WO Molecule Research Articles

Optical spectroscopy of CrO and electronic states of the Cr group metal monoxides

All of the experimentally known electronic states of the Cr group metal monoxides (CrO, MoO, and WO) have been presented in the paper. The optical spectra of the CrO molecule have been investigated in the gas phase through a combination of the laser-induced fluorescence (LIF) excitation and single-vibronic-level (SVL) emission spectroscopy in the supersonic expansion. The rotational constants of the vibronic electronic states, including X5Π−1 (v″ = 0–3), B5Π−1 (v′ = 0–10), and B5Π1 (v′ = 1, 5), and the vibrational constants of the spin–orbit components X5Π−1,0,1 have been obtained. The molecular constants of the MoO and WO molecules have been summarized by reviewing the previous spectroscopic studies, and a comprehensive energy level diagram of the Cr group metal monoxides has been constructed. By comparing the electronic configurations, bond lengths, and vibrational frequencies of all the transition metal monoxides in the ground electronic state, the significance of the relativistic effect in the bonding of the 5d transition metal monoxides has been discussed. The related spectroscopic data of the CrO molecule are available at https://doi.org/10.57760/sciencedb.j00113.00085.

Theoretical study of low-lying electronic states of WO

The low-lying Ω states of the WO molecule have been investigated using the MS-CASPT2 method and the spin-orbit coupling effects have been considered. From the constructed potential energy curves, spectroscopic constants are obtained. By comparing the obtained theoretical results with the experimental ones, the experimentally detected states are assigned with reasonable agreements on the whole. This work provides useful guidance for future experimental and theoretical studies of WO.

Spin-orbit splitting of the ground state of WO

Spin-orbit splitting of the ground electronic state X 3Σ− of the WO molecule has been detected in the single-vibronic-level emission spectra, in which the fluorescence emitted from the R-branch bandheads of excitation bands D′1 − X3Σ−1 (0–0) [Ram et al., J. Mol. Spectrosc.256, 216 (2009)] and [23.3]1 − X3Σ−0+ (0–0) [Zhang et al., J. Mol. Spectrosc.360, 7 (2019)] was dispersed. The emission spectra were assigned with the help of Franck-Condon factors calculation and proved that the two excited states D′1 and [23.3]1 are a common state. Therefore, the separation between the two spin components Ω′′ = 0+ and 1 of the ground electronic state X 3Σ− was determined as 2103.15(2) cm−1. Some previously observed electronic states were reassigned, and a new energy level diagram of WO was constructed.

Laser-induced fluorescence spectroscopy of jet-cooled WO in 18, 900–23, 500 cm−1

The laser-induced fluorescence (LIF) excitation spectra of WO molecule have been recorded in the energy range of 18,900–23,500 cm−1 using laser ablation of tungsten target and reaction with free jet expansion of oxygen. Totally 63 vibronic transition bands were observed, and 60 bands were grouped into 10 electronic transition progressions, where 8 electronic transition progressions have the X0+ state as the lower state, as well as 2 progressions have the X1 state as the lower state. The electronic transition systems [21.5]0+–X0+ and [23.3]1–X0+ were newly identified by LIF spectroscopy. The molecular constants, including rotational constant, vibrational frequency, vibrational anharmonic constant, in the electronic excited states were obtained through rotational analysis of the spectra. In addition, the fluorescence lifetimes of the vibronic states were measured under the collision-free condition by exponentially fitting the fluorescence decay.

Laser-induced fluorescence spectroscopic study of the [21.2]0+–X0+ and [22.2]0+–X0+ electronic transitions of tungsten monoxide

The laser-induced fluorescence (LIF) excitation spectra of jet-cooled WO molecule have been investigated in the range of 21,000–23,200 cm−1, and two electronic band systems have been observed for the first time and labeled as the [21.2]0+–X0+ and [22.2]0+–X0+ transitions. The vibrational and rotational constants of these two excited electronic states have been derived by rotational analysis of the spectra. The tungsten isotopic structures of these two excited states are clearly resolved, and the analysis of LIF spectra reveals that the isotopic shifts are due to the strong interstate perturbations between different vibronic states. Based on the ab initio calculation results by Ram et al., the primarily attributed configuration of these two newly identified states was discussed. In addition, the lifetimes of the observed vibronic states were measured under the collision-free condition.

Electron spectra of WO molecule. New electron state 3Π

The electron spectrum of the tungsten monooxide molecule is observed in the 550–800 nm region using intracavity laser absorption spectroscopy. The WO molecules are produced in a pulsed electric discharge through the mixture of tungsten hexacarbonyl vapors. The spectrum is recorded using a diffraction spectrometer (resolving power of 240000). The bands in the 16400–15500 cm–1 region are assigned to the 3Π0–X3Σ+ component of the 3Π0–X3Σ+–3XΣ+ electron transition. The rotational analysis of the 0-0 and 1-0 bands is carried out and the rotational constants for the ground X″3Σ and the exited 3Π0 states are computed: В′ = 0.385738 cm–1, B″ = 0.415538 cm–1.

