New BODIPY-triazine based tripod fluorescent systems

A new tripod fluorescent system was developed, which bears a triazine core for combining three different functional groups, such as fluorophore (BODIPY), ligand, and auxiliary group. This concept was confirmed by photophysical properties due to the different auxiliary subunits.     

Study on the BODIPY-triazine-based tripod fluorescent systems: various structures from similar procedure

We report a small library of fluorophore-triazine tripod fluorescent system that can accommodate a combination of three different functional groups, such as fluorophore (BODIPY), ligand (or ligands) and auxiliary group. Syntheses, photophysical properties as well as binding properties towards metal ions of these BODIPY-triazine derivatives are described.     

新型含双酚衍生物三枝氟硼二吡咯染料的合成及其光物理性能

以三聚氯氰为原料合成含醛基的二酚氧基取代中间体（1）; 1分别与酚衍生物（2a~2e）经取代反应制得三酚氧基中间体（3a~3e）; 3a~3e经缩合、氧化和配位等反应合成了5个新型的含双酚衍生物三枝氟硼二吡咯（BODIPY）荧光染料（4a~4e）,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。4a~4e的最大吸收波长和发射波长分别位于499 nm和508 nm,荧光量子产率为0.41~0.55,显示出BODIPY荧光核典型的光物理性能。     

Oligo(p-phenylene ethynylene)-BODIPY derivatives: synthesis, energy transfer, and quantum-chemical calculations

The synthesis and energy‐transfer properties of a series of oligo(p‐phenylene ethynylene)–BODIPY ( OPEB ) cassettes are reported. A series of oligo(p‐phenylene ethynylene)s ( OPE s) with different conjugated chain lengths as energy donor subunit in the energy‐transfer system were capped at both ends with BODIPY chromophores as energy‐acceptor subunits. The effect of the conjugated chain of OPE s on energy transfer in the OPEB cassettes was investigated by UV/Vis and fluorescence spectroscopy and modeling. With increasing number n of phenyl acetylene units (n=1–7), the absorption and emission maxima of OPEn are bathochromically shifted. In the OPEBn analogues, the absorption maximum assigned to the BODIPY moieties is independent of the length of the OPE spacer. However, the relative absorption intensity of the BODIPY band decreases when the number of phenyl acetylene units is increased. The emission spectra of OPEBn are dominated by a band peaking at 613 nm, corresponding to emission of the BODIPY moieties, regardless of whether excitation is at 420 or 550 nm. Furthermore, a very small band is observed with a maximum between 450 and 500 nm, and its intensity relative to that of the BODIPY emission increases with increasing n, that is, the excited state of OPE subunits is efficiently quenched in OPEBn by energy transfer to the BODIPY moieties. Energy transfer (ET) from OPEn to BODIPY in OPEBn is very efficient (all Φ_ET values are greater than 98 %) and only slightly decreases with increasing length of the OPE units. These results are supported by theoretical studies that show very high energy transfer efficiency (Φ_ET>75 %) from the OPE spacer to the BODIPY end‐groups for chains with up to 15–20 units.     

Fluorescence Quenching in BODIPY Dyes: The Role of Intramolecular Interactions and Charge Transfer

The fluorescence properties of the BODIPY dye and its two meso‐substituted derivatives, tert‐butyl‐ and phenyl‐BODIPY , are rationalized. The non‐emissive behavior of the latter two are attributed to the energetically accessible low‐lying conical intersection between the ground state and the lowest excited singlet state. Both intramolecular non‐covalent interactions and excited state charge transfer character are identified as being crucial for ‘stabilizing’ the intersection and prompting the nonradiative decay. Similar crossing was located in the bare BODIPY dye, however, being energetically less accessible, which correlates well with the high fluorescence quantum yields of the parent dye.     

