Ti+(CO2)2Ar and Ti+(CO2)n (n=3-7) complexes are produced by laser vaporization in a pulsed supersonic expansion. The ion complexes of interest are each mass-selected in a time- of-flight spectrometer, and stud...Ti+(CO2)2Ar and Ti+(CO2)n (n=3-7) complexes are produced by laser vaporization in a pulsed supersonic expansion. The ion complexes of interest are each mass-selected in a time- of-flight spectrometer, and studied with infrared photodissociation spectroscopy. For each complex, a sharp band in the CO stretching frequency region is observed, which confirms the formation of the OTi+CO(CO2)~_l oxide-carbonyl species. Small OTi+CO(CO2)~_1 complexes (n_〈5) exhibit CO stretching and antisymmetric CO2 stretching vibrational bands that are blue-shifted from those of free CO and CO2. The experimental observations indicate that the coordination number of CO and CO2 molecules around TiO+ is five. Evidence is also observed for the presence of another electrostatic bonding Ti+(CO2)2 structural isomer for the Ti+(CO2)2Ar complex, which is characterized to have a bent OCO-Ti+-OCO structure stabilized by argon coordination.展开更多
The mass-selected infrared photodissociation (IRPD) spectroscopy was utilized to investigate the interactions of cationic cobalt with carbon dioxide molecules. Quantum chemical calculations were performed on the [Co(C...The mass-selected infrared photodissociation (IRPD) spectroscopy was utilized to investigate the interactions of cationic cobalt with carbon dioxide molecules. Quantum chemical calculations were performed on the [Co(CO2)n]^+ clusters to identify the structures of the low-lying isomers and to assign the observed spectral features. All the [Co(CO2)n]^+(n=2-6) clusters studied here show resonances near the CO2 asymmetric stretch of free CO2 molecule. Experimental and calculated results indicate that the CO2 molecules are weakly bound to the Co+ cations in an end-on con guration via a charge-quadrupole electrostatic interaction. The present IRPD spectra of [Co(CO2)n]^+ clusters have been compared to those of Ar-tagged species ([Co(CO2)n]^+-Ar), which would provide insights into the tagging effect of rare gas on the weakly-bounded clusters.展开更多
The effect of solvation on the conformation of acetylene has been studied by adding one water molecule at a time. Quantum chemical calculations of the n+ (C2H2)(H2O)n (n=1-5) clusters indicate that the H2O mole...The effect of solvation on the conformation of acetylene has been studied by adding one water molecule at a time. Quantum chemical calculations of the n+ (C2H2)(H2O)n (n=1-5) clusters indicate that the H2O molecules prefer to form the OH...Tr interaction rather than the CH...O interaction. This solvation motif is different from that of neutral (C2H2)(H2O)n (n=1-4) clusters, in which the H2O molecules prefer to form the CH...O and OH...C Hbonds. For the H+(C2H2)(H2O)n cationic clusters, the first solvation shell consists of one ring structure with two OH...Tr H-bonds and three water molecules, which is completed at n=4. Simulated infrared spectra reveal that vibrational frequencies of OH... H-bonded O-H stretching afford a sensitive probe for exploring the solvation of acetylene by protonated water molecules. Infrared spectra of the H+ (C2H2)(H2O)n (n=1-5) clusters could be readily measured by the infrared photodissociation technique and thus provide useful information for the understanding of solvation processes.展开更多
Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal c...Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporiza- tion/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric struc- tures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metM-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.展开更多
The anionic carbonyl complexes of groupsⅣandⅤmetals TM(CO)6,7(TM=Ti,Zr,Hf,V,Nb,Ta)are prepared in the gas phase using a laser vaporation-supersonic expansion ion source.The infrared spectra of TM(CO)_(6,7)-anion com...The anionic carbonyl complexes of groupsⅣandⅤmetals TM(CO)6,7(TM=Ti,Zr,Hf,V,Nb,Ta)are prepared in the gas phase using a laser vaporation-supersonic expansion ion source.The infrared spectra of TM(CO)_(6,7)-anion complexes in the carbonyl stretching frequency region are measured by mass-selected infrared photodissociation spectroscopy.The six-coordinated TM(CO)_(6)-anions are determined to be the coordination saturate complexes for both the groupⅣand groupⅤmetals.The TM(CO)_(6)-complexes of groupⅣmetals(TM=Ti,Zr,Hf)are 17-electron complexes having a~2A1gground state with D3dsymmetry,while the TM(CO)_(6)-complexes of groupⅤmetals(TM=Ⅴ,Nb,Ta)are 18-electron species with a closed-shell singlet ground state possessing Ohsymmetry.The energy decomposition analyses indicate that the metal-CO covalent bonding is dominated by TM-(d)→(CO)6π-backdonation and TM-(d)←(CO)6σ-donation interactions.展开更多
文摘Ti+(CO2)2Ar and Ti+(CO2)n (n=3-7) complexes are produced by laser vaporization in a pulsed supersonic expansion. The ion complexes of interest are each mass-selected in a time- of-flight spectrometer, and studied with infrared photodissociation spectroscopy. For each complex, a sharp band in the CO stretching frequency region is observed, which confirms the formation of the OTi+CO(CO2)~_l oxide-carbonyl species. Small OTi+CO(CO2)~_1 complexes (n_〈5) exhibit CO stretching and antisymmetric CO2 stretching vibrational bands that are blue-shifted from those of free CO and CO2. The experimental observations indicate that the coordination number of CO and CO2 molecules around TiO+ is five. Evidence is also observed for the presence of another electrostatic bonding Ti+(CO2)2 structural isomer for the Ti+(CO2)2Ar complex, which is characterized to have a bent OCO-Ti+-OCO structure stabilized by argon coordination.
