Nonadiabatic Charge Transfer within Photoexcited Nickel Porphyrins.

Metalloporphyrins with open d-shell ions can drive biochemical energy cycles. However, their utilization in photoconversion is hampered by rapid deactivation. Mapping the relaxation pathways is essential for elaborating strategies that can favorably alter the charge dynamics through chemical design and photoexcitation conditions. Here, we combine transient optical absorption spectroscopy and transient X-ray emission spectroscopy with femtosecond resolution to probe directly the coupled electronic and spin dynamics within a photoexcited nickel porphyrin in solution. Measurements and calculations reveal that a state with charge-transfer character mediates the formation of the thermalized excited state, thereby advancing the description of the photocycle for this important representative molecule. More generally, establishing that intramolecular charge-transfer steps play a role in the photoinduced dynamics of metalloporphyrins with open d-shell sets a conceptual ground for their development as building blocks capable of boosting nonadiabatic photoconversion in functional architectures through "hot" charge transfer down to the attosecond time scale.

On the identity of Pardosa consimilis Nosek, 1905 with a first description of the male and notes on two related species (Araneae: Lycosidae).

More than a hundred years after its description in 1905, the wolf spider Pardosa consimilis Nosek, 1905 was known solely from the original description of a single female, the holotype. In the last decade there were reports of the species from Bulgaria. Several reports followed with possible records of the yet-unknown males but they were not described; these came from four countries at least: North Macedonia, Georgia, Albania and most recently from Iran. Pardosa consimilis belongs to the monticola group and can be assigned to separate albatula-complex. The aim of this article is to provide a description for the male of Pardosa consimilis for the first time and to redescribe the female, in comparison with its closest congeners P. albatula (Roewer, 1951) and P. blanda (C. L. Koch, 1833).

New taxonomic and faunistic data on the genus Zodarion Walckenaer, 1826 (Araneae: Zodariidae) in the Balkans, with the descriptions of two new species.

Two new species, Zodarion emilijae sp. n. () from North Macedonia and Z. weissi sp. n. () from Bulgaria are described and illustrated, and new taxonomic and faunistic data for six species, namely Z. blagoevi Bosmans, 2009, Z. epirense Brignoli, 1984, Z. konradi Bosmans, 2009, Z. rubidum Simon, 1914, Z. scutatum Wunderlich, 1980 and Z. zorba Bosmans, 2009 are presented. Five species are removed from the Bulgarian, the Greek or the North Macedonian checklists as doubtful, erroneous or definitely incorrectly identified records: Zodarion epirense Brignoli, 1984, Z. evvoia Bosmans, 2009, Z. germanicum (C. L. Koch, 1837), Z. graecum (C. L. Koch, 1843) and Z. italicum (Canestrini, 1868).

Fifty spider species new to the Bulgarian fauna, with a review of some dubious species (Arachnida: Araneae).

This study is a part of an ongoing comprehensive inventory of Bulgarian spiders. A total of fifty spider species belonging to thirteen families are reported for the first time from Bulgaria. Four species are rejected from the Bulgarian spider checklist due to misidentification: Callilepis concolor Simon, 1914, Centromerus capucinus (Simon, 1884), Hoplopholcus labyrinthi (Kulczynski, 1903) and Mansuphantes prope fragilis (Thorell, 1875). Another four species (Drassodes villosus (Thorell, 1856), Entelecara flavipes (Blackwall, 1834), Lepthyphantes notabilis Kulczynski, 1887 and Singa semiatra L. Koch, 1867) are rejected after a new interpretation of the locations. Six species were omitted from the list of Bulgarian spiders as obviously doubtful records (Dysdera nicaeensis Thorell, 1873, Haplodrassus rufipes (Lucas, 1846), Harpactea hispana (Simon, 1882), Macaroeris cata (Blackwall, 1867), Nomisia celerrima (Simon, 1914) and Tenuiphantes monachus (Simon, 1884)). A new synonymy is proposed for Cyclosa strandjae Drensky, 1915 (= Cyclosa sierrae Simon, 1870 syn. nov.). In addition, new images with essential taxonomic value are provided for twenty-five species to facilitate their identification or to illustrate their intraspecific variability. To ensure correct identification, DNA barcoding was additionally used in some species.