Synthesis of 3,8‐Dichloro‐6‐ethyl‐1,2,5,7‐tetramethyl–BODIPY from an Asymmetric Dipyrroketone and Reactivity Studies at the 3,5,8‐Positions

The asymmetric BODIPY 1 a (BODIPY=4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene), containing two chloro substituents at the 3,8‐positions and a reactive 5‐methyl group, was synthesized from the asymmetric dipyrroketone 3 , which was readily obtained from available pyrrole 2 a . The reactivity of 3,8‐dichloro‐6‐ethyl‐1,2,5,7‐tetramethyl‐BODIPY 1 a was investigated by using four types of reactions. This versatile BODIPY undergoes regioselective Pd⁰‐catalyzed Stille coupling reactions and/or regioselective nucleophilic addition/elimination reactions, first at the 8‐chloro and then at the 3‐chloro group, using a variety of organostannanes and N‐, O‐, and S‐centered nucleophiles. On the other hand, the more reactive 5‐methyl group undergoes regioselective Knoevenagel condensation with an aryl aldehyde to produce a monostyryl‐BODIPY, and oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) gives the corresponding 5‐formyl‐BODIPY. Investigation of the reactivity of asymmetric BODIPY 1 a led to the preparation of a variety of functionalized BODIPYs with λ_max of absorption and emission in the ranges 487–587 and 521–617 nm, respectively. The longest absorbing/emitting compound was the monostyryl‐BODIPY 16 , and the largest Stokes shift (49 nm) and fluorescence quantum yield (0.94) were measured for 5‐thienyl‐8‐phenoxy‐BODIPY 15 . The structural properties (including 16 X‐ray structures) of the new series of BODIPYs were investigated.     

α-Acrylaldehyde 3-Pyrrolyl BODIPY as a Specific Optical Sensor for Cysteine and Homocysteine

A new fluorophore, α-acrylaldehyde 3-pyrrolyl BODIPY was synthesized by treating 3-pyrrolyl BODIPY with a mixture of 3-(dimethylamino) acrolein and POCl₃ under Vilsmeier–Haack reaction conditions. The X-ray structure revealed that the fluorophore was almost planar, and the appended pyrrole was in the same plane with a small deviation from the mean plane. We investigated the potential use of α-acrylaldehyde 3-pyrrolyl BODIPY for sensing thiol containing amino acids such as cysteine/homocysteine (Cys/Hcy). Our studies showed that the α-acrylaldehyde- 3-pyrrolyl BODIPY was found to be useful for exclusive sensing of Cys/Hcy and to exhibit different optical signaling responses to Cys and Hcy at physiological pH in aq. CH₃CN (1 : 1 v/v, PBS) medium. The enhancement in optical properties for Cys and quenching in same properties for Hcy was attributed to different binding modes of Cys/Hcy with α-acrylaldehyde 3-pyrrolyl BODIPY.     

Benzo[c,d]indole‐Containing Aza‐BODIPY Dyes: Asymmetrization‐Induced Solid‐State Emission and Aggregation‐Induced Emission Enhancement as New Properties of a Well‐Known Chromophore

A series of symmetric and asymmetric benzo[c,d]indole‐containing aza boron dipyrromethene (aza‐BODIPY) compounds was synthesized by a titanium tetrachloride‐mediated Schiff‐base formation reaction of commercially available benzo[c,d]indole‐2(1H)‐one and heteroaromatic amines. These aza‐BODIPY analogues show different electronic structures from those of regular aza‐BODIPYs, with hypsochromic shifts of the main absorption compared to their BODIPY counterparts. In addition to the intense fluorescence in solution, asymmetric compounds exhibited solid‐state fluorescence due to significant contribution of the vibronic bands to both absorption and fluorescence as well as reduced fluorescence quenching in the aggregates. Finally, aggregation‐induced emission enhancement, which is rare in BODIPY chromophores, was achieved by introducing a nonconjugated moiety into the core structure.     

Efficient Intramolecular Energy Transfer between Two Fluorophores in a Bis‐Branched [3]Rotaxane

A bis‐branched [3]rotaxane, with two [2]rotaxane arms separated by an oligo(para‐phenylenevinylene) (OPV) fluorophore, was designed and investigated. Each [2]rotaxane arm employed a difluoroboradiaza‐s‐indacene (BODIPY) dye‐functionalized dibenzo[24]crown‐8 macrocycle interlocked onto a dibenzylammonium in the rod part. The chemical structure of the [3]rotaxane was confirmed and characterized by ¹H and ¹³C NMR spectroscopy and high‐resolution ESI mass spectrometry. The photophysical properties of [3]rotaxane and its reference systems were investigated through UV/Vis absorption, fluorescence, and time‐resolved fluorescence spectroscopy. An efficient energy‐transfer process in [3]rotaxane occurred from the OPV donor to the BODIPY acceptor because of the large overlap between the absorption spectrum of the BODIPY moiety and the emission spectrum of the OPV fluorophore; this shows the important potential of this system for designing functional molecular systems.     

