Nm In CH2Cl2 Research Articles

Synthesis and singlet oxygen generation of boron-2-(4,5-dibromo-1H-imidazole-2-yl)-3,5-dipyrazolopyridine complex for antimicrobial photodynamic therapy.

In this study, the pyridine side of a boron 2-(2'-pyridyl) imidazole (BOPIM) core, which has very few derivatives synthesized in the literature and can show fluorescence properties in solid form, was derivatized with 1-methylpyrazole, predicted to have activity against fungi or bacteria according to the literature. Additionally, its imidazole side was brominated to increase the efficiency of singlet oxygen production by increasing the intersystem crossing. The photophysical properties of the new synthesized BOPIM derivative were investigated in general organic solvents with different polarities. While the wavelength of the maximum absorbance was determined as 406 nm in CH2Cl2 and THF, the wavelength of the highest emission was measured at 497 nm in CH3CN solvent. The largest Stokes shift was determined as 104 nm in CH3CN. This value was considerably higher than those of many photosensitizers. The singlet oxygen generation potential of the BOPIM derivative was revealed using a 440-nm LED lamp in the presence of singlet oxygen scavenger 1,3-diphenylisobenzofuran (DPBF). Additionally, it was demonstrated that the BOPIM derivative had no toxic effects by measurements made in the dark.

Panchromatic and Perturbed Absorption Spectral Features and Multiredox Properties of Dicyanovinyl- and Dicyanobutadienyl-Appended Cobalt Corroles.

Four new β-functionalized π-extended cobalt corroles with one and two dicyanovinyl (DCV) or dicyanobutadienyl (DCBD) moieties at the 3- and 3,17-positions have been synthesized and characterized by various spectroscopic techniques. Interestingly, the synthesized DCV- and DCBD-appended cobalt corroles displayed panchromatic and near-infrared absorption in the range 300-1100 nm in CH2Cl2 and pyridine solvents. (MN)2-(Cor)Co and A2MN2-(Cor)Co exhibited 8-9 times enhancement in the molar absorptivity of the Q band compared to the parent corrole ((Cor)Co). The unique absorption spectral features of these β-functionalized cobalt corroles are splitting, broadening, and red-shifting in the Soret and Q bands. One DCV unit brings a 30-46 nm red shift, whereas one DCBD unit brings a 40-75 nm red shift in the Q band compared to the corresponding precursors. This is rare that the intensity of the longest Q band is greater than or equal to the Soret-like bands. These corrole derivatives exhibit UV-vis spectral features similar to those of chlorophyll a. A 220 mV positive shift per DCV group and 160 mV positive shift per DCBD group were observed in the first oxidation potentials compared to (Cor)Co in the desired direction for the utility of these cobalt complexes in electrocatalysis. DFT studies revealed that HOMO and LUMO were stabilized after appending DCV and DCBD groups on the corrole macrocycle and exhibited a "push-pull" behavior leading to promising material applications in nonlinear optics (NLO) and catalysis.

Synthesis of Near-Infrared-Absorbing Anionic Heptamethine Cyanine Dyes with Trifluoromethyl Groups.

A novel anionic heptamethine cyanine (HMC) dye with two trifluoromethyl groups that selectively absorb near-infrared light is synthesized. When contrasted with previously studied anionic HMC dyes with substituents such as methyl, phenyl, and pentafluorophenyl groups, the trifluoromethylated dye displays a red-shifted maximum absorption wavelength (for instance, 948 nm in CH2Cl2) along with enhanced photostability. Furthermore, HMC dyes with broad absorption in the near-infrared region are synthesized by combining a trifluoromethylated anionic HMC dye with a cationic HMC dye as a counterion.

Rigid and Photostable Shortwave Infrared Dye Absorbing/Emitting beyond 1200 nm for High-Contrast Multiplexed Imaging.

The shortwave infrared (SWIR) spectral region beyond 1200 nm offers optimal tissue penetration depth and has broad potential in diagnosis, therapy, and surgery. Here, we devised a novel class of fluorochromic scaffold, i.e., a tetra-benzannulated xanthenoid (EC7). EC7 absorbs/emits maximally at 1204/1290 nm in CH2Cl2 and exhibits an unparalleled molar absorptivity of 3.91 × 105 cm-1 M-1 and high transparency to light at 400-900 nm. It also exhibited high resistance toward both photobleaching and symmetry breaking due to its unique structural rigidity. It is feasible for in vivo bioimaging and particularly suitable to couple with the shorter-wavelength analogues for high-contrast multiplexing. High-contrast dual-channel intraoperative imaging of the hepatobiliary system and three-channel in vivo imaging of the intestine, the stomach, and the vasculature were showcased. EC7 is a benchmark fluorochrome for facile biomedical exploitation of the SWIR region beyond 1200 nm.

