Zhengbo Qin

Bio: Zhengbo Qin is an academic researcher from Anhui Normal University. The author has contributed to research in topics: Ab initio & X-ray photoelectron spectroscopy. The author has an hindex of 2, co-authored 3 publications receiving 52 citations. Previous affiliations of Zhengbo Qin include Pacific Northwest National Laboratory.

Electronic Structure and Stability of [B12X12]2- (X = F-At): A Combined Photoelectron Spectroscopic and Theoretical Study.

Abstract: The stability and electron loss process of numerous multiply charged anions (MCAs) have been traditionally explained in terms of the classical Coulomb interaction between spatially separated charged groups. An understanding of these processes in MCAs with not well-separated excess charges is still lacking. We report the surprising properties and physical behavior of [B12X12]2–, X = F, Cl, Br, I, At, which are MCAs with not well-separated excess charges and cannot be described by the prevailing classical picture. In this series of MCAs, comprising a “boron core” surrounded by a “halogen shell”, the sign of the total charge in these two regions changes along the halogen series from X = F–At. With the aid of experimental photoelectron spectroscopy and highly correlated ab initio electronic structure calculations, we demonstrate that the trend in the electronic stability of these MCAs is determined by the interplay between the Coulomb (de)stabilization originating from the “boron core” and “halogen shell” and...

Negative ion photoelectron spectra of ISO3-, IS2O3-, and IS2O4- intermediates formed in interfacial reactions of ozone and iodide/sulfite aqueous microdroplets.

Abstract: Three short-lived, anionic intermediates, ISO3–, IS2O3–, and IS2O4–, are detected during reactions between ozone and aqueous iodine/sulfur oxide microdroplets. These species may play an important role in ozone-driven inorganic aerosol formation; however their chemical properties remain largely unknown. This is the issue addressed in this work using negative ion photoelectron spectroscopy (NIPES) and ab initio modeling. The NIPE spectra reveal that all of the three anionic species are characterized by high adiabatic detachment energies (ADEs) − 4.62 ± 0.10, 4.52 ± 0.10, and 4.60 ± 0.10 eV for ISO3–, IS2O3–, and IS2O4–, respectively. Vibrational progressions with frequencies assigned to the S–O symmetric stretching modes are discernable in the ground state transition features. Density functional theory calculations show the presence of several low-lying isomers involving different bonding scenarios. Further analysis based on high level CCSD(T) calculations reveal that the lowest energy structures are charac...

Distonic radical anion species in cysteine oxidation processes.

Abstract: Oxidation of cysteine residues constitutes an important regulatory mechanism in the function of biological systems. Much of this behavior is controlled by the specific chemical properties of the thiol side-chain group, where reactions with reactive oxygen species take place. Herein, we investigated the entire cysteine oxidation cycle Cys-SH → Cys-SOnH (n = 1, 2, and 3) using cryogenic negative ion photoelectron spectroscopy and quantum-chemical calculations. The conventional view of the first reversible oxidation step (n = 1) is associated with sulfenate species. Yet our results indicate that an alternative option exists in the form of a novel distonic radical anion, ˙OS–CH2CH(NH2)–COO−, with an unpaired electron on the thiol group and excess negative charge on the carboxylate group. Higher order oxidation states (n = 2 and 3) are thought to be associated with irreversible oxidative damage, and our results show that excess negative charge in those cases migrates to the –SOn− group. Furthermore, these species are stable towards 1e oxidation, as opposed to the n = 1 case that undergoes intra-molecular proton transfer. The molecular level insights reported in this work provide direct spectroscopic evidence of the unique chemical versatility of Cys-sulfenic acid (Cys-SOH) in post-translational modifications of protein systems.

Boron: Its Role in Energy-Related Processes and Applications.

