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1.
J Mol Histol ; 51(1): 55-65, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32006186

RESUMO

p53 is known to advance the cell arrest and cell senescence in human tumors. In this study, we displayed that osteogenic ability of p53-knockout (p53-/-) mice was significantly increased in the tooth extraction socket compared with wild-type (WT) counterparts. Bone marrow mesenchymal stem cells (BM-MSCs) from mandibular were collected and exhibited with elevated proliferation potential and colony-forming units compared with the control, as well as stronger mineral deposits and osteogenic markers. Besides, the bone mass and bone parameter in p53-/- mice were markedly enhanced compared with the counterpart after extractions by micro-CT. Masson's trichrome staining and immunohistochemistry also revealed that new bone filling and osterix/osteocalcin (Osx/OCN)-immunopositive staining in p53-/- mice were remarkably increased at each time point. Furthermore, consistent with the enhanced osteogenic markers, the angiogenic marker of blood vessels (alpha smooth muscle actin, α-SMA) was significantly elevated in p53-/- mice in contrast to WT mice. Importantly, we found that the osteoclast numbers exhibited an increased trend in p53-/- mice compared with WT mice during socket healing. Collectively, our result suggest that p53 deficiency could promote the osteogenesis and angiogenesis in the tooth extraction socket and might lend possibility for p53-based therapeutic approaches in acceleration of extraction bone healing.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32011799

RESUMO

Herein, the trackable supramolecular transformation of a two-component molecular cage to a three-component cage through supramolecular fusion with another two-component molecular square is described. The use of tetraphenylethene (TPE), a chromophore with aggregation-induced emission (AIE) character, as a component for the molecular cages enables facile fluorescence monitoring of the transformation process: while both cages exhibit fluorescence emission via the restriction of intramolecular motion of the TPE motif, the interactions between TPE and 4,4'-bipyridine introduced in the supramolecular fusion process result in partial fluorescence quenching and shifts in the emission maximum. This study provides a simple and efficient approach towards complex supramolecular cages with emergent functions and demonstrates that AIE features could provide unique opportunities for the characterization of complex, dynamic supramolecular transformation processes.

3.
Inorg Chem ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31961145

RESUMO

In this report, we describe the synthesis of two porphyrin-containing Pt(II) supramolecular assemblies via coordination-driven self-assembly. X-ray crystallographic analysis on one assembly reveals that the metalla-assembly formation imposes large interchromophore distances, leading to a higher 1O2 generation efficiency, relative to the corresponding small molecular precursors. The metalla-assemblies were examined as photosensitizers for photodynamic therapy as the potential reduction of the unfavorable self-aggregation phenomenon. In vivo and in vitro investigations demonstrate that the metalla-assemblies exhibit enhanced anticancer activity with minimal dose requirement and side effects comparable to the small molecule precursors. Thus, our work demonstrates that self-assembly provides a promising methodology for enhancing the therapeutic effectiveness of anticancer agents.

5.
Proc Natl Acad Sci U S A ; 116(41): 20296-20302, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31548389

RESUMO

Photodynamic therapy (PDT) is a treatment procedure that relies on cytotoxic reactive oxygen species (ROS) generated by the light activation of a photosensitizer. The photophysical and biological properties of photosensitizers are vital for the therapeutic outcome of PDT. In this work a 2D rhomboidal metallacycle and a 3D octahedral metallacage were designed and synthesized via the coordination-driven self-assembly of a Ru(II)-based photosensitizer and complementary Pt(II)-based building blocks. The metallacage showed deep-red luminescence, a large 2-photon absorption cross-section, and highly efficient ROS generation. The metallacage was encapsulated into an amphiphilic block copolymer to form nanoparticles to encourage cell uptake and localization. Upon internalization into cells, the nanoparticles selectively accumulate in the lysosomes, a favorable location for PDT. The nanoparticles are almost nontoxic in the dark, and can efficiently destroy tumor cells via the generation of ROS in the lysosomes under 2-photon near-infrared light irradiation. The superb PDT efficacy of the metallacage-containing nanoparticles was further validated by studies on 3D multicellular spheroids (MCS) and in vivo studies on A549 tumor-bearing mice.

