Doubly Spiro-Conjugated Chiral Carbocycles Exhibiting SOMO-HOMO Inversion in Persistent Radical Cations.

Persistent chiral organic open-shell systems have captured growing interest due to their potential applications in organic spintronic and optoelectronic devices. Nevertheless, the integration of configurationally stable chirality into an organic open-shell system continues to pose challenges in molecular design. The π-extended skeleton incorporated in spiro-conjugated carbocycles can provide robust chiroptical properties and a significant stabilization of the excited and ionic radical states. However, this approach has been relatively less explored in the design of persistent organic open-shell systems. We report here the (S,S)-, (R,R)-, and meso-isomers of doubly spiro-conjugated carbocycles featuring flat and rigid carbon-bridged para-phenylenevinylene (CPV) of different conjugation lengths connected by two spiro-carbon centers, which we denote D-spiro-CPV for its quasi-dimeric structure. Our synthetic method based on a double lithiation cyclization approach enables facile production of D-spiro-CPV. D-spiro-CPVs exhibit circularly polarized luminescence (CPL) with high fluorescence quantum yields (ΦFL) resulting in a high CPL brightness of 21 M-1 cm-1 and also exhibit high thermal and photostability. The monoradical cation of D-spiro-CPV absorbing near-infrared light is notably persistent, exhibiting a half-life of 570 h under ambient conditions due to doubly spiro-conjugative stabilization. Theoretical and electrochemical studies indicate the radical cation of D-spiro-CPVs presents a non-Aufbau electron filling, exhibiting inversion of the energy level of the singly occupied molecular orbital (SOMO) and the highest (doubly) occupied molecular orbitals with the SOMO level even below the HOMO-1 level (double SHI effect). Our discoveries provide valuable insights into non-Aufbau molecules and the development of configurationally stable, optically active persistent radicals.

Luminescence and Excited-State Reactivity in a Heteroleptic Tricyanido Fe(III) Complex.

Harnessing sunlight via photosensitizing molecules is key for novel optical applications and solar-to-chemical energy conversion. Exploiting abundant metals such as iron is attractive but becomes challenging due to typically fast nonradiative relaxation processes. In this work, we report on the luminescence and excited-state reactivity of the heteroleptic [FeIII(pzTp)(CN)3]- complex (pzTp = tetrakis(pyrazolyl)borate), which incorporates a σ-donating trispyrazolyl chelate ligand and three monodentate σ-donating and π-accepting cyanide ligands. Contrary to the nonemissive [Fe(CN)6]3-, a broad emission band centered at 600 nm at room temperature has been recorded for the heteroleptic analogue attributed to the radiative deactivation from a 2LMCT excited state with a luminescence quantum yield of 0.02% and a lifetime of 80 ps in chloroform at room temperature. Bimolecular reactivity of the 2LMCT excited state was successfully applied to different alcohol photo-oxidation, identifying a cyanide-H bonding as a key reaction intermediate. Finally, this research demonstrated the exciting potential of [Fe(pzTp)(CN)3]- as a photo-oxidant, paving the way for further exploration and development of emissive Fe-based photosensitizers competent for photochemical transformations.

C60-based Multivalent Glycoporphyrins Inhibit SARS-CoV-2 Specific Interaction with the DC-SIGN Transmembrane Receptor.

Since WHO has declared the COVID-19 outbreak a global pandemic, nearly seven million deaths have been reported. This efficient spread of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is facilitated by the ability of the spike glycoprotein to bind multiple cell membrane receptors. Although ACE2 is identified as the main receptor for SARS-CoV-2, other receptors could play a role in viral entry. Among others, C-type lectins such as DC-SIGN are identified as efficient trans-receptor for SARS-CoV-2 infection, so the use of glycomimetics to inhibit the infection through the DC-SIGN blockade is an encouraging approach. In this regard, multivalent nanostructures based on glycosylated [60]fullerenes linked to a central porphyrin scaffold have been designed and tested against DC-SIGN-mediated SARS-CoV-2 infection. First results show an outstanding inhibition of the trans-infection up to 90%. In addition, a deeper understanding of nanostructure-receptor binding is achieved through microscopy techniques, high-resolution NMR experiments, Quartz Crystal Microbalance experiments, and molecular dynamic simulations.

Drivers of flower visit and resource sharing between the honeybee and native bees in Neotropical coastal sand dunes.

