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Tanaka Keiichi - One of the best experts on this subject based on the ideXlab platform.
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MILLIMETER-WAVE SPECTROSCOPY OF THE FeCO($X^3\Sigma^-$) AND FeNO($X^2\Delta_i$) RADICALS IN THE VIBRATIONAL EXCITED STATES
'The Ohio State University Libraries', 2006Co-Authors: Ikeda Seiki, Harada Kensuke, Hayashi Masato, Nakashima Motoki, Ai Sakamoto, Tanaka KeiichiAbstract:Author Institution: Department of Chemistry, Faculty of Science, Kyushu University,; Hakozaki, Higashiku, Fukuoka, 812-8581 JAPANRotational spectra of the FeCO and FeNO radicals produced by UV laser photolysis in the vibrational excited states were measured in the millimeter-wave region with the conventional absorption cell at room temperature. The rotational transitions of the FeCO radical in the ground and $\nu_2$ states have been observed by millimeter-wave spectroscopy}, 106, 6820-6824 (1997)}, and the $\nu_1$ fundamental band and hot band from $\nu_2$ state also have been studied by infrared diode laser spectroscopy. In the present work, the rotational transitions ($J$ = 33 - 32 $\sim$ 37 - 36 ) in the $\nu_3$ state of the $X^3\Sigma^-$ state were observed to split into 3 components due to the spin-rotation and spin-spin interactions. Molecular Constants including rotational Constant and Centrifugal Distortion Constant were determined by a least squares fitting. The equilibrium rotational Constant $B_e$ was calculated to be 4373.405(72) MHz from the vibration rotation Constant $\alpha_{\rm 3}$ = 20.2051(42) MHz, and previously reported $\alpha_{\rm 1}$ and $\alpha_{\rm 2}$. The bond length between Fe and C, calculated to be 1.725 ${\rm \AA} $ assuming $r_{\rm CO}$= 1.159 ${\rm \AA}$, agrees well with the {\it ab initio} result, $r_{\rm FeC} = 1.722$ \AA}. The 2$\nu_2$ state split into 9 substates due to the vibronic interaction, and the rotational transitions in the $P = 0$ component were observed. The rotational transitions of the FeNO radical in the ground and $\nu_2$ states}, and the $\nu_1$ band have been observed in the millimeter-wave and infrared region, respectively. The rotational transitions ($J$ = 28.5 - 27.5 $\sim$ 32.5 - 31.5 ) in the 2$\nu_2$ state of the $X^2\Delta_i$ state were observed in the present study. The 2$\nu_2$ state ($\Omega = 5/2$) splits into 3 substates, $^2\Gamma_{P = 9/2}, ^2\Delta_{P = 5/2}$ and $^2\Sigma_{P = 1/2}$, due to the vibronic interaction. The absorption lines in the $^2\Sigma_{P = 1/2}$ state split into two components because of the $p$-type doubling. The transition in the $\nu_3$ state is now under survey to determine the Constant $\alpha_3$ and the equilibrium rotational Constant
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HIGH RESOLUTION FOURIER TRANSFORM EMISSION SPECTROSCOPY OF THE $\tilde{A}^{2}\Sigma^{+}-\tilde{X}^{2}\Pi$ TRANSITION OF THE ${\rm ICN^{+}}$ ION
'The Ohio State University Libraries', 2006Co-Authors: Miyamoto Yutaka, Zelinger Zdenĕk, Nakashima Yoshihiro, Tanaka KeiichiAbstract:Author Institution: Department of Chemistry, Faculty of Sciences, Kyushu University,; Fukuoka, 812-8581 JAPANThe visible and near infrared emission spectrum in the 480 - 900 nm region of ${\rm ICN^{+}}$ was measured by Fourier transform spectrometer (Bruker IFS 120HR). The ${\rm ICN^{+}}$ was produced by Penning ionization of ICN with metastable He*. The ${\rm ICN^{+}}$ ion has much larger spin-orbit interaction Constant ($A=-4343{\rm cm^{-1}}$) than those of the ${\rm ClCN^{+}}(-276{\rm cm^{-1}})$ and the ${\rm BrCN^{+}}(-1477{\rm cm^{-1}})$}, {\it J. Phys. Chem.}, {\bf 89}, 4213-4219, (1985)}. The Renner-Teller effect appears in the $\nu_{2}$ excited state of $\tilde{X}^{2}\Pi$. It is interesting to study the Renner-Teller effect of ${\rm ICN^{+}}$. Eight vibronic bands of the $\tilde{A}^{2}\Sigma^{+}-\tilde{X}^{2}\Pi$ transition (both for the $\Omega=1/2$ and $3/2$ spin components) of ICN$^{+}$ were observed. So far, the rotational analysis was performed for two vibronic bands, $\tilde{A}^{2}\Sigma^{+}(000) -\tilde{X}^{2}\Pi_{3/2}(000)$ and $\tilde{A}^{2}\Sigma^{+}(000) - \mu^{2}\Sigma(010)$. Molecular Constants, including the band origin, the effective rotational Constant, Centrifugal Distortion Constant and spin-rotation interaction Constant, were determined for the $\tilde{A}^{2}\Sigma^{+}$ and $\tilde{X}^{2}\Pi_{3/2}$ states.