•Organelle-targeting regulating strategies and the characteristics of organelle-targeting metal complexes are summarized.•The bio-applications of organelle-targeting metal complexes are ...overviewed.•The existing opportunities/challenges of organelle targeting are outlined.
Cellular organelles, such the cytomembrane, lysosome, mitochondrion, Golgi apparatus, the endoplasmic reticulum, and nucleus, play important roles in the normal function of cells. Organelle-targeting bioimaging can aid our understanding of how organelles function, while the development of organelle-targeting therapy could deliver treatment for a variety of diseases. Possessing important advantages such as their photophysical properties, cytotoxicity, and cellular uptake mechanisms, metal complexes for organelle-targeting bio-applications have attracted increasing attention in recent years. In this review, organelle-targeting regulating strategies, and the characteristics of organelle-targeting metal complexes as well as their bio-applications are summarized. Moreover, the existing opportunities/challenges of organelle targeting are outlined and emphasized to inspire the design of a new generation of organelle-targeting metal complexes.
In this Review article, we systematically summarize the design and applications of various kinds of long-lived emissive probes for bioimaging and biosensing via time-resolved photoluminescence ...techniques. The probes reviewed, including lanthanides, transition-metal complexes, organic dyes, carbon and silicon nanoparticles, metal clusters, and persistent phosphores, exhibit longer luminescence lifetimes than that of autofluorescence from biological tissue and organs. When these probes are internalized into living cells or animals, time-gated photoluminescence imaging selectively collects long-lived signals for intensity analysis, while photoluminescence lifetime imaging reports the decay details of each pixel. Since the long-lived signals are differentiated from autofluorescence in the time domain, the imaging contrast and sensing sensitivity are remarkably improved. The future prospects and challenges in this rapidly growing field are addressed.
The development of new methods for the direct functionalization of unactivated C–H bonds is ushering in a paradigm shift in the field of retrosynthetic analysis. In particular, the catalytic ...enantioselective functionalization of C–H bonds represents a highly atom- and step-economic approach toward the generation of structural complexity. However, as a result of their ubiquity and low reactivity, controlling both the chemo- and stereoselectivity of such processes constitutes a significant challenge. Herein we comprehensively review all asymmetric transition-metal-catalyzed methodologies that are believed to proceed via an inner-sphere-type mechanism, with an emphasis on the nature of stereochemistry generation. Our analysis serves to document the considerable and rapid progress within in the field, while also highlighting limitations of current methods.
In this review, synthetic and mechanistic aspects of key methodologies that exploit C–C single-bond cleavage of strained ring systems are highlighted. The focus is on transition-metal-catalyzed ...processes that are triggered by C–C bond activation and β-carbon elimination, with the review concentrating on developments from mid-2009 to mid-2016.
After a brief introduction on the main transduction mechanisms for metal ion detection by fluorescence, this paper reviews ligand molecules containing fluorophores synthesized and employed in metal ...ions sensing in solution in the last few years. With the aim of making more readable the paper we have organized it by dividing the subject first for type of fluorophore, then type of metal ion. Because of many acronyms a glossary has been inserted.
Dinitrogen (N2) activation and functionalization is of fundamental interest and practical importance. This review focuses on N2 activation and addition to unsaturated substrates, including carbon ...monoxide, carbon dioxide, heteroallenes, aldehydes, ketones, acid halides, nitriles, alkynes, and allenes, mediated by transition metal complexes, which afforded a variety of N−C bond formation products. Emphases are placed on the reaction modes and mechanisms. We hope that this work would stimulate further explorations in this challenging field.
Dinitrogen activation and addition to unsaturated substrates such as carbon monoxide, carbon dioxide, ketones, acid halides, nitriles, alkynes, and allenes mediated by transition metal complexes efficiently afford a variety of N−C bond formation products.
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Innovative anticancer therapies based on the activation of the immune system offer promise in the battle against cancers resistant to traditional treatments. Examples of such ...therapeutic approaches include, along with various types of immunotherapies, photodynamic therapy (PDT). PDT is a photochemistry-based strategy that results not only from its direct effects on cancer cells but also from disruption of tumor vasculature and activation of the host immune system. However, to achieve therapeutic success manifested in the eradication of the primary tumor and distant metastases, it is necessary to design suitable photosensitizers (PSs) with the desired optical and photophysical properties to enable efficient generation of ROS under tumor microenvironmental (TME) conditions, especially hypoxia. Thus, in this review particular attention is paid to the photochemical properties of PSs, notably the sufficiently long-lived triplet states and mechanisms of energy/electron transfer reactions. Photogenerated ROS initiate inflammatory reaction, expression of heat-shock proteins, infiltration of immune cells and long-term immune memory. These unique features of PDT give new possibilities to combine PDT with agents stimulating immune response as well as with immunotherapy, especially based on PD-1/PD-L1 blockade. Most of the systems explored in this aspect so far are either derivatives of naturally occurring metal complexes (Heme, Chlorophyll a, and Bacteiochorophyll a - inspired PSs), synthetic (metallo)porphyrins and (metallo)phthalocyanines or hybrid materials containing metal nanoparticles. This work also summarizes recent reports on the synthesis of antibody-PS conjugates with desired spectroscopic and photochemical properties along with enhanced selectivity and biological activity. Finally, the most notable drawbacks of PDT are presented, and a scenario is outlined for the development of PDT alone and combined with immunotherapy to overcome these challenges in the future.
