Tin-Chelated Trisphosphineoxide Scorpionate Rare-Earth Porphyrinate Complexes: Synthesis and Photophysical Properties.

A series of seven-coordinated monoporphyrinate rare-earth(III) complexes featuring a novel tripodal tin-chelated trisphosphineoxide scorpionate ligand with the general formula [(TPP)Ln(PPhO)Sn] (Ln = Y, La, Dy, Er, Ho, Yb; TPP = 5,10,15,20-tetraphenylporphyrinate) were synthesized by reactions of the potassium tripodal scorpionate ligand [Sn(PPhO)K] with porphyrinate rare-earth metal chlorides [(TPP)LnCl(dme)] (Ln = Y, Dy, Er, Ho, Yb) or porphyrinate lanthanum borohydride [(TPP)LaBH(thf)]. The complexes were characterized by single-crystal X-ray diffraction, NMR spectroscopy, and ion mobility mass spectrometry. All complexes emit weak red TPP-based fluorescence, accompanied by near-infrared emission of Er, Ho (rather weak), and Yb (relatively intense with a quantum yield of 1% in dichloromethane solution) of the corresponding complexes.

Lanthanide chloride clusters, LnCl, = 1-6: an ion mobility and DFT study of isomeric structures and interconversion timescales.

Ion mobility spectrometry (IMS) (also including IMS-IMS measurements) as well as DFT calculations have been used to study isomer distributions and isomer interconversion in a range of electrospray-generated lanthanide chloride cluster anions, LnCl (where = 1-6, and Ln corresponds to the 15 lanthanide elements (except for radioactive Pm)). Where measurement and structural rearrangement timescales allow, we obtain almost quantitative agreement between experiment and theory thus confirming isomer predictions and reproducing isomer intensity ratios. LnCl structures reflect strong ionic bonding with limited directionality.

When feedback backfires: Knowledge of results can impair cognitive strategy choice.

Frequently, problems can be solved in more than one way. In modern computerised environments, more ways than ever exist. Naturally, human problem solvers do not always decide for the best-performing strategy available.

Revisiting the structure of [PdAu9(PPh3)8(CN)]2+ produced by atmospheric pressure plasma irradiation of [PdAu8(PPh3)8]2+ in methanol.

Some of the authors of the present research group have previously reported mass spectrometric detection of [PdAu9(PPh3)8(CN)]2+ (PdAu9CN) by atmospheric pressure plasma (APP) irradiation of [MAu8(PPh3)8]2+ (PdAu8) in methanol and proposed based on density functional theory (DFT) calculations that PdAu9CN is constructed by inserting a CNAu or NCAu unit into the Au-PPh3 bond of PdAu8 [Emori et al., J. Chem.

Switching between different cognitive strategies induces switch costs as evidenced by switches between manual and mental object rotation.

Switching between tasks entails costs when compared to repeating the same task. It is unclear whether switch costs also occur when repeating the same task but switching the underlying cognitive strategy (CS). Here, we investigated whether CS switch costs exist despite overlap in mental processing between CSs and a lack of abstract goal (always "solve task X") or answer key binding switches.

Cyclic ion mobility of doped [MAuL] superatoms and their fragments (M = Ni, Pd and Pt; L = alkynyl).

Collision-induced dissociation and high-resolution cyclic ion mobility mass spectrometry, along with quantum chemical calculations and trajectory simulations, were used to compare the structures of isolated [MAu(CCR)], M = Ni, Pd, or Pt, and their associated fragment ions. The three different alkynyl ligand-stabilized (CCR, R = 3,5-(CF)CH), transition metal-doped, gold cluster dianions showed mutually resolvable collision cross sections (CCS), which were ordered consistently with their molecular structures from X-ray crystallography. All three [MAu(CCR)] species fragment by sequential diyne loss to form [MAu(CCR)], with up to 12.

Overreliance on inefficient computer-mediated information retrieval is countermanded by strategy advice that promotes memory-mediated retrieval.

With ubiquitous computing, problems can be solved using more strategies than ever, though many strategies feature subpar performance. Here, we explored whether and how simple advice regarding when to use which strategy can improve performance. Specifically, we presented unfamiliar alphanumeric equations (e.

Tailoring Vacancy Defects in Isolated Atomically Precise Silver Clusters through Mercury-Doped Intermediates.