Abstract: Boron's unique position in the Periodic Table, that is, at the apex of the line separating metals and nonmetals, makes it highly versatile in chemical reactions and applications. Contemporary demand for renewable and clean energy as well as energy‐efficient products has seen boron playing key roles in energy‐related research, such as 1) activating and synthesizing energy‐rich small molecules, 2) storing chemical and electrical energy, and 3) converting electrical energy into light. These applications are fundamentally associated with boron's unique characteristics, such as its electron‐deficiency and the availability of an unoccupied p orbital, which allow the formation of a myriad of compounds with a wide range of chemical and physical properties. For example, boron's ability to achieve a full octet of electrons with four covalent bonds and a negative charge has led to the synthesis of a wide variety of borate anions of high chemical and electrochemical stability—in particular, weakly coordinating anions. This Review summarizes recent advances in the study of boron compounds for energy‐related processes and applications.

Rational design of an argon-binding superelectrophilic anion

Abstract: Chemically binding to argon (Ar) at room temperature has remained the privilege of the most reactive electrophiles, all of which are cationic (or even dicationic) in nature. Herein, we report a concept for the rational design of anionic superelectrophiles that are composed of a strong electrophilic center firmly embedded in a negatively charged framework of exceptional stability. To validate our concept, we synthesized the percyano-dodecoborate [B 12 (CN) 12 ] 2− , the electronically most stable dianion ever investigated experimentally. It serves as a precursor for the generation of the monoanion [B 12 (CN) 11 ] − , which indeed spontaneously binds Ar at 298 K. Our mass spectrometric and spectroscopic studies are accompanied by high-level computational investigations including a bonding analysis of the exceptional B-Ar bond. The detection and characterization of this highly reactive, structurally stable anionic superelectrophile starts another chapter in the metal-free activation of particularly inert compounds and elements.

Self-organizing layers from complex molecular anions.

Abstract: The formation of traditional ionic materials occurs principally via joint accumulation of both anions and cations. Herein, we describe a previously unreported phenomenon by which macroscopic liquid-like thin layers with tunable self-organization properties form through accumulation of stable complex ions of one polarity on surfaces. Using a series of highly stable molecular anions we demonstrate a strong influence of the internal charge distribution of the molecular ions, which is usually shielded by counterions, on the properties of the layers. Detailed characterization reveals that the intrinsically unstable layers of anions on surfaces are stabilized by simultaneous accumulation of neutral molecules from the background environment. Different phases, self-organization mechanisms and optical properties are observed depending on the molecular properties of the deposited anions, the underlying surface and the coadsorbed neutral molecules. This demonstrates rational control of the macroscopic properties (morphology and size of the formed structures) of the newly discovered anion-based layers. Using ions of one polarity to form functional layers on surfaces is usually challenging because of counter ions which are inevitably present in the condensed phase. Here the authors demonstrate accumulation of mass-selected anions and neutral molecules from the gas phase to form a self-organizing liquid-like layer on a surface.

Quantitative Assessment of B-B-B, B-H b -B, and B-H t Bonds: From BH 3 to B 12 H 12 2-

Abstract: We report the thermodynamic stabilities and the intrinsic strengths of three‐center‐two‐electron B−B−B and B−Hb−B bonds (urn:x-wiley:14394235:media:cphc201900364:cphc201900364-math-0001 : bridging hydrogen), and two‐center‐two‐electron B−Ht bonds (urn:x-wiley:14394235:media:cphc201900364:cphc201900364-math-0002 : terminal hydrogen) which can be served as a new, effective tool to determine the decisive role of the intermediates of hydrogenation/dehydrogenation reactions of borohydride. The calculated heats of formation were obtained with the G4 composite method and the intrinsic strengths of B−B−B, B−Hb−B, and B−Ht bonds were derived from local stretching force constants obtained at the B3LYP‐D2/cc‐pVTZ level of theory for 21 boron‐hydrogen compounds, including 19 intermediates. The Quantum Theory of Atoms in Molecules (QTAIM) was used to deepen the inside into the nature of B−B−B, B−Hb−B, and B−Ht bonds. We found that all of the experimentally identified intermediates hindering the reversibility of the decomposition reactions are thermodynamically stable and possess strong B−B−B, B−Hb−B, and B−Ht bonds. This proves that thermodynamic data and intrinsic B−B−B, B−Hb−B, and B−Ht bond strengths form a new, effective tool to characterize new (potential) intermediates and to predict their role for the reversibility of the hydrogenation/dehydrogenation reactions.