6.
J Am Chem Soc ; 141(30): 11837-11841, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31303001

RESUMO

Considerable progress in platinum metallacycle-based supramolecular polymerization has promoted the fabrication and application of supramolecular materials. However, despite recent advances, supramolecular polymers constructed through platinum metallacycle-based host-guest complexation remain rare because of the dynamics of platinum metallacycles. Here, we achieve linear supramolecular polymerization via platinum metallacycle-based host-guest complexation by following the design rule of suppressing the dynamics of the metallacycles. The establishment of the platinum metallacycle-based host-guest system and the realization of this type of supramolecular polymerization are expected to open opportunities for platinum metallacycle-based functional materials.

7.
J Am Chem Soc ; 141(24): 9673-9679, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31125220

RESUMO

The intrinsic relationship between the properties of green fluorescent protein (GFP) and its encapsulated small molecular light machine has spurred many biomimicking studies, aiming at revealing the detailed mechanism and further promoting its wide applications in different disciplines. However, how to build a similar confined microenvironment to mimic the cavity of a ß-barrel and the fluorescence turn-on process is a fundamental challenge for both chemists and biologists. Herein, two distinct exo- and endo-functionalized tetraphenylethylene (TPE)-based M12L24 nanospheres with precise distribution of anchored TPE moieties and unique photophysical properties were constructed by means of a coordination-driven self-assembly strategy. Under dilute conditions, the nanospheres fluoresce more strongly than the corresponding TPE subcomponents. Meanwhile, the endo-functionalized sphere is able to induce a higher local concentration and more restrained motion of the enclosed 24 TPE units compared with exo-functionalized counterpart and thus induces much stronger emission due to the restriction of the rotation of the pendant TPE units. The biomimetic methodology developed here represents a promising way to understand and construct artificial GFP materials on the platforms of supramolecular coordination complexes.

8.
Inorg Chem ; 58(11): 7141-7145, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31094513

RESUMO

A double metallacycle was prepared via the size-selective integrative self-sorting of four different building blocks driven by a reversible metal-ligand coordination interaction. A hydrophobic dendron was placed on a metallacycle and a hydrophilic dendron was attached to the other metallacycle, producing a two-faced Janus-type supramolecule with two distinct functionalities. In aqueous media, hierarchical self-assembly of the supramolecular system was induced by the combination of coordination interactions and hydrophobic-hydrophilic interactions resulting in the formation of micrometer-sized fiber-like structures, a morphology distinct from metallacycles bearing only one type of functionality. This study provides a versatile approach for the construction of Janus-type molecules and demonstrates that integrative self-sorting of a supramolecular coordination system can be utilized for the preparation of complex supramolecular systems with predesigned functionalities and morphologies.

9.
J Am Chem Soc ; 141(16): 6494-6498, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30966741

RESUMO

The recent progress in platinum(II) coordination-driven supramolecular polymers has had a substantial effect on the design of functional soft materials. However, the prospect of realizing polymerization induced by platinum(II) metallacycle-based host-guest interactions has received little attention until recently. Here we report the realization of supramolecular polymerization driven by platinum(II) metallacycle-based host-guest interactions both in the solid state and in solution. On the basis of the disclosed polymerization mechanism, we present a new strategy for the preparation of platinum(II) metallacycle-based supramolecular polymers.

10.
J Am Chem Soc ; 141(13): 5535-5543, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30835458

RESUMO

A series of platinum(II) metallacycles were prepared via the coordination-driven self-assembly of a phenazine-cored dipyridyl donor with a 90° Pt(II) acceptor and various dicarboxylate donors in a 1:1:2 ratio. While the metallacycles display similar absorption profiles, they exhibit a trend of blue-shifted fluorescence emission with the decrease in the bite angles between the carboxylate building blocks. Comprehensive spectroscopic and dynamic studies as well as a computational approach were conducted, revealing that the difference in the degree of constraint imposed on the excited-state planarization of the phenazine core within these metallacycles results in their distinct photophysical behaviors. As such, a small initial difference in the dicarboxylate building blocks is amplified into distinct photophysical properties of the metallacycles, which is reminiscent of the efficient functional tuning observed in natural systems. In addition to the pre-assembly approach, the photophysical properties of a metallacycle can also be modulated using a post-assembly modification to the dicarboxylate building block, suggesting another strategy for functional tuning. This research illustrated the potential of coordination-driven self-assembly for the preparation of materials with precisely tailored functionalities at the molecular level.