An Optically and Thermally Switchable Electronic Structure Based on an Anthracene–BODIPY Conjugate

An optically and thermally responsive boron dipyrromethene (BODIPY) dye, namely, meso‐2‐(9,10‐dihydro‐9,10‐ethanoanthracene‐11,12‐dione) (DK)‐linked, bicyclo[2.2.2]octadiene (BCOD)‐fused BODIPY ( BCOD‐DK ), was synthesized. The weakly luminous structure of BCOD‐DK can be changed quantitatively to that of the strongly fluorescent BODIPY BCOD‐Ant by optical excitation at the DK unit, which induces double decarbonylation of the DK unit to give an anthracene unit. The solvent effect on the fluorescence properties of BCOD‐DK suggests that the dramatic change in fluorescence intensity is controlled by intramolecular electron transfer from the BODIPY moiety to the meso‐DK substituent. BCOD‐DK is converted to meso‐ DK benzene‐fused BODIPY ( Benzo‐DK ) by heating at 220 °C with 64–70 nm redshift of absorption and fluorescence peaks without changing the fluorescence quantum yield of Φ_F=0.08 in dichloromethane. Benzo‐DK can be converted to strongly fluorescent meso ‐ anthracene benzene‐fused BODIPY Benzo‐Ant by optical excitation. Thus, BCOD‐DK can show four different optical performances simply by irradiation and heating, and hence may be applicable for optical data storage and security data encryption.     

DMAP‐BODIPY Alkynes: A Convenient Tool for Labeling Biomolecules for Bimodal PET–Optical Imaging

Several new boron dipyrromethene/N,N‐dimethylaminopyridine (BODIPY‐DMAP) assemblies were synthesized as precursors for bimodal imaging probes (optical imaging, OI/positron emission tomography, PET). The photophysical properties of the new compounds were also studied. The first proof‐of‐concept was obtained with the preparation of several new BODIPY‐labeled bombesins and evaluation of the affinity for bombesin receptors by using a competition binding assay. Fluorination reactions were investigated on DMAP‐BODIPY precursors as well as on DMAP‐BODIPY‐labeled bombesins. Chemical modifications on the BODIPY core were also performed to obtain luminescent dyes emitting in the therapeutic window (650–900 nm), suitable for in vivo imaging, making these compounds promising precursors for PET/optical dual‐modality imaging agents.     

Two π-Electrons Make the Difference: From BODIPY to BODIIM Switchable Fluorescent Dyes

(aza-)BODIPY dyes (boron dipyrromethene dyes) are well-established fluorophores due to their large quantum yields, stability, and diversity, which led to promising applications including imaging techniques, sensors, organic (opto)electronic materials, or biomedical applications. Although the control of the optical properties in (aza-)BODIPY dyes by peripheral functional groups is well studied, we herein present a novel approach to modify the 12 π-electron core of the dipyrromethene scaffold. The replacement of two carbon atoms in the β-position of a BODIPY dye by two nitrogen atoms afforded a 14 π-electron system, which was termed BODIIM (boron diimidazolylmethene) in systematic analogy to the BODIPY dyes. Remarkably, the BODIIM dye was obtained with a BH₂-rigidifying entity, which is currently elusive and highly sought after for the BODIPY dye class. DFT-Calculations confirm the [12+2] π-electron relationship between BODIPY and BODIIM and reveal a strong shape correlation between LUMO in the BODIPY and the HOMO of the BODIIM. The modification of the π-system leads to a dramatic shift of the optical properties, of which the fluorescent emission is most noteworthy and occurs at much larger Stokes shift, that is, ≈500 cm⁻¹ in BODIPY versus >4170 cm⁻¹ in BODIIM system in all solvents investigated. Nucleophilic reactivity was found at the meso-carbon atom in the formation of stable borane adducts with a significant shift of the fluorescent emission, and this behavior contrasts the reactivity of conventional BODIPY systems. In addition, the reverse decomplexation of the borane adducts was demonstrated in reactions with a representative N-heterocyclic carbene to retain the strongly fluorescent BODIIM compound, which suggests applications as fully reversible fluorescent switch.     