Catalytic Oxygenation of Hydrocarbons by Mono-µ-oxo Dicopper(II) Species Resulting from O-O Cleavage of Tetranuclear CuI /CuII Peroxo Complexes.

One of the challenges of catalysis is the transformation of inert C-H bonds to useful products. Copper-containing monooxygenases play an important role in this regard. Here we show that low-temperature oxygenation of dinuclear copper(I) complexes leads to unusual tetranuclear, mixed-valent µ4 -peroxo [CuI /CuII ]2 complexes. These Cu4 O2 intermediates promote irreversible and thermally activated O-O bond homolysis, generating Cu2 O complexes that catalyze strongly exergonic H-atom abstraction from hydrocarbons, coupled to O-transfer. The Cu2 O species can also be produced with N2 O, demonstrating their capability for small-molecule activation. The binding and cleavage of O2 leading to the primary Cu4 O2 intermediate and the Cu2 O complexes, respectively, is elucidated with a range of solution spectroscopic methods and mass spectrometry. The unique reactivities of these species establish an unprecedented, 100 % atom-economic scenario for the catalytic, copper-mediated monooxygenation of organic substrates, employing both O-atoms of O2 .

Exploring the light-induced dynamics in solvated metallogrid complexes with femtosecond pulses across the electromagnetic spectrum.

Oligonuclear complexes of d4-d7 transition metal ion centers that undergo spin-switching have long been developed for their practical role in molecular electronics. Recently, they also have appeared as promising photochemical reactants demonstrating improved stability. However, the lack of knowledge about their photophysical properties in the solution phase compared to mononuclear complexes is currently hampering their inclusion into advanced light-driven reactions. In the present study, the ultrafast photoinduced dynamics in a solvated [2 × 2] iron(II) metallogrid complex are characterized by combining measurements with transient optical-infrared absorption and x-ray emission spectroscopy on the femtosecond time scale. The analysis is supported by density functional theory calculations. The photocycle can be described in terms of intra-site transitions, where the FeII centers in the low-spin state are independently photoexcited. The Franck-Condon state decays via the formation of a vibrationally hot high-spin (HS) state that displays coherent behavior within a few picoseconds and thermalizes within tens of picoseconds to yield a metastable HS state living for several hundreds of nanoseconds. Systematic comparison with the closely related mononuclear complex [Fe(terpy)2]2+ reveals that nuclearity has a profound impact on the photoinduced dynamics. More generally, this work provides guidelines for expanding the integration of oligonuclear complexes into new photoconversion schemes that may be triggered by ultrafast spin-switching.

Modulating Charge-Carrier Dynamics in Mn-Doped All-Inorganic Halide Perovskite Quantum Dots through the Doping-Induced Deep Trap States.

Transition-metal ion doping has been demonstrated to be effective for tuning the photoluminescence properties of perovskite quantum dots (QDs). However, it would inevitably introduce defects in the lattice. As the Mn concentration increases, the Mn dopant photoluminescence quantum yield (PLQY) first increases and then decreases. Herein the influence of the dopant and the defect states on the photophysics in Mn-doped CsPbCl3 QDs was studied by time-resolved spectroscopies, whereas the energy levels of the possible defect states were analyzed by density functional theory calculations. We reveal the formation of deep interstitials defects (Cli) by Mn2+ doping. The depopulation of initial QD exciton states is a competition between exciton-dopant energy transfer and defect trapping on an early time scale (<100 ps), which determines the final PLQY of the QDs. The present work establishes a robust material optimization guideline for all of the emerging applications where a high PLQY is essential.

Exceptional Substrate Diversity in Oxygenation Reactions Catalyzed by a Bis(µ-oxo) Copper Complex.