Vacancy defects are known to have significant effects on the physical and chemical properties of nanomaterials. However, the formation and structural dynamics of vacancy defects in atomically precise coinage metal clusters have hardly been explored due to the challenges associated with isolation of such defected clusters. Herein, we isolate [Ag(BDT)] (BDT is 1,3-benzenedithiol), a cluster with a "missing atom" site compared to [Ag(BDT)], whose precise structure is known from X-ray diffraction.

Perseveration on cognitive strategies.

To acquire and process information, performers can frequently rely on both internal and extended cognitive strategies. However, after becoming acquainted with two strategies, performers in previous studies exhibited a pronounced behavioral preference for just one strategy, which we refer to as perseveration. What is the origin of such perseveration? Previous research suggests that a prime reason for cognitive strategy choice is performance: Perseveration could reflect the preference for a superior strategy as determined by accurately monitoring each strategy's performance.

Perceptual discrimination in the face perception of robots is attenuated compared to humans.

When interacting with groups of robots, we tend to perceive them as a homogenous group where all group members have similar capabilities. This overgeneralization of capabilities is potentially due to a lack of perceptual experience with robots or a lack of motivation to see them as individuals (i.e.

Primacy Effects in Extended Cognitive Strategy Choice: Initial Speed Benefits Outweigh Later Speed Benefits.

Background: Human performers often recruit environment-based assistance to acquire or process information, such as relying on a smartphone app, a search engine, or a conversational agent. To make informed choices between several of such extended cognitive strategies, performers need to monitor the performance of these options.

Objective: In the present study, we investigated whether participants monitor an extended cognitive strategy's performance-here, speed-more closely during initial as compared to later encounters.

Elucidating the Structures of Intermediate Fragments during Stepwise Dissociation of Monolayer-Protected Silver Clusters.

Fragmentation dynamics of ligated coinage metal clusters reflects their structural and bonding properties. So far methodological challenges limited probing structures of the fragments. Herein, we resolve the geometric structures of the primary fragments of [Ag L ] , i.

Exploring Isomerism in Isolated Cyclodextrin Oligomers through Trapped Ion Mobility Mass Spectrometry.

Cyclodextrin (CD) macrocycles are used to create a wide range of supramolecular architectures which are also of interest in applications such as selective gas adsorption, drug delivery, and catalysis. However, predicting their assemblies and identifying the possible isomers in CD oligomers have always remained challenging due to their dynamic nature. Herein, we interacted CDs (α, β, and γ) with a divalent metal ion, Cu, to create a series of Cu-linked CD oligomers, from dimers to pentamers.

Quantitation of Enantiomeric Excess in an Achiral Environment Using Trapped Ion Mobility Mass Spectrometry.

We present a novel, straightforward method to determine the enantiomeric excess (ee) of tryptophan (Trp) and --butyloxycarbonyl--benzylserine (BBS) solutions without chiral additives. For this, lithium carbonate, sodium carbonate, or silver acetate was added to solutions of Trp or BBS. Singly negatively charged dimer and trimer clusters were then formed by electrospray ionization and analyzed using trapped ion mobility spectrometry (TIMS) and time-of-flight mass spectrometry.

The verb-self link: An implicit association test study.

Agency is defined as the ability to assign and pursue goals. Given people's focus on achieving their own goals, agency has been found to be strongly linked to the self. In two studies (N = 168), we examined whether this self-agency link is visible from a linguistic perspective.

Ion Mobility Studies of Pyrroloquinoline Quinone Aza-Crown Ether-Lanthanide Complexes.

Lanthanide-dependent enzymes and their biomimetic complexes have arisen as an interesting target of research in the past decade. These enzymes, specifically, pyrroloquinoline quinone (PQQ)-bearing methanol dehydrogenases, efficiently convert alcohols to the respective aldehydes. To rationally design bioinspired alcohol dehydrogenation catalysts, it is imperative to understand the species involved in catalysis.

Anionic Stacks of Alkali-Interlinked Yttrium and Dysprosium Bicyclooctatetraenes in Isolation.

Electrospray ionization of THF solutions of preformed [K(18-c-6)][M(COT)] (M = Dy(III), Y(III); COT = CH,18-c-6 = CHO) yields the isolated species [(M(COT)) + K] with = 0-3. High-resolution ion mobility spectrometry combined with density functional theory calculations performed for the = 0-2 aggregates indicate that anionic multidecker stacks interlinked by potassium cations are formed. The alternating metal ions are aligned linearly: COT-M-COT-K-COT-M-COT.