Synthesis,Computational Modeling,and Properties of Benzo‐Appended BODIPYs

A series of new functionalized mono‐ and dibenzo‐appended BODIPY dyes were synthesized from a common tetrahydroisoindole precursor following two different synthetic routes. Route A involved the assembly of the BODIPY core prior to aromatization, while in Route B the aromatization step was performed first. In general, Route A gave higher yields of the target dibenzo‐BODIPYs, due to the ease of aromatization of the BODIPYs compared with the corresponding dipyrromethenes, probably due to their higher stability under the oxidative conditions (2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone in refluxing toluene). However, due to the slow oxidation of highly electron‐deficient BODIPY 3 c bearing a meso‐C₆F₅ group, dibenzo‐BODIPY 4 c was obtained, in 35 % overall from dipyrromethane, only by Route B. Computational calculations performed at the 6‐31G(d,p) level are in agreement with the experimental results, showing similar relative energies for all reaction intermediates in both routes. In addition, BODIPY 3 c had the highest molecular electrostatic potential (MEPN), confirming its high electron deficiency and consequent resistance toward oxidation. X‐ray analyses of eight BODIPYs and several intermediates show that benzannulation further enhances the planarity of these systems. The π‐extended BODIPYs show strong red‐shifted absorptions and emissions, about 50–60 nm per benzoannulated ring, at 589–658 and 596–680 nm, respectively. In particular, db‐BODIPY 4 c bearing a meso‐C₆F₅ group showed the longest λ_max of absorption and emission, along with the lowest fluorescence quantum yield (0.31 in CH₂Cl₂); on the other hand monobenzo‐BODIPY 8 showed the highest quantum yield (0.99) of this series. Cellular investigations using human carcinoma HEp2 cells revealed high plasma membrane permeability for all dibenzo‐BODIPYs, low dark‐ and photo‐cytotoxicities and intracellular localization in the cell endoplasmic reticulum, in addition to other organelles. Our studies indicate that benzo‐appended BODIPYs, in particular the highly stable meso‐substituted BODIPYs, are promising fluorophores for bioimaging applications.     

Dual Emission of meso-Phenyleneethynylene–BODIPY Oligomers: Synthesis,Photophysics, and Theoretical Optoelectronic Study

Two series of 2,5-di(butoxy)phenyleneethynylenes, one halogenated ( n PEC4-X ; n=2, 3, or 4) and the other boron-dipyrromethene (BODIPY) terminated ( n PEC4-By ; n=3, 4, or 5; By=BODIPY), were synthesized monodirectionally by the step-by-step approach and the molecular structure was corroborated by NMR spectroscopy (¹H, ¹³C-DEPTQ-135, COSY, HSQC, HMBC, ¹¹B, ¹⁹F) and MALDI-TOF mass spectrometry. The multiplicity and J-coupling constants of ¹H, ¹¹B, and ¹⁹F/¹¹B NMR signals revealed, in the n PEC4-By series, that the phenyl in the meso position of BODIPY becomes electronically part of the conjugation of the phenyleneethynylene chain, whereas BODIPY is electronically isolated. The photophysical, electrochemical, and theoretical studies confirm this finding because the properties of n PEC4-By are comparable to those of the n PEC4-X oligomers and BODIPY, indicating negligible electron communication between BODIPY and the n PEC4 moieties. Nevertheless, energy transfer (ET) from n PEC4 to BODIPY was rationalized by spectroscopy and theoretical calculations. Its yield decreases with the n PEC4 conjugation length, according to the increase in distance between the two chromophores, resulting in dual emission for the longest oligomer in which ET is quenched.     