The enzyme tyrosinase contains a reactive side-on peroxo dicopper(II) center as catalytically active species in C-H oxygenation reactions. The tyrosinase activity of the isomeric bis(µ-oxo) dicopper(III) form has been discussed controversially. The synthesis of bis(µ-oxo) dicopper(III) species [Cu2 (µ-O)2 (L1)2 ](X)2 ([O1](X)2 , X=PF6 - , BF4 - , OTf- , ClO4 - ), stabilized by the new hybrid guanidine ligand 2-{2-((dimethylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (L1), and its characterization by UV/Vis, Raman, and XAS spectroscopy, as well as cryo-UHR-ESI mass spectrometry, is described. We highlight selective oxygenation of a plethora of phenolic substrates mediated by [O1](PF6 )2 , which results in mono- and bicyclic quinones and provides an attractive strategy for designing new phenazines. The selectivity is predicted by using the Fukui function, which is hereby introduced into tyrosinase model chemistry. Our bioinspired catalysis harnesses molecular dioxygen for organic transformations and achieves a substrate diversity reaching far beyond the scope of the enzyme.

Revealing Hot and Long-Lived Metastable Spin States in the Photoinduced Switching of Solvated Metallogrid Complexes with Femtosecond Optical and X-ray Spectroscopies.

An atomistic understanding of the photoinduced spin-state switching (PSS) within polynuclear systems of d4-d7 transition metal ion complexes is required for their rational integration into light-driven reactions of chemical and biological interest. However, in contrast to mononuclear systems, the multidimensional dynamics of the PSS in solvated molecular arrays have not yet been elucidated due to the expected complications associated with the connectivity between the metal centers and the strong interactions with the surroundings. In this work, the PSS in a solvated triiron(II) metallogrid complex is characterized using transient optical absorption and X-ray emission spectroscopies on the femtosecond time scale. The complementary measurements reveal the photoinduced creation of energy-rich (hot) and long-lived quintet states, whose dynamics differ critically from their mononuclear congeners. This finding opens major prospects for developing novel schemes in solution-phase spin chemistry that are driven by the dynamic PSS process in compact oligometallic arrays.

Description of Titanoeca deltshevi sp. n. from Bulgaria with faunistic notes on related species in the Balkans (Araneae, Titanoecidae).

Titanoeca deltshevi sp. n. is described and illustrated from Bulgaria. It appears closely related to T. praefica (Simon, 1870), T. spominima (Taczanowski, 1866) and partially (males only) to T. flavicoma L. Koch, 1872. A faunistic synopsis of the genus Titanoeca Thorell, 1870 in Bulgaria is also presented that is based on new field data and a review of the published literature. Titanoeca flavicoma is newly recorded for Bulgaria and T. turkmenia Wunderlich, 1995 is new for Bulgaria and Albania. Titanoeca incerta (Nosek, 1905) is removed from the Bulgarian, and therefore from the European spider checklists. The possible division of the European members of Titanoeca into three groups based on differences in copulatory and somatic traits is discussed.

Continental data on cave-dwelling spider communities across Europe (Arachnida: Araneae).

BACKGROUND: Spiders (Arachnida: Araneae) are widespread in subterranean ecosystems worldwide and represent an important component of subterranean trophic webs. Yet, global-scale diversity patterns of subterranean spiders are still mostly unknown. In the frame of the CAWEB project, a European joint network of cave arachnologists, we collected data on cave-dwelling spider communities across Europe in order to explore their continental diversity patterns. Two main datasets were compiled: one listing all subterranean spider species recorded in numerous subterranean localities across Europe and another with high resolution data about the subterranean habitat in which they were collected. From these two datasets, we further generated a third dataset with individual geo-referenced occurrence records for all these species. NEW INFORMATION: Data from 475 geo-referenced subterranean localities (caves, mines and other artificial subterranean sites, interstitial habitats) are herein made available. For each subterranean locality, information about the composition of the spider community is provided, along with local geomorphological and habitat features. Altogether, these communities account for > 300 unique taxonomic entities and 2,091 unique geo-referenced occurrence records, that are made available via the Global Biodiversity Information Facility (GBIF) (Mammola and Cardoso 2019). This dataset is unique in that it covers both a large geographic extent (from 35° south to 67° north) and contains high-resolution local data on geomorphological and habitat features. Given that this kind of high-resolution data are rarely associated with broad-scale datasets used in macroecology, this dataset has high potential for helping researchers in tackling a range of biogeographical and macroecological questions, not necessarily uniquely related to arachnology or subterranean biology.