The honeybee (Apis mellifera) is one of the most important pollinator species because it can gather resources from a vast variety of plant species, including both natives and introduced, across its geographical distribution. Although A. mellifera interacts with a large diversity of plants and shares resources with other pollinators, there are some plant species with which it interacts more frequently than others. Here, we evaluated the plant traits (i.e., plant length, abundance of bloomed individuals, number of open flowers, and stamen length) that would affect the honeybee visit frequencies to the flowers in a coastal environment in the Gulf of Mexico. Moreover, we evaluated which native bee species (and their body size) overlap floral resource with A. mellifera. We registered 998 plant-bee interactions between 35 plant species and 47 bee species. We observed that plant species with low height and with high abundances of bloomed individuals are positively related to a high frequency of visits by A. mellifera. Moreover, we found that A. mellifera tends to share a higher number of plant species with other bee species with a similar or smaller body size than with bigger species, which makes them a competitor for the resource with honeybees. Our results highlight that the impacts of A. mellifera on plants and native bees could be anticipated based on its individual's characteristics (i.e., plant height and abundance of bloomed individuals) and body size, respectively.

Additional Insights into the Design of Cr(III) Phosphorescent Emitters Using 6-Membered Chelate Ring Bis(imidazolyl) Didentate Ligands.

The interest in Cr(III) complexes has been renewed over the past decades for building practical guidelines in the design of efficient earth-abundant phosphorescent near-infrared emitters. In that context, we report the first family of homoleptic tri(didentate) Cr(III) complexes [CrL3]3+ based on polyaromatic ligands inducing 6-membered chelate rings, namely, the bis(1-methylimidazol-2-yl)ketone (L = bik), bis(1-methylimidazol-2-yl)methane (L = bim), and bis(1-methylimidazol-2-yl)ethane (L = bie) ligands. The programmed close-to-perfect octahedral microsymmetry of {CrIIIN6} chromophores found in [Cr(bik)3](OTf)3 (1), [Cr(bim)3](OTf)3 (2), and [Cr(bie)3](BF4)3 (3) ensures a ligand-field strength large enough to induce intense and long-lived Cr-based phosphorescence. Impressive excited-state lifetimes (5.0-8.2 ms) were obtained at low temperatures for the [Cr(L)3]3+ series. Additionally, the photoluminescent quantum yield climbs to 0.8% for compound 1 in deaerated solutions. Moreover, the photophysical features of the three homoleptic complexes are barely influenced by the presence of dioxygen presumably because of the poor overlap between the Cr-based phosphorescence spectra (ca. 14100 cm-1) and the 1Σg+ ← 3Σg- transition in the absorption spectrum of dioxygen (13100 cm-1). The multiredox electrochemical pattern of 1 is evidenced by cyclic voltammetry as well as its strong photooxidant behavior. The pH sensitivity of 2 and 3 luminescence is discussed, along with the reactivity of their ß-diketiminate derivatives.

Dehydration of alcohols catalyzed by copper(II) sulfate: type II dyotropic reactions and stepwise mechanisms.

Dehydration of alcohols in the presence of copper(II) sulfate has been analyzed computationally. Density functional theory (DFT) calculations on selected alcohols indicate that this reaction can take place via two possible mechanisms: (a) concerted - although asynchronous - type II dyotropic reactions, or (b) stepwise E1-like processes, in which cleavage of the C-O bond occurs in the first step, followed by syn proton elimination. Our calculations show the relationship between the initial alcohol structure and the preferred mechanism, which is a type II dyotropic reaction for primary alcohols, whereas a stepwise process is the favored one when stable carbocation intermediates are energetically accessible. The dehydration of dehydrolinalool (2,7-dimethyl-6-en-1-yn-3-ol, DHL) to yield different alkenes of interest in the fragrance industry is discussed as a case study of its regiochemistry.

Doxofylline as a steroid-sparing treatment in Mexican children with asthma.