Hypercorroles Formed via the Tail that Wagged the Dog: Charge Transfer Interactions from Innocent Corroles to Meso-Nitrophenyl Substituents.

A series of cobalt nitrophenylcorroles were spectrally characterized in CH2Cl2, and under certain solution conditions, several compounds were shown to exhibit hypercorrole spectra resulting from charge transfer interactions from the corrole π-system to the redox-active meso-NO2Ph substituents. The resulting spectral pattern has not previously been reported for metallocorroles and in the case of the cobalt derivatives was shown to depend upon the number and position of the meso-nitrophenyl groups on the macrocycle, the position of the NO2 substituent on the meso-phenyl ring(s) (para or meta), and the electronic structure of the corrole, which can exist in its innocent or noninnocent form depending in large part upon the type and number of axial ligands. Cobalt corroles bearing p-nitrophenyl groups at the 5,15- or 5,10,15-positions of the macrocycle exhibited the most marked hypercorrole spectra under solution conditions where the complex was innocent (i.e., Cor3-CoIII), and a systematic analysis of the spectral data suggests the root of this perturbation to be a corrole-to-aryl interaction (i.e., ligand-to-ligand charge transfer or LLCT). The largest interaction between the π-system and the NO2Ph substituents was seen upon coordination of anionic cyanide (CN-) axial ligands to the Co(III) center of the bis-(CN-)-5,15-dinitrophenyl derivative, resulting in a cobalt hypercorrole spectrum where the broad Q-band was red-shifted even further into the NIR region and located at 795 nm in CH2Cl2 and 827 nm in pyridine. Cyclic voltammetry of the bis-CN- adducts showed that the first electrons are added to the LUMOs of the p-NO2Ph substituents rather than the corrole, while the same orbitals for the mono-CN- adducts are nearly degenerate. This redox behavior contrasts with what is seen for the noninnocent nitrophenyl corroles having "normal" unperturbed UV-vis spectra where the first reduction involves the π-system of the macrocycle, followed by reduction of the p-NO2Ph groups at more negative potentials.

Highly efficient and concentration-insensitive OLEDs based on alkyl sterically modified red homoleptic phenylphthalazine iridium complexes

Four red homoleptic iridium (III) complexes (Ir1–Ir4) with steric phenylphthalazine ligands have been synthesized. Single X-ray structural analysis shows that the steric hindrance groups can prevent molecular aggregation. All complexes exhibited red emission with peaks between 614 and 629 nm in CH2Cl2 and photoluminescence quantum yields (QYs) of 44%–86% in doped films. They were concentration-insensitive, their QYs in neat powder and air atmosphere can reach a maximum of 15%. These complexes exhibited excellent thermal stability with Td higher than 416 °C. The OLEDs based on these complexes showed good performances at 10 wt% high doping concentration. Especially, the device based on Ir1 gave a peak current efficiency and external quantum efficiency (EQE) of 25.0 cd A−1 and 24.2% with mild efficiency roll-off, which is the most efficient OLED based on phthalazine iridium complexes. The maximum EQEs of non-doped devices are between 4.0% and 5.6%, which are considerably high, compared with the reported efficiency of iridium complexes based red-emitting non-doped devices. These studies show that increasing the density of the rigid steric groups of iridium complexes is very effective to achieve high efficiency and low concentration sensitive red phosphorescent devices.

