Novel Chiral PNNP-Ru Complexes:Synthesis and Application in Asymmetric Transfer Hydrogenation of Ketones

The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities（up to 99% conversion） and excellent enantioselectivities（up to 96% e.e.） under mild conditions. The chiral ruthenium（Ⅱ） complex （R,R）-3 has been prepared and characterized by NMR and X-ray crystallography.

Redox-responsive phenyl-functionalized polylactide micelles for enhancing Ru complexes delivery and phototherapy

Poly(ethylene glycol)-poly(lactic acid)block copolymer(PEG-PLA)is one of the most widely used biomedical polymers in clinical drug delivery owing to its biocompatibility and biodegradability.However,endowing PEG-PLA micelles with high drug loading,self-assembly stability and fast intracellular drug release is still challenging.Redox-responsive diblock copolymers(MPEG-SS-PMLA)of poly(ethylene glycol)and phenyl-functionalized poly(lactic acid)with disulfide bond as the linker are synthesized to prepare PLA-based micelles that demonstrate excellent colloidal stability and high Ru loading.Notably,MPEGSS-PMLA achieved a remarkably high Ru loading efficiency of 84.3%due to the existence of strongπ-πstacking between phenyl and Ru complex.MPEG-SS-PMLA exhibited good colloidal stability in physiological condition but quickly destabilized by reductive tumor microenvironment.Interestingly,about 74%of Ru complex was released under 10 mmol/L GSH concentration.Ru-loaded MEPG-SS-PMLA showed efficient delivery and release of Ru complex into MCF-7 cancer cells,achieving enhanced in vitro and in vivo antitumor activity of photodynamic therapy.This feasible functionalization method of MPEG-PLA has appeared to be a clinically viable platform for controlled delivery therapeutic agents and enhanced phototherapy.

Theoretical Studies on Structures and Spectroscopic Properties of Highly Efficient Phosphorescent [Ru（terpy）（phen）X]＋ Complexes

The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru（II） complexes [Ru（terpy）（phen）X]＋ （terpy=2,2＇,6＇,2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH （1）, X=Cl （2）, X-CN （3）） were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π＊（terpy） type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz （Ru）＋Tr/p（X）--π＊ （terpy） transition with MLCT/XLCT （metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer） character, whereas that of 3 at 529 nm is related to a dyz （Ru）＋π（terpy）-π＊ （terpy） transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm （1）, 913 nm （2）, and 838 nm （3） have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru（II） complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.

Synthesis, Fluorescence and Electrochemistry of Three New Ruthenium(Ⅱ) Complexes

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SARs Investigation of α-, β-, γ-, δ-, ε-RuCl2(Azpy)2 Complexes as Antitumor Drugs

Structure Activity-Relationships (SARs) of the five possible isomers of RuCl2(Azpy)2 were predicted thanks to DFT method. Azpy stands for 2-phenylazopyridine and the structure of the isomers α-RuCl2(Azpy)2, β-RuCl2(Azpy)2, γ-RuCl2(Azpy)2, δ-RuCl2(Azpy)2 and ε-RuCl2(Azpy)2 call respectively α-Cl, β-Cl, γ-Cl, δ-Cl and ε-Cl are defined according to chlorine atoms orientations. Hence, they are divided into two groups. In the first group comprising α-Cl, β-Cl and ε-Cl, both chlorine atoms are in cis position and Azpy ligands are intervertical. Whereas the two others isomers (γ-Cl and δ-Cl), they form the second group. Here, both chlorine are in trans position and Azpy are planar. The five synthesized isomers were investigated as potential antitumor agents. Then, regarding the DNA, its bases are stacked by pair. Therefore, complexes are assumed to insert and to stack on them through intercalative mode. So the electronic and geometric structures become more important to describe their SARs. Consequently, group 2 regarding γ-Cl and δ-Cl presents the best structure to allow intercalation between DNA base-pairs. Besides, the energy order of the lower unoccupied molecular orbital (LUMO) of the isomers is ELUMO(β-Cl) > ELUMO(α-Cl) > ELUMO(ε-Cl) > ELUMO(γ-Cl) > ELUMO(δ-Cl). The energy gap between LUMO and HOMO was also sorted as Δ(L-H)(β-Cl) > Δ(L-H)(α-Cl) > Δ(L-H)(ε-Cl) > Δ(L-H)(γ-Cl) > Δ(L-H)(δ-Cl). In addition, the total dipole moment was classified as μ(ε-Cl) > μ(β-Cl) > μ(α-Cl) > μ(γ-Cl) > μ(δ-Cl). Finally, net charge of the ligand Azpy was also classified as QL(δ-Cl) > QL(γ-Cl) > QL(ε-Cl) > QL(α-Cl) > QL(β-Cl). All those parameters show that δ-Cl isomer displays the highest activity as antitumor drug when intercalating between the DNA basepairs Cytosine-Guanine/Cytosine-Guanine (CG/CG).