Local- versus broad-scale environmental drivers of continental ß-diversity patterns in subterranean spider communities across Europe.

Macroecologists seek to identify drivers of community turnover (ß-diversity) through broad spatial scales. However, the influence of local habitat features in driving broad-scale ß-diversity patterns remains largely untested, owing to the objective challenges of associating local-scale variables to continental-framed datasets. We examined the relative contribution of local- versus broad-scale drivers of continental ß-diversity patterns, using a uniquely suited dataset of cave-dwelling spider communities across Europe (35-70° latitude). Generalized dissimilarity modelling showed that geographical distance, mean annual temperature and size of the karst area in which caves occurred drove most of ß-diversity, with differential contributions of each factor according to the level of subterranean specialization. Highly specialized communities were mostly influenced by geographical distance, while less specialized communities were mostly driven by mean annual temperature. Conversely, local-scale habitat features turned out to be meaningless predictors of community change, which emphasizes the idea of caves as the human accessible fraction of the extended network of fissures that more properly represents the elective habitat of the subterranean fauna. To the extent that the effect of local features turned to be inconspicuous, caves emerge as experimental model systems in which to study broad biological patterns without the confounding effect of local habitat features.

Structural dynamics upon photoexcitation-induced charge transfer in a dicopper(i)-disulfide complex.

The structural dynamics of charge-transfer states of nitrogen-ligated copper complexes has been extensively investigated in recent years following the development of pump-probe X-ray techniques. In this study we extend this approach towards copper complexes with sulfur coordination and investigate the influence of charge transfer states on the structure of a dicopper(i) complex with coordination by bridging disulfide ligands and additionally tetramethylguanidine units [CuI2(NSSN)2]2+. In order to directly observe and refine the photoinduced structural changes in the solvated complex we applied picosecond pump-probe X-ray absorption spectroscopy (XAS) and wide-angle X-ray scattering (WAXS). Additionally, the ultrafast evolution of the electronic excited states was monitored by femtosecond transient absorption spectroscopy in the UV-Vis probe range. DFT calculations were used to predict molecular geometries and electronic structures of the ground and metal-to-ligand charge transfer states with singlet and triplet spin multiplicities, i.e. S0, 1MLCT and 3MLCT, respectively. Combining these techniques we elucidate the electronic and structural dynamics of the solvated complex upon photoexcitation to the MLCT states. In particular, femtosecond optical transient spectroscopy reveals three distinct timescales of 650 fs, 10 ps and >100 ps, which were assigned as internal conversion to the ground state (Sn → S0), intersystem crossing 1MLCT → 3MLCT, and subsequent relaxation of the triplet to the ground state, respectively. Experimental data collected using both X-ray techniques are in agreement with the DFT-predicted structure for the triplet state, where coordination bond lengths change and one of the S-S bridges is cleaved, causing the movement of two halves of the molecule relative to each other. Extended X-ray absorption fine structure spectroscopy resolves changes in Cu-ligand bond lengths with precision on the order of 0.01 Å, whereas WAXS is sensitive to changes in the global shape related to relative movement of parts of the molecule. The results presented herein widen the knowledge on the electronic and structural dynamics of photoexcited copper-sulfur complexes and demonstrate the potential of combining the pump-probe X-ray absorption and scattering for studies on photoinduced structural dynamics in copper-based coordination complexes.

Faunistic diversity of spiders (Araneae) in Galichitsa mountain (FYR Macedonia).

A total of 294 species from 31 families have been found in Galichitsa Mt. Of them, 85 species are new to the mountain, while 20 are also new to the fauna of FYR of Macedonia. According to their current distribution the established species can be assigned to 17 zoogeographical categories, grouped into 5 complexes (Cosmopolitan, Holarctic, European, Mediterranean, Endemics of Balkans). Dominant are Holarctic species (66.0%) followed by European (16.5%) and Mediterranean (9.3%). The endemics (6.2%) and Southeast European species (1.7%) emphasize the local character of this fauna, but its low percentage suggests an important process of colonization.