\\ Due to the Renner-Teller effect, the $\tilde{X}^{2}\Pi(010)$ state was split into four vibronic components, $\mu^{2}\Sigma$, $\kappa^{2}\Sigma$, and $^{2}\Delta_{P}$($P=3/2$ and $P=5/2$). For the $\tilde{A}^{2}\Sigma^{+} - \mu^{2}\Sigma$ band, $P_{1}, P_{2}, R_{1}$ and $R_{2}$-branch were observed. For the $\mu^{2}\Sigma$ vibronic state, $\Omega$-type doubling Constant was determined as well as the rotational Constant and Centrifugal Distortion Constant. Renner parameter $\epsilon$ for the $\tilde{X}^{2}\Pi$ state was determined to be $-$0.197 from the $\Omega$-type doubling Constant. The determined Renner parameter $(\epsilon=-0.197)$ was close to that of BrCN$^{+}$($-$0.185). We are now analyzing the spectrum for the $\Omega=1/2$ spin component, $\tilde{A}^{2}\Sigma^{+}(000) -\tilde{X}^{2}\Pi_{1/2}(000)$ and $\tilde{A}^{2}\Sigma^{+}(000) -\kappa^{2}\Sigma(010)$, to study the Renner-Teller effect in more detail.\
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TIME-RESOLVED INFRARED DIODE LASER SPECTROSCOPY OF THE $\nu_1$ BAND OF THE FeNO RADICAL PRODUCED BY THE ULTRAVIOLET LASER PHOTOLYSIS OF Fe(CO)$_2$(NO)$_2$
'The Ohio State University Libraries', 2005Co-Authors: Ikeda Seiki, Nakashima Motoki, Tanaka KeiichiAbstract:{M. Zhou and L. Andrews, $J .Phys. Chem. A$, \textbf{104{Microwave session in this symposium.Author Institution: Department of Chemistry, Faculty of Science, Kyushu University,; Hakozaki, Higashiku, Fukuoka, 812-8581 JAPANRovibrational transitions of the $\nu_1$ band (N-O stretch) of the FeNO radical were observed in the 1750-1780 cm$^{-1}$ region. The FeNO radical was produced by 193 nm excimer laser photolysis of Fe(CO)$_2$(NO)$_2$ and the transient absorption signal was detected by time-resolved infrared diode laser spectroscopy.\\ More than 40 lines were assigned to the $\nu_1$ fundamental band of the $\Omega = 5/2$ spin component, together with ten $Q$-branch lines ($J$ = 2.5 - 11.5) in the 1760 cm$^{-1}$ region, to confirm the electronic ground state to be $X^2\Delta_i$. Effective molecular Constants for the $\Omega = 5/2$ spin component, including the band origin $\nu_0$ (1767.26093(38) cm$^{-1}$), the rotational Constant $B$ (4610.17754(93) MHz) and the Centrifugal Distortion Constant $D$ (1.17003(47) kHz), were derived from a least squares fitting of the observed transitions. The average bond length $r_{\rm Co-N}$ between Co and N was calculated to be 1.621 \AA from the rotational Constant $B_0$ assuming $r_{\rm N-O} = $1.186 \AA as given by $ab initio$ calculation}, 3915 (2000)}. The $\nu_1$ hot band lines originated from the $\nu_2$ (Fe-N-O bending; 308 cm$^{-1} ^a$) vibrationally excited state were also observed. Pure rotational lines of FeNO were also observed by the millimeter wave spectroscopy with the UV photolysis of Fe(CO)$_2$(NO)$_2$}
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HIGH RESOLUTION FOURIER TRANSFORM EMISSION SPECTROSCOPY OF THE $\tilde{A}^2\Sigma^+ - \tilde{X}^2\Pi$ TRANSITION OF THE BrCN$^+$ ION
'The Ohio State University Libraries', 2005Co-Authors: Nakashima Yoshihiro, Ogawa Tomoki, Matsuo Maki, Tanaka KeiichiAbstract:Author Institution: Department of Chemistry, Faculty of Science, Kyushu University 33, Hakozaki, Higashiku,; Fukuoka 812-8581, JapanThe BrCN$^+$ ion was produced by Penning ionization of BrCN with metastable He$^*$, and the near-infrared emission in the 690 - 870 nm region was measured by Fourier transform spectrometer. Thirteen vibronic bands of the $\tilde{A}^2\Sigma^+ - \tilde{X}^2\Pi$ transition of $^{79}$BrCN$^+$ and $^{81}$BrCN$^+$ were observed. The rotational analysis was performed for the $\tilde{A}^2\Sigma^+(000) - \tilde{X}^2\Pi_{\Omega}(000)$ and $\tilde{A}^2\Sigma^+(000) - \tilde{X}^2\Pi_{\Omega}(010)$ transitions, both for the $\Omega=3/2$ and 1/2 spin components. \\ Molecular Constants, including the effective rotational Constant, Centrifugal Distortion Constant, $\Lambda$-type doubling Constant in the $\tilde{X}^2\Pi_{1/2}$ state, and spin-rotation interaction Constant in the $\tilde{A}^2\Sigma^+$ state, were determined from the observed spectrum. Spin-orbit interaction Constants for the $\tilde{X}^2\Pi$ ground state were determined to be $-$1476.4669(48) and $-$1476.4841(60) cm$^{-1}$, respectively, for $^{79}$BrCN$^+$ and $^{81}$BrCN$^+$. The $r_0$-structures for the $\tilde{X}^2\Pi$ and $\tilde{A}^2\Sigma^+$ states of BrCN$^+$ were derived to be compared with that for the $\tilde{X}^1\Sigma^+$ state of BrCN. The geometrical change of the BrCN$^+$ ion from the BrCN molecule was turned out to be small. \\ Due to the Renner-Teller effect, the $\tilde{X}^2\Pi$(010) state was split into four components, $\mu ^2\Sigma$, $\kappa ^2\Sigma$, and $^2\Delta_{P}$ ($P=5/2$ and 3/2), and the rotational analysis was performed both for the $\tilde{A}^2\Sigma^+ - \mu^2\Sigma$ and $\tilde{A}^2\Sigma^+ - \kappa^2\Sigma$ transitions. For the $\mu^2\Sigma$ and $\kappa^2\Sigma$ vibronic states, $\Omega$-type doubling Constants were determined as well as the rotational Constants and Centrifugal Distortion Constants. Renner parameter $\epsilon$ for the $\tilde{X}^2\Pi$ state was determined to be $-0.185$ from the $\Omega$-type doubling Constants for both the isotopic species
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MILLIMETER-WAVE SPECTRUM OF FeNO($X^2 \Delta_i$) IN THE GROUND AND VIBRATIONALLY EXCITED STATES
'The Ohio State University Libraries', 2005Co-Authors: Nakashima Motoki, Hayashi Masato, Harada Kensuke, Tanaka KeiichiAbstract:{Radicals and Ions session in the present symposium.Author Institution: Department of Chemistry, Faculty of Science, Kyushu University 33,; Hakozaki, Higashiku, Fukuoka 812-8581, JapanRotational spectrum of the FeNO radical generated by the ultraviolet photolysis of Fe(CO)$_2$(NO)$_2$ was measured in the millimeter-wave region. The measurements were performed in the supersonic jet expansion with a millimeter-wave multi-reflection cell. Three rotational transitions ($J = 9.5 - 8.5$ $\sim$ $11.5 - 10.5$) in the $\Omega = 5/2$ spin substate of the $X^2 \Delta_i$ ground vibronic state were measured in the frequency region of 87$-$106 GHz. The rotational lines were split into 2 components ($\Delta F = 0,+1$) due to the hyperfine interaction of the N($I = 1$) nucleus. In the upper spin substate $\Omega = 3/2$ ($A_{\rm SO} \approx -417 {\rm cm}^{-1}$) of the electronic ground state, seven rotational transitions ($J = 28.5 - 27.5$ $\sim$ $34.5 - 33.5$) were measured with a conventional absorption cell (2.7 m in length) in the room temperature. Moreover, six rotational transitions ($J = 28.5 - 27.5$ $\sim$ $33.5 - 32.5$) in the $\nu_2$ vibrationally excited state (for both $P$ = 3/2 and 7/2 components) and the high-$J$ lines of $\Omega = 5/2$ spin substate of the ground state were also observed with the conventional absorption cell. Rotational line intensity of the $\Omega = 3/2$ substate was about one tenth of that for the $\Omega = 5/2$ substate because of the large spin-orbit interaction Constant $A_{\rm SO}$. Molecular Constants, including the rotational Constant $B$, Centrifugal Distortion Constant $D$, hyperfine Constant $a+b_F/4+c/6$, and vibration rotation Constant $\alpha_2$, were determined by a least squares fitting of the observed spectrum. The electronic ground state of FeNO was confirmed to be $X^2 \Delta_i$ as in the case of CoCO and the unpaired electron is localized almost in the 3{\it d} orbital of Fe. The hyperfine Constant of FeNO, $a+b_F/4+c/6 = -1.359(57)$ MHz, is much smaller than that of CoCO, 466.073(54) MHz. Rovibrational transitions were also observed by the infrared diode laser spectroscopy with the ultraviolet photolysis of Fe(CO)$_2$(NO)$_2$.
Legon A. C. - One of the best experts on this subject based on the ideXlab platform.