11.
J Am Chem Soc ; 141(8): 3717-3722, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30702872

RESUMO

The local environment surrounding luminophores can significantly influence their photophysical properties. Herein, we report the self-assembly of a highly emissive platinum(II)-based metallacage. In order to accommodate the connectivity of the platinum(II) building block used in the self-assembly process, the luminophore-containing building block adopts a highly twisted geometry relative to its free form, leading to the emergence of an emissive transition with a radiative rate constant an order of magnitude higher than that of the free luminophore. This increased rate constant is the primary driver for the 10-fold increase in quantum yield from 4.2% to 40%. Model complexes with platinum or methyl groups bound to the nitrogen were synthesized. These complexes had lower quantum yields (10% and non-emissive, respectively) due mainly to decreases in radiative rate constants. Computational studies were conducted and indicated that the excited state of the ensembles, as well as the model complexes, is a result of charge transfer to the pyridyl groups, in contrast to the free luminophore, which involves the diphenyl sulfone moiety. The differences in quantum yields can be explained by a twist in the chromophore upon coordination of platinum or methylation on the pyridyl group, leading to intersystem crossing to a triplet state. This state then becomes more emissive with the addition of platinum, which increases the radiative rate constant via the heavy atom effect. The formation of a metallacage also decreases the non-radiative rate constant by inhibiting the intramolecular motions of the incorporated luminophore.

12.
Proc Natl Acad Sci U S A ; 116(6): 1968-1973, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30670648

RESUMO

Fluorescent theranostics probes at the second near-IR region (NIR-II; 1.0-1.7 µm) are in high demand for precise theranostics that minimize autofluorescence, reduce photon scattering, and improve the penetration depth. Herein, we designed and synthesized an NIR-II theranostic nanoprobe 1 that incorporates a Pt(II) metallacycle 2 and an organic molecular dye 3 into DSPE-mPEG5000 (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-5000]). This design endows 1 with good photostability and passive targeting ability. Our studies show that 1 accurately diagnoses cancer with high resolution and selectively delivers the Pt(II) metallacycle to tumor regions via an enhanced permeability and retention effect. In vivo studies reveal that 1 efficiently inhibits the growth of tumor with minimal side effects. At the same time, improved fluorescent imaging quality and signal-to-noise ratios are shown due to the long emission wavelengths. These studies demonstrate that 1 is a potential theranostic platform for tumor diagnosis and treatment in the NIR-II region.


Assuntos
Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Nanomedicina Teranóstica/métodos , Animais , Imagem por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/terapia , Fótons , Razão Sinal-Ruído
13.
J Am Chem Soc ; 141(4): 1757-1765, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30608681

RESUMO

Constructing polycyclic aromatics-based, highly emissive fluorophores with good solubility and tunable aggregated structures and properties is of great importance for film fabrication, solution processing, and relevant functionality studies. Herein, we describe a general strategy to endow conventional organic fluorophores with enhanced solubility and modulated fluorescent properties via their incorporation into coordination-driven self-assembled metallacycles. A widely used fluorophore, pyrene, was decorated with two pyridyl groups to yield functionalized pyrene 4. Mixing 4 with three aromatic dicarboxylates with different lengths and a 90° Pt(II) metal acceptor in a 2:2:4 stoichiometric ratio resulted in the formation of three metallacycles, 1, 2, and 3. The metallacycles display good solubility in polar organic solvents, highly aggregation-dependent fluorescence, and size-dependent emissions at higher concentrations. Moreover, metallacycle 2-based, silica-gel-supported film as fabricated not only is more emissive than the ligand 4-based one but also displays much improved sensing properties for amines in the vapor state, as demonstrated by significantly increased response speed and decreased recovery time. The enhanced solubility, unique fluorescence behavior, and multi-factor modulation character show that coordination-driven self-assembly can be utilized for the development of new fluorophores through simple modification of conventional fluorophores. The fluorophores synthesized this way possess not only complex topological structures but also good modularity and tunability in fluorescence behavior, which are important for grafting multi-stage energy-transfer systems necessary for the development of high-performance sensing materials.

