Metal(iso)cyanides dominate the molecular inventory of metal-bearing species in the interstellar medium.Their oxide counterparts,metal(iso)cyanates,have potential as interstellar molecules and have received significan...Metal(iso)cyanides dominate the molecular inventory of metal-bearing species in the interstellar medium.Their oxide counterparts,metal(iso)cyanates,have potential as interstellar molecules and have received significant attention.However,cationic complexes HNCOM^(+)as precursors to metal(iso)cyanates are rarely studied.Herein,we investigated HNCOCa^(+)by exploiting infrared spectrometry with isotopic substitutions and quantum chemical calculations.For comparison,the light and heavy alkaline earth metal cationic complexes HNCOBe^(+)and HNCOBa^(+)were also explored.HNCOCa^(+)and HNCOBe^(+)rather than HNCOBa^(+)can be experimentally generated by the reactions of metal cations with HNCO.The observed antisymmetric and symmetric NCO stretching vibrations in HNCOCa^(+)(2362.6 and 1330.4 cm^(−1))are higher than those in free HNCO(2268.5 and 1320.3 cm^(−1))but lower than those in HNCOBe^(+)(2426.4 and 1355.2 cm^(−1)).These shifts can be explained by the charge polarization within the NCO fragment in HNCOBe^(+)and HNCOCa^(+).Bonding analysis suggests that HNCO−Be^(+)bond favors covalent character(54%)while HNCO−Ca^(+)bond has higher electrostatic character(57%).The dominant electrostatic interaction(64%)in HNCO−Ba^(+)bond results in the low bond energy,which might account for its absence in experiments.展开更多
Contactless,spatiotemporal droplet maneuvering plays a critical role in a wide array of applications,including drug delivery,microfluidics,and water harvesting.Despite considerable advancements,challenges persist in t...Contactless,spatiotemporal droplet maneuvering plays a critical role in a wide array of applications,including drug delivery,microfluidics,and water harvesting.Despite considerable advancements,challenges persist in the precise transportation,split-ting,controlled steering,and functional adaptability of droplets when manipulated by electrical means.Here,we propose the use of orbital electrowetting(OEW)on slippery surfaces to enable versatile droplet maneuvering under a variety of condi-tions.The asymmetric electrowetting force that is generated allows highly efficient droplet manipulation on these surfaces.Our results demonstrate that droplets can be split,merged,and steered with exceptional flexibility,precision,and high velocity,even against gravity.Additionally,the OEW technique facilitates the manipulation of droplets across different compositions,volumes,and arrays in complex environments,leaving no residue.This novel droplet maneuvering mechanism and control strategy are poised to impact a range of applications,from chemical reactions and self-cleaning to efficient condensation and water harvesting.展开更多
Relativistic quantum chemistry investigations are carried out to tackle the puzzling oxidation state problem in a series of MO3 trioxide anions of all d- and f-block elements with five valence electrons. We have shown...Relativistic quantum chemistry investigations are carried out to tackle the puzzling oxidation state problem in a series of MO3 trioxide anions of all d- and f-block elements with five valence electrons. We have shown here that while the oxidation states of V, Nb, Ta, Db, Pa are, as usual, all ＋V with divalent oxygen O（-II） in MO3- anions, the lanthanide elements Pr and Gd cannot adopt such high ＋V oxidation state in similar trioxide anions. Instead, lanthanide element Gd retains its usual ＋III oxi- dation state, while Pr retains a ＋IV oxidation state, thus forcing oxygen into a non-innocent ligand with an uncommon mono- valent radical （O＇） of oxidation state -I. A unique Pr＂- ＂（0）3 biradical with highly delocalized unpairing electron density on Pr（IV） and three O atoms is found to be responsible for stabilizing the monovalent-oxygen species in PRO3- ion, while GdO3 ion is in fact an OGd＋（O22-） complex with Gd（III）. These results show that a naive assignment of oxidation state of a chemical element without electronic structure analysis can lead to erroneous conclusions.展开更多
Understanding the reaction mechanism at the atomic and molecular level is a central task of chemistry.Within the Born-Oppenheimer approximation,a chemical reaction is envisioned as nuclear dynamics evolving from react...Understanding the reaction mechanism at the atomic and molecular level is a central task of chemistry.Within the Born-Oppenheimer approximation,a chemical reaction is envisioned as nuclear dynamics evolving from reactants to products on a potential energy surface(PES).To reveal the detailed mechanistic origin of such an old bond-breaking and new bond-forming process,a measurement of state-to-state differential cross-sections(DCSs)is essential.Its fine structure often serves as a fingerprint to identify quantum dynamics phenomena in a bimolecular reactive encounter.Observation of these fine structures is,however,difficult,because the interference feature may appear in the state-to-state DCSs only with very high angular resolution。展开更多
基金This work was supported by the National Natural Science Foundation of China(No.22025301,No.22273012,and No.22321003).