OBJECTIVE: The aim of this pilot study was to assess the efficacy of doxofylline as an ICS-sparing agent in the treatment of Mexican children with asthma. METHODS: 10-week, open-label, crossover, pilot study, we examined the steroid-sparing effect of doxofylline in Mexican children with asthma. Patients aged 6-16 years treated with inhaled corticosteroids (ICS) for at least 8 wk before enrollment were divided randomly into two groups at the baseline visit. Group A (n = 31) received doxofylline (18 mg/kg/day) plus standard-dose budesonide (D + SDB) for the first 4-week period followed by doxofylline plus reduced-dose budesonide (D + RDB) for the second 4-week period. Group B (n = 30) received D + RDB followed by D + SDB. Clinical outcomes assessed included lung function (forced expiratory volume; in 1 s, FEV1), fractional exhaled nitric oxide (FeNO), asthma control, number of exacerbations and use of rescue medication (salbutamol). RESULTS: It was shown that combined use of doxofylline and ICS may allow children with asthma to reduce their daily dose of ICS while maintaining lung function and improving asthma control (p = 0.008). There were few asthma exacerbations and only one patient required treatment with systemic corticosteroids. Rescue medication use decreased significantly in patients receiving D + SDB during the first 4-week period. CONCLUSIONS: Our results suggest that doxofylline may be a steroid-sparing treatment in asthma, but longer-term, controlled studies are needed to confirm these observations.

Global patterns of raptor distribution and protected areas optimal selection to reduce the extinction crises.

Globally, human-caused environmental impacts, such as habitat loss, have seriously impacted raptor species, with some 50% of species having decreasing populations. We analyzed global patterns of distribution of all 557 raptor species, focusing on richness, endemism, geographic range, conservation status, and population trends. Highest species diversity, endemism, species at risk, or restricted species were concentrated in different regions. Patterns of species distribution greatly differed between nocturnal and diurnal species. To test the efficiency of the global protected areas in conserving raptors, we simulated and compared global reserve systems created with strategies aiming at: 1) constraining the existing system into the final solution; and 2) minimizing the socioeconomic cost of reserve selection. We analyzed three targets of species distribution to be protected (10, 20, 30%). The first strategy was more efficient in meeting targets and less efficient in cost and compactness of reserves. Focusing on actions in the existing protected areas is fundamental to consolidate conservation, and politically and economically more viable than creating new reserves. However, creating new reserves is essential to protect more populations throughout the species' geographic range. Our findings provide a fundamental understanding of reserves to maintain raptor diversity and reduce the global population and species extinction crisis.

A Novel Experimental Apparatus for Characterizing Flow Regime in Mechanically Stirred Tanks through Force Sensors.

Pressure fluctuations in a mixing tank can provide valuable information about the existing flow regime within the tank, which in turn influences the degree of mixing that can be achieved. In the present work, we propose a prototype for identifying the flow regime in mechanically stirred tanks equipped with four vertical baffles through the characterization of pressure fluctuations. Our innovative proposal is based on force sensors strategically placed in the baffles of the mixing tank. The signals coming from the sensors are transmitted to an electronic module based on an Arduino UNO development board. In the electronic module, the pressure signals are conditioned, amplified and sent via Bluetooth to a computer. In the computer, the signals can be plotted or stored in an Excel file. In addition, the proposed system includes a moving average filtering and a hierarchical bottom-up clustering analysis that can determine the real-time flow regime (i.e., the Reynolds number, Re) in which the tank was operated during the mixing process. Finally, to demonstrate the versatility of the proposed prototype, experiments were conducted to identify the Reynolds number for different flow regimes (static, laminar, transition and turbulent), i.e., 0≤Re≤ 42,955. Obtained results were in agreement with the prevailing consensus on the onset and developed from different flow regimes in mechanically stirred tanks.

Enantiopure [6]-Azairidahelicene by Dynamic Kinetic Resolution of a Configurationally Labile [4]-Helicene.

A pair of enantiopure [6]-azairidahelicenes incorporating chirality at the metal center and on the helicenic ligand were synthesized by dynamic kinetic resolution (dkr) of a configurationally labile [4]-helicenic ligand (4-(2-pyridyl)-benzo[g]phenanthrene, L1H) using bis-cyclometalated chiral-at-metal only iridium(III) precursors as chiral inductors. The origin of the observed dkr is attributed to the different conformation and stability of diastereomeric reaction intermediates formed during the cyclometalation process. The isolated enantiomers exhibited circularly polarized phosphorescence (CPP), with |gphos| values of 1.8×10-3.

π-Radical Cascade to a Chiral Saddle-Shaped Peropyrene.