Structural revisions of small molecules reported to cross-link G-quadruplex DNA in vivo reveal a repetitive assignment error in the literature.

Two molecules of mistaken identity are addressed. Uncovering these assignment errors led us to formulate more general guidelines about additional misassignments in cases of published bis-imines derived from 1,2-phenylenediamine and hydroxybenzaldehydes having no substituent in ortho-positions. The main purpose of this article is to highlight this repetitive assignment error in the literature and thus increase the likelihood of correct assignments in future papers.

Cavitand Scission by Transition‐Metal Centres – Cleaved Cavitand Chirality and Its Consequences

AbstractTwo molecules of the phosphine cavitand 5‐diphenylphosphanyl‐4(24),6(10),12(16),18(22)‐tetramethylenedioxy‐2,8,14,20‐tetrapentylresorcin[4]arene (1) each underwent cleavage of an O–CH2O bond when treated with 1 equiv. of [Ni(η5‐C5H5)(1,5‐cyclooctadiene)]BF4 to form a bis(phosphino–phenolato) complex (2) without a cyclopentadienyl ligand. The partially cleaved (P,O) ligands in 2 are chiral, and a single‐crystal X‐ray structure determination of 2 has shown that the complex molecule has close to twofold rotational symmetry with both ligand units in the same absolute configuration. As expected, the primary coordination sphere has a cis‐NiO2P2 geometry. In contrast, C–O bond breaking occurred only once per metal centre when 1 was treated with [RuBr2(p‐cymene)]2. This led to a crystallographically characterised complex [RuBr(P,O)(p‐cymene)] (4) along with a minor amount of a species (5) that is assumed to be a stereoisomer. Upon crystallisation of 4, two distinct types of crystals were isolated from the same solution; some of these were the racemic compound, while the others were the racemic conglomerate.

The [formula omitted] ground state of WO

The WO molecule was formed as an impurity during the excitation of a mixture of WCl 6 vapor and He in a microwave discharge lamp. The emission spectra were recorded using a high-resolution Fourier transform spectrometer. A rotational analysis of the strong bands in the 9000–25 000 cm −1 interval has been carried out and the bands have been classified into two groups with different lower states. The two lower states have been assigned as the Ω=0 + and Ω=1 spin components of the X 3 Σ − ground state. Ab initio calculations have also been performed and they confirm our experimental assignments.

Intramolecular Coaggregation Behavior in Novel Cyclotriveratrylenes with Cholic Acid Podants

AbstractTwo molecules la and 1b consisting of one cyclotriveratrylene (CTV) and three cholic acid podants have been designed and synthesized. Fluorescent studies in water/dimethoxyethane mixtures reveal an intramolecular coaggregation between the CTV and the attached cholic acid moieties. Their fluorescent emission intensity increases and then decreases with the increase of water content, whereas under the same measuring conditions the intensity of CTV derivative 2a, which possesses no similar cholic acid moiety, increases and then reaches a maximum value. The intensity decrease in la and 1b has been attributed to the decrease of the microenvironmental polarity in media of increasing polarity because of the shielding effect of the hydrophobic face of the cholic acid moiety.

小笠原群島父島に産する高Ｃａおよび低Ｃａボニナイト

Chichijima, Bonin archipelago, is a Tertiary volcanic island approximately 1000 km south-south east of Tokyo, and has been known as the type locality of boninite. Two types of boninite are found in the Bonin archipelago: one is high-Ca boninite from the Mikazukiyama Formation (Mk-HCB) and the Marubewan Formation (Mr-HCB) in Chichijima, and another is low-Ca boninite from the Marubewan Formation (Mr-LCB), Anijima (Ani-LCB), and Mukojima (Muko-LCB). High-Ca boninite is distinguished by CaO content from dominant low-Ca boninite, and contains augite phenocrysts. The bulk MgO, Ni and Cr contents and the magnesian compositions of olivines and pyroxenes in Mk-HCB and Mr-LCB indicate their primitive nature. Bronzite phenocrysts in Mk-HCB and Mr-HCB are highly enriched in Wo molecule, implying existence of high-Ca primitive boninite magmas. Mr-HCB is a mixing product between a high-Ca boninite magma and a differentiate from Mr-LCB. Sr isotopic ratios and incompatible element ratios of Mr-HCB, Mr-LCB, Ani-LCB and Muko-LCB are nearly the same and therefore they could have been produced from the common source. In contrast, Mk-HCB has different Sr isotopic and incompatible element ratios from the others and then it may have been produced from different parental materials. Both REE model calculations and Cr-spinel compositions imply that the parental mantle of the Mr-LCB is more depleted than that of the Mk-HCB. The large enrichment of LILE and LREE in Mr-LCB compared to Mk-HCB suggests that Mr-LCB has been generated under more hydrous condition than Mk-HCB.