14.
J Bone Miner Metab ; 37(4): 584-593, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30238429

RESUMO

CBX7 is shown to down-regulate the expression of osteopontin (OPN) that is associated with osteoblast function. Here, we studied the role of CBX7 in the wound healing of tooth extraction socket in which osteoblast activity is critical via comparison between CBX7-knockout (CBX7-/-) mice and their wild-type (WT) counterparts of 6 weeks old with maxillary first molar extracted. Mice were euthanized at 7, 14, and 21 days after extractions, and alveolar sockets were assessed by semi-quantitative histomorphometry for hard tissue healing, including new bone fill (Masson's trichrome staining), osteoblast activity (OPN/osterix, Osx), osteoclast activity (tartrate-resistant acid phosphatase, TRAP), and for soft tissue healing, including blood vessels (alpha smooth muscle actin, α-SMA). Also, the bone microarchitecture was evaluated by micro-CT. In radiological analysis, CBX7-/- mice increased bone mass significantly more than WT mice did. Consistently, both the amount of new bone fill and OPN/Osx-immunopositive cells in the extraction sockets were significantly increased in CBX7-/- mice at each time point with respect to their WT siblings, while osteoclast number exhibited a trend of more increase in CBX7-/- mice at all time points as well. In agreement with enhanced bone formation during socket healing, significantly elevated α-SMA-immunopositive area was noted in CBX7-/- mice in contrast to WT mice. Taken together, these data suggest that CBX7 deficiency has a positive effect on tooth extraction socket healing.


Assuntos
Complexo Repressor Polycomb 1/deficiência , Extração Dentária , Alvéolo Dental/patologia , Cicatrização , Animais , Densidade Óssea , Reabsorção Óssea/patologia , Masculino , Camundongos Knockout , Neovascularização Fisiológica , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Complexo Repressor Polycomb 1/metabolismo , Fatores de Tempo , Alvéolo Dental/irrigação sanguínea , Alvéolo Dental/diagnóstico por imagem , Alvéolo Dental/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
15.
Pediatr Rheumatol Online J ; 16(1): 72, 2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30458860

RESUMO

OBJECTIVE: To follow up the refractory juvenile dermatomyositis (JDM) with autologous hematopoietic stem cell transplantation (AHSCT) in a long time and to investigate whether AHSCT is effective and safe to treat refractory JDM. METHODS: We collected the AHSCT and follow-up data of three patients with refractory JDM who received autologous peripheral blood CD34+ cell transplantation in our hospital between June 2004 and July 2015. Those data include: hight, weight, routine blood and urine tests, ESR, CK, ALT, AST, LDH, renal functional tests, lymphocyte subpopulations, HRCT and muscle MRI. The last follow-up was done in June 2017. RESULTS: All three patients had complete remission and could stop prednisone after 3-12 months. None of them relapsed at 144, 113 and 23 months follow-up. Twelve months after their AHSCT, all of their monitoring indexes have returned to normal and they have stopped all medications. Until the date of this article, none of them relapsed or need medicine. CONCLUSION: Our study suggests that AHSCT is safe and effective in treating refractory JDM, and it can provides long term drug-free survival. However, more cases are needed for further confirmation.