文摘Metal(iso)cyanides dominate the molecular inventory of metal-bearing species in the interstellar medium.Their oxide counterparts,metal(iso)cyanates,have potential as interstellar molecules and have received significant attention.However,cationic complexes HNCOM^(+)as precursors to metal(iso)cyanates are rarely studied.Herein,we investigated HNCOCa^(+)by exploiting infrared spectrometry with isotopic substitutions and quantum chemical calculations.For comparison,the light and heavy alkaline earth metal cationic complexes HNCOBe^(+)and HNCOBa^(+)were also explored.HNCOCa^(+)and HNCOBe^(+)rather than HNCOBa^(+)can be experimentally generated by the reactions of metal cations with HNCO.The observed antisymmetric and symmetric NCO stretching vibrations in HNCOCa^(+)(2362.6 and 1330.4 cm^(−1))are higher than those in free HNCO(2268.5 and 1320.3 cm^(−1))but lower than those in HNCOBe^(+)(2426.4 and 1355.2 cm^(−1)).These shifts can be explained by the charge polarization within the NCO fragment in HNCOBe^(+)and HNCOCa^(+).Bonding analysis suggests that HNCO−Be^(+)bond favors covalent character(54%)while HNCO−Ca^(+)bond has higher electrostatic character(57%).The dominant electrostatic interaction(64%)in HNCO−Ba^(+)bond results in the low bond energy,which might account for its absence in experiments.
基金National Natural Science Foundation of China,Grant/Award Number:52276146International Science and Technology Cooperation Plan of Liaoning Province,Grant/Award Number:2023JH2/10700001Fundamental Research Funds for the Central Universities,Grant/Award Number:DUT22YG108。
文摘Contactless,spatiotemporal droplet maneuvering plays a critical role in a wide array of applications,including drug delivery,microfluidics,and water harvesting.Despite considerable advancements,challenges persist in the precise transportation,split-ting,controlled steering,and functional adaptability of droplets when manipulated by electrical means.Here,we propose the use of orbital electrowetting(OEW)on slippery surfaces to enable versatile droplet maneuvering under a variety of condi-tions.The asymmetric electrowetting force that is generated allows highly efficient droplet manipulation on these surfaces.Our results demonstrate that droplets can be split,merged,and steered with exceptional flexibility,precision,and high velocity,even against gravity.Additionally,the OEW technique facilitates the manipulation of droplets across different compositions,volumes,and arrays in complex environments,leaving no residue.This novel droplet maneuvering mechanism and control strategy are poised to impact a range of applications,from chemical reactions and self-cleaning to efficient condensation and water harvesting.
基金supported by the National Basic Research Program of China(2013CB834603)the National Natural Science Foundation of China(21173053,21433005,91426302,21221062,21201106)
文摘Relativistic quantum chemistry investigations are carried out to tackle the puzzling oxidation state problem in a series of MO3 trioxide anions of all d- and f-block elements with five valence electrons. We have shown here that while the oxidation states of V, Nb, Ta, Db, Pa are, as usual, all ＋V with divalent oxygen O（-II） in MO3- anions, the lanthanide elements Pr and Gd cannot adopt such high ＋V oxidation state in similar trioxide anions. Instead, lanthanide element Gd retains its usual ＋III oxi- dation state, while Pr retains a ＋IV oxidation state, thus forcing oxygen into a non-innocent ligand with an uncommon mono- valent radical （O＇） of oxidation state -I. A unique Pr＂- ＂（0）3 biradical with highly delocalized unpairing electron density on Pr（IV） and three O atoms is found to be responsible for stabilizing the monovalent-oxygen species in PRO3- ion, while GdO3 ion is in fact an OGd＋（O22-） complex with Gd（III）. These results show that a naive assignment of oxidation state of a chemical element without electronic structure analysis can lead to erroneous conclusions.
文摘Understanding the reaction mechanism at the atomic and molecular level is a central task of chemistry.Within the Born-Oppenheimer approximation,a chemical reaction is envisioned as nuclear dynamics evolving from reactants to products on a potential energy surface(PES).To reveal the detailed mechanistic origin of such an old bond-breaking and new bond-forming process,a measurement of state-to-state differential cross-sections(DCSs)is essential.Its fine structure often serves as a fingerprint to identify quantum dynamics phenomena in a bimolecular reactive encounter.Observation of these fine structures is,however,difficult,because the interference feature may appear in the state-to-state DCSs only with very high angular resolution。