Theoretical Studies on the Excited-state Properties of Ru(Ⅱ)Polypyridyl Complexes

Using DFT/TDDFT methods,the excited-state lifetimes of Ru（Ⅱ） polypyridyl complexes were computed accurately and the reason of Ru（Ⅱ） polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru（Ⅱ） polypyridyl complexes.

Supramolecular metallopolymer for hypoxia-activated ruthenium complexes delivery and smart chemo-photodynamic therapy

The Ru complexes have garnered a great deal of attention for antitumor phototherapy;however, achieving efficient cellular uptake and tumor-specific activation represents a major challenge. Herein, we synthesize a hypoxia-activated Ru complex(Ru ANM) and construct it into supramolecular polymers(Poly Ru ANM) through high binding affinity interaction. The amphiphilic supramolecular polymers possess self-assembly, resulting in the formation of diverse nanostructures exhibiting a range of morphologies by simply adjusting the host-guest ratio. As the polymer nanostructure size and morphology have been optimized, Poly Ru ANM prevents premature drug leakage and accumulates rapidly in the tumor cells. In the tumor hypoxia microenvironment, the polymer undergoes selective activation and disintegration, leading to the unlock of Ru complexes.Notably, the subsequent application of red light irradiation exacerbates the hypoxia and potentiates the liberation of the Ru complexes. This polymer design concept provides some novel insights into on-demand drug delivery and smart chemophotodynamic therapy.

Doping [Ru(bpy)3]^(2+ )into metal-organic framework to facilitate the separation and reuse of noble-metal photosensitizer during CO2 photoreduction

It is desirable to develop highly efficient and sustainable catalytic systems for CO_(2) photoreduction using efficient heterogeneous photosensitizers(PSs);however,this remains a great challenge.In this study,we doped[Ru(bpy)3]^(2+) into UiO-metal-organic frameworks(MOFs)to facilitate the separation and reuse of noble metal PS.By simply adjusting the loading amount,a series of heterogeneous photoactive MOFs,namely,UiO-Ru-1,UiO-Ru-2,and UiO-Ru-3,were constructed to act as heterogeneous PSs to drive the efficient CO_(2) photoreduction under visible-light irradiation.Remarkably,UiO-Ru-2 exhibited the best photosensitizing ability among the prepared MOFs in sensitizing the iron quarterpyridine catalyst(C-l),and the CO yield reached as high as 171 mmol/g with ca.100%selectivity,which is a record value among all the MOF-based photocatalysts.This photoactive MOF can be recycled and reused three times without any obvious activity loss,signifying its good photochemical stability.Experimental investigations confirmed that the strong visible absorption,long-lived excited state,appropriate redox potential,good photocatalytic stability,and excellent collaboration with C-l were attributable to the superior catalytic activity.This work highlights an avenue for constructing heterogeneous PSs with excellent recyclability using MOF as the platform for efficient CO_(2) reduction.

Electrochemical Studies on the Interactions of Dipyridophenazine Complex of Ruthenium and Herring Sperm DNA

Cyclic voltammetry (CV) and single-step chronocoulometry were used to study the interaction of [Ru(phen)2dppz]2+ (phen=1,10-phenanthroline; dppz=dipyrido[3,2-a:2′,3′-c]phen- azine) with herring sperm DNA. The addition of DNA caused a diminution in the peak current and a positive shift in the peak potential of the complex of [Ru(phen)2dppz]2+. The 12 mV positive shift in the peak potential of [Ru(phen)2dppz]2+ indicates that [Ru(phen)2dppz]2+ binds 2.6 times more strongly to DNA than its reductive form. In addition, by using fluorimetric and UV-spectrophotometric methods and studies of denatured DNA and the effect of NaCl solution, it was also found that the binding mode was intercalation. The decrease of peak current is proportional to the concentration of DNA, which can be applied to estimate DNA concentration.