Reactions of open-shell molecular graphene fragments are typically thought of as undesired decomposition processes because they lead to the loss of desired features like π-magnetism. Oxidative dimerization of phenalenyl to peropyrene shows, however, that these transformations hold promise as a synthetic tool for making complex structures via formation of multiple bonds and rings in a single step. Here, we explore the feasibility of using this "undesired" reaction of phenalenyl to build up strain and provide access to non-planar polycyclic aromatic hydrocarbons. To this end, we designed and synthesized a biradical system with two phenalenyl units linked via a biphenylene backbone. The design facilitates an intramolecular cascade reaction to a helically twisted saddle-shaped product, where the key transformations-ring-closure and ring-fusion-occur within one reaction. The negative curvature of the final peropyrene product, induced by the formed eight-membered ring, was confirmed by single-crystal X-ray diffraction analysis and the helical twist was validated via resolution of the product's enantiomers that display circularly polarized luminescence and high configurational stability.

Can Magnetic Dipole Transition Moment Be Engineered?

The development of chiral compounds with enhanced chiroptical properties is an important challenge to improve device applications. To that end, an optimization of the electric and magnetic dipole transition moments of the molecule is necessary. Nevertheless, the relationship between chemical structure and such quantum mechanical properties is not always clear. That is the case of magnetic dipole transition moment (m) for which no general trends for its optimization have been suggested. In this work we propose a general rationalization for improving the magnitude of m in different families of chiral compounds. Performing a clustering analysis of hundreds of transitions, we have been able to identify a single group in which |m| value is maximized along the helix axis. More interestingly, we have found an accurate linear relationship (up to R2 =0.994) between the maximum value of this parameter and the area of the inner cavity of the helix, thus resembling classical behavior of solenoids. This research provides a tool for the rationalized synthesis of compounds with improved chiroptical responses.

Neuromodulation as a Potential Disease-Modifying Therapy for Osteoarthritis.

PURPOSE OF REVIEW: The following review discusses the therapeutic potential of targeting the autonomic nervous system (ANS) for osteoarthritis (OA) treatment and encourages the field to consider the candidacy of bioelectronic medicine as a novel OA treatment strategy. RECENT FINDINGS: The study of OA pathogenesis has focused on changes occurring at the joint level. As such, treatments for OA have been aimed at the local joint environment, intending to resolve local inflammation and decrease pain. However, OA pathogenesis has shown to be more than joint wear and tear. Specifically, OA-related peripheral and central sensitization can prompt neuroplastic changes in the nervous system beyond the articular joint. These neuroplastic changes may alter physiologic systems, like the neuroimmune axis. In this way, OA and related comorbidities may share roots in the form of altered neuroimmune communication and autonomic dysfunction. ANS modulation may be able to modify OA pathogenesis or reduce the impact of OA comorbidities. Moreover, blocking chronic nociceptive drive from the joint may help to prevent maladaptive nervous system plasticity in OA.

A multicenter case-control study comparing sun exposure habits and use of photoprotection measures in patients diagnosed with different types of skin cancer.

BACKGROUND: While skin cancer awareness programs have significantly furthered public understanding about the harmful effects of the sun, there is a disparity between photoprotection knowledge and protection practices. OBJECTIVE: To compare sun exposure habits and photoprotection measures in patients diagnosed with basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma versus controls. METHODS: Multicentre case-control observational study carried out by 13 Spanish dermatologists between April 2020 and August 2022. Patients diagnosed with BCC, SCC, or melanoma were considered cases. The control group consisted of individuals with no history of skin cancer. RESULTS: Of the 254 cases (56.2% female; mean age, 62.67 ± 15.65), 119 (31.2%) had BCC, 62 (16.27%) SCC, and 73 (19.1%) melanoma. The control group consisted of 127 (33.33%) individuals. Avoiding sun exposure between 12:00 and 16:00 was the most commonly used photoprotection measure (habitually/always: 63.1%), followed by the use of sunscreen (habitually/always: 58.9%). Patients with melanoma were less likely to use clothing and shade to avoid sun exposure (p < .05), whereas those with BCC and SCC reported greater use of head coverings (p = .01). BCC and SCC groups reported greater sun exposure 15 years prior, whereas controls reported greater use of sunscreen. However, at the time of this study all groups reported using SPF ≥ 21, and the majority SPF > 50. No differences were observed in photoprotection measures between people with and without a previous history of skin cancer. CONCLUSIONS: We describe differences in photoprotection measures and sun exposure patterns among patients diagnosed with different skin tumor types. Whether these differences may influence the type of tumor each developed will require further investigation.