Investigating the Role of Novel Benzotrithiophene-Based Bat-Shaped Non-Fullerene Acceptors for High Performance Organic Solar Cells

The development of an effective building blocks considered the boon in constructing highly efficient nonfullerene electron acceptors (NFEAs). The first theoretical design and investigation of environmental-friendly groups for changing potential end-capped electron acceptor molecules for high-performance environmental-friendly OSCs is proposed in this study. We developed BTT-based [Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text] (acceptor–bridge–core–bridge–acceptor) type, neoteric Bat-shaped environmental-friendly acceptor molecules (K1–K6) for the first time by replacing the electronegative –F group of BTT with four electron-withdrawing (–CN, –COOCH3, –NO2, –Cl) groups. K1–K6 has its exciton-binding energy ([Formula: see text]), open-circuit voltage ([Formula: see text]), frontier molecular orbital analysis (FMO), transition density matrix (TDM) analysis, electron and hole reorganization energy ([Formula: see text]e, [Formula: see text]h), density of state (DOS) graphs, and transition energy Ex values computed and compared to the recently proposed high-performance BTT molecule. According to the research, the photovoltaic, photo-physical and electrical applications of proposed molecules K1–K6 are comparable to those of [Formula: see text]. When compared to reference [Formula: see text] and proposed molecules, K6 tested to be the proverbial optoelectronic compound for OSCs due to its low [Formula: see text] (2.05[Formula: see text]eV), lowest [Formula: see text] (1.57[Formula: see text]eV), highest [Formula: see text] max values of 790.61[Formula: see text]nm in CHCl3, 0.95[Formula: see text]V value for [Formula: see text] and comparable [Formula: see text] (0.482[Formula: see text]eV). The superposition of orbitals and lucrative charge shift from the highest occupied molecular orbital (HOMO) (PTB7-Th) to the lowest unoccupied molecular orbital (LUMO) were verified by charge transfer study among the K6: PTB7-Th combine. As a result, the proposed molecules (K1–K6) with exceptional optoelectronic capabilities are suggested as the best harmless alternative materials for creating proficient and environmental-friendly OSCs.

Synthesis and photoluminescence properties of fluorine‐containing poly(phenylene vinylene) bearing hexafluorocyclopentene‐fused phenanthrene unit

AbstractThe intramolecular oxidative photocyclization of 1,2‐diarylhexafluorocyclopentene (1) under light irradiation (λ = 365 nm) provided hexafluorocyclopentene‐fused phenanthrene with formyl groups (2) in moderate yield. The copolymerization of 2 with tetraethyl(2,5‐bis(dodecyloxy)‐1,4‐phenylene)bis(methylene)diphosphonate by the Horner–Wadsworth–Emmons reaction gave a fluorine‐containing poly(phenylene vinylene), Polymer‐2, in 41% yield. For comparison, a diphenylethene‐type copolymer, Polymer‐1, was also prepared analogously. The number‐average molecular weights of Polymer‐1 and Polymer‐2 were 8900 and 3300 g mol−1, respectively. The copolymers showed high thermal stability, as revealed by their thermogravimetric analysis. UV–visible spectra of the copolymers in CHCl3 showed π–π* transition peaks at around 420 nm, and the peaks shifted to longer wavelengths by ca 10 nm for samples in film form. The photoluminescence spectra of Polymer‐1 and Polymer‐2 exhibited peaks at 542 and 560 nm in CHCl3, respectively, whereas the photoluminescence intensity of Polymer‐2 was very low in the solid state, presumably owing to the partial aggregation of the polymer molecules. © 2021 Society of Industrial Chemistry.

Substituent Modulation for Highly Bright 9-Borafluorene Derivatives with Carbazole Pendant.

A series of 3,6-di-tert-butyl carbazole-functionalized 9-borafluorene derivatives have been prepared with outstandingly strong photoluminescence with quantum yields up to ca. 100 and 94% for Mes*BF-pCz in solution and film, respectively. 1,3,5-Tris(trifluoromethyl)benzene (FMes)-substituted compounds exhibit enhanced Lewis acidity with coordination to weak nucleophiles like tetrahydrofuran, resulting in a long afterglow at low temperature. The large two-photon absorption cross-section of ca. 1103 GM for Mes*BF-pCz at 800 nm in CH2Cl2 indicated its potential application in bioimaging.