Interaction of Mixed Porphyrin-polypyridyl Ru(II) Complex with Bovine Serum Albumin

The interactions of mixed porphyrin-polypyridyl Ru（Ⅱ） complexes [m（Py-3＇）TPP-Ru（phen）2Cl]^＋（1） and its derivatives [Nim（Py-3＇）TPP-Ru（phen）2Cl]＋（2） and [Cum（Py-3＇）TPP-Ru（phen）2Cl]^＋（3）（phen=1,10-phenanthroline; m（Py-3＇）TPP=5-（3＇-pyridyl）-10,15,20-triphenylporphyrin） with bovine serum albumin（BSA） were investigated by fluorescence, UV-Vis and circular dichroism（CD） spectroscopies. The UV-Vis and CD spectral experiments indicated that the secondary structures of the protein were perturbed in the presence of the porphyrin Ru（Ⅱ） complex and the perturbation was enhanced under the irradiation with ultra-violet light. The fluorescence quenching mechanism of BSA by the three complexes was determined to be a static process, and the apparent binding constant K values for complexes 1, 2 and 3 measured by fluorescence quenching method were （3.86±0.03）×10^3 L/mol（n=0.94±0.04）, （5.69±0.04）× 103 L/mol（n=1.03±0.06）, and （6.54±0.02）× 10^3 L/mol（n=1.03±0.05）, respectively.

SPECTROSCOPIC STUDIES ON A HETEROMETALLOBINUCLEAR COMPLEX IN WHICH Ru(BPY)_3^(2+)WAS COVALENTLY ATTACHED TO N_i^-(CYCLAM)^(2+)

The spectroscopic properties for a recently synthesized hetero-metallo- binuclear complex Ru(bpy)_2 (bpy-cyclam-Ni)^(4+)(3)and its related complexes 1 and 2 were investigated by UV-vis and emission spectral methods.A drastic quenching of fluorescence from the Ru(bpy)_3^(2+) subunit by the covalently attached quencher sub- unit Ni(cyclam)^(2+) was observed for complex 3,and the mechanism was discussed.

Synthesis and Structure of Ru (pap)_2Cl_2 · 4EtOH

The reaction of Ru (DMSO)_4Cl_2 with Dipheny1-[(pyrid-2-y1 ) amino]phosphine (pap) (1:2) gives the title compound Ru(PAP)_2Cl_2· 4EtoH. The crystallographic data for C_(24)H_(54)C_(12)N_4O_4P_2Ru: monoclinic,space group C2/c .α= 20. 47 (1) . b = 15. 431(9), c=15. 958(8) A , β=16. 82(4)°, V=4509(9) A3￣, Z=4, M_r= 912. 85, D_c= 1. 35 g/cm￣3,μ(MoKα) = 5. 71 cm￣(-1), F(000) =1092, R= 0. 073 and R_w = 0. 081 for 1700 observed reflections. The Ru atom is coordinated by two P atoms, two N atoms and two Cl atoms, forming octahedral coordination geomery.

Base-controlled NHC-Ru-catalyzed transfer hydrogenation andα-methylation/transfer hydrogenation of ketones using methanol

Herein,we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol.By simply changing the base,a broad range of structurally diverse ketones,could be selectively and efficiently converted to the correspondingβ-methylated secondary alcohols or secondary alcohols.Remarkably,this catalytic system was very effective for the synthesis of bio-related molecules and deuterated alcohols,as well as the three-component coupling between methyl ketones,primary alcohols,and methanol.The reaction mechanism was further revealed by experiment and DFT mechanistic investigations.

Photoelectrical performance of nanocrystalline TiO_2 film electrode sensitized by Ru(Ⅱ)-bipyridine complexes

Two kinds of Ru(Ⅱ)-bipyridine complexes, cis-di(thiocyanate)bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium(Ⅱ) and cis-di(thiocyanate)bis(2,2′-bipyridyl-3,3′-dicarboxylate) ruthenium(Ⅱ), were utilized as the sensitizers to the nanocrystalline TiO-2 film electrodes. Study shows that the two dyes have quite different sensitization properties due to the strong steric effect of carboxyl groups. In addition, the pretreatment to nanocrystalline TiO-2 film electrodes with TiCl-4 was investigated, which is an effective way to improve the photoelectric conversion performances of sensitized TiO-2 electrodes.