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UNEXPECTED GENERATION AND OBSERVATION OF A T-SHAPED COMPLEX OF H$_{2}$C$_{2}$$\cdots$AgCCH
'The Ohio State University Libraries', 2013Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, Bedson Building, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, U.K.; School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.An experiment to probe species generated within a supersonically-expanding jet consisting of SF$_{6}$, Ag, C$_{2}$H$_{2}$ and argon by broadband rotational spectroscopy revealed the existence of a T-shaped complex of hitherto unknown origin. Empirical tests revealed that this complex requires the presence of C$_{2}$H$_{2}$ and Ag within the gas sample. While the intensity of the associated transitions are enhanced by the presence of SF$_{6}$, theoretical calculations and empirical tests implied that the identified complex is H$_{2}$C$_{2}$$\cdots$AgCCH rather than the original target of the experiment, H$_{2}$C$_{2}$$\cdots$AgF. This deduction is now supported by evidence acquired through experiments exploiting $^{13}$C-enriched isotopic samples. Transitions have been assigned for the H$_{2}$$^{13}$C$_{2}$$\cdots$Ag$^{13}$C$^{13}$CH isotopologue. Data acquired from each isotopologue allows determination of the rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$. The data are consistent with a T-shaped complex in which the Ag atom of AgCCH binds to electrons within the ${\pi}$-orbitals of ethyne. Preliminary determinations of bond lengths will be presented. Experiments are in progress to measure the spectra of deuterated isotopologues
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MICROWAVE SPECTRUM AND GEOMETRY OF H$_{3}$P$\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.The pure rotational spectrum of the vibrational ground state of H$_{3}$P$\cdots$AgI has been measured by chirped-pulse FTMW spectroscopy. The complex is generated via laser ablation (532 nm) of a silver rod in the presence of CF$_{3}$I, PH$_{3}$ and argon. It is subsequently stabilized and interrogated in the cold environment of a supersonic jet. The rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, have been measured for H$_{3}$P$\cdots$$^{107}$AgI and H$_{3}$P$\cdots$$^{109}$AgI. The spectrum of the complex is consistent with a {\it{C}}$_{3v}$ geometry and a linear arrangement of the P, Ag and C atoms. The measured rotational Constants allow a preliminary determination of the geometry of the molecule. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I) , is also established. The experimental results are compared with theory performed at the explicitly-correlated coupled-cluster singles, doubles and perturbative triples level
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BROADBAND ROTATIONAL SPECTRUM AND MOLECULAR GEOMETRY OF OC $\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the ground vibrational states of six isotopologues of OC$\cdots$AgI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are assigned to determine the rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, of the complex. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I), has also been measured. The complex is linear. The length of the C{\textemdash}O bond, r(CO), in the {\it{r}}$_{0}$ geometry for OC$\cdots$AgI is 0.008 {\r{A}} shorter than that found in the free CO molecule. The length of the Ag{\textemdash}I bond, {\it{r}}(AgI), is 0.013 {\r{A}} shorter than in free AgI. The nuclear quadrupole coupling Constant of the iodine atom is determined to be -769.84(22) MHz for OC$\cdots$$^{107}$AgI implying an ionic character of 0.66 for the metal halide bond. The molecular structure and spectroscopic parameters determined from the experimental data are presented alongside the results of calculations at the explicitly-correlated CCSD(T) level. The design features of a laser ablation source constructed for the present work will be described
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MICROWAVE SPECTRA AND GEOMETRIES OF H$_{2}$C$_{2}$$\cdots$AgCl AND H$_{2}$C$_{2}$$\cdots$CuCl
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the vibrational ground states of H$_{2}$C$_{2}$$\cdots$AgCl and H$_{2}$C$_{2}$$\cdots$CuCl have been measured by chirped-pulse FTMW spectroscopy. Each complex is generated via laser ablation of the metal in the presence of small percentages of CCl$_{4}$ and C$_{2}$H$_{2}$ in argon. The complexes are stabilized and interrogated in the cold environment of a supersonic jet. Rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and the Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$, have been measured for six isotopologues of H$_{2}$C$_{2}$$\cdots$AgCl and three isotopologues of H$_{2}$C$_{2}$$\cdots$CuCl with substitutions at the metal, chlorine and carbon atoms in each case. The spectrum of each complex is consistent with a {\it{C}}$_{2v}$ structure in which the metal atom is coordinated by the ${\pi}$-orbital of ethyne. The measured rotational Constants allow determination of the length of the bond between the metal and chlorine atoms, {\it{r}}(M{\textemdash}Cl), and the distance between the metal atom and the centre of the ethyne double bond, {\it{r}}(M{\textemdash}*). Nuclear quadrupole coupling Constants have been measured for the chlorine atom in each complex and also for copper in H$_{2}$C$_{2}$$\cdots$CuCl
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MICROWAVE SPECTRA AND STRUCTURES OF H$_2$O$\cdots$AgF
'The Ohio State University Libraries', 2011Co-Authors: Stephens S. L., Walker N. R., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.KA Balle-Flygare FT-MW spectrometer coupled to a laser ablation source has been used to measure the pure rotational spectra of H$_{2}$O$\cdots$AgF. Generation is via laser ablation (532 nm) of a silver rod in the presence of SF$_{6}$, argon, a low partial pressure of H$_{2}$O and the molecules are stabilized by supersonic expansion. The spectra of eight isotopologues have been measured. Rotational Constants, $\it{B}_{\rm{0}}$ and $\it{C}_{\rm{0}}$, and the Centrifugal Distortion Constant, \Delta $_\it{J}$ have been determined. Isotopic substitutions are available at the silver, oxygen and hydrogen atoms. The spectra are consistent with a linear arrangement of oxygen, silver and fluorine atoms and the structure is either $\it{C}_{\rm{2v}}$ planar at equilibrium or $\it{C}_{\rm{S}}$ pyramidal but with a low potential-energy barrier to planarity such that the v = 0 and 1 states associated with the motion that inverts the configuration at the O atom are well separated
Tanaka Takehiko - One of the best experts on this subject based on the ideXlab platform.
