Reaching neutral territory: The title compound, the first tetrasubstituted deltahedral Zintl cluster, is no longer an ion (see picture; Ge green, Si purple, Sn blue). It is a neutral molecule formed ...by a reaction of the trisilylated anion with Ph3SnCl.
The π‐complexes of cationic coinage metal ions (Cu(I), Ag(I), Au(I)) provide useful experimental support for understanding fundamental characteristics of bonding and 13C‐NMR patterns of the group 11 ...triad. Here, we account for the role of relativistic effects on olefin‐coinage metal ion interaction for cationic, homoleptic tris‐ethylene, and tris‐norbornene complexes, M(η2‐C2H4)3+ and M(η2‐C7H10)3+ (M = Cu, Ag, Au), as representative case of studies. The M‐(CC) bond strength in the cationic, tris‐ethylene complexes is affected sizably for Au and to a lesser extent for Ag and Cu (48.6%, 16.7%, and 4.3%, respectively), owing to the influence on the different stabilizing terms accounting for the interaction energy in the formation of coinage metal cation‐π complexes. The bonding elements provided by olefin → M σ‐donation and olefin ← M π‐backbonding are consequently affected, leading to a lesser covalent interaction going down in the triad if the relativistic effects are ignored. Analysis of the 13C‐NMR tensors provides further understanding of the observed experimental values, where the degree of backbonding charge donation to π2*‐olefin orbital is the main influence on the observed high‐field shifts in comparison to the free olefin. This donation is larger for ethylene complexes and lower for norbornene counterparts. However, the bonding energy in the later complexes is slightly stabilized given by the enhancement in the electrostatic character of the interaction. Thus, the theoretical evaluation of metal‐alkene bonds, and other metal‐bonding situations, benefits from the incorporation of relativistic effects even in lighter counterparts, which have an increasing role going down in the group.
An increasing number of manufacturing companies have initiated designing and implementing AI systems in manufacturing, however, with limited success. Within our overarching research objective of ...establishing a methodology for the development of AI systems in manufacturing with socio-technical system consideration, this paper focuses on the early design phase of the development life cycle and aims to identify factors that are essential in the phase but whose importance has been less addressed in the manufacturing literature. To this aim, a case study was conducted adopting a design science approach. The case company was developing an ML-based anomaly detection system for a casting process. The researcher organised an AI system design workshop where participants from the company used the Human-AI design guidelines created by a leading large software company. The workshop enabled the participants to explore a wide range of design concerns. It, however, caused the confusing experience that they had to deal with too many questions simultaneously without clear guidance. Analysing this negative experience has led to identifying four design issues requiring further attention in the research. An example of these issues is that the interdependency of design decisions on operational procedures, human-machine interfaces, ML models, pre-processing, and input data makes it challenging to design these elements in isolation. The study found that a structured approach to dealing with the identified issues was currently lacking. This paper contributes to the manufacturing research community by addressing key unresolved issues in the research through highlighting practical details of designing AI systems in manufacturing.
Ions appear as active components in diverse materials. Here, the bonding energy between mechanically interlocked molecules (MIMs) or their acyclic/cyclic molecular derivatives and i) Cl− and Br− ions ...and/or ii) Na+ and K+ ions, have been investigated. The chemical environment provided by MIMs is less preferably to recognize ionic species compared to unconstrained interactions that are furnished by acyclic molecules. However, MIMs can be more adequate structures for ionic recognition than cyclic compounds if a chemical arrangement of the bond sites that relevantly support more favorable interactions with ions compared to Pauli repulsive ambient is provided. The hydrogen replacement by electron donor (−NH2) or acceptor (−NO2) groups in MIMs favors the anion/cation recognition due to decreased Pauli repulsion energy and/or more attractive non‐covalent bonds. This study clarifies the chemical environment provided by MIMs to interact with ions and highlights these molecules as relevant structures to realize ionic sensing.
Anions and cations develop several roles in nature. Thus, compounds capable to interact with ions show large relevancy. Mechanically interlocked molecules (MIMs) appear as potential candidates to perform efficient ionic recognition. Here, DFT calculations have been realized to elucidate and tune the MIM⋅⋅⋅(anion and/or cation) chemical bonds and compare them with the acyclic/cyclic molecular structures⋅⋅⋅(anion and/or cation) interactions.
Expanding the versatility of well‐defined clusters is a fundamental issue in the design of functional nanostructures. In this sense, the concept of super atoms allows us to gain a deeper ...understanding and rationalization of the different properties of metallic clusters by invoking more familiar aspects. Recently, the super atoms appear to be intimately connected to other relevant tools of great chemical significance which enhance a rational design of superatomic clusters mimicking more complex structures and networks. Here, we expect to account for the research efforts from Latin American groups in the field, highlighting their valuable contribution to superatomic and related clusters.
The concept of superatoms allows to gain a deeper understanding and rationalization of the different properties of metallic clusters by invoking more familiar considerations. Superatoms appear to be intimately connected to other relevant tools of great chemical significance which enhance a rational design of superatomic clusters mimicking more complex structures and networks. This review highlights the important efforts of researchers based in Latin America in this field.