Deep NIR-I Emissive Iridium(III) Complex Bearing D-A Ligand: Synthesis, Photophysical Properties and DFT/TDDFT Calculation

Near-infrared (NIR) phosphorescent iridium(III) complexes have been demonstrated to possess photophysical properties superior to those of traditional NIR dyes. However, the NIR emission wavelength is restricted in the range of 700–800 nm. For realizing deeper NIR emission, a novel type of iridium(III) complex was designed and synthesized in this work. The main ligand of the iridium(III) complex was constructed using a donor-acceptor structure containing benzothiophene as the donor and quinoxaline as the acceptor. The β-diketone derivative was chosen as the auxiliary ligand owing to its symmetrical structure and p-donating character. The complex exhibits deep NIR-I phosphorescence (764 nm in CH2Cl2, 811 nm in aqueous solution) and broad full width at half maximum (108 nm in CH2Cl2, 154 nm in aqueous solution). Theoretical calculations based on the density function and time-dependent density function were carried out to support the experimental data. Moreover, in vitro biological performance of the complex was determined as well. This work supports the possibility that via a systematic transformation between the D and A units, the photophysical performance of NIR emissive iridium(III) complexes can be greatly improved.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

Diradical Character of Neutral Heteroleptic Bis(1,2-dithiolene) Metal Complexes: Case Study of [Pd(Me2timdt)(mnt)] (Me2timdt = 1,3-Dimethyl-2,4,5-trithioxoimidazolidine; mnt2- = 1,2-Dicyano-1,2-ethylenedithiolate).

The reaction of the bis(1,2-dithiolene) complex [Pd(Me2timdt)2] (1; Me2timdt•– = monoreduced 1,3-dimethyl-2,4,5-trithioxoimidazolidine) with Br2 yielded the complex [Pd(Me2timdt)Br2] (2), which was reacted with Na2mnt (mnt2– = 1,2-dicyano-1,2-ethylenedithiolate) to give the neutral mixed-ligand complex [Pd(Me2timdt)(mnt)] (3). Complex 3 shows an intense solvatochromic near-infrared (NIR) absorption band falling between 955 nm in DMF and 1060 nm in CHCl3 (ε = 10700 M–1 cm–1 in CHCl3). DFT calculations were used to elucidate the electronic structure of complex 3 and to compare it with those of the corresponding homoleptic complexes 1 and [Pd(mnt)2] (4). An in-depth comparison of calculated and experimental structural and vis–NIR spectroscopic properties, supported by IEF-PCM TD-DFT and NBO calculations, clearly points to a description of 3 as a dithione-dithiolato complex. For the first time, a broken-symmetry (BS) procedure for the evaluation of the singlet diradical character (DC) of heteroleptic bis(1,2-dithiolene) complexes has been developed and applied to complex 3. The DC, predominant for 1 (nDC = 55.4%), provides a remarkable contribution to the electronic structures of the ground states of both 3 and 4, showing a diradicaloid nature (nDC = 24.9% and 27.5%, respectively). The computational approach developed here clearly shows that a rational design of the DC of bis(1,2-ditiolene) metal complexes, and hence their linear and nonlinear optical properties, can be achieved by a proper choice of the 1,2-dithiolene ligands based on their electronic structure.

Luminescent mesogenic dimeric borondifluoride complexes

ABSTRACT Two new families of dimeric borondifluoride complexes derived from β-enaminoketones containing terminal phenyl and naphthalenyl groups were prepared, and their mesomorphic and optical properties investigated. One single crystallographic structure of mesogenic complex 1a-BF2 (n = 12) was determined by X-ray analysis; it crystallises in a monoclinic space group P21/c and the geometry on boron atoms was all tetrahedral. The crystal was considered as linear-shaped with a length of ~51.95 Å. A relatively large dihedral angle of ~38.85° between the central phenyl spacer and tetrahedral BF2 moiety was observed. Mesomorphic properties were crucially impacted by the structure of the central spacer and terminal group; all bis(borondifluoride) complexes formed SmC or SmA phase except complexes 1b-BF2 (m = 2, 3) and 1c-BF2 . H–bond interactions supported by FT-IR spectra were attributed to the induction of SmA phase in compound 2 c-BF2 . The optical property of the boron complexes was related with their molecular structures, and they emitted blue-to-green emissions at λmax = 420–538 nm in CH2Cl2. This is the first twin liquid crystal of bis(BF2) complexes derived from Schiff baseβ-enaminoketones.

The [3+2] Annulation of CF3-Ketimines by Re Catalysis: Access to CF3-Containing Amino Heterocycles and Polyamides.

