipyridine-5,5'-diyl metal coordinating unit. The photophysical properties of the free oligomers and metallated oligomers that contain the -Ru(bpy)22+ and -Re(CO)3Cl transition metal complexes coordinated to the bpy-diyl unit have been characterized by absorption, photoluminescence and transient absorption spectroscopy. In addition, we report the photophysics of a novel organometallic “square” that features “sides” consisting of a PPE-type π-conjugated oligomer and “corners” that consist of (dbubpy)PtII(acetylide)2 units (where dbubpy = 4,4'-di-tert-butyl-2,2'-bipyridine).

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Ruthenium(II)-bis(4′-(4-ethynylphenyl)-2,2′:6′, 2″-terpyridine) — A versatile synthon in supramolecular chemistry. Synthesis and characterization

Open Chemistry ◽

10.2478/s11532-011-0087-6 ◽

2011 ◽

Vol 9 (6) ◽

pp. 990-999 ◽

Cited By ~ 5

Author(s):

Ronald Siebert ◽

Florian Schlütter ◽

Andreas Winter ◽

Martin Presselt ◽

Helmar Görls ◽

...

Keyword(s):

Charge Transfer ◽

Supramolecular Chemistry ◽

Photophysical Properties ◽

Resonance Raman Spectroscopy ◽

Bathochromic Shift ◽

Resonance Raman ◽

Electronic Effects ◽

Charge Transfer Transition ◽

Click Reactions ◽

Ligand Charge Transfer

AbstractA homoleptic ethynyl-substituted ruthenium(II)-bisterpyridine complex representing a versatile synthon in supramolecular chemistry was synthesized and analyzed by NMR spectroscopy, mass spectrometry and X-ray diffractometry. Furthermore, its photophysical properties were detailed by UV/Vis absorption, emission and resonance Raman spectroscopy. In order to place the results obtained in the context of the vast family of ruthenium coordination compounds, two structurally related complexes were investigated accordingly. These reference compounds bear either no or an increased chromophore in the 4′-position. The spectroscopic investigations reveal a systematic bathochromic shift of the absorption and emission maximum upon increasing chromophore size. This bathochromic shift of the steady state spectra occurs hand in hand with increasing resonance Raman intensities upon excitation of the metal-to-ligand charge-transfer transition. The latter feature is accompanied by an increased excitation delocalization over the chromophore in the 4′-position of the terpyridine. Thus, the results presented allow for a detailed investigation of the electronic effects of the ethynyl substituent on the metal-to-ligand charge-transfer states in the synthon for click reactions leading to coordination polymers.

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