Energy Transfer in Aminonaphthalimide‐Boron‐Dipyrromethene (BODIPY) Dyads upon One‐ and Two‐Photon Excitation: Applications for Cellular Imaging

Aminonaphthalimide–BODIPY energy transfer cassettes were found to show very fast (k_EET≈10¹⁰–10¹¹ s^?1) and efficient BODIPY fluorescence sensitization. This was observed upon one‐ and two‐photon excitation, which extends the application range of the investigated bichromophoric dyads in terms of accessible excitation wavelengths. In comparison with the direct excitation of the BODIPY chromophore, the two‐photon absorption cross‐section δ of the dyads is significantly incremented by the presence of the aminonaphthalimide donor [δ≈10 GM for the BODIPY versus 19–26 GM in the dyad at λ_exc=840 nm; 1 GM (Goeppert–Mayer unit)=10^?50 cm⁴ s molecule^?1 photon^?1]. The electronic decoupling of the donor and acceptor, which is a precondition for the energy transfer cassette concept, was demonstrated by time‐dependent density functional theory calculations. The applicability of the new probes in the one‐ and two‐photon excitation mode was demonstrated in a proof‐of‐principle approach in the fluorescence imaging of HeLa cells. To the best of our knowledge, this is the first demonstration of the merging of multiphoton excitation with the energy transfer cassette concept for a BODIPY‐containing dyad.     

Synthesis,photoluminescence, and electroluminescence characterization of double tetraphenylethene‐tethered BODIPY luminogens

Three double tetraphenylethene (TPE)‐tethered 4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indance (BODIPY) fluorophores, 35TPEBODP , 88TPEBODP , and 26TPEBODP , have been synthesized and characterized. The green 35TPEBODP with deep red fluorescence shows serious thermal decomposition in the purification process of sublimation, which prohibits its test for an organic light‐emitting diode (OLED) fabricated by the vacuum–thermal evaporation process. The tethered TPE is attached to BODIPY at three different positions, resulting in different photoluminescence (emission wavelength and quantum yield) and electroluminescence (EL). Different from TPE‐tethered BODIPY fluorophores reported in literature, none of the BODIPY fluorophores studied here exhibits aggregation‐induced emission (AIE), aggregation‐induced enhanced emission (AIEE), or twisted intramolecular charge transfer (TICT) characteristics. Although solution (10^?5 M THF) photoluminescence quantum yields (?s) are relatively high at 78%, 68%, and 86% for 35TPEBODP , 88TPEBODP , and 26TPEBODP , respectively, which are all higher than 41% of PhBODP (a non‐TPE‐tethered BODIPY), the ? is significantly decreased to 1–6% in 5 wt% dopant polystyrene thin film or as a solid powder, except for 13% of 26TPEBODP . Therefore, due to the low ? of dopant thin film or solid powder, either dopant or nondopant OLEDs exhibit inferior external quantum efficiency (EQE) and intensity of EL. The best OLED in this study is the 26TPEBODP device, and its EQE reaches 1.3%, and the highest EL intensity is approximately 1,600 cd/m².     

Synthesis and Characterization of Far‐Red/NIR‐Fluorescent BODIPY Dyes,Solid‐State Fluorescence,and Application as Fluorescent Tags Attached to Carbon Nano‐onions

A series of π‐extended distyryl‐substituted boron dipyrromethene (BODIPY) derivatives with intense far‐red/near‐infrared (NIR) fluorescence was synthesized and characterized, with a view to enhance the dye’s performance for fluorescence labeling. An enhanced brightness was achieved by the introduction of two methyl substituents in the meso positions on the phenyl group of the BODIPY molecule; these substituents resulted in increased structural rigidity. Solid‐state fluorescence was observed for one of the distyryl‐substituted BODIPY derivatives. The introduction of a terminal bromo substituent allows for the subsequent immobilization of the BODIPY fluorophore on the surface of carbon nano‐onions (CNOs), which leads to potential imaging agents for biological and biomedical applications. The far‐red/NIR‐fluorescent CNO nanoparticles were characterized by absorption, fluorescence, and Raman spectroscopies, as well as by thermogravimetric analysis, dynamic light scattering, high‐resolution transmission electron microscopy, and confocal microscopy.     