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MILLIMETER-WAVE SPECTROSCOPY OF CoNO IN THE GROUND $(X^{1}\Sigma)$ STATE
'The Ohio State University Libraries', 2004Co-Authors: Ai Sakamoto, Tanaka Keiichi, Harada Kensuke, Hayashi Masato, Tanaka TakehikoAbstract:$^{a}$ Mingfei Zhou and Lester Andrews, J. Phys. Chem., A104, 3915 (2000)Author Institution: Department of Chemistry, Faculty of Sciences, Kyushu University, HakozakiInfrared spectrum of CoNO has been measured in low temperature Ar matrix and the $\nu_{1}$ and $\nu_{3}$ band origins were reported to be 1761.0 and $620.1 cm^{-1}$ $respectively.^{a}$ Recent DFT calculations suggested that the linear form $(X^{1}\Sigma)$ and bent form $(X^{3}A^{\prime})$ of CoNO have almost the same $energies.^{a}$ In the present study, the pure rotational spectrum of CoNO generated in a supersonic jet expansion by ultraviolet photolysis of $Co(CO)_{3}NO$ was observed in the millimeter-wave region. This is the first observation of the rotationally resolved spectrum of the transition metal nitrosyl in the gas phase. Seven rotational transitions (from $J = 6 - 5$ to $12 - 11$) were measured in the frequency region of $56 - 112$ GHz. Each rotational transition was split into $8-11$ components due to hyperfine interaction of the Co $(I = 7/2)$ nucleus. The spectrum was analyzed to determine molecular Constants, including the rotational Constant B, Centrifugal Distortion Constant D, nuclear quadrupole interaction Constant eQq, and nuclear spin-rotation interaction Constant $C_{I}$. From the observed spectral pattern, it is confirmed that CoNO has a linear structure and the electronic ground state is $^{1}\Sigma$. The Co-N bond length was calculated to be 1.588 \AA from the rotational Constant, which is by 0.1 \AA shorter than the Co-C bond length of CoCO. Measurement of rotational transitions in the $\nu_{2}$ vibrationally excited state is in progress
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MILLIMETER WAVE SPECTRUM OF $CoCO(X^{2}\Delta_{i})$ IN THE GROUND AND VIBRATIONALLY EXCITED STATES
'The Ohio State University Libraries', 2003Co-Authors: Hayashi Masato, Tanaka Keiichi, Hikida Toshihide, Harada Kensuke, Tanaka TakehikoAbstract:Author Institution: Department of Chemistry, Faculty of Science, Kyushu University 33Rotational spectrum of the CoCO radical generated by ultraviolet photolysis of $Co(CO)_{3}NO$ was measured in the millimeter wave region to determine rotational and hyperfine interaction Constants. Rotational transitions ranging from J = 29.5 - 28.5 to 34.5 - 33.5 were assigned in the $\Omega = 3/2$ and $\Omega = 5/2$ spin substates of the $X^{2}\Delta_{i}$ ground vibronic state as well as in the vibrationally excited states $\nu_{2}, \nu_{3}$, and $2\nu_{2}$ of the $\Omega = 5/2$ spin substate. Each rotational transition was split into 8 hyperfine components due to the $^{59}Co$ nucleus. Molecular Constants, including the rotational Constant B, Centrifugal Distortion Constant D, nuclear spin-orbit interaction Constant a, Fermi contact interaction Constant $b_{F}$, magnetic dipolar interaction Constant c, and nuclear quadrupole interaction Constant eQq, were determined for the vibrationally ground state by least squares fitting of the observed spectrum. The equilibrium rotational Constant $B_{e}$ was determined to be 4435.7510(18) MHz and the internuclear distance between Co and C was evaluated to be $1.688 \AA$. The a and c values are consistent with the values estimated from the hyperfine Constants of the $^{59}Co$ atom. The $b_{F}$ value is nearly equal to zero
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TIME-RESOLVED INFRARED DIODE LASER SPECTROSCOPY OF THE $Co(CO)_{2}$ RADICAL
'The Ohio State University Libraries', 2003Co-Authors: Nakashima Motoki, Tanaka Keiichi, Hikida Toshihide, Ikeda Seiki, Tanaka TakehikoAbstract:Author Institution: Department of Chemistry, Faculty of Sciences, Kyushu UniversityRovibrational transitions of the $\nu_{3}$ band (C-O anti-symmetric stretch) of the $Co(CO)_{2}$ radical were observed in the frequency region of $1944 - 1964 cm^{-1}$. The $Co(CO)_{2}$ radical was produced by the 248 nm excimer laser photolysis and the transient absorption signal was detected by time-resolved infrared diode laser spectroscopy. More than 160 absorption lines were assigned to the $\nu_{3}$ fundamental band. The $\nu_{3}$ band consists of two series of spectral lines spaced approximately by four times the rotational Constant, due to the spin statistics of identical C and O nuclei, and the electronic ground state was confirmed to be $X^{2}\Delta_{g}$. Molecular Constants including the band origin $\nu_{0}$, rotational Constant, and Centrifugal Distortion Constant were derived from the observed transitions. Hot bands originating from the $\nu_{7}$ and $2\nu_{7}$ vibrational excited states, where $\nu_{7}$ refers to the C-Co-C bending mode, were also observed. Because of the rovibronic interaction, each of the observed lines for the $\nu_{3} + \nu_{7} \leftarrow \nu_{7}$ and $\nu_{3} + 2\nu_{7} \leftarrow 2\nu_{7}$ hot bands was split into two and three components, respectively. Ab initio calculation in $BP86/6-311+G^{\ast}$ level suggests that the $Co(CO)_{2}$ radical is slightly bent and has the $X^{2}A_{1}$ electronic ground state. The present experiment shows that the $Co(CO)_{2}$ radical is linear in average, and it may probably be a quasi-linear molecule in which the ground state has energy higher than the top of the potential bump
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MILLIMETER WAVE SPECTROSCOPY OF THE CoCO RADICAL PRODUCED IN A SUPERSONIC JET EXPANSION BY THE ULTRAVIOLET PHOTOLYSIS OF $Co(CO)_{3}NO$.