Chiral‐at‐metal RhIII complexes catalyze the efficient enantioselective Mannich reaction of 2‐acyl imidazoles with 1,3,5‐triazinanes, affording the corresponding adducts in 81–99 % yield with up to ...>99 % enantioselectivity. This protocol performs with 0.1 mol‐% of RhIII complex on gram scale without any loss in enantioselectivity.
An efficient enantioselective Mannich reaction of 2‐acyl imidazoles with 1,3,5‐triazinanes catalyzed by chiral‐at‐metal RhIII complexes has been developed, affording the corresponding adducts in good yields with excellent enantioselectivities.
•Understanding the influence of metal ions on tetrapyrroles photoproperties.•Special attention is paid to the design of NIR absorbing photosensitizers (PSs).•The interaction between excited PS and ...molecular oxygen is highlighted.•Engineering of PS excited states and channelling energy to biomedical applications.
Applications of metalloporphyrins and related molecules have been extensively pursued in the context of photodynamic therapy of cancer (PDT) and other biomedical applications. This review discusses photophysical and photochemical properties of metalloporphyrins and their analogues, such as metallochlorins, metallobacteriochlorins and metallophthalocyanines that are relevant for photodynamic processes. We specially emphasize the search for sensitizers strongly absorbing in phototherapeutic window (650–850 nm), the most penetrating and least harmful radiation to human tissues. Molecular engineering is guided by the understanding of the influence of the central metal ion and substituents on the electronic structure and photophysical properties of these compounds. The effects of the structural modifications are elucidated via studies of the electronic absorption and emission spectra, fluorescence and triplet state lifetimes and quantum yields, as well as quantum yields of singlet oxygen generation. The interaction between electronically excited (metallo)porphyrin derivatives and molecular oxygen is specially highlighted, because it leads to the generation of reactive oxygen species (ROS), the major players in photomedicine and photocatalysis. The parameters analysed and correlated encompass photophysical and electrochemical properties, cellular uptake and localization of the photosensitizer, as well as the mechanism of photodynamically induced cell death. The factors that determine the efficacy of PDT (drug and light doses, drug to light interval, oxygen concentration and tumour margin) are also emphasized. This review explores the most recent research performed on metalloporphyrin-based materials in photodynamic therapy, photodynamic inactivation of microorganisms, photodiagnosis and drug delivery, demonstrating their perspectives for biomedical applications.
Metalloporphyrins and their derivatives are characterized by a variety of photophysical and photochemical properties that can be explored for a number of biomedical applications including photodynamic therapy, photodiagnosis and photodynamic inactivation of microorganisms.
•The review about speciation analysis of HMCs is important but scarce.•Prevalent methods for aqueous HMC mitigation were introduced.•Technologies for aqueous HMC analysis were summarized and ...discussed.•The importance role of species transformation in HMC decomplexation was elucidated.•Outlook and perspective were provided based on current challenges.
Efficient mitigation of toxic and recalcitrant heavy metal complexes (HMCs) from water and wastewater is critical to guarantee the environmental health and safety, but still faces many challenges. Although a number of techniques have been developed to deal with HMCs laden water/wastewater, there is still a lack of comprehensive and insightful understanding of the relevant mechanisms. One of the main reasons is the complicated heavy metal speciation in water/wastewater, which masks the speciation distribution and coordination circumstance of heavy metals. In this review, prevalent methods for HMC elimination (e.g., physical separation and chemical decomplexation) are briefly presented and evaluated. Especially, the characterization methods of HMCs, which afford to provide valuable information on the speciation distribution of heavy metals, are underlined and discussed. Furthermore, typical cases are provided to elucidate the essential role of species transformation in the decomplexation of HMCs and the implications for enhanced mitigation of HMCs are also discussed. Finally, the current challenges and perspectives for future study in this field are proposed.
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