Assuntos
Dermatomiosite/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Indução de Remissão , Estudos Retrospectivos , Transplante Autólogo/métodos , Resultado do Tratamento
16.
J Am Chem Soc ; 140(49): 16920-16924, 2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30465423

RESUMO

Herein, we present a method for the preparation of supramolecular polymers with tunable fluorescence via the combination of metal-ligand coordination and phenanthrene-21-crown-7 (P21C7)-based host-guest interactions. A suite of rhomboidal metallacycles with different substituents were prepared via the coordination-driven self-assembly of a P21C7-based 60° diplatinum(II) acceptor and 120° dipyridyl donors. Upon variation of the substituents on the dipyridyl donors, the metallacycles exhibit emission wavelengths spanning the visible region (λmax = 427-593 nm). Metallacycle-cored supramolecular polymers were obtained via host-guest interactions between bis-ammonium salts and P21C7. The supramolecular polymers exhibit emission wavelengths similar to those of the individual metallacycles and higher fluorescent efficiency in solution and thin films. Utilizing a yellow-emitting supramolecular polymer thin film with high quantum yield (0.22), a white-light-emitting LED was fabricated by painting the thin film onto an ultraviolet LED. This study presents an efficient approach for tuning the properties of fluorescent supramolecular polymers and the potential of the metallacycle-cored supramolecular polymers as a platform for the fabrication of light-emitting materials with good processability and tunability.


Assuntos
Complexos de Coordenação/química , Éteres de Coroa/química , Corantes Fluorescentes/química , Fenantrenos/química , Polímeros/química , Benzilaminas/síntese química , Benzilaminas/química , Complexos de Coordenação/síntese química , Éteres de Coroa/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Estrutura Molecular , Fenantrenos/síntese química , Platina/química , Polímeros/síntese química , Solubilidade
17.
Mol Genet Genomic Med ; 6(6): 1157-1167, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30411541

RESUMO

BACKGROUND: The genetic etiology of nonsyndromic cleft lip with or without cleft palate (NSCL/P) has not been fully clarified to date. Epidermal growth factor receptor (EGFR) was reportedly involved in its biological establishment and regulation of cell migration during the embryonic stage. METHODS: We selected a super pathway of endocytic trafficking of EGFR and investigated the associations of single-nucleotide polymorphisms (SNPs) in the super pathway with the risk of NSCL/P by analyzing our published genome-wide association study (GWAS) data from 504 NSCL/P individuals and 455 controls. After the false discovery rate (FDR) control, we conducted linkage disequilibrium (LD) analyses and conditional regression analyses to obtain independent lead SNPs. We performed LD analyses between the lead SNPs and the reported SNPs to find novel ones from our study. We annotated the lead SNPs and investigated their mapped genes in silico. RESULTS: A total of 82 SNPs showed a statistical association with the risk of NSCL/P after FDR control. They contained three reported SNPs which were g.117068049G>A (rs7078160), g.117086783C>G (rs10886040), and g.117101266G>T (rs17095681). Four independent lead SNPs were obtained, including g.116979803 T>C (rs1905539) and g.117037960A>G (rs7902502) at 10q25.3, g.35720163G>C (rs75656820) at 17q12, and g.156864512G>A (rs1800877) at 1q23.1. Three of them were in low LD (r2  < 0.5) with the reported SNPs except g.117037960A>G (rs7902502), so these three were newly identified. Lead SNPs were mapped to three genes: SHTN1, AP2B1, and NTRK1. The three genes were relatively more highly expressed in the human craniofacial region and in the proximal maxillary location during the craniofacial development stage of the embryonic mouse. CONCLUSION: Our results suggested that SHTN1, AP2B1, and NTRK1 might be associated with the development of NSCL/P.


Assuntos
Subunidades beta do Complexo de Proteínas Adaptadoras/genética , Proteínas de Transporte/genética , Fenda Labial/genética , Fissura Palatina/genética , Polimorfismo de Nucleotídeo Único , Receptor trkA/genética , Estudos de Casos e Controles , Fenda Labial/patologia , Fissura Palatina/patologia , Humanos , Desequilíbrio de Ligação
18.
J Am Chem Soc ; 140(40): 12819-12828, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30212221

RESUMO

Cubic metallacages were arranged into multidimensional (one-, two-, and three-dimensional) suprastructures via multistep assembly. Four new shape-controllable, hybrid metallacages with modified substituents and tunable electronic properties were prepared using dicarboxylate ligands with various substituents (sodium sulfonate, nitro, methoxyl, and amine), tetra-(4-pyridylphenyl) ethylene, and cis-(PEt3)2Pt(OTf)2. The as-prepared metallacages were used as building blocks for further assembly. Diverse suprastructures with tunable emissions (λmax from 451 to 519 nm) and various substituents (-SO3Na, -NO2, -OCH3, and -NH2) were prepared depending on the substituents and solvents used.


