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(E)-6-Methoxy-1-methyl-3-(2-(3-methyl-4-nitroisoxazol-5-yl)vinyl)quinolin-2(1H)-one dye (MQI) has been synthesized, and its structural and electronic properties have been characterized by employing UV-vis spectroscopy in combination with computational methods. The MQI dye has been assessed as an activated Michael acceptor-type probe toward bisulfite ions. This reaction was kinetically tested in different mild, cationic (cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, and cetylpyridinium bromide), and zwitterionic (N-decyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, and N-hexacyl-N,N-dimethyl-3-ammonio-1-propanesulfonate) micellar solutions at pH ∼ 5.5. Both micellar media remarkably allow the addition reactions, increasing the reactivity of MQI towards bisulfite ions, the biggest effects were found in the presence of cationic micelles. The binding constants of MQI with the micelles and the rate constants were determined from kinetic data, which were interpreted on the basis of the pseudophase kinetic model. The kinetic study and the product analysis allow us to highlight the relevant role of the association between MQI dye and the micellized surfactant, allowing efficient nucleophilic addition of bisulfite ions. The findings of this work will be valuable for the use of micellar solutions as an alternative medium to replace the use of toxic solvents to carry out organic reactions to perform nucleophilic addition reactions of bisulfite. [ABSTRACT FROM AUTHOR]

This study examines systems containing planar tetracoordinate group 13–15 atoms (E) within pentagonal C4H2E rings bridged by Si or Ge atoms. A detailed chemical bonding analysis of eleven candidates shows that true tetracoordination is achieved only in the C4H2NGe2+ system. [ABSTRACT FROM AUTHOR]

In 1977 Weiss and Grimes, by means of mass spectrometry and 1H and 11B NMR spectroscopy, proposed two structures (I and II) for the ferraborane (η5‐C5H5)Fe(B5H10), isoelectronic with ferrocene. In this work, by means of high‐level quantum‐chemical computations, we confirm the experimental structures of the two isomers with their corresponding energies, and assign the reported 1H and 11B NMR chemical shifts. A striking result from this study is the planarization (3D→2D) of the B5H10− ligand – an unknown isolated anion, isoelectronic with aromatic cyclopentadienyl anion C5H5− – when attached to the (η5‐C5H5)Fe+ moiety, thus resulting in a more stable ferraborane isomer II. [ABSTRACT FROM AUTHOR]

In this study, we delved into the structure of B5H5 and questioned some of its accepted assumptions. By exploring the potential energy surface, we found a new three-dimensional structure as the global minimum. This finding is in contrast with the previously hypothesized planar and cage-like models. Our exploration extends to the kinetic stability of various B5H5 isomers, offering insights into the dynamic behavior of these molecules. [ABSTRACT FROM AUTHOR]

When (4n +2) π‐electrons are located in single planar ring, it conventionally qualifies as aromatic. According Hückel's rule, systems possessing ten π‐electrons should be aromatic. Herein we report a series of D5h Li6E5Li6 sandwich structures, representing the first global minima featuring ten π‐electrons E510− ring (E=Si−Pb). However, these π‐electrons localize as five π‐lone‐pairs rather than delocalized orbitals. The high symmetry structure achieved is a direct consequence of σ‐aromaticity, particularly favored in elements from Si to Pb, resulting in a pronounced diatropic ring current flow that contributes to the enhanced stability of these systems. [ABSTRACT FROM AUTHOR]

Nowadays, an active research topic is the connection between Clar's rule, aromaticity, and magnetic properties of polycyclic benzenoid hydrocarbons. In the present work, we employ a meticulous magnetically induced current density analysis to define the net current flowing through any cyclic circuit, connecting it to aromaticity based on the ring current concept. Our investigation reveals that the analyzed polycyclic systems display a prominent global ring current, contrasting with subdued semi‐local and local ring currents. These patterns align with Clar's aromatic π‐sextets only in cases where migrating π‐sextet structures are invoked. The results of this study will enrich our comprehension of aromaticity and magnetic behavior in such systems, offering significant insights into coexisting ring current circuits in these systems. [ABSTRACT FROM AUTHOR]

Using various exploration strategies, in this study, we investigated the potential energy surfaces (PES) of CBe5H5+ and CnBe3n+2H2n+22+ (n = 2–4) clusters. Previous studies proposed that the planar pentacoordinate carbons (ppCs) were the global minima of these clusters. However, our study identified new putative global minima and competitive isomers, refuting some previous assignments. We employed several methods, including evolutive-inspired stochastic approaches guided by "chemical criteria", and ab initio molecular dynamics simulations at elevated temperatures. Our results showed that the size of the scanned population significantly affected the evolutive method and that constrained or guided procedures showed an advantage in identifying better minima for larger systems. This study demonstrated that using multiple complementary strategies can result in a wider variety of minima in a given energy range. Our findings provide valuable insights into exploring the potential energy surfaces of clusters, mainly medium-sized clusters, which could be the connections between small clusters and nanomaterials. [ABSTRACT FROM AUTHOR]

Planar boron clusters have often been regarded as "π‐analogous" to aromatic arenes because of their similar delocalized π‐bonding. However, unlike arenes such as C5H5− and C6H6, boron clusters have not previously shown the ability to form sandwich complexes. In this study, we present the first sandwich complex involving beryllium and boron, B7Be6B7. The global minimum of this combination adopts a unique architecture having a D6h geometry, featuring an unprecedented monocyclic Be6 ring sandwiched between two quasi‐planar B7 motifs. The thermochemical and kinetic stability of B7Be6B7 can be attributed to strong electrostatic and covalent interactions between the fragments. Chemical bonding analysis shows that B7Be6B7 can be considered as a [B7]3−[Be6]6+[B7]3− complex. Moreover, there is a significant electron delocalization within this cluster, supported by the local diatropic contributions of the B7 and Be6 fragments. [ABSTRACT FROM AUTHOR]

Here, we present evidence that the D2h M2C50/2+ (M = Li-K, Be-Ca, Al-In, and Zn) species comprises planar hexacoordinate carbon (phC) structures that exhibit four covalent and two electrostatic interactions. These findings have been made possible using evolutionary methods for exploring the potential energy surface (AUTOMATON program) and the Interacting Quantum Atoms (IQA) methodology, which support the observed bonding interactions. It is worth noting, however, that these structures are not the global minimum. Nonetheless, incorporating two cyclopentadienyl anion ligands (Cp) into the CaC52+ system has enhanced the relative stability of the phC isomer. Moreover, cycloparaphenylene ([8]CPP) provides system protection and kinetic stability. These results indicate that using appropriate ligands presents a promising approach for expanding the chemistry of phC species. [ABSTRACT FROM AUTHOR]