SummaryTransition metal catalyzed [3 + 2] annulation of imines with double bonds via directed C-H activation offers a direct access to amino cyclic motifs. However, owing to weak coordination and steric hindrance, trifluoromethylated ketimines have been an unaddressed challenge for TM-catalyzed annulations. Here, a rhenium-catalyzed [3 + 2] annulation of trifluoromethylated ketimines with isocyanates via C(sp2)-H activation has been disclosed. This approach provides an efficient platform for rapid access to a privileged library of CF3-containing iminoisoindolinones and polyamides by utilizing challenging CF3-ketimines as the annulation component. The capability of gram scale synthesis, the post-functionalization of the cyclization adduct, the derivation of complex natural molecules and the facile synthesis of polyamides highlight a diversity of synthetic potential of the current methodology.

Synthesis and characterization of stereoregular π-conjugated polyarylenynes, (-Ar-(E)-CH=CHC≡C-)n, decorated with branched bis-alkoxy side chains

Novel poly(p-phenyleneethynylenevinylene)s (PPEV) have been synthesized by step-growth oligomerization of 2,5-diethynyl-1,4-dialkoxybenzene monomers promoted by the ruthenium pre-catalyst [{RuCl(μ-Cl)(η6-p-cymene)}2] in the solvent mixture AcOH/CH2Cl2. The presence of the branched side chains 2-ethylhexyloxy or 3,7-dimethyloctyloxy in the phenylene unit allows for the formation of soluble π-conjugated short polymers, with slightly increased degree of polymerization (Xn = 5 - 10) and red-shifted photophysical properties (λem ≅ 515 nm in CHCl3) with respect to the analogues with linear alkoxy side chains. The aggregation properties of the polymer with 2-ethylhexyloxy groups have been investigated by an osmosis driven procedure, yielding nanospheres of different size depending on the adapted solvent/nonsolvent mixture.

Synthesis, structure and photoluminescence properties of naphthalene-based chiral zinc(II) complexes

Two novel chiral zinc(II) complexes containing naphthalene moieties, namely [Zn(CMN)Cl2] (1) and [Zn(CBN)Cl2] (2), were obtained through the reaction of zinc(II) chloride with, respectively, (1R,2R)-N1-(naphthalen-2-ylmethyl)cyclohexane-1,2-diamine (CMN) and (1R,2R)-N1,N2-bis(naphthalen-2-ylmethyl)cyclohexane-1,2-diamine (CBN) in ethanol. The ligands CMN and CBN were characterized via infrared, nuclear magnetic resonance and absorption spectroscopic analyses. As regards to the two complexes, a comprehensive single crystal X-ray diffraction investigation showed that in both cases the zinc(II) ion is surrounded by two N atoms of CMN/CBN and two chloro groups, and has a distorted tetrahedral structure, though 2 also contains an additional naphthalene group. The photo-physical properties of 1 and 2 were examined based on their electronic absorption and photoluminescence spectra. Both complexes exhibited ultraviolet emissions (both at 335 nm in CHCl3; 336 and 385 nm for 1 and 337 nm for 2 in their solid states) under 278–298 nm excitation.

1,2‐Disubstituted 3,3,4,4,5,5‐Hexafluorocyclopentenes as Bent Light‐Emitting π‐Conjugated Luminophores

Herein, a series of 1,2‐disubstituted 3,3,4,4,5,5‐hexafluorocyclopentene derivatives is synthesized from the commercially available octafluorocyclopentene via addition‐elimination reactions, and their photophysical properties are investigated in detail. 1,2‐Bis[2‐(4‐alkoxyaryl)ethyn‐1‐yl]‐3,3,4,4,5,5‐hexafluorocyclopentene exhibits UV‐absorption at 345 nm in CH2Cl2 and deep blue photoluminescence (PL). The PL properties of these derivatives, including color and maximum wavelength (λPL), are strongly affected by the electron‐density distribution induced by the electronic characteristics of the alkoxy‐substituents at the 4‐position of the benzene ring, with more electron‐donating substituents resulting in a larger shift of λPL to longer wavelengths. Note that the present light‐emitting π‐conjugated luminophores also exhibit relatively strong PL in the crystalline state, where λPL shifts can be introduced by modulation of the terminal alkoxy‐chain length, resulting in different PL colors from light‐blue to orange.

A Near-Infrared Absorption Small Molecule Acceptor for High-Performance Semitransparent and Colorful Binary and Ternary Organic Photovoltaics.