Assuntos
Estruturas Metalorgânicas/química , Aminas/química , Ácidos Carboxílicos/química , Etilenos/química , Modelos Moleculares , Nitrocompostos/química , Piridinas/química , Ácidos Sulfônicos/química
19.
J Am Chem Soc ; 140(24): 7674-7680, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29856215

RESUMO

Herein, we report the preparation of a multifunctional metallacage-core supramolecular gel by orthogonal metal coordination and host-guest interactions. A tetragonal prismatic cage with four appended 21-crown-7 (21C7) moieties in its pillar parts was first prepared via the metal-coordination-driven self-assembly of cis-Pt(PEt3)2(OTf)2, tetraphenylethene (TPE)-based sodium benzoate ligands and linear dipyridyl ligands. Further addition of a bisammonium linker to the cage delivered a supramolecular polymer network via the host-guest interactions between the 21C7 moieties and ammonium salts, which formed a supramolecular gel at relatively higher concentrations. Due to the incorporation of a TPE derivative as the fluorophore, the gel shows emission properties. Multiple stimuli responsiveness and good self-healing properties were also observed because of the dynamic metal coordination and host-guest interactions used to stabilize the whole network structure. Moreover, the storage and loss moduli of the gel are 10-fold those of the gel without the metallacage cores, indicating that the rigid metallacage plays a significant role in enhancing the stiffness of the gel. The studies described herein not only enrich the functionalization of fluorescent metallacages via elegant ligand design but also provide a way to prepare stimuli-responsive and self-healing supramolecular gels as robust and smart materials.


Assuntos
Complexos de Coordenação/química , Géis/química , Substâncias Macromoleculares/química , Compostos Organoplatínicos/química , Polímeros/química , Compostos de Benzilideno/síntese química , Compostos de Benzilideno/química , Complexos de Coordenação/síntese química , Éteres de Coroa/síntese química , Éteres de Coroa/química , Fluorescência , Géis/síntese química , Substâncias Macromoleculares/síntese química , Compostos Organoplatínicos/síntese química , Polímeros/síntese química , Reologia
20.
J Am Chem Soc ; 140(24): 7723-7729, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29782153

RESUMO

The synthesis, characterization, and temperature-responsive properties of two fluorescent organoplatinum(II) metallacycles are reported. Metallacycles M1 and M2 were prepared via the coordination-driven self-assembly of a 120° triarylamine ligand L1 and a 120° diplatinum(II) acceptor Pt-1 or 180° diplatinum(II) acceptor Pt-2, respectively. M1 and M2 are hexagonal metallacycles, comprising of three or six freely rotating anthracene pendants on their periphery, respectively. In response to the temperature variation between -20 and 60 °C, the ligand displays irregular emission changes, whereas both metallacycles show reversible absorption and emission spectral changes in THF. The changes in their green emission intensity also exhibit a linear correlation with the temperature variation, with an average sensitivity of -0.67% and -0.77% per °C for M1 and M2, respectively. Furthermore, in coordinating solvents, such as DMF and CH3CN, M1 and M2 show different behaviors: in the lower temperature range, i.e., below 30 °C, their spectral changes are similar to those observed in THF; however, at a higher temperature the metallacycles were presumably destroyed by the solvents and displayed ratiometric fluorescent responses, including a cyan emission of the ligand L1.


Assuntos
Complexos de Coordenação/química , Corantes Fluorescentes/química , Compostos Organoplatínicos/química , Complexos de Coordenação/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Ligantes , Modelos Químicos , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Teoria Quântica , Solventes/química , Temperatura Ambiente
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