Intracavity Electronic Absorption Spectra of MoO and WO Molecules in the Visible Region

Absorption electronic spectra of MoO and WO molecules have been investigated by a intracavity laser technique in the region 550–800 run. New features have been discovered. As for MoO molecule the rotational analysis of the four bands have been carried out for the first time. Two of these bands were referred to 0–0 transitions arisen from the new (probable triplet) low-lying electronic state, two other bands were referred to transitions arisen from excited components of X5II ground state. As for WO molecule the rotational analysis of 0–0 and 1–0 bands represented A-X and B-X systems have been carried out for the first time. The new band has been discovered which has been referred to new electronic transition. Molecular constants of new states of both molecules studied have been evaluated.

The Formation of Carbenium Ions and Naked Anions by the Protonation of Phthalophenone with a Super Acid

AbstractTwo molecules of a strong acid such as CF3SO3H are necessary to cleave the lactone ring of phthalophenone. NMR and conductivity measurements reveal that the carboxylate group has to be protonated for this purpose followed by its solvation with an additional molecule of acid. But CF3SO3‐ which is simultaneously formed behaves as a naked anion in the solvent dichloromethane. CNDO‐Calculations indicate a strong interaction between the charged central carbon atom and the ‐COOH group in which is accompanied by an unusually large twisting of the phenyl rings.

Electronic spectrum of the 186W 16O molecule

Absorption spectrum of the WO molecule has been investigated in the region 2600–6800 Å. The spectrum was obtained by flash photolysis of a mixture of W(CO) 6 vapors with 16O 2 (or 18O 2) and Ar. Sixty bands of 186W 16O and 14 bands of 186W 18O were recorded. The majority of them were assigned to 10 systems. An analysis of the rotational structure of 14 bands of 186W 16O was carried out. Results indicate that Hund's case (c) of angular momenta coupling applies to this molecule. The following molecular constants (cm −1) have been obtained for the ground state X0 +: ω e = 1068.2, ω e χ e = 5.8, B e = 0.4165, D e = 2.39 × 10 −7, α 1 = 2.3 × 10 −3, and r e = 1.6578 A ̊ .

Solid Complex Formation of Oxalic Acid with a-Amino Acids

SOIid complex formation of oxal ie acid with several a-ami no acids was studied by usi ng an X-ray diffractometer, a R i ltfrared spectrometer and a differential thermobalance a Ralyser.Oxalic acid forms enly o ne ki nd of complex with dlnt-ala nine, dl-nerleucine or dl-leucine i n a molar ratio of 1:1, while it ferms two kinds of complexes with glyei qe, dl-a-ami Robutylic aeid, dl-val i ne. dl-norvaline o r dl-isoleuci ne i n molar ratios of 1:1 a nd 1:2. lt was presurned that the formation of the cemplexes was promoted by proten-transfer from the carboxyl group in oxalic aeid to the ca rboxyl ion of amino aeid i n t he case of 1:1 complex and by the intermolecular hydrogeR bond between two hydregen atoms of t h e carboxyl groups i R oxalic acid a nd t he carboxyl ions ef t wo molecules of ami no acid i lt t he case of 1:2 complex.The difference i n com plex formatioA amoRg a-ami nO acids is suppostxl to resu l t from the steric request of a-ami no acid, although it can hardly be explai ned enly by the size of the alkyi group at a-position.

The crystal structure of the 2:1 intermolecular complex containing 1‐melhyl‐5‐flourouracil and 9‐ethyl‐2,6‐diaminopurine

AbstractTwo molecules of 1‐methyl‐5‐fluorouracil complex with one molecule of 9‐erthyl‐2, ‐6‐diaminopurine and crystsallize in a triclinic unit cell. The crystal structure was solves by analysis of 3‐dimensional x‐ray diffraction data. Asharpened Patterson map was used to dertermine the structure with apsuedo‐heavy atom technique. The three molecule from a planar hydrogen bonded Watson‐Crick pair with the purine while the other pyrimide forms hydrogen bond to adenine through the imdazole nitrogen. The network is compeleted by purine‐purine hydrogen bond.

Vaporization of Beryllium Oxide and Its Reaction with Tungsten

The composition of the vapor above beryllium oxide held in a tungsten Knudsen cell in the range 1900°-2400°K has been determined mass spectrometrically. The vapor consists predominantly of Be and O atoms and (BeO)3 and (BeO)4 molecules. Smaller amounts of the following molecules were detected: O2, BeO, (BeO)2, (BeO)5, (BeO)6, WO2, WO3, and WOx·(BeO)y where x=1, 2 and y=1, 2, 3. A thermodynamic treatment of the data yielded a value of 4.6±0.1 ev for the dissociation energy of the BeO molecule. Heats of vaporization have been measured for the other (BeO)4 molecules and the data suggest a ring structure for these molecules. The boiling point of BeO has been crudely estimated as 3850±200°C at which temperature the vapor consists mostly of (BeO)4 and somewhat smaller amounts of (BeO)3 and (BeO)5. The atomization energies of the WO2 and WO3 molecules have been measured to be 13.6±0.4 ev and 19.3±0.4 ev, respectively. The dissociation energy of the WO molecule is estimated to be about 7.2 ev.