Thallium(I) complexes of B-methylated and B-phenylated tris(pyridyl)borates featuring trifluoromethyl groups at the pyridyl ring 6-positions have been synthesized by metathesis using the ...corresponding potassium salts MeB(6-(CF3)Py)3K and PhB(6-(CF3)Py)3K with thallium(I) acetate. The closely related tris(pyrazolyl)borate analogue PhB(3-(CF3)Pz)3Tl has also been prepared, and comparisons of structural and spectroscopic features between the two scorpionate families are presented. MeB(6-(CF3)Py)3Tl displays κ3-coordination of the tris(pyridyl)borate similar to that of tris(pyrazolyl)borate in MeB(3-(CF3)Pz)3Tl, while PhB(6-(CF3)Py)3Tl and PhB(3-(CF3)Pz)3Tl feature κ2-N,N ligand coordination modes with the B-phenyl groups flanking the thallium sites. 19F NMR spectroscopy of MeB(6-(CF3)Py)3Tl reveals the presence of a remarkably large 1208 Hz four-bond thallium–fluorine coupling constant in chloroform at room temperature, which is considerably larger than 878 Hz observed for the pyrazolyl borate analogue MeB(3-(CF3)Pz)3Tl. Although PhB(6-(CF3)Py)3Tl is structurally nonrigid at room temperature in chloroform, at lower temperatures, the ligand arm exchange slows down, revealing 4 J Tl–F = 1110 Hz. Steric demands of these ligands have been quantified using the buried volume concept. In addition, ligand transfer chemistry from MeB(6-(CF3)Py)3Tl and PhB(6-(CF3)Py)3Tl to copper(I) under ethylene and computational analyses of the various coordination modes of tris(pyrazolyl)borates and tris(pyridyl)borates are reported.
Inorganic fullerene clusters have attracted widespread attention due to their highly symmetrical geometric structures and intrinsic electronic properties. However, cage-like clusters composed of ...heavy metal elements with high symmetry are rarely reported, and their synthesis is also highly challenging. In this study, we present the synthesis of a K2(Bi@Pd12@Bi20)4– cluster that incorporates a {Bi20} cage with pseudo-I h symmetry, making it the largest main group metal cluster compound composed of the bismuth element to date. Magnetic characterization and theoretical calculations suggest that the spin state of the overall cluster is a quartet. Quantum chemical calculations reveal that the Bi203– cluster has a similar electronic configuration to C60 6– and the Bi@Pd12@Bi206– cluster exhibits a unique open-shell aromatic character.
Rhodium(I) complexes bearing N‐heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry, but there are very few reports of biological properties of these organometallics. A ...series of RhI‐NHC derivatives with 1,5‐cyclooctadiene and CO as secondary ligands were synthesized, characterized, and biologically investigated as prospective antitumor drug candidates. Pronounced antiproliferative effects were noted for all complexes, along with moderate inhibitory activity of thioredoxin reductase (TrxR) and efficient binding to biomolecules (DNA, albumin). Biodistribution studies showed that the presence of albumin lowered the cellular uptake and confirmed the transport of rhodium into the nuclei. Changes in the mitochondrial membrane potential (MMP) were observed as well as DNA fragmentation in wild‐type and daunorubicin‐ or vincristine‐resistant Nalm‐6 leukemia cells. Overall, these studies indicated that RhI‐NHC fragments could be used as partial structures of new antitumor agents, in particular in those drugs designed to address resistant malignant tissues.
No resistance to special agents: Rhodium(I) N‐heterocyclic carbene (NHC) derivatives with 1,5‐cyclooctadiene (COD) and CO as secondary ligands were synthesized, characterized, and biologically investigated as prospective antitumor drug candidates. Pronounced antiproliferative effects were noted for all complexes, along with efficient binding to biomolecules. RhI‐NHC fragments could be used as partial structures of new antitumor agents, particularly in drugs designed to address daunorubicin‐ (DNR) and vincristine (VCR)‐resistant malignant tissues (see figure).
Synthetic exploration and theoretical characterization of metal clusters are actively developing branches of modern inorganic chemistry. Advances in these areas constantly expand the rich structural ...diversity of viable species, allowing a detailed study of the fundamental characteristics of bench‐stable compounds. In this minireview, we summarize recent achievements in synthesis and computational analyses of main‐group and heterometallic clusters containing multiple aromatic/antiaromatic units. These systems range from bare clusters to ligand‐decorated aggregates, providing a fundamental understanding of the aromaticity and antiaromaticity concepts in species exhibiting unprecedented shapes and composition. The review gives a comprehensive summary of bonding and magnetic response properties of such systems deciphered from the Adaptive Natural Density Partitioning (AdNDP) approach and induced magnetic field analyses.
Recent achievements in synthesis and computational analyses of main‐group and heterometallic clusters composed of multiple aromatic/antiaromatic units are reviewed. These examples, nicely provide a deeper understanding of the aromaticity and antiaromaticity concepts in species with unprecedented shapes and composition. The review focuses on bonding and magnetic response properties deciphered by the Adaptive Natural Density Partitioning (AdNDP) and induced magnetic field analyses.
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