'The Ohio State University Libraries', 2002Co-Authors: Hikida Toshihide, Tanaka Keiichi, Harada Kensuke, Tanaka TakehikoAbstract:Author Institution: Department of Chemistry, Faculty of Science, Kyushu University, 33, HakozakiRotational transitions of the CoCO radical were observed by millimeter wave spectroscopy. The CoCO radical was produced in a supersonic expansion by the ultraviolet photolysis of $Co(CO)_{3}NO$. The $J = 8.5 - 7.5, 9.5 - 8.5, 10.5 - 9.5$, and 11.5 - 10.5 rotational transitions in the $\Omega = 5/2$ spin state of the $X^{2}\Delta_{i}$ electronic ground state were assigned in the 75-130 GHz region. Each rotational transition was split into 8 hyperfine components due to the electron orbital-nuclear spin interaction, electron spin-nuclear spin interaction, and nuclear quadropole interaction of the Co atom. The A-type doublet was not resolved in the $\Omega = 5/2$ spin state. Effective molecular Constants for the $\Omega = 5/2$ spin state, including rotational Constant, B, Centrifugal Distortion Constant, D, nuclear quadropole interaction Constant, eQq, and the linear combination, $a + (1/4)b + (1/6)c$, of the electron orbital-nuclear spin interaction a, Fermi contact interaction b, and magnetic dipole interaction of the electron spin and nuclear spin c, were determined by the least squares fitting of the observed spectrum
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MILLIMETER-WAVE SPECTROSCOPY OF THE $HCN-H_{2}$ CLUSTER
'The Ohio State University Libraries', 2000Co-Authors: Ishiguro M., Tanaka Takehiko, Harada Kensuke, Whitham C. J., Tanaka KeiichiAbstract:Author Institution: Department of Chemistry, Faculty of Science, Kyushu University; Department of Chemistry, Faculty of Science, Institute for Molecular ScienceMillimeter-wave absorption spectroscopy combined with a pulsed-jet expansion technique was applied to the measurement of the rotational and rovibrational transitions of the $HCN-H_{2}$ cluster in the frequency region of 75 - 150 GHz. So far, four rotational lines for the ground $\Sigma_{0}$ state of the $HCN-(o-H_{2})$ cluster split into hyperfine structure due to the nitrogen nucleus were observed. Rotational Constant $B_{0}=12899.718(20)$ MHz and Centrifugal Distortion Constant $D_{0} = 12.2470(16)$ MHz were derived together with its higher Constants. The hyperfine Constants determined $eqQ =-2.830(33) MHz$ which is smaller than that of HCN molecule means a large amplitude motion of HCN of $= 31.1$ degree in the ground linear form. The bond length between HCN and $H_{2}$ parts is derived to be $3.90 {\AA}$. Some lines belonging to the $\Sigma_{1}-\Sigma_{0}$ van der Waals bending band of $HCN-(o-H_{2})$ were also observed. The $\Sigma_{1}-\Sigma_{0}$ van der Waals bending frequency 136.831 GHz of $HCN-(o-H_{2})$ is larger than that of He-HCN 98.70 GHz, but much smaller than that of Ar-HCN 164.89 GHz. The hyperfine Constant in the $\Sigma_{0}$ state indicate the cluster has T-shape in the excited state of the vdW bending mode. A search of the rotational lines of the ground $\Sigma_{0}$ state of $HCN -(p-H_{2})$ and the $\Pi_{0}$ state of $HCN-(o-H_{2})$ are now in progress as well as the vdW mode rovibrational lines for both $HCN-(o-H_{2})$ and $-(p-H_{2})$ clusters
Walker N. R. - One of the best experts on this subject based on the ideXlab platform.
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UNEXPECTED GENERATION AND OBSERVATION OF A T-SHAPED COMPLEX OF H$_{2}$C$_{2}$$\cdots$AgCCH
'The Ohio State University Libraries', 2013Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, Bedson Building, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, U.K.; School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.An experiment to probe species generated within a supersonically-expanding jet consisting of SF$_{6}$, Ag, C$_{2}$H$_{2}$ and argon by broadband rotational spectroscopy revealed the existence of a T-shaped complex of hitherto unknown origin. Empirical tests revealed that this complex requires the presence of C$_{2}$H$_{2}$ and Ag within the gas sample. While the intensity of the associated transitions are enhanced by the presence of SF$_{6}$, theoretical calculations and empirical tests implied that the identified complex is H$_{2}$C$_{2}$$\cdots$AgCCH rather than the original target of the experiment, H$_{2}$C$_{2}$$\cdots$AgF. This deduction is now supported by evidence acquired through experiments exploiting $^{13}$C-enriched isotopic samples. Transitions have been assigned for the H$_{2}$$^{13}$C$_{2}$$\cdots$Ag$^{13}$C$^{13}$CH isotopologue. Data acquired from each isotopologue allows determination of the rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$. The data are consistent with a T-shaped complex in which the Ag atom of AgCCH binds to electrons within the ${\pi}$-orbitals of ethyne. Preliminary determinations of bond lengths will be presented. Experiments are in progress to measure the spectra of deuterated isotopologues
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MICROWAVE SPECTRUM AND GEOMETRY OF H$_{3}$P$\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.The pure rotational spectrum of the vibrational ground state of H$_{3}$P$\cdots$AgI has been measured by chirped-pulse FTMW spectroscopy. The complex is generated via laser ablation (532 nm) of a silver rod in the presence of CF$_{3}$I, PH$_{3}$ and argon. It is subsequently stabilized and interrogated in the cold environment of a supersonic jet. The rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, have been measured for H$_{3}$P$\cdots$$^{107}$AgI and H$_{3}$P$\cdots$$^{109}$AgI. The spectrum of the complex is consistent with a {\it{C}}$_{3v}$ geometry and a linear arrangement of the P, Ag and C atoms. The measured rotational Constants allow a preliminary determination of the geometry of the molecule. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I) , is also established. The experimental results are compared with theory performed at the explicitly-correlated coupled-cluster singles, doubles and perturbative triples level