Hypersensitivity reactions to anticancer chemotherapy and monoclonal antibodies: Safety and efficacy of desensitization.

BACKGROUND: Hypersensitivity reactions to anticancer chemotherapy and monoclonal antibodies may lead to discontinuation of first-line treatment options. Identification of these reactions can provide specific diagnosis and treatment by rapid drug desensitizations. OBJECTIVE: To determine the hypersensitivity reactions involved in anticancer chemotherapy and monoclonal antibodies, and the safety and efficacy of rapid drug desensitization. METHODS: We conducted an observational study of hypersensitivity reaction presented after the administration of anticancer chemotherapy and monoclonal antibodies in Mexico. We documented the symptoms of initial reaction and their severity, and the results of skin tests. We also report our experience of the administration of 12-step (mild-moderate reactions) and 16-step (severe reactions) desensitization protocols in these patients. RESULTS: Overall, 93 patients received 336 rapid drug desensitization; 105 to taxanes, 115 to platinum drugs, 101 to monoclonal antibodies, and 15 other anticancer chemotherapy. Hypersensitivity reaction to taxanes occurred in the first or second administration, platinum drugs after the sixth cycle, and rituximab in the first cycle. The most common symptom in carboplatin was urticaria, paclitaxel back pain, oxaliplatin and docetaxel dyspnea, and in the monoclonal antibodies cardiovascular symptoms. Skin tests were positive in 75% of the carboplatin group, and only 16.7% in docetaxel. There was a rapid drug desensitization success rate of 99.4% and 85.7% did not present any related hypersensitivity reaction. CONCLUSION: The diagnosis of hypersensitivity reaction to anticancer chemotherapy and monoclonal antibodies offers a panorama in the management of oncological diseases. Our standardized desensitization protocol is safe and effective and can be reproduced in other centers to treat patients who need to maintain first-line treatment.

Interleukin-6 as a biomarker of hypersensitivity reactions in chemotherapeutics and monoclonal antibodies.

BACKGROUND: In recent years, a new type of immediate hypersensitivity reaction known as cytokine release began to emerge, and within this phenotype of reactions, interleukin-6 is the most frequently associated with the presence during drug administration. Chemotherapeutic agents (QT) and monoclonal antibodies. OBJECTIVE: Determine interleukin-6 levels in hypersensitivity reactions to QT and monoclonal antibodies. METHODS: Observational and prospective study that was carried out from March 1, 2021 to March 1, 2022 in a university hospital in northeastern Mexico. Symptoms, severity, interleukin-6 levels, and skin tests of hypersensitivity reaction were evaluated at QT and monoclonal antibodies. RESULTS: A total of 41 patients with oncological disease were included, the most frequent being ovarian cancer. Symptoms as initial hypersensitivity reaction were neuromuscular in taxanes and cutaneous in Platinums.41.5% presented elevation of interleukin-6, and it was found more frequently in presence of metastases. Positive skin tests were found more frequently in the carboplatin and doxorubicin groups. The most frequently presented phenotype was type I in paclitaxel, carboplatin, and doxorubicin, and mixed-reaction (type I and cytokine release) in oxaliplatin. CONCLUSION: With the increasing prevalence of hypersensitivity reactions to biologic and antineoplastic therapies, interleukin-6 should be recognized as a biomarker in immediate hypersensitivity reactions to QT and monoclonal antibodies.

Risk factors and clinical characteristics of acute and chronic cutaneous graft-versus-host disease in pediatric patients undergoing hematopoietic stem cell transplantation.

Acute and chronic cutaneous graft-versus-host disease (GVHD) are common complications following hematopoietic stem cell transplantation (HSCT) in pediatric patients. In this retrospective study, we explored the risk factors and clinical characteristics of acute and chronic cutaneous GVHD in a case series of children undergoing HSCT at a tertiary referral hospital. We found that 36% of acute cutaneous GVHD was severe and these patients were more likely to have an unrelated donor, and that children with acute cutaneous GVHD who progressed to chronic cutaneous GVHD had a higher proportion of malignant diseases, total body irradiation, and bronchiolitis obliterans compared to those who did not progress to chronic cutaneous GVHD. Our study highlights the importance of identifying and monitoring these high-risk patients to improve the clinical management and outcomes of cutaneous GVHD in pediatric HSCT recipients.