An acceptor-donor-acceptor (A-D-A)-type non-fullerene acceptor (NFA), PTTtID-Cl, featuring thieno[3,2-b]thieno[2''',3''':4'',5'']-pyrrolo[2'',3'':4',5']thieno[2',3':4,5]thieno-[2,3-d]pyrrole (DTPTt) as the electron-rich core and 2-(5,6-dichloro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (ID-Cl) as the peripheral electron-deficient terminal group was synthesized and characterized. PTTtID-Cl exhibited strong absorption in the range of 700-850 nm in CHCl3 and redshifted absorption centered at 881 nm in a thin film. The near infrared (NIR)-absorption of PTTtID-Cl was combined with a low-bandgap polymer donor (PTB7-Th) to achieve binary and semitransparent organic photovoltaics (OPVs) with a power conversion efficiency (PCE) of 8.9 % and 7.7 % (with an average visible transmittance (AVT) of 16.7 %), respectively. A ternary device with a ratio of PM7/PTTtID-Cl/IT-4F=1:0.15:0.85 (w/w) achieved a short-circuit current density of 19.46 mA cm-2 , an open-circuit voltage of 0.87 V, and a fill factor of 71.2 %, giving a PCE of 12.0 %. In addition, by employing the Ag/ITO/Ag microcavity structure, semitransparent colorful binary organic photovoltaics (OPVs) with superior transparency of 27.9 % at 427 nm and 22.7 % at 536 nm for blue and green devices, respectively, were prepared. The semitransparent colorful devices based on the optimized ternary blend gave PCEs of 8.7 %, 8.4 %, and 9.1 % for blue, green, and red devices, respectively. These results indicate the promising potential of PTTtID-Cl as a NIR-absorption NFA for applications in semitransparent colorful binary and ternary OPVs.

Synthesis and characterization of antimony(V)-oxo corrole complexes

Two corrolato-antimony(III) complexes have been prepared for the first time and characterized by a series of spectroscopic techniques. Both the complexes have been oxidized by iodosobenzene and the corresponding oxidized derivatives have been isolated and thoroughly characterized. All the four antimony complexes, including two corrolato-antimony(III) complexes and two (corrolato)(oxo)antimony(V) complexes are diamagnetic in nature as is evident from their “normal” chemical shifts. For one of the structurally characterized corrolato-antimony(III) complexes, we have obtained two different conformers in two different solvents with slightly different bond lengths and angles. SbIII corroles are dome shaped and the deviation of SbIII ion with respect to the plane consisting four pyrrolic nitrogen atoms is ~0.963–0.966 Å. The two corrolato-antimony(III) complexes exhibited split Soret bands in the range of 440–462 nm due to the low symmetric nature of these molecules. The two (corrolato)(oxo)antimony(V) complexes exhibited single Soret band in the range of 408–413 nm. All the four antimony complexes displayed weak emission in the range of 630–650 nm and a shoulder at 690–710 nm in CH2Cl2. These emission bands are assigned as fluorescence bands due to the observation of smaller Stokes shift in reference to the lowest energy Q-type bands.

Near-IR/Visible-Emitting Thiophenyl-Based Ru(II) Complexes: Efficient Photodynamic Therapy, Cellular Uptake, and DNA Binding.

Near-IR-emitting and/or efficiently photodynamic water-soluble Ru(II) complexes that hold great application potentials as photodynamic therapy and/or photodetection agents for cancers have been poorly explored. In this paper, the solvatochromism, calf thymus DNA binding, and singlet oxygen generation properties of a known ruthenium(II) complex of visible-emitting [Ru(bpy)2(dtdpq)](ClO4)2 (Ru1) and a new homoleptic complex of near-IR-emitting [Ru(dtdpq)3](ClO4)2 (Ru2) (bpy = 2,2'-bipyridine, dtdpq = 2,3-bis(thiophen-2-yl)pyrazino[2,3-f][1,10]phenanothroline) in water are reported. Moreover, DNA photocleavage, singlet oxygen generation in HeLa cells, cellular uptake/localization, and in vitro photodynamic therapy for cancer cells of water-soluble Ru1 are described in detail. The results show that Ru1 acted as potent photodynamic cancer therapy and mitochondrial imaging agents. Ru2 exhibited very strong solvatochromism from a visible emission maximum at 588 nm in CH2Cl2 to the near-IR region at 700 nm in water and singlet oxygen generation yield in water (23%) and DNA binding properties (intercalative DNA binding constant on the order of 106 M-1) comparable to those of Ru1, which should make Ru2 attractive for the aforementioned applications of Ru1 if the water solubility of Ru2 can be improved enough for the studies above.