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BROADBAND ROTATIONAL SPECTRUM AND MOLECULAR GEOMETRY OF OC $\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the ground vibrational states of six isotopologues of OC$\cdots$AgI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are assigned to determine the rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, of the complex. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I), has also been measured. The complex is linear. The length of the C{\textemdash}O bond, r(CO), in the {\it{r}}$_{0}$ geometry for OC$\cdots$AgI is 0.008 {\r{A}} shorter than that found in the free CO molecule. The length of the Ag{\textemdash}I bond, {\it{r}}(AgI), is 0.013 {\r{A}} shorter than in free AgI. The nuclear quadrupole coupling Constant of the iodine atom is determined to be -769.84(22) MHz for OC$\cdots$$^{107}$AgI implying an ionic character of 0.66 for the metal halide bond. The molecular structure and spectroscopic parameters determined from the experimental data are presented alongside the results of calculations at the explicitly-correlated CCSD(T) level. The design features of a laser ablation source constructed for the present work will be described
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MICROWAVE SPECTRA AND GEOMETRIES OF H$_{2}$C$_{2}$$\cdots$AgCl AND H$_{2}$C$_{2}$$\cdots$CuCl
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the vibrational ground states of H$_{2}$C$_{2}$$\cdots$AgCl and H$_{2}$C$_{2}$$\cdots$CuCl have been measured by chirped-pulse FTMW spectroscopy. Each complex is generated via laser ablation of the metal in the presence of small percentages of CCl$_{4}$ and C$_{2}$H$_{2}$ in argon. The complexes are stabilized and interrogated in the cold environment of a supersonic jet. Rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and the Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$, have been measured for six isotopologues of H$_{2}$C$_{2}$$\cdots$AgCl and three isotopologues of H$_{2}$C$_{2}$$\cdots$CuCl with substitutions at the metal, chlorine and carbon atoms in each case. The spectrum of each complex is consistent with a {\it{C}}$_{2v}$ structure in which the metal atom is coordinated by the ${\pi}$-orbital of ethyne. The measured rotational Constants allow determination of the length of the bond between the metal and chlorine atoms, {\it{r}}(M{\textemdash}Cl), and the distance between the metal atom and the centre of the ethyne double bond, {\it{r}}(M{\textemdash}*). Nuclear quadrupole coupling Constants have been measured for the chlorine atom in each complex and also for copper in H$_{2}$C$_{2}$$\cdots$CuCl
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MICROWAVE SPECTRA AND STRUCTURES OF H$_2$O$\cdots$AgF
'The Ohio State University Libraries', 2011Co-Authors: Stephens S. L., Walker N. R., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.KA Balle-Flygare FT-MW spectrometer coupled to a laser ablation source has been used to measure the pure rotational spectra of H$_{2}$O$\cdots$AgF. Generation is via laser ablation (532 nm) of a silver rod in the presence of SF$_{6}$, argon, a low partial pressure of H$_{2}$O and the molecules are stabilized by supersonic expansion. The spectra of eight isotopologues have been measured. Rotational Constants, $\it{B}_{\rm{0}}$ and $\it{C}_{\rm{0}}$, and the Centrifugal Distortion Constant, \Delta $_\it{J}$ have been determined. Isotopic substitutions are available at the silver, oxygen and hydrogen atoms. The spectra are consistent with a linear arrangement of oxygen, silver and fluorine atoms and the structure is either $\it{C}_{\rm{2v}}$ planar at equilibrium or $\it{C}_{\rm{S}}$ pyramidal but with a low potential-energy barrier to planarity such that the v = 0 and 1 states associated with the motion that inverts the configuration at the O atom are well separated
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UNEXPECTED GENERATION AND OBSERVATION OF A T-SHAPED COMPLEX OF H$_{2}$C$_{2}$$\cdots$AgCCH
'The Ohio State University Libraries', 2013Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, Bedson Building, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, U.K.; School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.An experiment to probe species generated within a supersonically-expanding jet consisting of SF$_{6}$, Ag, C$_{2}$H$_{2}$ and argon by broadband rotational spectroscopy revealed the existence of a T-shaped complex of hitherto unknown origin. Empirical tests revealed that this complex requires the presence of C$_{2}$H$_{2}$ and Ag within the gas sample. While the intensity of the associated transitions are enhanced by the presence of SF$_{6}$, theoretical calculations and empirical tests implied that the identified complex is H$_{2}$C$_{2}$$\cdots$AgCCH rather than the original target of the experiment, H$_{2}$C$_{2}$$\cdots$AgF. This deduction is now supported by evidence acquired through experiments exploiting $^{13}$C-enriched isotopic samples. Transitions have been assigned for the H$_{2}$$^{13}$C$_{2}$$\cdots$Ag$^{13}$C$^{13}$CH isotopologue. Data acquired from each isotopologue allows determination of the rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$. The data are consistent with a T-shaped complex in which the Ag atom of AgCCH binds to electrons within the ${\pi}$-orbitals of ethyne. Preliminary determinations of bond lengths will be presented. Experiments are in progress to measure the spectra of deuterated isotopologues