Theoretical study on second-order nonlinear optical properties of 1,10-phenanthroline Ru(Ⅱ) complexes

The dynamic first hyperpolarizabilities of a series of 1,10-phenanthroline Ru（II） complexes were carried out using density functional theory （DFT）. The results indicate that these complexes have large second-order nonlinear optical （NLO） responses. Specially, complex 6b has a maximal first hyperpolarizability βtot value. The first hyperpolarizabilities can be tuned by changing the ancillary ligand, introducing electron-acceptor group NO2 and/or increasing r-conjugation on phenanthroline. Calculations on absorption spectra demonstrate that the second-order NLO responses of complexes in series a are ascribed to the intraligand charge transfer （ILCT）, while the complexes in series b exhibit metal-to-ligand charge transfer （MLCT） and lig- and-to-ligand charge transfer （LLCT） transition at relatively low-energy absorptions.

Synthesis, DNA and Photocleavage Studies of Ru（ll） Polypyridyl Complexes： [Ru（dppz）（pyz）4]（ClO4）2 and [Ru（dppz）（dmpyz）4]（ClO4）2 Complexes

In view of the growing interest for the synthesis of metal complexes and their interaction with DNA, we have synthesized and characterized two complexes containing ruthenium as metal center. The complexes are of the type [Ru（dppz）L4]（C104）2 where L are biologically important ligands such as pyrazole and dimethylpyrazole. The characterization of these complexes is done by 1 H NMR, 13C NMR, elemental analysis and mass spectroscopy. The interaction of these complexes with CT DNA was monitored and binding constants were determined using absorption and fluorescence spectroscopy. The mode of binding was found to be intercalative for both complexes and was determined using hydrodynamic viscosity studies. The complexes were further studied for photocleavage studies with supercoiled plasmid pBR322 DNA.

Fast repetition rate fs pulsed lasers for advanced PLIM microscopy

Simultaneous metabolic and oxygen imaging is promising to follow up therapy response,dis-ease development and to determine prognostic factors.FLIM of metabolic coenzymes is now widely accepted to be the most reliable method to determine cellular bioenergetics.Also,oxygen consumption has to be taken into account to understand treatment responses.The phosphorescence lifetimne of oxygen sensors is able to indicate local oxygen changes.For phosphorescence lifetime imaging(PLIM)dyes based on ruthenium(I)coordination com-plexes are useful,in detaill TLD1433 which possesses a variety of different triplet states,enables complex photochemistry and redox reactions.PLIM is usally reached by two photon exci-tation of the drug with a femtosecond(fs)pulsed Ti:Sapphire laser working at 80 MHz repe-tition rate and(time-correlated single photon counting)(TCSPC)detection electronics.The interesting question was whether it is possible to follow up PLIM 1using faster repetition rates.Faster repetition rates could be advantageous for the induction of specific photochemical reactions because of similar light doses used normally in standard CW light treatments.For this,a default 2p-FLIM-PLIM system was expanded by adding a second fs pulsed laser("helixx")which provides 50 fs pulses at a repetition rate of 250 MHz,more than 2.3 w average power and tunable from 720 nm to 920 nm.The laser beam was coupled into the AOM instead of the default 80 MHz laser.We demonstrated siuccessful applications of the 250 MHz laser for PLIM which correlates well with measurements done by excitation with the conventional 80MHx laser source.

Preparation, Characterization, Luminescent and Electrochemical Properties of Ru（bpy）e-functionalized Silica Nanoparticles

Ru（II）-complex functionalized silica nanoparticles（nano-SiO2） were prepared via a coordination reaction of cis-dichlorobis（2,2＇-bipyridine）ruthenium[Ru（bpy）2C12] complex with poly（4-vinylpyridine）（P4VP）-modified na- no-SiO2 particles. Both the Ru-complex and the functionalized nano-SiO2P4VP-Ru（bpy） hybrids were doped in poly（methyl methacrylate）（PMMA） to form optically transparent thin films. The composition and spectroscopic properties of the nano-SiO2P4VP-Ru（bpy） hybrids were evaluated with the help of thermogravimetric and elemental analysis, and UV-Vis absorption spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and fluores- cence spectroscopy. Microscopy images revealed that the nanohybrids were approximately 12 nm in diameter and readily formed aggregates following the functionalization with P4VP and Ru（bpy）2C12. The as-prepared na- no-SiO2P4VP-Ru（bpy） hybrids produced emissions at approximately 604 and 654 nm under radiation both in solution and in doped thin films. Finally, cyclic voltammetry studies on the nanohybrid-modified electrode revealed a redox couple with the cathodic and anodic potentials at approximately 0.28 and 0.73 V（vs. Ag/AgCI）, attributed to the one electron transfer of Ru（bpy）22＋/3＋ immobilized on the nano-SiO2 particles.