Metal-to-Metal Distance Modulated Au(I)/Ru(II) Cyclophanyl Complexes: Cooperative Effects in Photoredox Catalysis.

The modular synthesis of Au(I)/Ru(II) decorated mono- and heterobimetallic complexes with π-conjugated [2.2]paracyclophane is described. [2.

Intrinsic Structure and Electronic Spectrum of Deprotonated Biliverdin: Cryogenic Ion Spectroscopy and Ion Mobility.

We investigated the structural and spectroscopic properties of singly deprotonated biliverdin anions , using a combination of cryogenic ion spectroscopy, ion mobility spectrometry, and density functional theory. The ion mobility results show that at least two conformers are populated, with the dominant conformer at 75-90% relative abundance. The vibrational NH stretching signatures are sensitive to the tetrapyrrole structure, and they indicate that the tetrapyrrole system is in a helical conformation, consistent with simulated ion mobility collision cross sections.

On the Hydrogen Oxalate Binding Motifs onto Dinuclear Cu and Ag Metal Phosphine Complexes.

We report the binding geometries of the isomers that are formed when the hydrogen oxalate ((CO ) H=HOx) anion attaches to dinuclear coinage metal phosphine complexes of the form [M M dcpm (HOx)] with M=Cu, Ag and dcpm=bis(dicyclohexylphosphino)methane, abbreviated [MM] . These structures are established by comparison of isomer-selective experimental vibrational band patterns displayed by the cryogenically cooled and N -tagged cations with DFT calculations of the predicted spectra for various local minima. Two isomeric classes are identified that feature either attachment of the carboxylate oxygen atoms to the two metal centers (end-on docking) or attachment of oxygen atoms on different carbon atoms asymmetrically to the metal ions (side-on docking).

Novel Cofacial Porphyrin-Based Homo- and Heterotrimetallic Complexes of Transition Metals.

We present a straightforward and generally applicable synthesis route for cofacially linked homo- and heterotrimetallic trisporphyin complexes. The protocol encompasses synthesising the first aryl-based, trans-o-phenylene trisporphyrin starting from pyrrole and benzaldehyde with an overall yield of 3.6 %.

Kinetics of Intercluster Reactions between Atomically Precise Noble Metal Clusters [Ag(DMBT)] and [Au(PET)] in Room Temperature Solutions.

The kinetics of intercluster metal atom exchange reactions between solvated [Ag(DMBT)] and [Au(PET)] (DMBT and PET are 2,4-dimethylbenzenethiol and 2-phenylethanethiol, respectively, both CHS) were probed by electrospray ionization mass spectrometry and computer-based modeling. Anion mass spectra and collision induced dissociation (CID) measurements show that both cluster monomers and dimers are involved in the reactions. We have modeled the corresponding kinetics assuming a reaction mechanism in which metal atom exchange occurs through transient dimers.

Pyrroloquinoline Quinone Aza-Crown Ether Complexes as Biomimetics for Lanthanide and Calcium Dependent Alcohol Dehydrogenases*.

Understanding the role of metal ions in biology can lead to the development of new catalysts for several industrially important transformations. Lanthanides are the most recent group of metal ions that have been shown to be important in biology, that is, in quinone-dependent methanol dehydrogenases (MDH). Here we evaluate a literature-known pyrroloquinoline quinone (PQQ) and 1-aza-15-crown-5 based ligand platform as scaffold for Ca , Ba , La and Lu biomimetics of MDH and we evaluate the importance of ligand design, charge, size, counterions and base for the alcohol oxidation reaction using NMR spectroscopy.

A Synthetic Strategy for Cofacial Porphyrin-Based Homo- and Heterobimetallic Complexes.

We present a straightforward and generally applicable synthesis route for cofacially linked homo- and heterobimetallic porphyrin complexes. The protocol allows the synthesis of unsymmetrical aryl-based meso-meso as well as β-meso-linked porphyrins. Our method significantly increases the overall yield for the published compound known as o-phenylene-bisporphyrin (OBBP) by a factor of 6.

Expanded Cyclotetrabenzoins.

Cyclobenzoins are shape-persistent macrocycles of interest in the preparation of optoelectronic and porous materials. New cyclotetrabenzoins derived from biphenyl, naphthalene, and tolane skeletons were synthesized using -heterocyclic carbene-catalyzed benzoin condensation. Their preparation proceeded with different regioselectivity than that observed in the cyanide-catalyzed preparation of the parent cyclotetrabenzoin.