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MICROWAVE SPECTRUM AND GEOMETRY OF H$_{3}$P$\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.The pure rotational spectrum of the vibrational ground state of H$_{3}$P$\cdots$AgI has been measured by chirped-pulse FTMW spectroscopy. The complex is generated via laser ablation (532 nm) of a silver rod in the presence of CF$_{3}$I, PH$_{3}$ and argon. It is subsequently stabilized and interrogated in the cold environment of a supersonic jet. The rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, have been measured for H$_{3}$P$\cdots$$^{107}$AgI and H$_{3}$P$\cdots$$^{109}$AgI. The spectrum of the complex is consistent with a {\it{C}}$_{3v}$ geometry and a linear arrangement of the P, Ag and C atoms. The measured rotational Constants allow a preliminary determination of the geometry of the molecule. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I) , is also established. The experimental results are compared with theory performed at the explicitly-correlated coupled-cluster singles, doubles and perturbative triples level
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BROADBAND ROTATIONAL SPECTRUM AND MOLECULAR GEOMETRY OF OC $\cdots$AgI
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the ground vibrational states of six isotopologues of OC$\cdots$AgI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are assigned to determine the rotational Constant, {\it{B}}$_{0}$, and the Centrifugal Distortion Constant, {\it{D}}$_{\it{J}}$, of the complex. The nuclear quadrupole coupling Constant of the iodine atom, ${\chi}_{aa}$(I), has also been measured. The complex is linear. The length of the C{\textemdash}O bond, r(CO), in the {\it{r}}$_{0}$ geometry for OC$\cdots$AgI is 0.008 {\r{A}} shorter than that found in the free CO molecule. The length of the Ag{\textemdash}I bond, {\it{r}}(AgI), is 0.013 {\r{A}} shorter than in free AgI. The nuclear quadrupole coupling Constant of the iodine atom is determined to be -769.84(22) MHz for OC$\cdots$$^{107}$AgI implying an ionic character of 0.66 for the metal halide bond. The molecular structure and spectroscopic parameters determined from the experimental data are presented alongside the results of calculations at the explicitly-correlated CCSD(T) level. The design features of a laser ablation source constructed for the present work will be described
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MICROWAVE SPECTRA AND GEOMETRIES OF H$_{2}$C$_{2}$$\cdots$AgCl AND H$_{2}$C$_{2}$$\cdots$CuCl
'The Ohio State University Libraries', 2012Co-Authors: Walker N. R., Stephens S. L., Mizukami W., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K.Pure rotational spectra of the vibrational ground states of H$_{2}$C$_{2}$$\cdots$AgCl and H$_{2}$C$_{2}$$\cdots$CuCl have been measured by chirped-pulse FTMW spectroscopy. Each complex is generated via laser ablation of the metal in the presence of small percentages of CCl$_{4}$ and C$_{2}$H$_{2}$ in argon. The complexes are stabilized and interrogated in the cold environment of a supersonic jet. Rotational Constants ({\it{B}}$_{0}$, {\it{C}}$_{0}$) and the Centrifugal Distortion Constant, $\Delta$$_{\it{J}}$, have been measured for six isotopologues of H$_{2}$C$_{2}$$\cdots$AgCl and three isotopologues of H$_{2}$C$_{2}$$\cdots$CuCl with substitutions at the metal, chlorine and carbon atoms in each case. The spectrum of each complex is consistent with a {\it{C}}$_{2v}$ structure in which the metal atom is coordinated by the ${\pi}$-orbital of ethyne. The measured rotational Constants allow determination of the length of the bond between the metal and chlorine atoms, {\it{r}}(M{\textemdash}Cl), and the distance between the metal atom and the centre of the ethyne double bond, {\it{r}}(M{\textemdash}*). Nuclear quadrupole coupling Constants have been measured for the chlorine atom in each complex and also for copper in H$_{2}$C$_{2}$$\cdots$CuCl
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MICROWAVE SPECTRA AND STRUCTURES OF H$_2$O$\cdots$AgF
'The Ohio State University Libraries', 2011Co-Authors: Stephens S. L., Walker N. R., Tew D. P., Legon A. C.Abstract:Author Institution: School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.KA Balle-Flygare FT-MW spectrometer coupled to a laser ablation source has been used to measure the pure rotational spectra of H$_{2}$O$\cdots$AgF. Generation is via laser ablation (532 nm) of a silver rod in the presence of SF$_{6}$, argon, a low partial pressure of H$_{2}$O and the molecules are stabilized by supersonic expansion. The spectra of eight isotopologues have been measured. Rotational Constants, $\it{B}_{\rm{0}}$ and $\it{C}_{\rm{0}}$, and the Centrifugal Distortion Constant, \Delta $_\it{J}$ have been determined. Isotopic substitutions are available at the silver, oxygen and hydrogen atoms. The spectra are consistent with a linear arrangement of oxygen, silver and fluorine atoms and the structure is either $\it{C}_{\rm{2v}}$ planar at equilibrium or $\it{C}_{\rm{S}}$ pyramidal but with a low potential-energy barrier to planarity such that the v = 0 and 1 states associated with the motion that inverts the configuration at the O atom are well separated