Insights into the Molecular Basis of Huanglongbing Tolerance in Persian Lime (Citrus latifolia Tan.) through a Transcriptomic Approach.

Huanglongbing (HLB) is a vascular disease of Citrus caused by three species of the α-proteobacteria "Candidatus Liberibacter", with "Candidatus Liberibacter asiaticus" (CLas) being the most widespread and the one causing significant economic losses in citrus-producing regions worldwide. However, Persian lime (Citrus latifolia Tanaka) has shown tolerance to the disease. To understand the molecular mechanisms of this tolerance, transcriptomic analysis of HLB was performed using asymptomatic and symptomatic leaves. RNA-Seq analysis revealed 652 differentially expressed genes (DEGs) in response to CLas infection, of which 457 were upregulated and 195 were downregulated. KEGG analysis revealed that after CLas infection, some DEGs were present in the plant-pathogen interaction and in the starch and sucrose metabolism pathways. DEGs present in the plant-pathogen interaction pathway suggests that tolerance against HLB in Persian lime could be mediated, at least partly, by the ClRSP2 and ClHSP90 genes. Previous reports documented that RSP2 and HSP90 showed low expression in susceptible citrus genotypes. Regarding the starch and sucrose metabolism pathways, some genes were identified as being related to the imbalance of starch accumulation. On the other hand, eight biotic stress-related genes were selected for further RT-qPCR analysis to validate our results. RT-qPCR results confirmed that symptomatic HLB leaves had high relative expression levels of the ClPR1, ClNFP, ClDR27, and ClSRK genes, whereas the ClHSL1, ClRPP13, ClPDR1, and ClNAC genes were expressed at lower levels than those from HLB asymptomatic leaves. Taken together, the present transcriptomic analysis contributes to the understanding of the CLas-Persian lime interaction in its natural environment and may set the basis for developing strategies for the integrated management of this important Citrus disease through the identification of blanks for genetic improvement.

A systematic review of measurement instruments for oral health assessment of older adults in long-term care facilities by nondental professionals.

BACKGROUND: Regular oral health assessment of older adults living in Long-term Care Facilities (LTCF) can improve their oral health. AIMS: This study aimed to systematically review studies describing the development of instruments employed by nondental professionals to assess the oral health of older adults in LTCF and to evaluate their measurement properties. MATERIAL & METHODS: Electronic searches were conducted in the MEDLINE (PubMed), Embase, Web of Science, Scopus, and LILACS databases. Measurement properties of the identified instruments were evaluated using the Consensus-based Standards to select health Measurement Instruments (COSMIN) checklist. Studies assessing at least one measurement property (validity, reliability, or responsiveness) of instruments used to assess oral health of older adults living in LTCF by nondental professionals were considered. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) checklist was used to evaluate the quality of evidence. RESULTS: Fifteen studies reporting measurement properties of seven instruments were selected. The ohr-interRAI and the OHAT were considered to have sufficient content validity, with high and moderate evidence quality, respectively. OHAT, BOHSE, and DHI showed acceptable results on reliability but with very low quality of evidence. DHI and OHSTNP also showed acceptable results for criterion validity, but, with low quality of evidence, insufficient or unclear results were observed for the remaining measurement properties. Studies evaluating the validity criteria of BOHSE and hypotheses testing of ohr-MDS were considered to have high evidence quality. DISCUSSION AND CONCLUSION: The ohr-interRAI can be provisionally recommended for use until further evidence is provided. Further methodologically rigorous studies are needed to assess the measurement properties of the existing instruments.

Heptagon-Containing Nanographene Embedded into [10]Cycloparaphenylene.

We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C60 and C70 , with remarkably large binding constants (ca. 107  M-1 ), as estimated by fluorescence measurements. Nanosecond and femtosecond spectroscopic analysis show that these host-guest complexes are capable of quasi-instantaneous charge separation upon photoexcitation, due to the ultrafast charge transfer from the macrocycle to the complexed fullerene. These results demonstrate saddle-shaped PAHs with dibenzocycloheptatrienone motifs as structural components for new macrocycles displaying molecular receptor abilities and versatile photochemical responses with promising electron-donor properties in host-guest complexes.