Dual Chromophoric Meso-Aryl BODIPYs with Aggregation Induced Red-Emission Characteristics: Optical Properties and their Application in Fe3+ Detection

Herein, we report the design of meso-aryl BODIPYs as a structural motif for aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE) transformation. A series of meso-aryl BODIPY derivatives were synthesized, by systematically increasing the size of the chromophore at the meso-position from phenyl to pyrene. The effect of various factors, such as the aryl ring size, solvents, viscosity, and metal cations, on the photophysical properties was analyzed. The emission properties are well correlated with the flexibility of the aromatic ring for free rotation around the C_aryl−C_BODIPY bond. Accordingly, meso-phenanthrene BODIPY ( PhB ) has the highest emission characteristics. The emission property of less bulky aryl-substituted BODIPYs increases by increasing the solvent viscosity. The interaction of Fe³⁺ ions with aryl-BODIPYs provides a prominent photophysical response based on Lewis-acid supported decomplexation of BF₂ in aryl-BODIPYs. The bichromophoric meso-aryl BODIPYs exhibit notable intramolecular excitation energy transfer from the aromatic ring to the BODIPY core, which is higher in meso-anthracene BODIPY( AB ). Hence, decorating BODIPYs with polycyclic aromatic systems generates a twisted structure, which inhibits the π-π stacking between the planar aromatic molecules. This can be proposed as an effective approach at the molecular level to convert planar aryl luminophores having ACQ to AIEgens. Besides, the meso-pyrene BODIPY derivative shows excellent mechanofluorochromic behaviour.     

Long‐Lived Room‐Temperature Near‐IR Phosphorescence of BODIPY in a Visible‐Light‐Harvesting N^C^N PtII–Acetylide Complex with a Directly Metalated BODIPY Chromophore

Room‐temperature long‐lived near‐IR phosphorescence of boron‐dipyrromethene (BODIPY) was observed (λ_em=770 nm, Φ_P=3.5 %, τ_P=128.4 μs). Our molecular‐design strategy is to attach Pt^II coordination centers directly onto the BODIPY π‐core using acetylide bonds, rather than on the periphery of the BODIPY core, thus maximizing the heavy‐atom effect of Pt^II. In this case, the intersystem crossing (ISC) is facilitated and the radiative decay of the T₁ excited state of BODIPY is observed, that is, the phosphorescence of BODIPY. The complex shows strong absorption in the visible range (ε=53800 M ^?1 cm^?1 at 574 nm), which is rare for Pt^II–acetylide complexes. The complex is dual emissive with ³M LCT emission at 660 nm and the ³IL emission at 770 nm. The T₁ excited state of the complex is mainly localized on the BODIPY moiety (i.e. ³IL state, as determined by steady‐state and time‐resolved spectroscopy, 77 K emission spectra, and spin‐density analysis). The strong visible‐light‐harvesting ability and long‐lived T₁ excite state of the complex were used for triplet‐triplet annihilation based upconversion and an upconversion quantum yield of 5.2 % was observed. The overall upconversion capability (η=ε×Φ_UC) of this complex is remarkable considering its strong absorption. The model complex, without the BODIPY moiety, gives no upconversion under the same experimental conditions. Our work paves the way for access to transition‐metal complexes that show strong absorption of visible light and long‐lived ³IL excited states, which are important for applications in photovoltaics, photocatalysis, and upconversions, etc.     

Meso-Carbon Atom Nucleophilic Attack Susceptibility in the Sterically Strained Antiaromatic Bis-BODIPY Macrocycle and Extended Electron-Deficient BODIPY Precursor**

A sterically strained 32π-electron antiaromatic bis-BODIPY macrocycle in which two BODIPY fragments are linked by p-divinylbenzene groups was prepared and characterized. Unlike regular BODIPYs, the fluorescence in this macrocycle is quenched. The broad signals in the NMR spectra of the macrocycle were explained by the vibronic freedom of the p-divinylbenzene fragments. The possible diradicaloid nature of the macrocycle was excluded on the basis of variable-temperature EPR spectra in solution and in solid state, which is indicative of its closed-shell quinoidal structure. The meso-C−H bond in the macrocycle and its precursor BODIPY dialdehyde 3 forms a weak hydrogen bond with THF and is susceptible for the nucleophilic attack by organic amines and cyanide anion. The reaction products of such a nucleophilic attack have meso-sp³ carbon atoms and were characterized by NMR, mass spectrometry and, in one case, X-ray crystallography. Unlike the initial bis-BODIPY macrocycle, the adducts have strong fluorescence in the 400 nm region. The electronic structure and spectroscopic properties of new chromophores were probed by density functional theory (DFT) and time-dependent DFT (TDDFT) calculations and correlate well with the experimental data.