基金supported by the National Natural Science Foundation of China(No.21327901,No.21503222,No.21673231,and No.21688102)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB17000000)China Postdoctoral Science Foundation(No.2018M641718 and No.2018M641719)
文摘The mass-selected infrared photodissociation (IRPD) spectroscopy was utilized to investigate the interactions of cationic cobalt with carbon dioxide molecules. Quantum chemical calculations were performed on the [Co(CO2)n]^+ clusters to identify the structures of the low-lying isomers and to assign the observed spectral features. All the [Co(CO2)n]^+(n=2-6) clusters studied here show resonances near the CO2 asymmetric stretch of free CO2 molecule. Experimental and calculated results indicate that the CO2 molecules are weakly bound to the Co+ cations in an end-on con guration via a charge-quadrupole electrostatic interaction. The present IRPD spectra of [Co(CO2)n]^+ clusters have been compared to those of Ar-tagged species ([Co(CO2)n]^+-Ar), which would provide insights into the tagging effect of rare gas on the weakly-bounded clusters.
基金This work was supported by the National Natural Science Foundation of China (No.21273232 and No.21327901) and the Key Research Program of the Chinese Academy of Science (No.KGZD-EW-T05). Ling Jiang acknowledges Hundred Talents Program of Chinese Academy of Sciences and Collaborative Innovation Center of Chemistry for Energy and Materials.
文摘The effect of solvation on the conformation of acetylene has been studied by adding one water molecule at a time. Quantum chemical calculations of the n+ (C2H2)(H2O)n (n=1-5) clusters indicate that the H2O molecules prefer to form the OH...Tr interaction rather than the CH...O interaction. This solvation motif is different from that of neutral (C2H2)(H2O)n (n=1-4) clusters, in which the H2O molecules prefer to form the CH...O and OH...C Hbonds. For the H+(C2H2)(H2O)n cationic clusters, the first solvation shell consists of one ring structure with two OH...Tr H-bonds and three water molecules, which is completed at n=4. Simulated infrared spectra reveal that vibrational frequencies of OH... H-bonded O-H stretching afford a sensitive probe for exploring the solvation of acetylene by protonated water molecules. Infrared spectra of the H+ (C2H2)(H2O)n (n=1-5) clusters could be readily measured by the infrared photodissociation technique and thus provide useful information for the understanding of solvation processes.
基金supported by the National Natural Science Foundation of China(No.21688102,No.21573047and No.21273045)
文摘Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporiza- tion/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric struc- tures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metM-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.
基金supported by the National Natural Science Foundation of China(No.21873020 and No.21688102)。
文摘The anionic carbonyl complexes of groupsⅣandⅤmetals TM(CO)6,7(TM=Ti,Zr,Hf,V,Nb,Ta)are prepared in the gas phase using a laser vaporation-supersonic expansion ion source.The infrared spectra of TM(CO)_(6,7)-anion complexes in the carbonyl stretching frequency region are measured by mass-selected infrared photodissociation spectroscopy.The six-coordinated TM(CO)_(6)-anions are determined to be the coordination saturate complexes for both the groupⅣand groupⅤmetals.The TM(CO)_(6)-complexes of groupⅣmetals(TM=Ti,Zr,Hf)are 17-electron complexes having a~2A1gground state with D3dsymmetry,while the TM(CO)_(6)-complexes of groupⅤmetals(TM=Ⅴ,Nb,Ta)are 18-electron species with a closed-shell singlet ground state possessing Ohsymmetry.The energy decomposition analyses indicate that the metal-CO covalent bonding is dominated by TM-(d)→(CO)6π-backdonation and TM-(d)←(CO)6σ-donation interactions.